July 2008 Archives
Last week we reviewed the Woodgas-Stove by iENERGY over on Biomass Authority and came away very impressed with the product. This week we wanted to explore the solar power option for this stove and provide some tips for sustainable camping. While the woodgas stove is more of a biomass product than a solar one, it does rely on a small electric fan to achieve high burn temperatures and this fan can be powered either by traditional batteries or solar power. Guess which option we prefer?
In case you haven't read our review of the wood gas stove we'll catch you up here before we move on. The stove weighs under 2lbs and is built for portability; instead of using white gas or liquid fuel this stove simply uses twigs and other organic matter which can be found along the trail. The stove functions like a blast furnace directing air up and through the fire to help it burn hotter and more consistently, and it includes a metal range for resting a pot or pan on so you can grill up that morning feast or roast marsh mallows... your choice!
Since the real value of this product is convenience, not having to cary around fuel, the solar option is a no-brainer. We put this option through a series of tests in Yosemite National Park, California this past week and were very pleased with the results. The solar panel is an add-on third party device that is simply resold with the woodgas-stove and includes the correct dongle attachment. It comes with two rechargeable double A batteries and ideally those would be charging as you prepared the stove. You could almost think of it as using solar to charge batteries which in turn power the stove. Unfortunately, this concept is a bit of a letdown because it means batteries still have to be made and sold with this product vs. pure solar.
In our opinion some of the romance is lost when you think of the solar option as a battery charger instead of an energy source in itself. For this reason we chose to "forget" our rechargeable AA batteries at home which allowed us to test the solar option in survival mode, as if we had been in the woods for years trying to heat our food (and hands) even as the batteries came to the end of their life. Maybe we're on Gilligan's Island and the professor just used those rechargeable double-A's for his latest project? Maybe we're on Lost and fire is the only way to keep away the "Others". Would the stove still work without those batteries??
Amazingly, even without the batteries in tow the solar panel was able to power the little woodgas stove. Granted, It did take a few extra seconds to get the fan spinning, and it was a sunny day, but the fact that this little system could run indefinitely just using the sun and a few twigs is a very romantic concept indeed! With the stove costing just under $50 it's worth checking out and the solar option is a must have in our opinion!
In case you haven't read our review of the wood gas stove we'll catch you up here before we move on. The stove weighs under 2lbs and is built for portability; instead of using white gas or liquid fuel this stove simply uses twigs and other organic matter which can be found along the trail. The stove functions like a blast furnace directing air up and through the fire to help it burn hotter and more consistently, and it includes a metal range for resting a pot or pan on so you can grill up that morning feast or roast marsh mallows... your choice!
Since the real value of this product is convenience, not having to cary around fuel, the solar option is a no-brainer. We put this option through a series of tests in Yosemite National Park, California this past week and were very pleased with the results. The solar panel is an add-on third party device that is simply resold with the woodgas-stove and includes the correct dongle attachment. It comes with two rechargeable double A batteries and ideally those would be charging as you prepared the stove. You could almost think of it as using solar to charge batteries which in turn power the stove. Unfortunately, this concept is a bit of a letdown because it means batteries still have to be made and sold with this product vs. pure solar.
In our opinion some of the romance is lost when you think of the solar option as a battery charger instead of an energy source in itself. For this reason we chose to "forget" our rechargeable AA batteries at home which allowed us to test the solar option in survival mode, as if we had been in the woods for years trying to heat our food (and hands) even as the batteries came to the end of their life. Maybe we're on Gilligan's Island and the professor just used those rechargeable double-A's for his latest project? Maybe we're on Lost and fire is the only way to keep away the "Others". Would the stove still work without those batteries??Amazingly, even without the batteries in tow the solar panel was able to power the little woodgas stove. Granted, It did take a few extra seconds to get the fan spinning, and it was a sunny day, but the fact that this little system could run indefinitely just using the sun and a few twigs is a very romantic concept indeed! With the stove costing just under $50 it's worth checking out and the solar option is a must have in our opinion!
There are two common ways to collect energy from the sun. One is to use a thermal solar collector to gather the sun's heat and the other is to use a photovoltaic (PV) array which converts the sun's energy to electricity. Which is better?
In the case of solar thermal, the conversion efficiency is much higher than PV. You can extract as much as 70% of the sun's energy with a solar collector, which is accomplished by circulating a fluid through a solar panel collector and capturing the heat rise that naturally occurs when the sun shines on the collector. On the other hand, a PV collector will only convert about 12% of the sunlight into electrical energy on average. A general rule of thumb is that the energy available from the sun is about 1kW per square meter. This translates to about 3400 BTU/hr per square meter. If you can get 70% of that heat using thermal solar collector, then you would only need about 42 square meters (450 sq. ft) to generate as much heat as a typical home's gas furnace (100,000 BTU/hr). Another advantage is that solar thermal panels only cost a small fraction (about 20%) of what PV panels cost per square meter. When you combine 6 times the efficiency with 5 times better pricing, you get something that is 30 times better, right? Well, not exactly.
A furnace is by far the largest energy user in a typical household in North America, consuming as much as 10 times the energy when it's running as an average house uses in electricity. In my own home in Colorado, by looking at my gas bill, I computed that during this past December my furnace ran about 30% of the time. So the average heating load was 33,000 BTU/hr. This is equivalent to 9.7 kW, or about 10 times my average electric usage during the same month. I should also mention that natural gas costs about 1/3 as much per BTU as electric resistance heating. So my gas bill wasn't 10 times as much, but closer to 3 times as much as my electric bill for that month.
If solar thermal is so much more efficient and less costly, and my heating needs require up to 10 times the amount of energy as my electrical needs, then why isn't solar thermal space heating generating as much interest as PV solar these days?
There are several reasons for it. One is that heat is very difficult to store and distribute. The only way to store heat is with a thermal mass. Passive solar homes, that is, those with solar systems that have no moving parts or liquids, generally use masonry to store and release heat to achieve a comfortable temperature equilibrium. This is done by constructing the home so that it has a large south-facing window and a large thermal mass such as thick masonry walls and floors to hold the heat. But a house generally must be designed with the passive solar collector from the start. It would be difficult to add a passive solar collector to an existing house. More commonly to retrofit an existing home with solar heat, one would use an active solar system with a fluid to extract, store, and then distribute the heat, and that requires a large insulated water storage tank in the house to hold the heat. If you wanted to store enough heat for an entire day's heating for my home during a cold winter day (33,000 BTU/hr x 24 hours), it would require a tank that held 2500 gallons of water (assuming a 40 degree temperature delta). By temperature delta, I mean how much temperature change could occur before the hot water was no longer effective at heating the house. My estimate is that the water would be raised to around 160 degrees in the tank and that once it got below 120 degrees, it would lose its effectiveness at radiating heat. As a side note, solar thermal could be used for radiant floor heating but you need lower water temperatures for that application, usually around 85-120F, and so you couldn't heat the water to a very high temperature and thus you'd need an even bigger tank to store equivalent energy. However, I can envision a system that employed radiators (which require water at 120-160F) and radiant floor heating that take advantage of the water once it got below 120F. If you could do that, then the deltaT could be expanded to 75 degrees, allowing for a smaller 1300 gallon storage tank. Needless to say, this would add considerable complexity to the system and would likely need to be designed into the house prior to construction because radiant floor heating is quite difficult to retrofit in an existing house.
In the scenario I mentioned previously where a solar collector would need to be around 450 square feet to match the size of a house furnace, I didn't take into consideration that the sun doesn't shine all the time. In Colorado in the winter time, the sun only averages about 4 hours of full intensity per day. That is about a 17% duty cycle and my house requires as much as 33% duty cycle from my gas furnace during the coldest months. So I'd need to double the size of the collector to 900 square feet to compensate for this shortfall.
Sometimes we get cloudy weather for several days in a row, so I'd need to have a backup system, likely a gas heater, to kick in when the water temperature fell below 120 degrees and could no longer heat the house. To help make all the decisions about when to circulate the fluid to the solar collector, pump the fluid to the various zones in the house, and turn on the gas heater when a backup is needed, it would require a computerized controller.
