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WalkerARCHITECTS
Joined: 25 Sep 2007
Posts: 105
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 Posted: Sat Oct 18, 2008 8:33 pm Post subject: Solar Electric Basics |
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I am frequently asked to explain photo-voltaic solar energy systems. I am sharing knowledge that has been shared with me. This is the Solar Electric basic's without the math.
Each solar module receives the energy from the sun as photons. The module is able to harvest these photons and convert them into electricity. Solar modules can typically convert about 13% of the energy they receive into actual electricity. The solar modules convert the sun's energy into DC voltage.
The existing power infrastructure utilizes alternating current to transmit power from the point where power is generated to the places where we use it. The DC voltage output of the solar array needs to be converted into 60 Hz AC power and have its voltage either increased or decreased to 120V. We need to have an inverter or use the DC current directly. This conversion to 120V AC is what the inverter does. It takes the solar array's DC power and transforms it into your house and utility grid's 120V AC, 60 Hz electricity. The inverter is typically mounted close to your electric panel either on the inside or outside wall.
The 120V AC power leaving the inverter is then connected directly to a dedicated breaker in your home's main electric panel. This ties in the solar electricity to all of your house's electrical loads and to the entire utility grid. Essentially your system is always a part of the utility grid, much like a drop of water is to the sea.
During the day time, when no one is home and the sun is shining, your solar electricity will easily be able to power any items that are left on, plus there will be much excess energy that will flow back into the grid. For your solar energy to go into the grid it must flow "backwards" through your electric meter. This results in the kWh reported to the utility company to be less and less throughout the day. Essentially you are decreasing the amount of money you will have to pay to the utility company at month's end. If it is a sunny family weekend at the house with air conditioners and all other appliances running, then most likely all of your solar energy will be used and any additional power that you need will come from the utility grid. Since only a small amount will be from the utility grid, your meter will only spin forward minimally compared to what it would have if you didn't have solar. Once again, resulting in less money that you pay to your utility company.
When you think of it, the utility company is really like a big electrical savings bank from which you can deposit solar credits in the day time and withdraw them at night time. This also works for the summer and winter months, because if you continually deposit more solar kWh's than you use in the summer, they are available for usage in the winter time when you can start withdrawing them.
In Washington State we very fortunate to have additional incentive programs that reward us for the solar energy produced every year. For this to be possible, it is necessary to know exactly how much solar energy (kWh) your system produced for the year, regardless if you use it or not. This requires that an additional electric meter be installed in between the inverter and your house's electric panel, so that it can be record all your solar kWh's before your house or the utility grid uses them. Regardless if you use the solar energy or if any un-used solar energy feeds backwards into the utility grid, your solar meter records every single kWh of it. Every year this meter is read by your utility company and a check is written to you for $.15 per kWh, up to a maximum of $2000 per year.
The above explanation should make it easier to understand how a solar energy system interfaces with your home or business and the utility grid. In review:
• The solar modules are connected in series somewhat like batteries to generate the final system DC voltage
• The solar array's output is routed from the roof to the inverter (normally mounted next to the electric panel)
• The inverter converts the solar array's power from a high voltage DC to a clean 120V AC.
• The 120V AC output of the inverter goes through a dedicated electric meter who's only function is to record all the solar energy kWh that are produced for the entire year.
• The 120V AC continues to flow from the solar meter to a dedicated breaker in your house's electric panel.
• This integrates your solar electricity to both your house and the utility grid.
• When your solar system is providing the exact amount of power that your house is currently using, then your electric meter will stand still.
• When your solar system is providing more power than your house or business is using, then any excess will flow backwards through the utility meter and you will be building a credit with your utility company.
• When your solar system is providing less power than your house is using, then the utility grid will provide the rest; however, your meter will be spinning forward only for the excess electricity that is required.
The Current State of the Solar Energy solution here in Washington State
The situation now is that your power is generated in large central plants and distributed over large interconnected networks of high voltage power lines. Sources of generation include coal, gas, nuclear, and hydro power.
