The American Recovery and Reinvestment Act of 2009 included more than $70 billion in direct spending and tax credits for clean energy and associated transportation programs. This policy-stimulus combination represents the largest federal commitment in United States history for renewable energy, advanced transportation, and energy conservation initiatives. These new initiatives were expected to encourage many more utilities to strengthen their clean energy programs. While the Department of Energy has come under criticism for providing loan guarantees to Solyndra, its SunShot initiative has funded successful companies such as EnergySage and Zep Solar.
The top diagra m shows how the strength of sunlight is less nearer the Earth’s poles. The lower map shows how much solar energy hits the Earth’s surface after clouds and dust have reflected and absorbed some solar energy.
There are numerous organizations within the academic, federal, and commercial sectors conducting large scale advanced research in the field of renewable energy. This research spans several areas of focus across the renewable energy spectrum. Most of the research is targeted at improving efficiency and increasing overall energy yields. Multiple federally supported research organizations have focused on renewable energy in recent years. Two of the most prominent of these labs are Sandia National Laboratories and the National Renewable Energy Laboratory (NREL), both of which are funded by the United States Department of Energy and supported by various corporate partners. Sandia has a total budget of $2.4 billion while NREL has a budget of $375 million.
The combination of wind and solar PV has the advantage that the two sources complement each other because the peak operating times for each system occur at different times of the day and year. The power generation of such solar hybrid power systems is therefore more constant and fluctuates less than each of the two component subsystems. Solar power is seasonal, particularly in northern/southern climates, away from the equator, suggesting a need for long term seasonal storage in a medium such as hydrogen or pumped hydroelectric. The Institute for Solar Energy Supply Technology of the University of Kassel pilot-tested a combined power plant linking solar, wind, biogas and hydrostorage to provide load-following power from renewable sources.
Solar-powered electric demonstration vehicles have been built by universities and manufacturers. Solar collector areas have proved to be too large for conventional cars, however. Development continues on solar cell design.
Linear Fresnel reflector (LFR) systems are similar to parabolic trough systems in that mirrors (reflectors) concentrate sunlight onto a receiver located above the mirrors. These reflectors use the Fresnel lens effect, which allows for a concentrating mirror with a large aperture and short focal length. These systems are capable of concentrating the sun’s energy to approximately 30 times its normal intensity. The only operating linear Fresnel reflector system in the United States is a compact linear Fresnel reflector (CLFR)—also referred to as a concentrating linear Fresnel reflector—a type of LFR technology that has multiple absorbers within the vicinity of the mirrors. Multiple receivers allow the mirrors to change their inclination to minimize how much they block adjacent reflectors’ access to sunlight. This positioning improves system efficiency and reduces material requirements and costs.
means any excess energy your system generates can be stored for use later even when the sun is not shining. When the battery is fully charged, you can send the excess energy back to the grid (step 5).
Solar water heating makes an important contribution to renewable heat in many countries, most notably in China, which now has 70% of the global total (180 GWth). Most of these systems are installed on multi-family apartment buildings and meet a portion of the hot water needs of an estimated 50–60 million households in China. Worldwide, total installed solar water heating systems meet a portion of the water heating needs of over 70 million households. The use of biomass for heating continues to grow as well. In Sweden, national use of biomass energy has surpassed that of oil. Direct geothermal for heating is also growing rapidly. The newest addition to Heating is from Geothermal Heat Pumps which provide both heating and cooling, and also flatten the electric demand curve and are thus an increasing national priority (see also Renewable thermal energy).
Commercial concentrating solar power (CSP) plants, also called “solar thermal power stations”, were first developed in the 1980s. The 377 MW Ivanpah Solar Power Facility, located in California’s Mojave Desert, is the world’s largest solar thermal power plant project. Other large CSP plants include the Solnova Solar Power Station (150 MW), the Andasol solar power station (150 MW), and Extresol Solar Power Station (150 MW), all in Spain. The principal advantage of CSP is the ability to efficiently add thermal storage, allowing the dispatching of electricity over up to a 24-hour period. Since peak electricity demand typically occurs at about 5 pm, many CSP power plants use 3 to 5 hours of thermal storage.
Like many of the American entrepreneurs I met in Africa, Poindexter has a background in finance. A graduate of Harvard Business School, she worked as a derivatives trader before leading business development at Opower, a software platform for utilities customers that was acquired by Oracle last year. (Unlike many of these entrepreneurs, who tend to skew white and male, Poindexter is African-American.) She decided to start the company in 2015, after she began to learn about energy poverty. She recalled watching TV coverage of the Ebola epidemic in Liberia. “There was a lot of coughing in the background, and I was thinking, That’s someone with Ebola,” she said. “But it wasn’t. It was from the smoke in the room from the fire.” Last year, in the Ghanaian community of Kofihuikrom, one of the first towns that Black Star served, the company erected twenty-two solar panels. Today, the local clinic no longer has to deliver babies by flashlight. The town chief, Nana Kwaku Appiah, said that he was so excited that he initially left his lights on inside all night. “Our relatives from the city used to not come here to visit,” he said. “Now they do.”