When you add up all the cost of the pumps, tank, controller, plumbing, radiators, and installation, the savings in fuel would take a long time to pay for the system. So that may be why, despite the significant advantage of solar collector panel cost and efficiency compared with PV systems, thermal solar space heating systems haven't taken off. In addition, the system would sit idle about 6 month out of the year when I don't need much heat. In several of those months, I need air conditioning and a solar thermal system wouldn't do me much good for that application. A PV system could generate usable energy year-round, and would generate 50% more in the longer summer days when I tend use more electricity anyway.
Using a solar thermal system to provide a home's hot water seems like it has the potential to make more economic sense. After space heating, hot water requires the most energy in a typical home. I will cover that in a future article.
In the case of solar thermal, the conversion efficiency is much higher than PV. You can extract as much as 70% of the sun's energy with a solar collector, which is accomplished by circulating a fluid through a solar panel collector and capturing the heat rise that naturally occurs when the sun shines on the collector. On the other hand, a PV collector will only convert about 12% of the sunlight into electrical energy on average. A general rule of thumb is that the energy available from the sun is about 1kW per square meter. This translates to about 3400 BTU/hr per square meter. If you can get 70% of that heat using thermal solar collector, then you would only need about 42 square meters (450 sq. ft) to generate as much heat as a typical home's gas furnace (100,000 BTU/hr). Another advantage is that solar thermal panels only cost a small fraction (about 20%) of what PV panels cost per square meter. When you combine 6 times the efficiency with 5 times better pricing, you get something that is 30 times better, right? Well, not exactly.
A furnace is by far the largest energy user in a typical household in North America, consuming as much as 10 times the energy when it's running as an average house uses in electricity. In my own home in Colorado, by looking at my gas bill, I computed that during this past December my furnace ran about 30% of the time. So the average heating load was 33,000 BTU/hr. This is equivalent to 9.7 kW, or about 10 times my average electric usage during the same month. I should also mention that natural gas costs about 1/3 as much per BTU as electric resistance heating. So my gas bill wasn't 10 times as much, but closer to 3 times as much as my electric bill for that month.If solar thermal is so much more efficient and less costly, and my heating needs require up to 10 times the amount of energy as my electrical needs, then why isn't solar thermal space heating generating as much interest as PV solar these days?
There are several reasons for it. One is that heat is very difficult to store and distribute. The only way to store heat is with a thermal mass. Passive solar homes, that is, those with solar systems that have no moving parts or liquids, generally use masonry to store and release heat to achieve a comfortable temperature equilibrium. This is done by constructing the home so that it has a large south-facing window and a large thermal mass such as thick masonry walls and floors to hold the heat. But a house generally must be designed with the passive solar collector from the start. It would be difficult to add a passive solar collector to an existing house. More commonly to retrofit an existing home with solar heat, one would use an active solar system with a fluid to extract, store, and then distribute the heat, and that requires a large insulated water storage tank in the house to hold the heat. If you wanted to store enough heat for an entire day's heating for my home during a cold winter day (33,000 BTU/hr x 24 hours), it would require a tank that held 2500 gallons of water (assuming a 40 degree temperature delta). By temperature delta, I mean how much temperature change could occur before the hot water was no longer effective at heating the house. My estimate is that the water would be raised to around 160 degrees in the tank and that once it got below 120 degrees, it would lose its effectiveness at radiating heat. As a side note, solar thermal could be used for radiant floor heating but you need lower water temperatures for that application, usually around 85-120F, and so you couldn't heat the water to a very high temperature and thus you'd need an even bigger tank to store equivalent energy. However, I can envision a system that employed radiators (which require water at 120-160F) and radiant floor heating that take advantage of the water once it got below 120F. If you could do that, then the deltaT could be expanded to 75 degrees, allowing for a smaller 1300 gallon storage tank. Needless to say, this would add considerable complexity to the system and would likely need to be designed into the house prior to construction because radiant floor heating is quite difficult to retrofit in an existing house.
In the scenario I mentioned previously where a solar collector would need to be around 450 square feet to match the size of a house furnace, I didn't take into consideration that the sun doesn't shine all the time. In Colorado in the winter time, the sun only averages about 4 hours of full intensity per day. That is about a 17% duty cycle and my house requires as much as 33% duty cycle from my gas furnace during the coldest months. So I'd need to double the size of the collector to 900 square feet to compensate for this shortfall.
Sometimes we get cloudy weather for several days in a row, so I'd need to have a backup system, likely a gas heater, to kick in when the water temperature fell below 120 degrees and could no longer heat the house. To help make all the decisions about when to circulate the fluid to the solar collector, pump the fluid to the various zones in the house, and turn on the gas heater when a backup is needed, it would require a computerized controller.
When you add up all the cost of the pumps, tank, controller, plumbing, radiators, and installation, the savings in fuel would take a long time to pay for the system. So that may be why, despite the significant advantage of solar collector panel cost and efficiency compared with PV systems, thermal solar space heating systems haven't taken off. In addition, the system would sit idle about 6 month out of the year when I don't need much heat. In several of those months, I need air conditioning and a solar thermal system wouldn't do me much good for that application. A PV system could generate usable energy year-round, and would generate 50% more in the longer summer days when I tend use more electricity anyway.
Using a solar thermal system to provide a home's hot water seems like it has the potential to make more economic sense. After space heating, hot water requires the most energy in a typical home. I will cover that in a future article.
In most situations over half the cost of installing a solar power system on a residential house is spent on inverters, brackets, structural support (reinforcing the roof, repairing the roof, patching holes, etc.), and retrofitting the homes electrical system. For example, in California a 5Kw system costs about $45,000 and is reduced to $35K after the rebate. Most people don't realize that nearly $15,000 of the total cost on a system like this would be spent on installation costs...
Having been inspired by a post we found on the Tesla Founders Blog (Tesla is a company that makes electric cars), we decided to break out the installation costs for installing solar power on a home and describe how money could be saved if homes were proactively built "solar ready".
As estimated by the example case above, the total cost of these minor additions to a standard house would be ~$360 which could be as low as 3% of the overall cost of the house (especially in California where homes are very expensive)! In contrast, if those same additions are made after the house has already been constructed it could cost up to $15K as we discussed earlier, so the end homeowner would be saving $12,000 and that would add value to the home, the neighborhood, and our environment.
Even if the new home owner didn't ever choose to install solar, the price of being "solar ready" would be very low. They might eventually move and the second owner would benefit from the solar options thus increasing the value of the house. If they did however decide to get panels at some point the process would only require connecting the panels to the roof and tying them into the pre-set electrical system as well as installing the breaker at the main panel. This would avoid most of the attic work to install wiring, cutting holes in home siding, customizing an old electrical panel or worse, having to upgrade, using foam or glue to plug holes from the roof electrical jacks, and installing struts in the attic to support rafters experiencing sag.
Imagine if home builders were regularly constructing solar ready houses. They would be in a prime position to up-sell the entire solar system through companies like the Home Depot.
If an update were made to the California Title 24 or to similar legislation in other states solar ready homes could become the norm. Not every house is positioned well for solar but just like other pieces of legislation there could be exemptions. It goes without saying that this type of legislation would have an enormous impact on the number of homes that would become solar powered thus increasing demand for solar technology, lowering prices and helping the environment.
Having been inspired by a post we found on the Tesla Founders Blog (Tesla is a company that makes electric cars), we decided to break out the installation costs for installing solar power on a home and describe how money could be saved if homes were proactively built "solar ready".
- $20 - Two additional slots on the electrical main panel of the house for a 240V breaker.
- $20 - Creating a reserve location (probably on an outside wall of the house) for an inverter with standardized mounting points.
- $20 - Creating a conduit from the main panel location to the inverter location.
- $100 - Creating another conduit from the inverter location through the attic and onto the roof where the panels would be installed.
- $100 - Reinforced roof rafter structure to support the weight of solar panels.
- $100 - Electrical jacks through the roofing material with standardized connection and spacing.
