What are the Impacts of the technology?
The sun provides a tremendous resource for generating clean and sustainable electricity without toxic pollution or global warming emissions.
Solar energy has
the potential to dramatically change the way the world gets its power. Enough
solar energy falls on a 100-square-mile area of the southwestern United States
to power the entire nation. While solar is among the world's cleanest forms of
energy, plans to develop utility scale solar farms have raised concerns about
potential environmental impacts
Effects to the economic?
Solar energy has a positive impact in not only the Maryland solar economy, but the national economy as well. The first, and most obvious example, is the decrease in the use of foreign imported oil as an energy source. In 2010, the US imported 19.1 million barrels of foreign oil a day. This is estimated to cost more than $200,000 a minute – over $25 billion a year – that is being spent on foreign oil imports. This is money leaving our country, and contributing to our national trade deficit. Renewable, sustainable solar power can help keep that money in the United States.As a whole, the solar energy industry grew a total of 67% between 2009 and 2010. Nationally, solar energy is now responsible for over 100,000 American jobs, in over 5,000 businesses in every state. These workers are primarily employed by small to middle-size companies in local communities. Many of these companies are able to take advantage of tax credits for new hires as well. Right here in Maryland, the state is offering $5,000 for new hires in the field of renewable energy. This explosive growth has helped spur the creation of new jobs and provided employment for various companies involved in the renewable energy industry.
There are many more ways solar energy benefits the economy, directly and indirectly. By reducing your home’s use of traditional energy sources, you help keep natural ecosystems intact, reducing tax payer funded clean-ups and potentially devastating oil spills like the recent BP disaster along the Gulf Coast. If your photovoltaic solar panels generate more energy than your home uses, you can sell back energy to your local utility company, leaving more money in your pocket to spend at restaurants, movie theaters, or financial investments.
Energy pricing & incentives?
Solar panel systems are entitled to a number of small-scale technology
certificates (STCs) if the system is eligible. This is based on the amount of
electricity in megawatt hours (MWh) the system generates over the course of its
lifetime. In addition, your system may be eligible for Solar Credits which
multiplies the number of STCs the system can receive.
Approximate
financial incentives available
The below tables demonstrate the approximate financial incentives you
may receive after you have installed your solar panels. This is based
on
- an STC price between $15 and
$40.
- the 2x Solar Credits
multiplier.
- the 1x Solar Credits multiplier
(ie no multiplier)
|
The below tables are intended as a guide only. Prices may vary so do
not expect that these are the discounts you will receive.
|
If you live outside of these areas, or want to be more specific with
your calculations you can use the SGU Calculator to see how many STCs you will
receive and then multiply by a $15-$40 STC price.
Visit – SGU calculator
Make sure you shop around and ask solar panel Agents the STC price they
are offering for your system.
2x multiplier
1.5 kW
3 kW
5 kW
10 kW
1x multiplier (ie
no multiplier)
1.5 kW
3 kW
5 kW
10 kW
Cheaper Alternative?
A new type of solar cell, made from a material that is
dramatically cheaper to obtain and use than silicon, could generate as much
power as today’s commodity solar cells.
Researchers developing the technology say that it could lead
to solar panels that cost just 10 to 20 cents per watt. Solar panels now
typically cost about 75 cents a watt, and the U.S. Department of Energy says 50
cents per watt will allow solar power to compete with fossil fuel.
In the past, solar researchers have been divided into two
camps in their pursuit of cheaper solar power. Some have sought solar cells
that can be made very cheaply but that have the downside of being relatively
inefficient. Lately, more researchers have focused on developing very high
efficiency cells, even if they require more expensive manufacturing techniques.
The new material may make it possible to get the best of
both worlds—solar cells that are highly efficient but also cheap to make.
One of the world’s top solar researchers, Martin Green of
the University of New South Wales, Australia, says the rapid progress has been
surprising. Solar cells that use the material “can be made with very simple and
potentially very cheap technology, and the efficiency is rising very
dramatically,” he says.
Perovskites have been known for over a century, but no one
thought to try them in solar cells until relatively recently. The particular
material the researchers are using is very good at absorbing light. While
conventional silicon solar panels use materials that are about 180 micrometers
thick, the new solar cells use less than one micrometer of material to capture
the same amount of sunlight. The pigment is a semiconductor that is also good
at transporting the electric charge created when light hits it.
“The material is dirt cheap,” says Michael Grätzel, who is
famous within the solar industry for inventing a type of solar cell that bears
his name. His group has produced the most efficient perovskite solar cells so
far—they convert 15 percent of the energy in sunlight into electricity, far
more than other cheap-to-make solar cells. Based on its performance so far, and
on its known light-conversion properties, researchers say its efficiency could
easily rise as high as 20 to 25 percent, which is as good as the record
efficiencies (typically achieved in labs) of the most common types of solar
cells today. The efficiencies of mass-produced solar cells may be lower. But it
makes sense to compare the lab efficiencies of the perovskite cells with the
lab records for other materials. Grätzel says that perovskite in solar cells
will likely prove to be a “forgiving” material that retains high efficiencies
in mass production, since the manufacturing processes are simple.