The problem for you is that
• cost of fossil fuel goes up
• nuclear generation is expensive and dangerous
• hydro power development is limited
• power is lost in transmission over long distances
• the aging grid becomes increasingly vulnerable to breakdown
• all of these systems have negative environmental effects.
The implication is that your power costs are out of your control and your power comes from a grid that is vulnerable and unreliable. Further, your power consumption contributes to the kinds of environmental problems that are changing health and weather patterns, and the kinds of political problems that result from reliance on foreign and declining energy sources.
In Washington we have enjoyed cheap hydro power. But the government intends to raise our costs to match markets in the rest of the country, which will more than double them. Why would anyone do that? While our hydropower is renewable, it does have environmental consequences, and there is no opportunity to expand it.
We advocate the commercial development of rooftop power plants. But even homeowner installed systems will pencil out as money makers.
Generating your own power at home using mature renewable energy technologies can provide relief from a host of problems. We advocate taking local control over the very probable sustained energy shortage problem, we anticipate that problem based upon the limited development of alternative energy systems, the existing state of the fossil fuel power on demand generation system and the global trend to have increasingly higher prices for fossil fuel generated energy in the future.
In Washington State we can lock in your electric rates now for the future.
Depending on the system you choose and where you live or work, you can reduce your utility costs by up to 90% or even eliminate your electric bill entirely, if you have the money to install a solar electric system. In fact, when your solar production exceeds your demand, your meter actually spins backwards - the utility company credits you for the power you produce! In Washington State there are significant incentives and rebates for businesses and individuals who have solar electric systems installed. Walker Architects has detailed this information in our reports.
Power Reliability
Solar is the number one choice where power reliability is a concern. The first systems built and designed in the 1950's are not only still functional but produce significant power even now! When NASA needed trouble free, durable power for the space race, satellites, and for the exploration of other planets they turned to solar. A solar electric system is completely automatic; it has no moving parts, and is virtually maintenance free, and with a supplemental inverter and battery storage your system can keep your lights on in the event of an emergency or a blackout.
Net Metering
You can actually look forward to opening your electricity bill, with a solar electric system. Your meter will spin forward when electricity is used from the grid, and spin backwards, generating a credit, when the solar system creates more electricity than is used. In the summer when you are using less electricity and generating more, you build up a credit each month, so that in the winter when you will experience greater need and demand, along with lesser production you use those credits. At the end of the year you pay the "NET" difference between production and use.
Rebates and Incentives
Currently, some utilities offer subsidies that cover some of the cost of a system. Also, there is a 30 % federal tax credit to help reduce the cost of the system even further. In addition, there are subsidies for your production, paying you beyond net metering for the power you generate. And, you are exempt from paying sales tax on your system and installation.
Increased Appraised value of Your Home
Based on a recent study by ICF consulting, (funded by HUD and the EPA and published in The Appraisal Journal (October 1998) energy saving measures such as solar can add up to $20 of home value for every $1 of yearly energy cost savings. What's better is that you are exempt from property tax on your increased value!
Environmentally Friendly
And finally, utilizing a solar system allows you to make a difference. Installing a solar electric system will preserve the earth's finite fossil-fuel resources and reduce air-pollution. A solar system does not release or produce any harmful by-products. It is 100% clean energy! A typical 2kw solar system produces up to 3,600 kW hours per year which, in turn, prevents the need to burn 3.7 tons of coal to produce the same amount of electricity. 3.7 tons of coal burned releases 10,000 pounds of green house gases into our atmosphere.
I hope you're considering solar/photovoltaic because it can save you money, to ensure you have electricity during power outages, or because you want to have a less harmful impact on the environment, solar electric solutions are the intelligent, infinitely renewable choice for anyone.
Increasingly feasible in the United States
While the cost of solar power still has a ways to go, Washington State has made some strides in boosting its accessibility among residential users.
Government Involvement:
Ballot measure Initiative 937 that passed last fall requires utilities to get at least 15 percent of their energy from renewable resources by 2020. Plus, under state law, any public or private utility company can credit its customers for the energy they generate through "net metering."