Many of these plants are integrated with agriculture and some use tracking systems that follow the sun’s daily path across the sky to generate more electricity than fixed-mounted systems. There are no fuel costs or emissions during operation of the power stations.
By 2040, renewable energy is projected to equal coal and natural gas electricity generation. Several jurisdictions, including Denmark, Germany, the state of South Australia and some US states have achieved high integration of variable renewables. For example, in 2015 wind power met 42% of electricity demand in Denmark, 23.2% in Portugal and 15.5% in Uruguay. Interconnectors enable countries to balance electricity systems by allowing the import and export of renewable energy. Innovative hybrid systems have emerged between countries and regions.
Historically hydroelectric power came from constructing large hydroelectric dams and reservoirs, which are still popular in third world countries. The largest of which is the Three Gorges Dam(2003) in China and the Itaipu Dam(1984) built by Brazil and Paraguay.
The Hassi R’Mel power station in Algeria, is an example of combining CSP with a gas turbine, where a 25-megawatt CSP-parabolic trough array supplements a much larger 130 MW combined cycle gas turbine plant. Another example is the Yazd power station in Iran.
Photovoltaics (PV) uses solar cells assembled into solar panels to convert sunlight into electricity. It’s a fast-growing technology doubling its worldwide installed capacity every couple of years. PV systems range from small, residential and commercial rooftop or building integrated installations, to large utility-scale photovoltaic power station. The predominant PV technology is crystalline silicon, while thin-film solar cell technology accounts for about 10 percent of global photovoltaic deployment. In recent years, PV technology has improved its electricity generating efficiency, reduced the installation cost per watt as well as its energy payback time, and has reached grid parity in at least 30 different markets by 2014. Financial institutions are predicting a second solar “gold rush” in the near future.
Power purchase agreements (PPAs) are very similar to how people pay their electric bills today — the equipment is owned by a third party, and customers are only charged for the kilowatt-hours of solar power that they use. In fact, some companies will simplify your solar and electric billing so you just receive one bill, to save on transaction costs. But overall, the lack of an up-front installation cost makes PPAs a very attractive proposition for solar-seeking homeowners. In fact, says Kimbis, overall, the majority of solar customers enter leases and PPAs instead of buying their own equipment outright.
There are many practical applications for the use of solar panels or photovoltaics. It can first be used in agriculture as a power source for irrigation. In health care solar panels can be used to refrigerate medical supplies. It can also be used for infrastructure. PV modules are used in photovoltaic systems and include a large variety of electric devices:
Floatovoltaics are an emerging form of PV systems that float on the surface of irrigation canals, water reservoirs, quarry lakes, and tailing ponds. Several systems exist in France, India, Japan, Korea, the United Kingdom and the United States. These systems reduce the need of valuable land area, save drinking water that would otherwise be lost through evaporation, and show a higher efficiency of solar energy conversion, as the panels are kept at a cooler temperature than they would be on land. Although not floating, other dual-use facilities with solar power include fisheries.
In 2007, General Electric’s Chief Engineer predicted grid parity without subsidies in sunny parts of the United States by around 2015; other companies https://www.youtube.com/edit?o=U&video_id=qgvaBpQ1tWY an earlier date: the cost of solar power will be below grid parity for more than half of residential customers and 10% of commercial customers in the OECD, as long as grid electricity prices do not decrease through 2010.
Solar is the Latin word for sun—a powerful source of energy that can be used to heat, cool, and light our homes and businesses. That’s because more energy from the sun falls on the earth in one hour than is used by everyone in the world in one year. A variety of technologies convert sunlight to usable energy for buildings. The most commonly used solar technologies for homes and businesses are solar water heating, passive solar design for space heating and cooling, and solar photovoltaics for electricity.
Hydroelectric power is currently the largest producer of renewable power in the United States. It produced around 6.52% of the nation’s total electricity in 2016 which was 43.62% of the total renewable power in the country. The United States is the fourth largest producer of hydroelectricity in the world after China, Canada and Brazil. The Grand Coulee Dam is the 5th largest hydroelectric power station in the world and another six U.S. hydroelectric plants are among the 50 largest in the world. The amount of hydroelectric power generated is strongly affected by changes in precipitation and surface runoff.
Many people are looking for ways to save a little extra money any way that they can, especially when times are tough. Eco-friendly products and services can sometimes cost more up front but often pay off…