How to get FREE Standard Shipping: Ship to an address within the United States (including U.S. territories) Place your online order of $25 or more* - after promotions and before tax are applied. Use Standard shipping option at checkout.
alternative energy-energy derived from sources that do not use up natural resources or harm the environment. energy, free energy - (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs; energy can take a wide variety of forms.
solar energy definition. The energy the Earth receives from the sun, primarily as visible light and other forms of electromagnetic radiation. (See renewable resource.) Note: The term solar energy often refers to processes that use this energy to generate heat or electricity for human use. (See solar cells.)