As estimated by the example case above, the total cost of these minor additions to a standard house would be ~$360 which could be as low as 3% of the overall cost of the house (especially in California where homes are very expensive)! In contrast, if those same additions are made after the house has already been constructed it could cost up to $15K as we discussed earlier, so the end homeowner would be saving $12,000 and that would add value to the home, the neighborhood, and our environment.
Even if the new home owner didn't ever choose to install solar, the price of being "solar ready" would be very low. They might eventually move and the second owner would benefit from the solar options thus increasing the value of the house. If they did however decide to get panels at some point the process would only require connecting the panels to the roof and tying them into the pre-set electrical system as well as installing the breaker at the main panel. This would avoid most of the attic work to install wiring, cutting holes in home siding, customizing an old electrical panel or worse, having to upgrade, using foam or glue to plug holes from the roof electrical jacks, and installing struts in the attic to support rafters experiencing sag.Imagine if home builders were regularly constructing solar ready houses. They would be in a prime position to up-sell the entire solar system through companies like the Home Depot.
If an update were made to the California Title 24 or to similar legislation in other states solar ready homes could become the norm. Not every house is positioned well for solar but just like other pieces of legislation there could be exemptions. It goes without saying that this type of legislation would have an enormous impact on the number of homes that would become solar powered thus increasing demand for solar technology, lowering prices and helping the environment.
We just received this press release from Coherent Solar - a local company that we've written about before on Solar Power Authority when they were presenting at the Photovoltaics Summit 2008 in San Diego. This press release announces the details of a new laser system that they have developed to produce solar cells.
The Talisker system is a new ultra-short-pulse laser designed to produce high efficiency cell concepts. It is optimized for next-generation solar cell manufacturing and was designed as a drop-in turn-key solution to benefit both production line equipment suppliers and cell manufacturers.
Traditionally, laser scribers akin to the Talisker have been limited to short pulses of nanosecond duration and laser emission in the infra-red spectral region at 1064 nanometers. In order to optimize the scribing precision and minimize laser damage (or microcracking) within c-Si wafers however, an ultra-short pulse 'picosecond' duration would be required with ultra-short laser emission in the green or UV output level. The new Talisker laser brings these features to solar cell manufacturing for the first time ever!
The Talisker laser draws upon Coherent's established position as a leading supplier of short-pulse nanosecond AVIATM and PRISMATM lasers for existing c-Si and Thin-Film equipment tools (most of which run in 24 / 7 high-volume environments). The Talisker laser operates with similar output energies and speed (pulsing repetition-rate). But the key difference is the shorter pulse-width of the Talisker. This provides orders of magnitude higher peak intensities for precision scribing, and reduces vastly the thermal damage, sometimes seen with certain laser/material interaction.
The other strength of the Talisker laser is that it delivers different outputs in the infra-red, green, or UV spectral regions, by software control. UV and green wavelengths are essential for highly localized surface scribing on c-Si wafers, due to the very short penetration depths in the green and in particular UV at 355 nm. Combining ultra-short picosecond pulse operation with high-energy green / UV output wavelengths brings a new level of precision for many applications of lasers in high-efficiency c-Si cell manufacturing. One example is Selective Ablation of dielectric materials, where minimizing damage in the underlying bulk silicon is essential. Equally, within Thin-Film patterning, the ability to scribe layers with increasing precision is critical. An example here is laser scribing the P2 and P3 steps for CIGS.
The Talisker is a modular and scalable design based on fiber-laser technology. It operates off single-phase electricity and requires no external consumables. Complete with on-board diagnostics and remote Ethernet preventative-maintenance access, the Talisker can be easily integrated within inline turn-key tools. Benefiting from a hybrid fiber / free-space laser head design, the footprint measures less than 40 cm x 100 cm.
If you made it through that uber-technical press release congrats! It sounds like this tool will make solar cell research and manufacturing more efficient while keeping costs down with it's turnkey approach. Congrats Coherent! We'll be watching this company and posting updates as time goes on.
The Talisker system is a new ultra-short-pulse laser designed to produce high efficiency cell concepts. It is optimized for next-generation solar cell manufacturing and was designed as a drop-in turn-key solution to benefit both production line equipment suppliers and cell manufacturers.
Traditionally, laser scribers akin to the Talisker have been limited to short pulses of nanosecond duration and laser emission in the infra-red spectral region at 1064 nanometers. In order to optimize the scribing precision and minimize laser damage (or microcracking) within c-Si wafers however, an ultra-short pulse 'picosecond' duration would be required with ultra-short laser emission in the green or UV output level. The new Talisker laser brings these features to solar cell manufacturing for the first time ever!The Talisker laser draws upon Coherent's established position as a leading supplier of short-pulse nanosecond AVIATM and PRISMATM lasers for existing c-Si and Thin-Film equipment tools (most of which run in 24 / 7 high-volume environments). The Talisker laser operates with similar output energies and speed (pulsing repetition-rate). But the key difference is the shorter pulse-width of the Talisker. This provides orders of magnitude higher peak intensities for precision scribing, and reduces vastly the thermal damage, sometimes seen with certain laser/material interaction.
The other strength of the Talisker laser is that it delivers different outputs in the infra-red, green, or UV spectral regions, by software control. UV and green wavelengths are essential for highly localized surface scribing on c-Si wafers, due to the very short penetration depths in the green and in particular UV at 355 nm. Combining ultra-short picosecond pulse operation with high-energy green / UV output wavelengths brings a new level of precision for many applications of lasers in high-efficiency c-Si cell manufacturing. One example is Selective Ablation of dielectric materials, where minimizing damage in the underlying bulk silicon is essential. Equally, within Thin-Film patterning, the ability to scribe layers with increasing precision is critical. An example here is laser scribing the P2 and P3 steps for CIGS.
The Talisker is a modular and scalable design based on fiber-laser technology. It operates off single-phase electricity and requires no external consumables. Complete with on-board diagnostics and remote Ethernet preventative-maintenance access, the Talisker can be easily integrated within inline turn-key tools. Benefiting from a hybrid fiber / free-space laser head design, the footprint measures less than 40 cm x 100 cm.
If you made it through that uber-technical press release congrats! It sounds like this tool will make solar cell research and manufacturing more efficient while keeping costs down with it's turnkey approach. Congrats Coherent! We'll be watching this company and posting updates as time goes on.
Solar Panels aren't cheap, most of them aren't light either and that means you need a professional crew to help you get them onto your roof, set up a rack system, and configure the electrical system. All of these points aside, there are definitely ways that the average homeowner can get solar and save money along the way with a do-it-yourself DIY approach. This resource is based partially on a series of videos on our site that discuss solar installation, the first of which can be found here with more resources on choosing the right panels and inverters.
Most people are told that installing solar panels on their house will cost somewhere in the ballpark of $10,000 with a 14 to 18 year payback period depending on the weather and exposure to sunlight along with the angle and direction of their roof. With a little bit of elbow grease however, you can reduce that initial 10K estimate to as little as $7,000. It's worth noting that in many states in order to work on the electrical aspects of an installation you will have to pass a short test (usually around 30 questions with a 70% to pass, although many of these tests allow you to retry). Additionally, unpermitted or unlicensed modifications to a home or other building may void insurance coverage so it's important to check with your local state ordinances, we have some resources on colorado solar for you to begin.
Most people are told that installing solar panels on their house will cost somewhere in the ballpark of $10,000 with a 14 to 18 year payback period depending on the weather and exposure to sunlight along with the angle and direction of their roof. With a little bit of elbow grease however, you can reduce that initial 10K estimate to as little as $7,000. It's worth noting that in many states in order to work on the electrical aspects of an installation you will have to pass a short test (usually around 30 questions with a 70% to pass, although many of these tests allow you to retry). Additionally, unpermitted or unlicensed modifications to a home or other building may void insurance coverage so it's important to check with your local state ordinances, we have some resources on colorado solar for you to begin.
If you have any tips on installing solar panels and saving money please leave a comment for the community below or head on over to our forums and check out some of the discussions already going on.