It allows homeowners to get full retail value for most, or all of the electricity they produce by banking their excess electricity into the electric grid to withdraw it later, free of charge.
Also, homeowners who install Washington-made solar equipment are now entitled to subsidies.
This is all good news for bringing solar into the residential market. Walker Architects advocates solar electric power; “ the federal government and each state needs to "artificially intervene" and heavily subsidize solar so it can become cost effective in the residential market sooner rather than later”.
The cost will decrease as we implement the technology, Walker Architects is active in pursuing programs through state and local governments that aim to infiltrate the market with renewable energy technologies.
We marvel at the relative simplicity of the technology. The core of the solar cell, or photovoltaic cell, is a thin layer of silicon, which is produced from silica, or sand, one of the most common elements in the Earth's crust. Sunlight causes photons and electrons to react, pressure builds and is converted to usable energy.
We encourage everyone to do the math and examine the cost of developing commercially available solar power on the top of the residential infrastructure. We advocate integrated passive and active solar technologies in all architectural works. This is as close to magic as we're going to get . This is good efficient technology. Anyone who is telling you it's not efficient just isn't doing the math.
But if solar technology saves money for homeowners and utility companies, why is it not leading the energy market? We have a simple explanation.
It's not the cheapest short term way to do something, The idea that is promoted is that homeowners and tax payers foot the bill for the cost. As Americans, we have to learn to get over that. We need to develop commercial roof top power plants. We need to create new utility companies and the existing ones won't do it unless they are forced into it by congressional pressure. No bureaucracy changes course voluntarily They are all captains of the Titanic.
While solar is still primarily an idea here, European countries that have taken an American born technology and made it a reality. The Dutch and the Germans are way ahead of us.
The Dutch have development policies that mandate solar technology on new buildings, including residential. Germany has entire cities that run on solar energy; 59 percent of all solar systems are in Germany. About 470 systems have been installed in Washington State where we practice architecture, with the bulk here on the Western side of the state.
Total energy usage is expected to grow significantly during the next century, and the stock of fossil fuels will continue to decline.
With China and India consuming coal-we're seeing peak coal in the same era. We are concerned about the impact of expanding uses of coal for power generation. We advocate aggressive use of solar energy and new technology. We can't rely on old methods of energy planning to get us through the very difficult problems we face in the next 15 years.
Still, billions more is spent federally on coal and oil than renewable energy technologies. From 1943 to 1999, only $4 billion was spent on solar research and development, compared to $400 billion on coal and $150 billion on oil. We are not embracing opportunities for positive global change aggressively.
It's widely known that coal and oil prices will only go up, but we believe prices for solar electricity will fall not rise.
Solar is the only thing I know of on a downward curve, we have lost muscle in terms of developing the technology that was born here in the United States and we need to embrace opportunities to rebuild our economy.
Contrary to an obvious assumption that overcast Seattle doesn't make for good solar breeding ground, this area is primed and ready to use solar energy. Net metering allows Seattle and Western Washington to store summer sun for the wintery, rainy months and engage new technologies to store electrical energy. We need large scale energy storage technologies. We currently use hydroelectric dams, by generating energy in the summer and reverse metering, the summer surplus energy can be stored and conserved in the Northwest's hydroelectric dams.
Energy issues are essential to architecture. What are your views, do you have projects to share? |
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cousinbirgco
Joined: 15 Aug 2008
Posts: 141
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| Posted: Sun Oct 19, 2008 5:17 am Post subject: |
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Walker, I couldn't agree with you more. The mass use of solar power and other alternative technologies in our country could transform the U.S. from the world's leading energy waster to the world's clean energy leader. We only lack the political will from Washington to declare a Marshall type plan to accomplish this. It is critical to our survival economically and environmentally. The technology only needs a boost to catapult it from fringe to mainstream and it is a task that can be accomplished.
I became frustrated with the current state of affairs so last year I started a project to build an energy efficient house with a traditional style, reasoning that if folks could see a home that is virtually indistinguishable from standard built homes, it could demonstrate the possibilities for anyone to integrate energy efficiency into their project.
