Any energy generated from the natural resources such as sunlight, wind rain, tides and geothermal heat, whichever is renewable i.e. naturally replenished is known as renewable energies. The renewable energy can be transformed from solar power, wind power, hydroelectricity/micro hydro, biomass and bio-fuels for all kinds of transportation. The process is very natural; it can be continuously replenished, which includes various forms of biomass. All these type of energy resources does not dissipate and it is constantly consumed.
There is another term which is generally used is called alternative energy. It uses fossil fuels according to some sources. Generally it is known for environment friendly.
Biomass is one of the renewable energies which is totally an organic matter and can include biological material derived from living beings, such as wood, waste and alcohol fuels. Wood is a derivative of both harvested wood as a fuel and from the wood waste products. This waste energy can be generated from municipal waste.
Wood heat has been considered to be powerful leading to double duty warming water ever since it was invented. The bucket can hold water over the fire. It is enough for heating your whole house. It also has enough hot water to fill up a whole pool. It totally depends on the insulated pipes for moving the water from your home to the heater and back again, with an insulated tank which holds water unless it is needed.
Photovoltaic energy is converted from light (photons) to electricity (voltage). The solar cells are typically combined with the modules that have up to 40 cells in it. These modules are mounted in PV arrays that can be measured up to several meters on side. These panels are flat PV arrays with are fixed in a specific angle, facing south. Solar photovoltaic is one of the highly effective sources for a heat pump water heating system. It is wondered that soon water to water heat pumps will be available in the market for more competitive edge.