Given all the variables involved, it’s not surprising that predicting the efficiency of solar panels over time is so challenging. Every residential solar photovoltaic (PV) installation is unique. The amount of sunlight exposure and air temperature may not only vary from installation to installation, but from day to day.
In order to warranty products, however, solar panel manufacturers require an estimation of a system’s life, which is a hugely important solar rating for homeowners to know.
What’s Covered in Most Solar Warranties?
Until recently, the industry wisdom for solar panel efficiency has been that PV systems will operate at 90 percent% after 10 years, and at 80% efficiency at 25 years.
A recent study at the Fraunhofer Institute for Solar Energy Systems in Freiburg, Germany, showed that efficiency degradation might be far less than previously thought. The study analyzed 17 systems that have been operating for more than five years, revealing no significant loss of efficiency.
Anecdotal evidence is even more impressive. A Swedish PV installation that has been operating continuously since 1984 has shown no significant loss in efficiency. Solar panels at the Technical University of Berlin have been running for 31 years. It’s becoming apparent that systems last longer and work better than standard solar panel warranties indicate. Top solar brands are beginning to respond with better warranties.
Suntech Warranty
Suntech, the world’s largest manufacturer of solar panels, recently changed their warranties to ensure specific outputs:
- 95% at year 5
- 90% at year 12
- 85% at year 18
- 80% at year 25
This results in 6.7 percent more power than industry standard warranties.
Yingli Green Warranty
Yingli Green Panda panels are guaranteed to provide:
- 98% output during the first year
- 92% for 10 years
- 82% for 25 years
The company is also offering linear-based warranties that spread the decreased output expectation incrementally over 25 years.
Trina Solar Warranty
Trina Solar offers linear-based warranties for both polycrystalline and monocrystalline products, with slightly different percentages:
- Polycrystalline module output at 80.7% at 25 years
- Monocrystalline module output at 80.18%
Solar World also offers a similarly linear-based warranty.
SunPower Solar Warranty
Sunpower‘s warranty covers:
- 90% output at year 12
- 80% output at year 25
Other solar companies that now offer 25-year warranties, including First Solar, Canadian Solar, Sharp and Sanyo.
As most homeowners now recoup upfront PV installation costs in less than 10 years, every additional year that their system operates efficiently means more money in their pockets.
How Long is the Average Solar Panel Warranty?
The Solar Cube: Solving Emergency Water Problems
Spectra Watermakers, a company specializing in land-based water purification systems, has developed the Solar Cube, an off-grid fresh water maker. Powered by wind and solar energy, the Solar Cube holds a lot of promise for disaster relief and emergency preparation. Essentially, it is a portable fresh water supply. Imagine hurricane victims, left without electricity or running water for days, desperate for water. In comes the Solar Cube, using its reverse osmosis desalination system, which could literally be dropped off in someone’s front yard (as long as there’s a water source nearby) and immediately start producing potable drinking water.
And not just some water, but a lot of water. Spectra claims that the solar cube can produce 950 to 1500 gallons of fresh water daily. These units, recently on display and under scrutiny in Chile at the Western Hemisphere Information Exchange (WHIX), may have a wide array of implications, not only for disaster relief but also for the military in Iraq, village water supplies in underdeveloped countries, and more. It is no understatement to say that these solar and wind units could revolutionize emergency preparedness – yet another in a long line of positive applications for solar power. (more…)
Scientists Go Public about Infrared Solar Energy
Solar panels, both conventional PV and even third-generation, organic solar cells, absorb visible and, in some cases, ultra-violet light. All of these technologies are limited by shading, rainy days, and nightfall. Basically, photovoltaics, both the old and the new, collect direct sunlight. But what, researchers are asking, about indirect light?
Indirect light reflects, in the form of heat, off of buildings during the day and at night. This infrared energy is not limited to solar energy either. Energy radiating from machines and electronic devices could also be collected and recycled into usable electricity. Sound pretty radical? Well it is, and some very complex science at that. Nonetheless, scientists are becoming confident enough in the feasibility of infrared solar technology that they are going public and getting excited about it. (more…)
See-Through Solar Panels Now One Step Closer
One day, windows are likely to provide the electricity for homes and businesses. Invisible solar technology took another step towards reality this week when New Energy Technologies announced that collaboration with scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) resulted in a 70-square-inch see-through glass solar module.
The solar window is over 14 times larger than other see-through modules made at the NREL, and the largest in the world so far.Under the guidance of New Energy principle scientist Dr. Scott Hammond, NREL scientists applied electricity-generating coatings to glass. Made of conductive polymers, the coatings are produced through an organic synthesis process. The end result is revolutionary BIPV, or building-integrated photovoltaics.