I have posted some pictures of the architectural details over on the Residential Building and Design section of this forum. I will post the energy design features in the next few days.
Thank you for your efforts with this most important task. |
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csintexas
millennium club
Joined: 06 Feb 2006
Posts: 2166
Location: USA
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| Posted: Sun Oct 19, 2008 8:16 am Post subject: |
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I disagree that solar will be a panacea to our problems. The efficiency is still currently very poor. What is the cost of the average "zero energy" home? Particularly outside of ideal climates like California.
_________________
-Chris Stewart
http://bcshdb.blogspot.com >
The B/CS Home Design Blog |
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WalkerARCHITECTS
Joined: 25 Sep 2007
Posts: 105
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| Posted: Fri Nov 07, 2008 2:34 am Post subject: Challenge |
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The cost of the zero energy home is the same as the cost of any other home that is designed to optimize energy performance. Spec houses are not designed to optimize for energy performance. Which all housing should do.
I like designing for builders and recognize that builder housing design currently ignores orientation on the site and traditionally has not been site specific design. But orientation neutral spec housing is possible and can achieve optimal passive performance; that is the key to making zero energy homes with solar electric affordable.
Solar electric is cheaper when life cycle costs are considered. Spec housing discounts the significance of life cycle costs and focuses on sales costs. So you are correct to point out that sales cost of houses equipped with photo-voltaic systems will be higher than those that are not. I agree with that but the reality is that those houses that are not energy efficient will cost their owners much more money every month than those that are designed for optimal energy performance. If you capture the operational cost as part of the monthly bill then you are incorrect. So it is a challenge!
I propose an experiment where two houses are designed side by side. One designed to optimize for energy and the other to be the standard excellent product. Both designed to be built and sold in the same market. I will design one and you design the other. I am no stranger to market oriented housing. I will do the work for a comparable fee, but builder agrees to construct both as designed.
Typically we design such homes to be of a certain size and can ignore orientation. In this case any lot will do but I will need complete information about the site to design for performance.
What do you think? |
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RollST
Joined: 05 Dec 2008
Posts: 4
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| Posted: Fri Dec 05, 2008 6:29 am Post subject: |
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| csintexas wrote: | | I disagree that solar will be a panacea to our problems. The efficiency is still currently very poor. What is the cost of the average "zero energy" home? Particularly outside of ideal climates like California. |
You might be right for now, but if you are not starting to build environmently friendly now it is going to be a disater in the near future.
You don't have to build zero energy homes but low energy houses or pasiv houses are a good start i think! |
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Antisthenes
Joined: 28 Nov 2006
Posts: 756
Location: Phoenix
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| Posted: Fri Dec 05, 2008 9:49 am Post subject: |
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Myth 1: solar power is too expensive to be of much use
In reality, today's bulky and expensive solar panels capture only 10% or so of the sun's energy, but rapid innovation in the US means that the next generation of panels will be much thinner, capture far more of the energy in the sun's light and cost a fraction of what they do today. They may not even be made of silicon. First Solar, the largest manufacturer of thin panels, claims that its products will generate electricity in sunny countries as cheaply as large power stations by 2012.
Other companies are investigating even more efficient ways of capturing the sun's energy, for example the use of long parabolic mirrors to focus light on to a thin tube carrying a liquid, which gets hot enough to drive a steam turbine and generate electricity. Spanish and German companies are installing large-scale solar power plants of this type in North Africa, Spain and the south-west of America; on hot summer afternoons in California, solar power stations are probably already financially competitive with coal. Europe, meanwhile, could get most of its electricity from plants in the Sahara desert. We would need new long-distance power transmission but the technology for providing this is advancing fast, and the countries of North Africa would get a valuable new source of income.
_________________
The most necessary/useful piece of learning is that which unlearns what is untrue: 'evil'
may be acquired, Happiness through virtue which is based on knowledge!/? |
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nanrehvasconez
Joined: 25 Feb 2008
Posts: 329
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| Posted: Fri Dec 05, 2008 3:42 pm Post subject: |
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[quote]Other companies are investigating even more efficient ways of capturing the sun's energy, for example the use of long parabolic mirrors to focus light on to a thin tube carrying a liquid,
The largest solar energy farm is already in existense in the Mohave Desert, CA.