This morning one of our readers sent us a little do it yourself tip for heating a swimming pool based on what one of her friends is doing. The full comment follows: "Not a question, but a little info: Knowing how hot the water gets in a
garden hose, a friend with a swimming pool bought a bunch, I do not know
how much, of black garden hose. She spread it out in big curls on top
of a nearby flat roofed building. She then fixed up a small
recirculating pump, ran the water to the swimming pool to warm the
water. Worked great!"
While this comment doesn't come with too many details about how much hose was used, what kind of pump was used, or even where in the US this is being done... The fact that nearly anyone can harness solar energy to do something useful is very evident. This dog for example, found a great way to enjoy a black garden hose and harness a little solar energy to stay comfortable.
After receiving this comment we decided to figure out just how much something like this would cost to do so we sought out some pricing information online. First off we looked for a hot water recirculating pump and found out that there are several different types in the range of $200 to $300 all designed to connect to a hot water heater. Since water heaters connect using smaller pipes than a garden hose, you would probably need an adapter or two from the Home Depot or other similar store. Next up is black garden hose; we found a nice bundle measuring 100 feet long at $50 that would work pretty well but you might need even more length which would require an extender like this, you would also want to be sure that the system didn't leak because your motor could burn out that way. You can buy little rolls of sealant tape at most hardware stores to be used when screwing in one end of hose to another.
Here are a few more tips to keep in mind if you do try to setup a makeshift pool heater using solar energy.
Please share your success stories, better prices on garden hoses and circulators, and other comments below.
While this comment doesn't come with too many details about how much hose was used, what kind of pump was used, or even where in the US this is being done... The fact that nearly anyone can harness solar energy to do something useful is very evident. This dog for example, found a great way to enjoy a black garden hose and harness a little solar energy to stay comfortable.
After receiving this comment we decided to figure out just how much something like this would cost to do so we sought out some pricing information online. First off we looked for a hot water recirculating pump and found out that there are several different types in the range of $200 to $300 all designed to connect to a hot water heater. Since water heaters connect using smaller pipes than a garden hose, you would probably need an adapter or two from the Home Depot or other similar store. Next up is black garden hose; we found a nice bundle measuring 100 feet long at $50 that would work pretty well but you might need even more length which would require an extender like this, you would also want to be sure that the system didn't leak because your motor could burn out that way. You can buy little rolls of sealant tape at most hardware stores to be used when screwing in one end of hose to another.
Here are a few more tips to keep in mind if you do try to setup a makeshift pool heater using solar energy.
- Don't leave the system on overnight, that will just waste electricity and potentially even cool your pool down.
- Realize that while solar heat energy is free the electricity needed to run a water circulator is not free - you might want to consider electric solar panels from Home Depot to power your solar water heater!
- If water leaks out of your system (from any of the hoses attached to the pump running through the pool) the circulator could get ruined or burn out.
- Do not use an extension chord to connect the hot water circulator, it needs to connect directly to a house outlet, always be careful when dealing with electricity and water (Solar Power Authority is not providing professional advice here, simply tips that a user has submitted to us) please consult an expert and be very careful with projects like this.
Please share your success stories, better prices on garden hoses and circulators, and other comments below.
Question submitted to Solar Power Authority on July 10th: Where in Colorado can you get training for PV and solar hot water, other than the place in Carbondale? Thanks.
Question clarification to sender by Solar Power Authority: Thanks for your question! In order to help you find the best answer we wanted to clarify your question. It sounds like you are searching for places in Colorado where you can get training on how to install electric generating and water heating solar panels. Is that correct? Are you a do-it-yourselfer or are you actually looking to become a professional installer? Are there any more details you would like us to include in this question as we circulate it in our company and try to provide the best answer?
Clarification by asker: I am looking to become a professional solar installer not a DIY.
To answer this question we looked far and wide for resources detailing the different training options in Colorado but the best ones we came up with were already posted on our site under Colorado Solar Resources near the bottom under "Education". The facility referred to in the question in Carbondale Colorado is called Solar Energy International (SEI) and ufortunately that is the only training company that we know of. Other places to look for answers to this question or repost it include the Colorado Renewable Energy Society (CRES). They may know of something else out there, however, when we searched their site we couldn't see any other links or answers.
In any case, as solar options grow in popularity we will update this entry and we also encourage our readers to comment on any training spots that they know of!
Question clarification to sender by Solar Power Authority: Thanks for your question! In order to help you find the best answer we wanted to clarify your question. It sounds like you are searching for places in Colorado where you can get training on how to install electric generating and water heating solar panels. Is that correct? Are you a do-it-yourselfer or are you actually looking to become a professional installer? Are there any more details you would like us to include in this question as we circulate it in our company and try to provide the best answer?
Clarification by asker: I am looking to become a professional solar installer not a DIY.
To answer this question we looked far and wide for resources detailing the different training options in Colorado but the best ones we came up with were already posted on our site under Colorado Solar Resources near the bottom under "Education". The facility referred to in the question in Carbondale Colorado is called Solar Energy International (SEI) and ufortunately that is the only training company that we know of. Other places to look for answers to this question or repost it include the Colorado Renewable Energy Society (CRES). They may know of something else out there, however, when we searched their site we couldn't see any other links or answers.In any case, as solar options grow in popularity we will update this entry and we also encourage our readers to comment on any training spots that they know of!
Question received by Solar Power Authority on July 11th 2008: South Padre Island Texas area--winter temp 40-50-60 degrees--took a fast food carry out plastic container black bottom half clear top half filled with water put in sun 2 hrs later to hot for finger---outside temp. 90 degrees---clear cover covered with water drops still worked--any thing wrong with this concept--then took foam cooler painted black inside put 50 lb. water @ 80 degrees in cooler covered with clear plastic end of day picked up 36 degrees--averaged 1100 btu per sq foot collector area--will this concept work in winter?
While this question is a bit challenging to read we always do our best here at Solar Power Authority to answer questions as best we can! With that in mind we get the general idea and have put together our thoughts below. As always, we encourage the community to take a shot and add their own comments below. For anyone with your own question just go to our Ask Page.
First off, it's hard to know the intentions of this question but it sounds like this person wants to generate heated water using solar energy. We suggest using a commercial solar collector because it's not clear how one would get the heat from a fast food container, or even a larger plastic device into a living space without facing leaks and other challenges. That said, if this water is not being used to heat a living space then it might be a very affordable way to heat water - simply using a plastic container with a clear top and black bottom. In general though, be careful not to ingest paint or other chemicals used to color your solar heating container. Chemicals such as Bisphenol A (BPA) which may raise the risk of certain forms of cancer. Below is a picture of a professional solar water heater mounted on a roof:
Back to the question... Since the sun shines for fewer hours per day in the winter than in the summer and is lower in the sky (in the northern hemisphere) the home made solar water heater definitely won't work as well during those months. Also, there will be more thermal losses occurring in transport of the water (now referring to a professional solar water heater) due to conduction and convection of heat from the water to the atmosphere. This will occur when pumping the water through the plumbing to go from the solar collector to the living space in the winter because the outside temperature will be lower.
While this question is a bit challenging to read we always do our best here at Solar Power Authority to answer questions as best we can! With that in mind we get the general idea and have put together our thoughts below. As always, we encourage the community to take a shot and add their own comments below. For anyone with your own question just go to our Ask Page.
First off, it's hard to know the intentions of this question but it sounds like this person wants to generate heated water using solar energy. We suggest using a commercial solar collector because it's not clear how one would get the heat from a fast food container, or even a larger plastic device into a living space without facing leaks and other challenges. That said, if this water is not being used to heat a living space then it might be a very affordable way to heat water - simply using a plastic container with a clear top and black bottom. In general though, be careful not to ingest paint or other chemicals used to color your solar heating container. Chemicals such as Bisphenol A (BPA) which may raise the risk of certain forms of cancer. Below is a picture of a professional solar water heater mounted on a roof:
Back to the question... Since the sun shines for fewer hours per day in the winter than in the summer and is lower in the sky (in the northern hemisphere) the home made solar water heater definitely won't work as well during those months. Also, there will be more thermal losses occurring in transport of the water (now referring to a professional solar water heater) due to conduction and convection of heat from the water to the atmosphere. This will occur when pumping the water through the plumbing to go from the solar collector to the living space in the winter because the outside temperature will be lower.