Last month, New Energy announced that they were using a high-speed, high-volume solution coating process, another important development on the road towards a viable commercial organic photovoltaic (OPV) product.
New Energy confirmed that this latest solution-coating technique is compatible with roll-to-roll fabrication methods that are commonly used for printing, which means that OPVs have the potential to be manufactured on a large scale. New Energy foresees that the process will eventually mean that solar windows will be produced faster, cheaper and safer than conventional photovoltaic panels.
Although this latest achievement is a big step forward, obstacles to widespread OPV production remain. The biggest resistance to the technology comes from those who view it as too energy-inefficient. Compared to conventional residential solar panels that have efficiency rates that range from 11 to 15 percent, current OPVs on the market have 4 to 5 percent efficiencies.
So far, the efficiency of solar windows has been even lower. Low efficiency may not be a deterrent, however, if the costs of the windows become inexpensive enough.
The real challenge of solar window technology is developing a way to extend its lifetime, which currently is only a few years. Homeowners will expect the technology to last as long as conventional windows last. It’s possible that a “re-coating” service will eventually be provided. Presently, OPVs are used primarily for portable products, such as canopies, electronic mobile devices and backpacks.
What’s encouraging about these new advances in “see-through solar” is that research and development is continuing on a national level. For the solar industry to grow, it’s important to continue to stride towards new technologies.
As NREL Research Fellow Dr. David S. Ginley said, “The fabrication of a large-area see-through solar module of these dimensions is an important step.”
Get Active! With Active Solar Heating
It is here. The first day of fall has come and gone and, while it’s still sunny and mild up here in the Northwest, you can smell those first tinges of crisp, winter air after the sun sets. Already minds turn to soups and stews, blankets, and fireplaces. Yet it’s not time to settle in yet. You’ve got rising heating and energy costs to deal with in the upcoming months. Now is the time to get active! And what better way to do that than installing an active solar heating system. Especially if you spend more time than you like frowning at that old, ineffective furnace, there are plenty of reasons why an active solar heating system makes for a great fall project.
Liquid or Air?
Each and every active solar heater begins with one choice: liquid or air. Heaters may be liquid-based, usually incorporating an antifreeze mixture. Liquid-based systems can be used for hot water, a central air system, or a radiant floor system. Most residential purposes utilize flat-plate collectors for liquid-based heating systems.
Air collectors work when solar radiation heats the collector’s metal plate, which, in turn, heats the air in the collector. An electrically powered fan or blower pulls air from the room through the collector, and blows it back into the room. Air systems aren’t prone to freezing as liquid systems are, but they are far less efficient than liquid systems.
Ultimately, the system you choose will depend on your specific situation; a thorough review with your solar installer should bring to light the best choice for you.
Benefits
There are several benefits of an active solar heating system, besides the pleasure of warmth and free, clean energy from the winter sun. That’s right, free! Energy prices are rising and winters seem to be getting colder. The days of $50 winter electric or gas bills have been replaced by $150 to $200 utility bills. Why not take advantage of nature’s biggest (and brightest) heater? There’s plenty to go round.
That boils down to good economics. Solar heaters are much more cost-effective than their counterparts and the more you use them, the more they save! Ergo, the colder the climate you live in, the more reason you have to get active…with active solar heating! Furthermore, you can also incorporate your water heating needs with your space heat, giving the system twice the work at much less than twice the cost while saving nearly twice as much money. Water and space heating, after all, are the two biggest consumers of energy in the average American household.
But what about the expense of installation? (more…)
Solar Cylinders?
Proving that there is no lack of creativity in the solar industry, Solaroad Group has come up with a radical space-saving design for solar panels. What they dub the ElectraWall is a cylinder-shaped solar cell that can be clipped onto any number of surfaces including walls, poles, or rooftops. Using, of course, cylindrical solar cells, ElectraWall panels have a variety of proposed benefits. These include no need for direct sunlight, easy installation, and built-in battery storage. They’re also made with a good proportion of recycled materials. (more…)
Helping Homeowners Rebuild with Solar After a Disaster
For those who experience a disaster like a tornado or hurricane, losses can be heartbreaking. Rebuilding after a disaster not only typically requires a large financial investment, but a share of courage, resilience and determination, too.
Massachusetts is encouraging homeowners whose properties were devastated by last year’s tornados to take advantage of green technologies, products and materials as they rebuild their homes. The state is offering an additional incentive to their already long list of Massachusetts solar rebates that help make it affordable for homeowners to rebuild with solar.
Massachusetts has a broad array of existing solar incentive programs, including a state rebate, utility rebates, property tax and sales tax exemptions, tax credits and payments for the solar electricity that residential photovoltaic (PV) systems generate.
