Types of Renewable Energy
Solar
Solar energy is the utilization of the radiant energy from the Sun. Solar power is often used interchangeably with solar energy but refers more specifically to the conversion of sunlight into electricity, either by photovoltaics and concentrating solar thermal devices, or by one of several experimental technologies such as thermoelectric converters, solar chimneys and solar ponds.
Wind
Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines. At the end of 2007, worldwide capacity of wind-powered generators was 94.1 gigawatts. Although wind currently produces about 1% of world-wide electricity use,it accounts for approximately 19% of electricity production in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland (2007 data). Globally, wind power generation increased more than fivefold between 2000 and 2007.
Most wind power is generated in the form of electricity. Large scale wind farms are connected to electrical grids. Individual turbines can provide electricity to isolated locations. In windmills, wind energy is used directly as mechanical energy for pumping water or grinding grain.
Wind energy is plentiful, renewable, widely distributed, clean, and reduces greenhouse gas emissions when it displaces fossil-fuel-derived electricity. The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand, additional costs for compensation of intermittency are considered to be modest.
Bioenergy
Bioenergy refers to energy generated from Biomass. Biomass includes all types of living (and formerly living) including wood, plants, algae, wastewater treatment sludge, etc.
Tidal
Tidal energy is generated from the movement of the ocean. Some interesting examples of capturing the ocean’s energy either above the surface or below the surface can be found here or here.
Hydro
Hydro-energy is energy captured from moving water. Most often when people think of Hydro, they think of massive electric generation projects like the Niagra Falls, Hoover Dam or most recently the Three Gorges Dam project in China.
Energy Efficiency
Energy Efficiency is the least sexy and most cost-effective of all the energy forms available. Amory Lovins extolls the virtues of the negawatt (“The cheapest watt of energy to produce is the watt you don’t use”), and McKinsey Global Institute highlights the vast resource and business opportunity of energy efficiency which sits right in front of us.