In the past mirrors and lenses have been used to focus and direct
sunlight to increase efficiency in solar panels. One great example of
this is the Sunflower by Energy Innovations. New research at MIT
has created a way to focus light without using mirrors, lenses, or
motors to position panels. Instead, this new technique separates
wavelengths and disperses sunlight to the sides of glass just like an
LED pipe or fiber optics would do in electronics.
Think
about the affect that shining a colored light into a clear piece of
plexiglass has. The top portion of the Plexiglases is clear but each of
the sides lights up brightly. This type of thing is done on video game
consoles and all types of electronics to produce a low energy way to
create a neat look. Now imagine taking windows, skylights, or even
solar panels and applying the same sort of light effect. You would end
up with concentrated light at the sides and edges of the glass
structure which could be collected much more efficiently and therefore
cost effectively than by conventional means.
What the guys over at MIT have found is that not only can you direct light using organic compounds but you can actually separate wavelengths and then capture each one at optimal efficiency producing nearly four times the electricity generation as a normal panel might produce. The really good news is that this type of technology could be applied to current gen solar panels in three or four years (once it's out on the market) at a low price which means you don't have to hold off on current solar solutions to reap the benefits.
Think
about the affect that shining a colored light into a clear piece of
plexiglass has. The top portion of the Plexiglases is clear but each of
the sides lights up brightly. This type of thing is done on video game
consoles and all types of electronics to produce a low energy way to
create a neat look. Now imagine taking windows, skylights, or even
solar panels and applying the same sort of light effect. You would end
up with concentrated light at the sides and edges of the glass
structure which could be collected much more efficiently and therefore
cost effectively than by conventional means.What the guys over at MIT have found is that not only can you direct light using organic compounds but you can actually separate wavelengths and then capture each one at optimal efficiency producing nearly four times the electricity generation as a normal panel might produce. The really good news is that this type of technology could be applied to current gen solar panels in three or four years (once it's out on the market) at a low price which means you don't have to hold off on current solar solutions to reap the benefits.
Solar Power (and solar promotions) are popping up everywhere and just recently AT&T Park partnered with Pacific Gas and Electric (PG&E) and Sharp to bring solar power into the home of the San Francisco Giants. Along with other promotions around the city, PG&E is trying to create awareness that it generates over 50% of it's power from renewable energy sources including wind, solar, biomass, hydro, and nuclear.
At AT&T Park there are several billboard style ads in the stadium hallways advertising Sharp solar panels as the type being used around the stadium, and there is one large bright green billboard up near the scoreboard that actually has solar panels built into it as shown below.
In order to see any of the real solar panels that actually produce power for the stadium you will have to travel to the South Eastern side of the stadium (near the water fountains) and look over the railing. There you will find several awning style covers with built in solar panels. PG&E has said that nearly 600 panels have been installed and that the electricity from the panels is being sold to residents and businesses in the City. These panels from Sharp and PG&E are the first to ever be installed at a major league baseball stadium anywhere.
At AT&T Park there are several billboard style ads in the stadium hallways advertising Sharp solar panels as the type being used around the stadium, and there is one large bright green billboard up near the scoreboard that actually has solar panels built into it as shown below.
In order to see any of the real solar panels that actually produce power for the stadium you will have to travel to the South Eastern side of the stadium (near the water fountains) and look over the railing. There you will find several awning style covers with built in solar panels. PG&E has said that nearly 600 panels have been installed and that the electricity from the panels is being sold to residents and businesses in the City. These panels from Sharp and PG&E are the first to ever be installed at a major league baseball stadium anywhere.
Introduction
Household energy consumption is responsible for a significant amount of environmental impact. By increasing the number of households that run on renewable energy, this environmental impact can be greatly reduced. Australians want to go green but don't want to pay more for it (1). If people are shown a viable and simple way to convert their homes to renewable energy, there is a high probability that they will do so.
The aim of this report is to answer the question: at the present time, is it viable to convert your home to run on solar photovoltaic (PV) energy? Furthermore, this report aims to outline a process that you can follow for converting your home to solar.
In order to achieve the above aims, this report considers factors including: household energy use, system costs, installation requirements, system providers, rebates, feed-in tariffs, energy saving practices and energy plans. The information has been arranged in a way that will allow you to decide if it is viable for you to convert your home to solar.
How Much Energy Do I Use?
By finding out how much energy you currently use, you will be able to choose a suitable PV system that caters to your needs. To find out how much energy you use, see the front page of your electricity bill for the last three months.
An energy-efficient home is defined as consuming 7.5 kWh per day or less (2). The national average is 16kWh per day and it would require a 3.5 kW system to provide 100% of this energy consumption (3). A grid connected PV system of this calibre costs between $27,000 and $30,000. For most people, this outlay is far beyond their financial capacity. Therefore, a more suitable option would be a 1kW system, which generates approx 5kWh per day and costs between $4000 and $7000 (4).
In light of the above, a viable plan may be to cover a portion of your energy needs with solar power and at the same time use energy saving practices to lower your energy consumption in the home. Such practices may include using energy efficient appliances, turning off appliances when not in use etc. There are many ways to save energy in the home and this information is easily obtained by performing an Internet search or exploring the Solar Power Authority site.
How Much Roof Space Do I Have?
Once you have decided on a PV system that suits your budget and energy needs, check that you have enough spare roof space for panel installation. Ideally, this roof space should have a North aspect. The size of the system may vary depending on the manufacturer and type of panel but as a general guide, each kW of standard solar panels requires approximately 8sqm of roof space (3).
Provide your findings, along with some site photos, to your provider when you contact them for a formal quote. If necessary, the provider may arrange a site inspection prior to installation. If you do not have suitable roof space, ask your provider if they can provide you with alternative options. Most providers are very willing and able to cater to each individual situation.
Finding Providers and Obtaining Quotes
There are a number of BCSE accredited solar system providers around Australia. They can be found online (5), in the Yellow Pages and increasingly in newspapers. Whilst shopping for the best price, be sure to find a provider that has good service. Do they explain things in a way that is easy to understand? Do they cater to your specific situation? What is their warranty? What maintenance contracts do they offer? Will they help you apply for government rebates? Will they match or beat the prices of other providers? All of these questions should be considered when choosing a provider.
Additional Costs
There is an additional charge by ETSA Utilities of between $350 and $421 for fitting of a new single phase PV import/export meter. This will be charged direct to you by ETSA Utilities (6). Also note that solar installation costs may vary due to installation requirements and your location.
Australian Government Rebates
All system costs mentioned thus far include the maximum Australian Government rebate of $8000, under the Solar Homes and Communities Plan (SHCP). Therefore, it is important to make sure you are eligible for this rebate. Some important requirements are listed below.
The above list is not complete. There are other requirements, some of which relate to technical design and installation. Full details of requirements can be found in the SHCP Guidelines (7). If you are going through an accredited company, they will ensure you meet the requirements and assist you with the application process. You will need to file an SHCP Residential Application for Pre-Approval (8).
Note that the SHCP rebate is capped at a 1kW system, so as the system size increases above 1kW the rebate does not increase above $8000. This is another reason for choosing a 1kW system, as it attracts the maximum rebate for minimum financial outlay. Smaller rebates can be obtained for systems of at least 450W.
The SHCP will conclude at the end of the 2009-2010 financial year (9). Therefore, if you wish to take advantage of this rebate, you should aim to do so as soon as possible. If you live in a remote area, you should apply for the Renewable Remote Power Generation Program (RRPGP) rebate instead of the SHCP rebate (10).
Renewable Energy Certificate (REC) Rebates
In addition to the HSCP rebate, you can also get Renewable Energy Certificates (RECs) for the greenhouse gases you will be abating over a deeming period of 15 years. RECs have a monetary value but the price varies from day to day. Providers are often prepared to buy these from you in the form of an up-front discount, usually worth some hundreds of dollars (11). RECs are currently around $500 per kW of solar panels installed (4).