An other large energy plant set on the Toyota warehouse roof is located in Ontario, CA.
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September 03, 2005
About Parabolic Trough Solar
Trough solar systems use parabolic curved, trough shaped reflectors focus the sun's energy onto a receiver pipe running at the focus of the reflector. Because of their parabolic shape, troughs can focus the sun at 30-60 times its normal intensity on the receiver pipe. The concentrated energy heats a heat transfer fluid (HTF), usually oil, flowing through the pipe. This fluid is then used to generate steam which powers a turbine that drives an electric generator. The collectors are aligned on and east-west axis and the trough is rotated to follow the sun to maximize the suns energy input to the receiver tube. Click flow diagram above to see full size flow diagram of the new plants beig built in Spain. Current cost of electricity from these plants is $0.10 to $0.12 per kWh. The current goal of ongoing development by EERE is to reduce the cost to $0.035 to $0.043 per kWh by 2020.
Trough collector solar power, also called solar electric generating systems (SEGS), represent the most mature concentrating solar power (CSP) technology, with 354 MW of installed capacity in nine plants, built between 1984 and 1991, all located in the Mohave desert of California. There are several generations of plants, the newer generations incorporating features that would reduce the cost of electricity if they were new plants. All plants are still operating and producing power for the electrical grid at 99% availability.
The technology has been stagnant since 1993, but four new projects are now being developed.
In the US, a 1 MW plant is being built by Arizona Public Service's at its Saguaro Power Plant and a 64 MW plant is being built in Eldorado Valley near Boulder City, NV. Solargenix is the prime contractor on both projects in conjunction with EERE/NREL. SHOTT North America is supplying the receivers. The Boulder City plant is currently scheduled to go on line in Jone 2007. Funding for the American projects has been difficult, but on 10/4/04 the Western Governors Association and EERE announced funding and support of a 1000 MW goal of concentrating solar power for the region by 2010. Included in this program is support for the two afore mentioned projects. Nevada Power and Sierra Pacific Power Company have signed long term contracts to buy the power produced by the 64 MW plant.
Two identical 50 MW plants are being built by Solar Millinium AG in Granada, Spain. The first plant has received a €5 million (~$6.25 million) grant from the EU’s Fifth Framework Program and financial support from the German Ministry for Environment. To encourage this type of technology the Spanish government has set up regional funding programs. This is coupled with a bonus of 12 Eurocents per kWh generated from solar power has been instrumental in bringing such projects to Spain.
A 150 MW facility that is to be expanded to 500 MW In the Negev desert of Israel is being developed by Solel (the successor company to Luz). Solel will establish a consortium to finance and build the power station, which it estimates will cost $1 billion. The state has promised to buy the electricity under the terms of a contract to be signed by the parties.
The first solar trough plants were constructed in California by Luz International. The first started up in 1984, the last in 1991. Altogether, nine such plants were built, SEGS I–VII at Kramer junction and VIII and IX at Harper Lake and Barstow respectively. In February 2005, all but two (I and II) of the Kramer Junction SEGS plants were acquired by FPL Energy and Carlyle/Riverstone. A natural gas system “hybridizes” the plants and contributes up to 25% of their output, a feature that allows operation later at night or on cloudy days to meet the requirements of the grid. FPL now runs these systems, making it the largest solar power generator in the United States. All of the power generated from the SEGS projects is sold to Southern California Edison under long-term contracts negotiated by Luz back in the 1980s.
Development work is now proceeding on several components of the plants:
Improvements in the structural support system have received much attention as the collector assembly is the most expensive part of the system.
SolarGenix, the contractor for the two new American plants has developed a new structural support system for the collector. The design uses an aluminum frame patterned after the Luz design, but superior in terms of structural properties, weight, manufacturing simplicity, corrosion resistance, manufactured cost and installation ease. One key point of in design of the structure is that it has to have extreme tolerances and structural rigidity in order to focus the mirrors precisely on the receiver pipe. High resistance to large wind loadings on the large structure is a very important parameter. Solargenix used computer modeling techniques that were unavailable at the time that the original Luz design was made. The collector assembly has been tested at the NREL test facility. A new improved generation of reciever tubes supplied by SHOTT will be used in these plants.
