biggest energy challenges—our dependence on fossil fuels and the need to address global warming—while also boosting our economy.
America has the potential to obtain a large and increasing share of our energy from the sun. In the near term, America should set the ambitious goal of obtaining 10 percent or more of our total energy consumption from the sun by 2030, using a wide variety of technologies and tools.
Achieving that target would result in the sun providing us with more energy than we currently produce at nuclear power plants, more than half as much as we currently consume in our cars and light trucks, or nearly half as much as we currently obtain from burning coal.
A comprehensive suite of public policy strategies can remove many of the common barriers to solar energy development and help to make this vision a reality. There are many ways to take advantage of the sun’s energy.
Solar energy can be converted to electricity, or used for lighting, heating and cooling. It can replace the fossil fuels we burn at electric power plants, in factories, in our homes, and even in our cars, with electric vehicles. Solar energy technologies include:
-Photovoltaics (PV) – Photovoltaics directly convert solar radiation into electricity. PV can take the form of panels or be incorporated into building materials. PV is scalable, generates electricity anywhere the sun shines, including in cold climates, has no essential moving parts, uses virtually no water, and is one of the few power generation technologies well suited for use in urban areas.
-Concentrating solar power (CSP)
– CSP plants use mirrors to focus the sun’s energy to harness heat that can be used directly or to generate electricity. Because heat is cheaper and easier to store than electricity, CSP plants with thermal storage can be designed to provide energy from the sun even at night. CSP plants have been reliably generating power in desert areas of the West for decades and are now experiencing a resurgence due in part to falling costs and increasing demand for utility-scale renewable electricity.
-Solar water heaters – Rooftopmounted collectors capture solar energy as heat and produce hot water. Solar heat collectors can be extremely efficient; low-temperature heaters can capture up to 87 percent of the solar energy that reaches them. Solar water heaters can also be adapted for uses ranging from residential water heating to largescale industrial use.
-Solar space heating and cooling
– Collectors similar to those used for hot water can also be used to heat air in place of furnaces or boilers. These systems can contribute 50 percent or more of the energy needed to heat a building. Solar energy can even be used to cool buildings through the use of absorption chillers.
-Passive solar design – For centuries, skilled builders have designed homes and other buildings that take the best possible advantage
of solar energy. “Passive” solar design can contribute to the overall efficiency of a building, reducing the need for energy for lighting, heating and cooling.
Solar energy can help power virtually every aspect of America’s economy.
The United States could obtain 10% of energy consumption from solar energy by 2030. This is the ambitious target stated in a report, “Building a Solar Future: Repowering America’s Homes, Businesses and Industry with Solar Energy”, drawn up by Environment America (a major US environmental group) supported by independent Vermont Senator Bernie Sanders, well-known for his legislative efforts favouring renewables.
In order to meet 10% of overall gross energy consumption planned in the US for 2030, the study considers all currently available solar technologies (photovoltaics, thermodynamics, thermal panels, passive solar design), that must be adopted more or less intensively, in every field (construction, transport, industry, agriculture, etc.).
In the field of construction, for example, all new homes should be built so as be zero energy net, while 35-40% of residential buildings are suitable for photovoltaic panels and in 50% of them solar thermal systems can be installed.
"The US spends 350 billion dollars every year importing oil from Saudi Arabia and other countries. A dramatic expansion of solar power is a clean and economical way to help break our dependence on foreign oil, reduce greenhouse gas emissions that cause global warming, improve our geopolitical position, and create good-paying green jobs.”
Environment America recalled that solar energy can be used for electricity generation, lighting, building heating and cooling. In the future it will also be able to replace fossil fuels used in homes, businesses and for automobiles.