Feed-In Tariffs
On the 1st of July 2008, new laws will come into effect in South Australia and Queensland, whereby households and small electricity consumers will be rewarded for generating more energy than they use and feeding the excess back to the grid. These new laws, set to be in place for at least 20 years, will guarantee a feed-in tariff of $0.44 per kWh fed back to the grid - around three times the current general domestic use tariff of $0.15 per kWh (12) (13). In 2009, Victoria will introduce a feed-in tariff of $0.60 and the scheme will run for 15 years. Other Australian states currently have limited schemes or are considering the implementation of a scheme (14). If you live in a state where there is no feed-in tariff, you can check with available electricity retailers as to whether they will buy back any electricity your system generates (and on what terms). If they do, then you will need to check for any fees and the price you will be paid (11).
How it works: the output of the photovoltaic (PV) system is connected to the household loads which in turn are connected to the grid via a bi-directional or 'import/export meter'. When the output of the PV system exceeds the household loads, the excess electricity is fed into the grid via the 'export' register of the meter. The meter records the 'net export' rather than the 'gross production' of the PV system i.e. gross production - household load = net export (15).
Import/export calculations are instantaneous. Thus, even if your system does not produce more energy than you use for the day, you can still export energy at certain times. For example, if you were not home during the day and little energy was being consumed in your home during this time (e.g. fridge only), your PV system would be producing more energy than the household load. The excess would be fed back to the grid for $0.44 per kWh. If you then return home in the evening and your energy consumption increases (e.g. lights, TV, heating/cooling etc.) to an amount above that which your system generates, you would then be importing from the grid and not exporting. Regardless of how much you import, you will still get $0.44 for each kWh that you have exported at any given instant (16).
Switching Energy Plans
As well as installing solar panels and using energy efficient practices in the home, you may also be able to change to a cheaper energy plan to further reduce your energy costs. There is a website called "uSwitch" that allows you to compare the cost of available energy plans and see how green they are (17). Any savings could be put towards your solar energy system.
Is It Worth It?
With an average energy consumption of 16kWh per day and an energy cost of $0.15 per kWh, your annual energy bill would be $876. By investing approx $5000, you could install a 1kW system with an output of approx 5kWh per day and this would provide around one third of your energy needs, thus reducing your annual energy bill to $584. With this saving of $292 per annum, it would take approx 17 years to pay off the initial $5000 investment.
However, suppose you were to export 50% of the energy that your PV system generated. In this case, your system would provide around one sixth of your energy needs, thus initially reducing your annual energy bill to $730. You would also get $401.50 (2.5kWh X $0.44 X 365 days) for the energy you fed back to the grid, thus further reducing your annual energy bill to $328.50. With this saving of $547.50 per annum, it would take approx 9 years to pay off the initial $5000 investment. Depending on when you installed your system and the feed-in tariff duration, you could then save up to $6022.50 over the next 11 years.
Note that the above calculations do not take into account the implementation of any other energy saving practices, nor switching to a cheaper energy plan. This is because it could be argued that such savings could be made whether you installed a PV system or not.
Conclusion
With current government subsidies and feed-in schemes, solar is the most viable form of renewable energy for your household. However, solar power may be considered too expensive due to the upfront cost and payoff time. The viability of converting your home to solar will depend on your individual circumstances as per the key considerations outlined in this report. In particular, the more energy you can export back to the grid, the more viable it will be to convert your home to solar.
In order to make solar energy more viable for Australian households, changes must be made to current legislation. Every state should have a minimum feed-in tariff of at least $0.60 per kWh. As is the case in Germany and other countries, the tariff should be calculated on gross production as opposed to net export. As well, investments in the "clean coal" industry should be redirected to increase the maximum HSCP subsidy. Such changes would dramatically shorten the investment payoff time and encourage many more people to use solar energy in their home.
Finally, you may wish to write to your local state member of parliament and request that they take action to pass laws that will make it more viable for you to convert your home to solar and contribute to making Australia a sustainable country (18).
Reference List
1. The Daily Telegraph - Impose a green tax, study says
www.news.com.au/dailytelegraph/story/0,22049,22471803-5001028,00.html?from=public_rss
2. BP Solar grid connect brochure www.bp.com/liveassets/bp_internet/solar/bp_solar_australia/STAGING/local_assets/downloads_pdfs/e/Energizerbrochure-Oct07.pdf
3. Personal communication from Energy Matters, 19th May 08
4. Energy Matters price list
www.energymatters.com.au/docs/GridSolarPrices.pdf
5. List of BCSE accredited designers and installers
www.bcse.org.au/docs/STA/Installers%20List/AccInstallers%20List%20-%20all%20-%20080528.pdf
6. Personal communication from Solaris, 19th May 08.
7. Australian Government - SHCP Guidelines for Residential Applicants
www.environment.gov.au/settlements/renewable/pv/pubs/shcp-residential-guidelines-21may2008.pdf
8. Australian Government - SHCP Residential Application for Pre-Approval
www.environment.gov.au/settlements/renewable/pv/pubs/shcp-application-residential-21may2008.pdf
9. Australian Government - SHCP Questions and Answers
www.environment.gov.au/settlements/renewable/pv/faqs.html
10. Australian Government - Renewable Remote Power Generation Program
www.environment.gov.au/settlements/renewable/rrpgp/index.html
11. Australian Business Council of Sustainable Energy - FAQ
www.bcse.org.au/default.asp?id=119
12. South Australian Government - Feed In Scheme
www.climatechange.sa.gov.au/news/news_\5.htm
13. Queensland Government - Solar Bonus Scheme
www.dme.qld.gov.au/Energy/solar_feed_in_tariff.cfm
14. Wikipedia - Feed In Tariffs in Australia
http://en.wikipedia.org/wiki/Feed-in_tariffs_in_Australia
15. South Australian Government - Metering of PV Systems
www.climatechange.sa.gov.au/news/news_5_3.htm
16. Personal communication from the Sustainability & Climate Change Division
of the South Australian Government, 2nd June 08.
17. uSwitch - Compare Gas and Electricity Plans
www.uswitch.com.au/index.php?option=com_uswitchcalculator&Itemid=134
18. Australian Members of Parliament
www.aph.gov.au/House/members/mi-alpha.asp
Household energy consumption is responsible for a significant amount of environmental impact. By increasing the number of households that run on renewable energy, this environmental impact can be greatly reduced. Australians want to go green but don't want to pay more for it (1). If people are shown a viable and simple way to convert their homes to renewable energy, there is a high probability that they will do so.
The aim of this report is to answer the question: at the present time, is it viable to convert your home to run on solar photovoltaic (PV) energy? Furthermore, this report aims to outline a process that you can follow for converting your home to solar.
In order to achieve the above aims, this report considers factors including: household energy use, system costs, installation requirements, system providers, rebates, feed-in tariffs, energy saving practices and energy plans. The information has been arranged in a way that will allow you to decide if it is viable for you to convert your home to solar.
How Much Energy Do I Use?
By finding out how much energy you currently use, you will be able to choose a suitable PV system that caters to your needs. To find out how much energy you use, see the front page of your electricity bill for the last three months.
An energy-efficient home is defined as consuming 7.5 kWh per day or less (2). The national average is 16kWh per day and it would require a 3.5 kW system to provide 100% of this energy consumption (3). A grid connected PV system of this calibre costs between $27,000 and $30,000. For most people, this outlay is far beyond their financial capacity. Therefore, a more suitable option would be a 1kW system, which generates approx 5kWh per day and costs between $4000 and $7000 (4).
In light of the above, a viable plan may be to cover a portion of your energy needs with solar power and at the same time use energy saving practices to lower your energy consumption in the home. Such practices may include using energy efficient appliances, turning off appliances when not in use etc. There are many ways to save energy in the home and this information is easily obtained by performing an Internet search or exploring the Solar Power Authority site.
How Much Roof Space Do I Have?