For pricing on solar power systems, click here.
Residents rebuilding in the wake of the tornadoes can now get an additional $1.00 per-watt rebate for a residential solar system installation. The program is being operated by the Massachusetts Clean Energy Center (MassCEC), as part of the state’s Commonwealth Solar II Rebate Program.
The state’s rebate program is structured in tiers, or “adders,” with a base incentive of $.40 per watt. Homeowners who meet certain low-income requirements may get an additional $.40/watt. Homeowners with moderate home values are eligible for an additional $040/watt. If the solar installation components are produced in Massachusetts, the homeowners get an additional $.05/watt.
Better yet, homeowners rebuilding from the June 1, 2001 tornado get an additional $1.00/watt.
For every megawatt that a home solar system generates, Massachusetts awards homeowners with a Solar Renewable Energy Certificate (SREC). The state also mandates that state public electrical utilities purchase the SRECs. Homeowners are currently making about $550 for each SREC.
Utilities may offer their own solar incentive programs, too. The South Hadley Solar Rebate program, for example, offers a $1.50/watt rebate.
Massachusetts residents who qualify for the maximum state and federal solar rebates alone can save over 66% on the cost of a home solar system. A deeply-discounted PV system that will save you money for years to come may make starting over a bit easier.
Home Solar Panel Prices Dropped 50 Percent Last Year
A cool-down in European solar markets combined with an over-supply of panels from China has led to a massive decline in solar panel prices. Over the last year, prices for solar panels have fallen 50 percent. In the U.S., falling prices spell competition, and many solar providers are hustling to position themselves to take advantage of a rapidly changing solar industry.
While solar panel manufacturers have taken a hit from the 50-percent reduction caused by the glut of supplies, home solar contractors are seeing their profits rise. SolarCity, the nation’s largest residential solar installer, is expected to initiate a public offering this year.
As solar providers stabilize their bottom line, they attract more investors. Previously, investors have been drawn to large-scale solar energy projects, but as the market shifts, they are increasingly backing smaller installation contractors. Investment firms are predicting that if solar brands succeed with public offerings, the market could experience exponential growth.
To see what home solar pricing is like in your area, click here.
Homeowners have enjoyed lower installations costs as well. According to the Lawrence Berkeley National Lab’s Tracking the Sun report, the cost of installing home PV systems has dropped 43 percent over the last dozen years.
The most recent drop in solar panel prices, however, has been slow to make a difference in what homeowners pay. Savings from lower component prices first impact distributors, integrators and providers before showing up in installed prices.
A fragmented industry makes it harder to pass on savings to customers, too. As yet, there are no major wholesale solar parts distributors. Most solar contractors purchase the various equipment needed for installations from a number of manufacturers, driving up costs.
The industry is beginning to address this issue as well. You can expect to see installation costs continue to drop as players in the competitive solar market find their niche.
Solar Q&A: How Many Solar Panels Do I Need?
Of all the things you have to figure out when planning a solar power system, the number of panels you’ll need is a big one. Yet, all variables are interrelated and you can’t figure out how many panels you need unless you know some other important information first.
What is my daily power consumption?
You need to calculate how much power, in watts, you use on a daily basis. Your electric bill will be necessary for this. A lot of utilities actually break this down for you in your monthly statements. If you’re not so lucky, there are online tools to help you out.
How much sunlight do I get per day?
Another thing you’ll need to know is the average amount of peak sunlight you get per day. This means yearly average. So don’t think summer hours; many areas get great sun in the summer but you might not see it for what feels like a month in the winter. Be sure to calculate the average…and be conservative. There are online calculators to help you get this exact also.
How many panels do I need? (more…)
Solar Q&A: How Many Batteries Does My Solar System Need?
One of the more frequently asked questions about solar electric systems regards battery power. More specifically, the amount of battery power needed for a specific system and how to calculate that need. Well, as it turns out, that is a fairly easy question to answer. It all depends on your daily power usage, in watts.
You never want to drain your batteries completely. In fact, you want to stay as far from that as possible. With that in mind, you’ll want to have twice as much capacity in your battery bank as the amount of power you use each day. For example, if you use 2,000 watts of electricity each day, then you’ll need to have 4,000 watts of battery power available to you on any given day. There are several online tools to help you calculate all aspects of your solar system, including your daily energy consumption.
As for batteries, there is but one simple equation. A battery should have its voltage and amp-hour capacity (AH) labeled on it. Simply multiply those two numbers to get that battery’s watt capacity. Remember that 50% is the maximum that you want to drain the batteries, so always err on the side of more capacity. (more…)
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