Perovskite solar cells can be made by spreading the pigment
on a sheet of glass or metal foil, along with a few other layers of material
that facilitate the movement of electrons through the cell. This isn’t quite
the spray-on solar cells that some people have envisioned—a sci-fi ideal of
instantly converting any surface into one that can generate electricity—but the
process is so easy that it’s getting close. “It is highly unlikely that anyone
will ever be able to just buy a tub of ‘solar paint,’ but all the layers in the
solar cell can be fabricated as easily as painting a surface,” says Henry
Snaith, a physicist at Oxford University, who, working with researchers in
Asia, has posted some of the best efficiencies for the new type of solar cell.
When perovskites were first tried in solar cells in 2009,
efficiencies were low—they only converted about 3.5 percent of the energy in
sunlight into electricity. The cells also didn’t last very long, since a liquid
electrolyte dissolved the perovskite. Researchers barely had enough time to
test them before they stopped working. But last year a couple of technical
innovations—ways to replace a liquid electrolyte with solid materials—solved
those problems and started researchers on a race to produce ever-more-efficient
solar cells.
“Between 2009 and 2012 there was only one paper. Then in the
end of the summer of 2012 it all kicked off,” Snaith says. Efficiencies quickly
doubled and then doubled again. And the efficiency is expected to keep growing
as researchers apply techniques that have been demonstrated to improve the efficiency
of other solar cells.
Snaith is working to commercialize the technology through a
startup called Oxford Photovoltaics, which has raised $4.4 million. Grätzel,
whose original solar-cell technology is now used in consumer products such as backpacks
and iPad covers, is licensing the new technology to companies that have the
goal of taking on conventional silicon solar panels for large-scale solar-power
production.
Like any other new entrant into the highly competitive
solar-panel market, perovskites will have difficulty taking on silicon solar
cells. The costs of silicon solar cells are falling, and some analysts think
they could eventually fall as low as 25 cents per watt, which would eliminate
most of the cost advantage of perovskites and lessen the incentive for
investing in the new technology. The manufacturing process for perovskite solar
cells—which can be as simple as spreading a liquid over a surface or can
involve vapor deposition, another large-scale manufacturing process—is expected
to be easy. But historically, it has taken over a decade to scale up novel
solar-cell technologies, and a decade from now silicon solar cells could be too
far ahead to catch.
Green says one opportunity may be to use perovskites to
augment rather than replace silicon solar cells. It might be possible to paint
perovskites onto conventional silicon solar cells to improve their efficiency,
and so lower the overall cost per watt for solar cells. This might be an easier
way to break into the solar market than trying to introduce an entirely new
kind of solar cell.
A challenge may be the fact that the material includes a
small amount of lead, which is toxic. Tests will be needed to show how toxic it
is as part of the perovskite material. Steps can also be taken to ensure the
solar cells are collected and recycled to prevent the materials from getting
into the environment—the approach pursued now with the lead-acid starter
batteries used in cars. It may also be possible to substitute tin or some other
element for lead in the cells.
Will the technology lead to harmful emission?
Solar panels don’t come falling out of the sky – they have to be manufactured. Similar to computer chips, this is a dirty and energy-intensive process. First, raw materials have to be mined: quartz sand for silicon cells, metal ore for thin film cells. Next, these materials have to be treated, following different steps (in the case of silicon cells these are purification, crystallization and wafering). Finally, these upgraded materials have to be manufactured into solar cells, and assembled into modules. All these processes produce air pollution and heavy metal emissions, and they consume energy - which brings about more air pollution, heavy metal emissions and also greenhouse gases.what are those emission?
Solar energy has long been touted as better for the environment than fossil fuels.Increasingly, however, there are fears that making solar cells might release more hazardous pollution than fossil fuels would.
To ease those concerns, scientists studied the matter closely and now conclude that manufacturing solar cells produces far fewer air pollutants than conventional fossil-fuel-burning power plants.
The researchers gathered air pollution emissions data from 13 manufacturers of four major commercial types of solar cells in Europe and the United States from 2004 to 2006.
Making solar or photovoltaic cells requires potentially toxic heavy metals such as lead, mercury and cadmium. It even produces greenhouse gases, such as carbon dioxide, that contribute to global warming. Still, the researchers found that if people switched from conventional fossil fuel-burning power plants to solar cells, air pollution would be cut by roughly 90 percent.
Although manufacturing solar cells requires heavy metals, the researchers noted that coal and oil also contain heavy metals, which get released during combustion.