Once you have decided on a PV system that suits your budget and energy needs, check that you have enough spare roof space for panel installation. Ideally, this roof space should have a North aspect. The size of the system may vary depending on the manufacturer and type of panel but as a general guide, each kW of standard solar panels requires approximately 8sqm of roof space (3).
Provide your findings, along with some site photos, to your provider when you contact them for a formal quote. If necessary, the provider may arrange a site inspection prior to installation. If you do not have suitable roof space, ask your provider if they can provide you with alternative options. Most providers are very willing and able to cater to each individual situation.
Finding Providers and Obtaining Quotes
There are a number of BCSE accredited solar system providers around Australia. They can be found online (5), in the Yellow Pages and increasingly in newspapers. Whilst shopping for the best price, be sure to find a provider that has good service. Do they explain things in a way that is easy to understand? Do they cater to your specific situation? What is their warranty? What maintenance contracts do they offer? Will they help you apply for government rebates? Will they match or beat the prices of other providers? All of these questions should be considered when choosing a provider.
Additional Costs
There is an additional charge by ETSA Utilities of between $350 and $421 for fitting of a new single phase PV import/export meter. This will be charged direct to you by ETSA Utilities (6). Also note that solar installation costs may vary due to installation requirements and your location.
Australian Government Rebates
All system costs mentioned thus far include the maximum Australian Government rebate of $8000, under the Solar Homes and Communities Plan (SHCP). Therefore, it is important to make sure you are eligible for this rebate. Some important requirements are listed below.
- System installer must be BCSE accredited
- System must be connected to a main grid or be very close to a main grid.
- Maximum $8000 rebate is for a complete system of 1kW or larger.
- System must be installed at the applicant's principle place of residence and there can be only one rebate per residence.
- Must not have previously received a rebate for a photovoltaic system from the Australian Government
- Applicant's household taxable income must be less than $100,000.
The above list is not complete. There are other requirements, some of which relate to technical design and installation. Full details of requirements can be found in the SHCP Guidelines (7). If you are going through an accredited company, they will ensure you meet the requirements and assist you with the application process. You will need to file an SHCP Residential Application for Pre-Approval (8).
Note that the SHCP rebate is capped at a 1kW system, so as the system size increases above 1kW the rebate does not increase above $8000. This is another reason for choosing a 1kW system, as it attracts the maximum rebate for minimum financial outlay. Smaller rebates can be obtained for systems of at least 450W.
The SHCP will conclude at the end of the 2009-2010 financial year (9). Therefore, if you wish to take advantage of this rebate, you should aim to do so as soon as possible. If you live in a remote area, you should apply for the Renewable Remote Power Generation Program (RRPGP) rebate instead of the SHCP rebate (10).
Renewable Energy Certificate (REC) Rebates
In addition to the HSCP rebate, you can also get Renewable Energy Certificates (RECs) for the greenhouse gases you will be abating over a deeming period of 15 years. RECs have a monetary value but the price varies from day to day. Providers are often prepared to buy these from you in the form of an up-front discount, usually worth some hundreds of dollars (11). RECs are currently around $500 per kW of solar panels installed (4).
Feed-In Tariffs
On the 1st of July 2008, new laws will come into effect in South Australia and Queensland, whereby households and small electricity consumers will be rewarded for generating more energy than they use and feeding the excess back to the grid. These new laws, set to be in place for at least 20 years, will guarantee a feed-in tariff of $0.44 per kWh fed back to the grid - around three times the current general domestic use tariff of $0.15 per kWh (12) (13). In 2009, Victoria will introduce a feed-in tariff of $0.60 and the scheme will run for 15 years. Other Australian states currently have limited schemes or are considering the implementation of a scheme (14). If you live in a state where there is no feed-in tariff, you can check with available electricity retailers as to whether they will buy back any electricity your system generates (and on what terms). If they do, then you will need to check for any fees and the price you will be paid (11).
How it works: the output of the photovoltaic (PV) system is connected to the household loads which in turn are connected to the grid via a bi-directional or 'import/export meter'. When the output of the PV system exceeds the household loads, the excess electricity is fed into the grid via the 'export' register of the meter. The meter records the 'net export' rather than the 'gross production' of the PV system i.e. gross production - household load = net export (15).
Import/export calculations are instantaneous. Thus, even if your system does not produce more energy than you use for the day, you can still export energy at certain times. For example, if you were not home during the day and little energy was being consumed in your home during this time (e.g. fridge only), your PV system would be producing more energy than the household load. The excess would be fed back to the grid for $0.44 per kWh. If you then return home in the evening and your energy consumption increases (e.g. lights, TV, heating/cooling etc.) to an amount above that which your system generates, you would then be importing from the grid and not exporting. Regardless of how much you import, you will still get $0.44 for each kWh that you have exported at any given instant (16).
Switching Energy Plans
As well as installing solar panels and using energy efficient practices in the home, you may also be able to change to a cheaper energy plan to further reduce your energy costs. There is a website called "uSwitch" that allows you to compare the cost of available energy plans and see how green they are (17). Any savings could be put towards your solar energy system.
Is It Worth It?
With an average energy consumption of 16kWh per day and an energy cost of $0.15 per kWh, your annual energy bill would be $876. By investing approx $5000, you could install a 1kW system with an output of approx 5kWh per day and this would provide around one third of your energy needs, thus reducing your annual energy bill to $584. With this saving of $292 per annum, it would take approx 17 years to pay off the initial $5000 investment.
However, suppose you were to export 50% of the energy that your PV system generated. In this case, your system would provide around one sixth of your energy needs, thus initially reducing your annual energy bill to $730. You would also get $401.50 (2.5kWh X $0.44 X 365 days) for the energy you fed back to the grid, thus further reducing your annual energy bill to $328.50. With this saving of $547.50 per annum, it would take approx 9 years to pay off the initial $5000 investment. Depending on when you installed your system and the feed-in tariff duration, you could then save up to $6022.50 over the next 11 years.
Note that the above calculations do not take into account the implementation of any other energy saving practices, nor switching to a cheaper energy plan. This is because it could be argued that such savings could be made whether you installed a PV system or not.
Conclusion
With current government subsidies and feed-in schemes, solar is the most viable form of renewable energy for your household. However, solar power may be considered too expensive due to the upfront cost and payoff time. The viability of converting your home to solar will depend on your individual circumstances as per the key considerations outlined in this report. In particular, the more energy you can export back to the grid, the more viable it will be to convert your home to solar.
In order to make solar energy more viable for Australian households, changes must be made to current legislation. Every state should have a minimum feed-in tariff of at least $0.60 per kWh. As is the case in Germany and other countries, the tariff should be calculated on gross production as opposed to net export. As well, investments in the "clean coal" industry should be redirected to increase the maximum HSCP subsidy. Such changes would dramatically shorten the investment payoff time and encourage many more people to use solar energy in their home.
Finally, you may wish to write to your local state member of parliament and request that they take action to pass laws that will make it more viable for you to convert your home to solar and contribute to making Australia a sustainable country (18).
Reference List
1. The Daily Telegraph - Impose a green tax, study says
www.news.com.au/dailytelegraph/story/0,22049,22471803-5001028,00.html?from=public_rss
2. BP Solar grid connect brochure www.bp.com/liveassets/bp_internet/solar/bp_solar_australia/STAGING/local_assets/downloads_pdfs/e/Energizerbrochure-Oct07.pdf
3. Personal communication from Energy Matters, 19th May 08
4. Energy Matters price list
www.energymatters.com.au/docs/GridSolarPrices.pdf
5. List of BCSE accredited designers and installers
www.bcse.org.au/docs/STA/Installers%20List/AccInstallers%20List%20-%20all%20-%20080528.pdf
6. Personal communication from Solaris, 19th May 08.
7. Australian Government - SHCP Guidelines for Residential Applicants
www.environment.gov.au/settlements/renewable/pv/pubs/shcp-residential-guidelines-21may2008.pdf
8. Australian Government - SHCP Residential Application for Pre-Approval
www.environment.gov.au/settlements/renewable/pv/pubs/shcp-application-residential-21may2008.pdf
9. Australian Government - SHCP Questions and Answers
www.environment.gov.au/settlements/renewable/pv/faqs.html
10. Australian Government - Renewable Remote Power Generation Program
www.environment.gov.au/settlements/renewable/rrpgp/index.html
11. Australian Business Council of Sustainable Energy - FAQ
www.bcse.org.au/default.asp?id=119
12. South Australian Government - Feed In Scheme
www.climatechange.sa.gov.au/news/news_\5.htm
13. Queensland Government - Solar Bonus Scheme
www.dme.qld.gov.au/Energy/solar_feed_in_tariff.cfm
14. Wikipedia - Feed In Tariffs in Australia
http://en.wikipedia.org/wiki/Feed-in_tariffs_in_Australia
15. South Australian Government - Metering of PV Systems
www.climatechange.sa.gov.au/news/news_5_3.htm
16. Personal communication from the Sustainability & Climate Change Division
of the South Australian Government, 2nd June 08.
