Energy has several forms, some of which are easily convertible and can be changed to another form useful for work.
Most of the world's convertible energy comes from fossil fuels that are burned to produce heat that is then used as a transfer medium to mechanical or other means in order to accomplish tasks.
Electrical energy is usually measured in kilowatt hours, while heat energy is usually measured in British thermal units (Btu).
These changes can be physical or chemical, and allow energy to be converted to another form; for example, the chemical energy of fuel is converted into heat and then into mechanical energy in an engine.
2. A measure of the electrostatic potential of the barrier.
The energy capacity of a given cell varies with temperature, rate, age, and cut-off voltage. This term is more common to system designers than it is to the battery industry where capacity usually refers to ampere-hours.
The three main applications for battery energy storage systems include spinning reserve at generating stations, load leveling at substations, and peak shaving on the customer side of the meter.
Electric energy is measured in kilowatt hours.
"Femtosecond lasers are the fastest in the world and are capable of producing energy pulses that last a millionth of a billionth of a second and can be focused into beams less than one hundredth the diameter of a human hair."
Lists of words about Energy Sources and additional information.
To make a moving car stop, all its kinetic energy must be converted into other forms by heating up the brakes, for example.
A car at the top of a hill has potential energy because of its position. It can turn its potential energy into kinetic energy by going down the slope.
The Solar Energy Technologies Program focuses on developing cost-effective solar-energy technologies that have the greatest potential to benefit the nation and the world.
Solar technologies diversify the energy supply, reduce the country's dependence on imported fuels, improve air quality, and offset greenhouse gas emissions. A growing solar industry also stimulates the economy by creating jobs in solar manufacturing and installation.
It has been proposed as a storage option to support large-scale use of photovoltaics as a means to smooth out fluctuations in power generation.
Wind energy uses the energy in the wind for practical purposes like generating electricity, charging batteries, pumping water, or grinding grain.
Turbines are perched on high towers, usually 100 feet or higher, and often placed in large groups, or "farms", to generate electricity to towns and cities.
On a much smaller scale, stand-alone turbines are sometimes used by farmers and homeowners to generate supplemental electricity.
In the past twenty years, U.S. government incentives in the form of tax credits to producers and incentives for homeowners have helped to lower the price of wind power by an estimated eighty-five percent, making it a more feasible option.
There are people who object to wind farms because of their appearance or the noise the turbines make. Wind power raises few other environmental problems except danger to birds.
There is also a problem with having a consistent generation of electricity with wind energy because of the of the unknown features of the weather. Sometimes the wind is simply non-active.