Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, rain, tides, waves, and geothermal heat. Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation. Renewable energy often provides energy for electricity generation to a grid, air and water heating/cooling, and stand-alone power systems. About 20% of humans' global energy consumption is renewables, including almost 30% of electricity. About 8% of energy consumption is traditional biomass, but this is declining. Over 4% of energy consumption is heat energy from modern renewables, such as solar water heating, and over 6% electricity.
Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy including solar water heating, and solar architecture.
In passive solar building design, windows, walls, and floors are made to collect, store, reflect, and distribute solar energy, in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design because, unlike active solar heating systems, it does not involve the use of mechanical and electrical devices.
Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors.
Solar water heating (SWH) is heating water by sunlight, using a solar thermal collector. A variety of configurations is available at varying cost to provide solutions in different climates and latitudes. SWHs are widely used for residential and some industrial applications.
A solar thermal collector collects heat by absorbing sunlight. The term "solar collector" commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and solar towers or non water heating devices such as solar air heaters.
Solar air conditioning refers to any air conditioning (cooling) system that uses solar power.
Spain is one of the first countries to deploy large-scale solar photovoltaics, and is the world leader in concentrated solar power (CSP) production.
Solar power is the conversion of renewable energy from sunlight into electricity, either directly using photovoltaics (PV), indirectly using concentrated solar power, or a combination. Photovoltaic cells convert light into an electric current using the photovoltaic effect. Concentrated solar power systems use lenses or mirrors and solar tracking systems to focus a large area of sunlight to a hot spot, often to drive a steam turbine.
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and convert sunlight into electricity, a solar inverter to convert the output from direct to alternating current, as well as mounting, cabling, and other electrical accessories to set up a working system. It may also use a solar tracking system to improve the system's overall performance and include an integrated battery.
Solar architecture is an architectural approach that takes in account the Sun to harness clean and renewable solar power. It is related to the fields of optics, thermics, electronics and materials science. Both active and passive solar housing skills are involved in solar architecture.
The use of solar energy began in Israel in the 1950s with the development by Levi Yissar of a solar water heater to address the energy shortages that plagued the new country. By 1967 around 5% of water of households were solar heated and 50,000 solar heaters had been sold. With the 1970s oil crisis, Harry Zvi Tabor developed the prototype of the solar water heater now used in over 90% of Israeli homes. There are over 1.3 million solar water heaters installed as a result of mandatory solar water heating regulations.
Photovoltaic thermal collectors, typically abbreviated as PVT collectors and also known as hybrid solar collectors, photovoltaic thermal solar collectors, PV/T collectors or solar cogeneration systems, are power generation technologies that convert solar radiation into usable thermal and electrical energy. PVT collectors combine photovoltaic solar cells, which convert sunlight into electricity, with a solar thermal collector, which transfers the otherwise unused waste heat from the PV module to a heat transfer fluid. By combining electricity and heat generation within the same component, these technologies can reach a higher overall efficiency than solar photovoltaic (PV) or solar thermal (T) alone.
Solar power in California includes utility-scale solar power plants as well as local distributed generation, mostly from rooftop photovoltaics. It has been growing rapidly because of high insolation, community support, declining solar costs, and a Renewable Portfolio Standard which requires that 33% of California's electricity come from renewable resources by 2020, and 60% by 2030. Much of this is expected to come from solar power via photovoltaic facilities or concentrated solar power facilities.
Sun-free photovoltaics is a photovoltaics technology which does not require sunlight to produce electricity. This technique was developed by research team at Massachusetts Institute of Technology. Photovoltaic cells convert light to electricity most efficiently at specific wavelengths. The surface features of Sun-free photovoltaics is engineered such that it converts heat energy into the specific wavelengths. This increases the efficiency of existing thermophotovoltaic (TPV) systems.
Renewable energy has developed rapidly in Italy over the past decade and provided the country a means of diversifying from its historical dependency on imported fuels. Solar power accounted for around 8% of the total electric production in the country in 2014, making Italy the country with the highest contribution from solar energy in the world that year. Rapid growth in the deployment of solar, wind and bio energy in recent years lead to Italy producing over 40% of its electricity from renewable sources in 2014.
Solar energy – radiant light and heat from the sun. It has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar energy technologies include solar heating, solar photovoltaics, solar thermal electricity and solar architecture, which can make considerable contributions to solving some of the most urgent problems that the world now faces.
Solar power in Denmark contributes to a goal to use 100% renewable energy by 2050. The goal of 200 MW of photovoltaics by 2020 was reached eight years early, in 2012, and 36 MW was being installed each month. Denmark had 790 MW in late 2015. A total of 3,400 MW is expected to be installed by 2030. Many solar-thermal district heating plants exist and are planned in Denmark.
Solar energy conversion describes technologies devoted to the transformation of solar energy to other (useful) forms of energy, including electricity, fuel, and heat. It covers light-harvesting technologies including traditional semiconductor photovoltaic devices (PVs), emerging photovoltaics, solar fuel generation via electrolysis, artificial photosynthesis, and related forms of photocatalysis directed at the generation of energy rich molecules.
Solar augmented geothermal energy (SAGE) is an advanced method of geothermal energy that creates a synthetic geothermal storage resource by heating a natural brine with solar energy and adding enough heat when the sun shines to generate power 24 hours a day. The earth is given enough energy in one hour to provide all electrical needs for a year. Available energy is not the issue, but energy storage is the problem and SAGE creates effective storage and electrical power delivery on demand. This technology is especially effective for geothermal wells that have demonstrated inconsistent heat or idle oil or gas fields that have demonstrated the proper geology and have an abundance of solar.