17. uSwitch - Compare Gas and Electricity Plans
www.uswitch.com.au/index.php?option=com_uswitchcalculator&Itemid=134
18. Australian Members of Parliament
www.aph.gov.au/House/members/mi-alpha.asp
Recently I interviewed three solar experts in Colorado who have experience in the developing world and was surprised to find abundant confidence in village renewable energy (RE). There are many groups who do non-profit RE development around the world, but my fundamental question was this: is a for-profit model viable in poor communities?
There are more companies already doing solar in the developing world than I knew. Blake Jones, president of Boulder, CO's Namaste Solar, claims there is a thriving RE industry in Nepal--15 companies doing PV, dozens of solar hot water contractors, 50 biogas contractors, and more--all making profit.
"The list is actually huge," notes Laurie Stone, International Program Director for Solar Energy International. Some of the more successful ones are Lotus Energy in Nepal, Suni Solar in Nicaragua (pictured below), Soluz in Honduras, and the Solar Electric Light Company (SELCO) in India.
Stone also recognizes Grameen Shakti--a branch of the Grameen Bank in Bangladesh--for its successful micro-financing programs for renewable energy. Financing is one of the major obstacles to for-profit village RE. That's because, while solar may pay off in the long run, poor communities lack the capital to pay for their energy up-front--even while they spend money for batteries, kerosene, or even propane.
Zeke Yewdall, chief engineer for the Colorado division of Standard Renewable Energy, made his solar debut with Engineers Without Borders in Mauritania. "The village of Lemrevaig had applied to the US Embassy for funding for a solar water pump... since their existing propane-fired pump was old, expensive, and the water line [a cheap fire hose] had to be replaced every two years," he says.
The capital problem is often surmountable. "Lack of income is the biggest problem," Yewdall admits; "however, after we installed this [solar] water pump in Lemrevaig, the chief's brother-in-law was thinking about how he could sell part of his date orchard in order to buy another [solar water pump]" to irrigate what was left. It would take him years to save the money, but he knew it was worth it. "That was a small amount of money for the value it gave."
But that story is not universal. "In general, RE projects in Africa are plagued by a very high failure rate," Yewdall says. The reason he cites is a lack of community buy-in and participation. If a community doesn't ask for solar--and if it has no training in how to use or maintain it--then it usually abandons the system in a few years and scraps it for parts. This type of failure may actually be more common in the non-profit--or "donation model"--sector. When a community pays for solar or provides the labor to install it, even when financed through grants or micro-loans, it is more likely to want it, use it, and care for it.
That's not to say that NGOs don't have an important role in village RE. "Often times it takes non-profits to help kick-start an industry," notes Blake Jones. They help prove concepts and they take risks the private sector isn't willing to take. "A lot of places where I've seen industries get started in developing countries," he says, "was where foreigners came and brought with them the expertise." Then, they hand it off to for-profit companies, whose business model may ultimately be more sustainable.
Jones previously worked for Lotus Energy, a Nepali PV company. And even though Lotus is a successful, for-profit venture, sustainability was still a constant concern. Wherever he went, someone had to be learning right along with him. "We wanted to arrange my role such that I wasn't always doing the work," Jones says, "but instead was helping others learn how to do it so it wouldn't create a dependency."
Jones has also consulted for the Himalayan Light Foundation, which, through their Home Employment Lighting Program (HELP), helps communities develop micro-enterprises using solar electricity. They give people a solar home system as well as training in certain crafts. Then, the family pays for the system with the income from their crafts, plus they can use the electricity for other home appliances.
Ultimately, I found three things that help make a village solar project successful. Being conscious of dependency is one. Proper planning, naturally, is another, as the job site may be two days by bus and five more on foot from the nearest supply store. Finally, it takes someone on the ground, working from inside a community. Jones agrees: "nothing compares to living in a country."
There are more companies already doing solar in the developing world than I knew. Blake Jones, president of Boulder, CO's Namaste Solar, claims there is a thriving RE industry in Nepal--15 companies doing PV, dozens of solar hot water contractors, 50 biogas contractors, and more--all making profit.
"The list is actually huge," notes Laurie Stone, International Program Director for Solar Energy International. Some of the more successful ones are Lotus Energy in Nepal, Suni Solar in Nicaragua (pictured below), Soluz in Honduras, and the Solar Electric Light Company (SELCO) in India.
Stone also recognizes Grameen Shakti--a branch of the Grameen Bank in Bangladesh--for its successful micro-financing programs for renewable energy. Financing is one of the major obstacles to for-profit village RE. That's because, while solar may pay off in the long run, poor communities lack the capital to pay for their energy up-front--even while they spend money for batteries, kerosene, or even propane.Zeke Yewdall, chief engineer for the Colorado division of Standard Renewable Energy, made his solar debut with Engineers Without Borders in Mauritania. "The village of Lemrevaig had applied to the US Embassy for funding for a solar water pump... since their existing propane-fired pump was old, expensive, and the water line [a cheap fire hose] had to be replaced every two years," he says.
The capital problem is often surmountable. "Lack of income is the biggest problem," Yewdall admits; "however, after we installed this [solar] water pump in Lemrevaig, the chief's brother-in-law was thinking about how he could sell part of his date orchard in order to buy another [solar water pump]" to irrigate what was left. It would take him years to save the money, but he knew it was worth it. "That was a small amount of money for the value it gave."
But that story is not universal. "In general, RE projects in Africa are plagued by a very high failure rate," Yewdall says. The reason he cites is a lack of community buy-in and participation. If a community doesn't ask for solar--and if it has no training in how to use or maintain it--then it usually abandons the system in a few years and scraps it for parts. This type of failure may actually be more common in the non-profit--or "donation model"--sector. When a community pays for solar or provides the labor to install it, even when financed through grants or micro-loans, it is more likely to want it, use it, and care for it.
That's not to say that NGOs don't have an important role in village RE. "Often times it takes non-profits to help kick-start an industry," notes Blake Jones. They help prove concepts and they take risks the private sector isn't willing to take. "A lot of places where I've seen industries get started in developing countries," he says, "was where foreigners came and brought with them the expertise." Then, they hand it off to for-profit companies, whose business model may ultimately be more sustainable.
Jones previously worked for Lotus Energy, a Nepali PV company. And even though Lotus is a successful, for-profit venture, sustainability was still a constant concern. Wherever he went, someone had to be learning right along with him. "We wanted to arrange my role such that I wasn't always doing the work," Jones says, "but instead was helping others learn how to do it so it wouldn't create a dependency."
Jones has also consulted for the Himalayan Light Foundation, which, through their Home Employment Lighting Program (HELP), helps communities develop micro-enterprises using solar electricity. They give people a solar home system as well as training in certain crafts. Then, the family pays for the system with the income from their crafts, plus they can use the electricity for other home appliances.
Ultimately, I found three things that help make a village solar project successful. Being conscious of dependency is one. Proper planning, naturally, is another, as the job site may be two days by bus and five more on foot from the nearest supply store. Finally, it takes someone on the ground, working from inside a community. Jones agrees: "nothing compares to living in a country."
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