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Horizon Energy Systems 3801 Charter Park Court San Jose, Ca. 95136 Bruce Gordon, Owner Contractor License #829839 C46 Solar Contractor B General Contractor Connect with us today! • 408-978-0111 • info@gosolarnow.com |
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| Charts and Information (view on line or .PDF) •U.S. Geological Survey, "Estimated use of water in the United States in 2000" •The Safety of Photovoltaics.pdf •NREL PV Energy Payback.pdf •Homepower PV Energy Payback |
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Environmental Reasons to Go Solar Now!
Fossil fuel power plants emit massive amounts of CO2 from the combustion process. These emissions, in practice cannot be totally offset by planting trees, since the sheer quantity of CO2 emitted from current power plant operations is greater than what new forests are able to absorb. In the U.S. electricity generation is one of the largest sources of greenhouse gas emissions. Global Climate disruption is one of the most serious environmental issues of our time. In order to solve this problem we must implement large scale changes to the way we currently use fossil fuels. In addition to the compelling environmental reasons, oil and natural gas resource scarcities and price fluctuations may require renewable energy solutions.
Reducing greenhouse gas emissions make PV a great renewable energy choice. Photovoltaics emit no CO2 from operations and is considered one of the key renewable energy solutions that will help us make the much needed clean energy transition during the 21st century.
Photovoltaics produces no emissions from use. It will offset electrical generation from other sources that are not as clean. Fossil fuel power plants are major sources of air pollution such as particulate matter (causes lung damage), CO, CO2 (results in global heating), NOx (precursor to smog), SOx (causes acid rain), and toxic heavy metals such as arsenic, lead and mercury, and many other unwanted pollutants that are best kept out of our common, life sustaining air shed.
Most forms of electric energy generation require massive amounts of water during operations. No water is needed to operate a PV system other than occasionally hosed off dusty panels during the summer months to optimize output. Hydroelectric, coal, and natural gas power plants use water during operation can have detrimental impacts to aquatic species who share the water source, in the form of thermal changes to water temperature, appropriation of water sources, and species death caused by being sucked into inflow pipes and becoming trapped in the screens or swept into the unit and subjected to thermal and mechanical shocks. As human population grows and water competition becomes more common place, access to water will become a critical issue.
In the year 2000 the amount of water used to generate each kWh of electricity averaged 21 gallons (Solley and others, 1998). 136 billion gallons per day of fresh water were used in year 2000 by thermal electric power generators in the United States. (U.S. Geological Survey, Estimated use of water in the United States in 2000).
Quiet, Benign, No Moving Parts
Photovoltaics is the only known way to generate electricity without moving something. Some inverters have a small fan (like a personal computer), and thus do have a moving part and some sound. Other inverters have no fan and are silent and the only sound made is an imperceptible hum that can be heard by pressing one’s ear onto the inverter during operation. PV is also unique among power sources in that it does not require special training to operate, it is automatic and there is virtually no maintenance required.
Creatures are not killed from operating a solar electric system, since there are no spinning turbines. Thus it is wildlife friendly!
Reduces Demand for Dams, Natural Gas, Coal & Nuclear Power Plants
Power generated by clean, renewable energy sources displaces the need to generate power from polluting, traditional sources. Although solar power only works during the day, the sky is the limit on how much of this energy is tapped in the future. There is significant untapped capacity on all of our sunny roofs and parking structures. Within a few decades a large percentage of our energy needs could be met by solar and other renewable energy sources, it is up to each of us to make responsible choices in how we support this clean energy revolution.
Reduces Need to Drill for Natural Gas and Market Transport
Natural gas wells are being depleted and there is significant environmental damage caused from the continual exploration, development of natural gas infrastructure, drilling and building transportation infrastructure in pristine wilderness areas. Pipelines can disrupt wildlife migration routes and are targets for vandals.
Lowers Harmful Coal Mining Operations
Currently coal powers about half of the U.S. electricity supply. There are vast, untapped reserves of coal under the fertile wheat fields of the Great Plains region in North America and elsewhere. Tunnel and strip mining of coal is devastating to local ecosystems. Mining can be dangerous for workers as the dust gives rise to serious ailments such as black lung disease and tunnels can collapse and kill workers.
Mining spoils from tunnel and open pit strip mines are ugly as they consist of huge piles of rubble. Sulfur deposits are also associated with coal and this sulfur can react with water and air to produce sulfuric acid which could pollute streams and kill fish. These mining spoils can erode, clog streams and pollute water sources, as well as altering water flows and adversely affecting wildlife.
In 1977 in the U.S. the Surface Mining Control and Reclamation Act was passed to require the reclamation and restoration of lands used for coal mining, as well as banning mines in certain agricultural regions and requiring mining companies to minimize water pollution. But covering strip mines with layers of sub soil and top soil may not completely restore the area to its rich and fertile previous state. Regulating pollution from coal mining operations is not a proactive way to prevent this pollution in the first place. Coal mines disrupt agricultural and wildlife use of this otherwise productive land.
PV Construction and the Environment
PV manufacturing uses chemicals. Employee safety and environmentally correct disposal methods are important industry concerns. The National Renewable Energy Laboratory concluded, "by using well designed industrial processes and careful monitoring, PV manufactures have minimized risks to where they are far less than those in most major industries. All of these risks fall well within the range already protected by OSHA and similar regulations." ("The Safety of Photovoltaics")
What is the time needed for a photovoltaic module to generate as much electricity as was used to produce it? According to the U.S. Dept. of Energy in a December 2004 publication by the National Renewable Energy Laboratory entitled “What is the Energy Payback for PV” (PV Energy Payback), the energy used to make multicrystalline PV modules today is recouped after 4 years of operation. Assuming a 30 year system life, and sun availability in the continental U.S., a typical PV systems will provide a net gain of 26 years of pollution free electricity.
About half of the energy used to manufacture crystalline PV modules is in the materials, the other half in the manufacturing process. Most of the energy consumed in PV module production is from creating and processing the silicon which is the primary material for the solar cell. The aluminum frames and tempered glass also take a fair amount of energy to produce. The energy content used to make all of the other parts of the solar module is small by comparison. Home Power magazine published a study in December of 2000 on PV Energy Payback (PV Payback)