FLAGSOL Gmbh, who supplied all the collector assemblies at the California plants is supplying the trough assembly for Solar Millenium, has gone through a similar development process to develop a new steel structure. The collector assembly has been tested at the Kramer Junction SEGS plants in California.
Industrial Solar Technology Company (IST) has developed a concentrator system that incorporates the reflective surface as part of the collector structure. This results in a very lightweight, low-cost concentrator module that is also very strong.
Solel's solar collector assembly includes an upgraded version of the Luz parabolic collector. It is designed for mass production and cost reduction by economies of scale.
The reflectors are composed of individual concentrator modules that are a consist of a steel support structure with a mirror mounted on it. Development efforts are aimed at reducing the thickness of the mirror, improving the reliability of the glass to metal seal, surface coatings on the mirrors to improve their performance and development of a composite concentrator modules with lightweight, front-surface mirrors instead of heavy (4 mm) glass mirrors that were used on the original SEGS plants.
The heat collection element (HCE) is composed of a stainless steel pipe with a glass tube surrounding it, with the space between evacuated to provide low thermal losses from the pipe. The pipe is coated with a material that improves the absorption of solar energy. Several improvement have been made or developments are underway to improve performance:
Solel has supplied all the HCE's to date. In its newest model, the UVAC 2003, they have increased the annual average performance by more than 20% over the assemblies used in the Luz plants. Absorptivity, emissivity (radiative loss) and transmittivity (of the glass) all have been improved.
IST's innovations include a receiver that incorporates a highly efficient blackened nickel selective surface and an anti-reflective coating on the glass envelope. The receiver pipe surface has a high absorptance for incoming light in the visible range, and a low emittance in the infrared wavelength.
Shott Rohrgas has announced it is planning on producing HCE's and presumably will supply them for the Spanish plant.
The seal between the glass and the pipe has not been as reliable as desired and development of better seal materials/seal configuration is underway.
The HCE was connected to the stationary hot oil piping with a flexible tube in the Luz plants. Replacing the flexible tube with a ball joint will reduce the pressure drop in the hot oil piping piping by 50% and significantly reduce the parasitic power losses in the plant.
The fluid going through the receiver pipe is routed through a thermal storage system which permits the plant to keep operating for several hours after sunset while the electrical demand is still relatively high. The thermal storage system (to be used in Spain) is a two tank system in which the HTF flows through the solar field and then through a heat exchanger where it gives up a portion of its heat to heat a nitrate salt solution that is stored in a hot salt tank. The slightly cooled HTF continues on to the power generation system. At night the hot salt solution flows through the same heat exchanger heating up the HTF for generating power. The cooler oil flows from the heat exchanger to the cold storage tank where it stays until daytime when it is reheated and returned to the hot storage tank.
Several companies are involved in developing heat transfer fluid/thermal storage systems. The leading candidate appears to be a system designed by Sandia National Laboratories. Only a few details are available. The following is courtesy of Solarplaces:
Sandia has tested a thermocline storage system that uses a single tank that is only marginally larger than one of the tanks in the two-tank system. A low-cost filler material, which is used to pack the single storage tank, acts as the primary thermal storage medium.
Nexant has developed a near-term thermal storage option that uses biphenyl-diphenyl-oxide HTF in the solar field and then passes it through a heat ex-changer to heat molten salt in a thermal storage system.
Kearney and Associates is investigating using a lower temperature molten salt as the HTF in the solar field as an innovative approach for reducing the cost of thermal storage for troughs.