"One of the most promising photovoltaic technologies is based on cadmium telluride, but cadmium is one of the worst heavy metals. Still, if we compare direct emissions from production of cadmium telluride cells with coal power plants, toxic emissions would up 300 times lower," said researcher Vasilis Fthenakis, an environmental engineer at Brookhaven National Laboratory in Upton, N.Y.
In fact, most of the toxic emissions from making solar cells come indirectly from fossil fuel-burning power plants, which provide the electricity needed for manufacture. Ironically, solar cell factories will likely need to rely on fossil fuels for power for a while, since solar poweris too intermittent to use, Fthenakis explained, shutting down as it does when the sun goes down.
Still, Fthenakis added, scientists are researching ways to economically store power from solar cells on a large scale. Doing so could help lead to solar cell factories that run off solar power, "a self-sustained process," he told LiveScience.
Fthenakis and his colleagues detailed their findings in the March 15 issue of the journal Environmental Science & Technology.
Are there any improvent to the eviroment?
Land Use
Depending on their location, larger utility-scale solar facilities can raise concerns about land degradation and habitat loss. Total land area requirements varies depending on the technology, the topography of the site, and the intensity of the solar resource. Estimates for utility-scale PV systems range from 3.5 to 10 acres per megawatt, while estimates for CSP facilities are between 4 and 16.5 acres per megawatt.
Unlike wind facilities, there is less opportunity for solar projects to share land with agricultural uses. However, land impacts from utility-scale solar systems can be minimized by siting them at lower-quality locations such as brownfields, abandoned mining land, or existing transportation and transmission corridors [1, 2]. Smaller scale solar PV arrays, which can be built on homes or commercial buildings, also have minimal land use impact.
Water Use
Solar PV cells do not use water for generating electricity. However, as in all manufacturing processes, some water is used to manufacture solar PV components.
Concentrating solar thermal plants (CSP), like all thermal electric plants, require water for cooling. Water use depends on the plant design, plant location, and the type of cooling system.
CSP plants that use wet-recirculating technology with cooling towers withdraw between 600 and 650 gallons of water per megawatt-hour of electricity produced. CSP plants with once-through cooling technology have higher levels of water withdrawal, but lower total water consumption (because water is not lost as steam). Dry-cooling technology can reduce water use at CSP plants by approximately 90 percent [3]. However, the tradeoffs to these water savings are higher costs and lower efficiencies. In addition, dry-cooling technology is significantly less effective at temperatures above 100 degrees Fahrenheit.
Many of the regions in the United States that have the highest potential for solar energy also tend to be those with the driest climates, so careful consideration of these water tradeoffs is essential. (For more information, see How it Works: Water for Power Plant Cooling.)
Hazardous Materials
The PV cell manufacturing process includes a number of hazardous materials, most of which are used to clean and purify the semiconductor surface. These chemicals, similar to those used in the general semiconductor industry, include hydrochloric acid, sulfuric acid, nitric acid, hydrogen fluoride, 1,1,1-trichloroethane, and acetone. The amount and type of chemicals used depends on the type of cell, the amount of cleaning that is needed, and the size of silicon wafer [4]. Workers also face risks associated with inhaling silicon dust. Thus, PV manufactures must follow U.S. laws to ensure that workers are not harmed by exposure to these chemicals and that manufacturing waste products are disposed of properly.
Thin-film PV cells contain a number of more toxic materials than those used in traditional silicon photovoltaic cells, including gallium arsenide, copper-indium-gallium-diselenide, and cadmium-telluride[5]. If not handled and disposed of properly, these materials could pose serious environmental or public health threats. However, manufacturers have a strong financial incentive to ensure that these highly valuable and often rare materials are recycled rather than thrown away.
Life-Cycle Global Warming Emissions
While there are no global warming emissions associated with generating electricity from solar energy, there are emissions associated with other stages of the solar life-cycle, including manufacturing, materials transportation, installation, maintenance, and decommissioning and dismantlement. Most estimates of life-cycle emissions for photovoltaic systems are between 0.07 and 0.18 pounds of carbon dioxide equivalent per kilowatt-hour.
Most estimates for concentrating solar power range from 0.08 to 0.2 pounds of carbon dioxide equivalent per kilowatt-hour. In both cases, this is far less than the lifecycle emission rates for natural gas (0.6-2 lbs of CO2E/kWh) and coal (1.4-3.6 lbs of CO2E/kWh) [6].
References:
http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/environmental-impacts-solar-power.html
http://homeguides.sfgate.com/positive-negative-effects-solar-energy-79619.html
http://www.solareworld.com/2011/12/09/how-solar-energy-impacts-the-economy/
http://ret.cleanenergyregulator.gov.au/Solar-Panels/Incentives-for-your-Solar-Panels/incentives-solar-panels
http://www.technologyreview.com/news/517811/a-material-that-could-make-solar-power-dirt-cheap/
http://www.livescience.com/2324-solar-power-greenhouse-emissions-measured.html