Work at the University of Alabama and NREL is looking into using a new class of fluids known as organic salts (or ionic liquids) as the HTF and thermal storage media in a parabolic trough plant. Organic salts have the primary advantage of being liquid at room temperatures
The Plataforma Solar de Almería (PSA), the European Test Center for Solar Energy Applications, in southeastern Spain is Europe's test facility for concentrating solar power development. They are developing direct steam generation technology to eliminate the thermal oil system that is currently used in solar trough plants, which would greatly simplifies the plants. The two-phase heat transfer that occurs in the receiver tube required evaluation as there are unique condition that occur in the tube. Results of testing to date indicate that the heat transfer was very sensitive to the small changes in temperature that occur in solar troughs and that their measurement accuracy was not good enough to correlate the data properly. PSA is also developing new trough collector assemblies and coatings to improve the absorption of solar energy on the receiver tubes and to decrease the reflectivity of glass.
Status of new plants:
APS' 1 MW solar trough plant at the Saguaro power plant will heat mineral oil to between 250° and 500°F, lower temperature than used in other plants. Flowing through a heat exchanger, the heated oil will vaporize pentane, a hydrocarbon, which in turn will drive the turbine. The vapor then will condense back into liquid form and the cycle will repeat. This approach represents a departure from existing solar thermal plants, which use steam driven turbines. The capital cost for a steam turbine would be too great for such a small plant, instead, APS will use a 1-MW turbine similar to a geothermal plant’s.
In 2004, German company Solar Millennium AG started work on two parabolic-trough solar power plants in Grenada, southern Spain. Two 50 MW solar trough power plants, AndaSol-1 and 2, are being built jointly by ACS Cobra and Solar Millennium in the region of Andalucia, with a 510,120 m² solar collector field and 6 hours of molten salt storage. Construction will start in autumn 2005 and will be completed in 2007. ACS Cobra and Solar Millennium have started development of various 50 MW follow-up plants in Southern Spain.
The $1 billion Solel plant will be built in phases, in the first phase, a 150 MW plant will be build at a cost of approximately $250 million. The plants will incorporate a new trough Assembly incorporating their UVAC. No starting date for construction has been announced.
Revised 11/12/05 to update data on Solergenix Bouder City plant |
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csintexas
millennium club
Joined: 06 Feb 2006
Posts: 2166
Location: USA
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| Posted: Sat Dec 06, 2008 9:56 am Post subject: |
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Yeah, heating oil with the sun has been around since the eighties. This type of energy production is more efficient than PV.
What I was trying to point out is that PV is not the solution. (although with new technologies it may one day)
In order to use it houses will need to be designed and built much better than they currently are.
What I am concerned about is that we tend to put to much emphasis on some future technology saving us. No need to design an efficient house, we will just put PV panels on it someday in the future when they become affordable. This sort of unrealistic optimism will only set us up for failure.
_________________
-Chris Stewart
http://bcshdb.blogspot.com >
The B/CS Home Design Blog |
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Antisthenes
Joined: 28 Nov 2006
Posts: 756
Location: Phoenix
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| Posted: Mon Dec 08, 2008 9:53 am Post subject: |
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well there are many people having success for a very long time on a individual basis, decentralize
_________________
The most necessary/useful piece of learning is that which unlearns what is untrue: 'evil'
may be acquired, Happiness through virtue which is based on knowledge!/? |
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nanrehvasconez
Joined: 25 Feb 2008
Posts: 329
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| Posted: Mon Dec 08, 2008 2:56 pm Post subject: |
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Solar power plant is a beacon of light
This tower, being bathed in rays of glorious light from all sides, might look like some sort of religious icon, but it's not. No, it's actually a new power plant in Spain that harnesses the power of the sun via 600 mirrors that beam the sun up at it from the surrounding ground, creating a stunning site for miles around.
Towering 40 stories above the earth outside Seville, Spain, the solar thermal plant is completely green. It generates 11 megawatts without emitting a single puff of greenhouse gasses into the atmosphere, all by using both the surface of the tower and the ground surrounding it to soak up as much sun as possible. It's a pretty amazing structure, both aesthetically and functionally, creatively harnessing the sun and providing energy that doesn't pollute the environment. Will we ever see something this awesome here in the States? Time will tell. — Adam Frucci
BBC, via BoingBoing |
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