Energy is deposited in a range of energy sources, which can be non-renewable or renewable. Renewable sources of energy are those that can be refilled in a short period of time, as opposed to non-renewable sources of energy. The use of renewable sources of energy is less polluting, compared to that of non-renewable sources. Specifically, increased dependence on renewable sources of energy is a key element of efforts to avert climate change. Renewable sources of energy today make an irrelevant contribution to total energy use, compared to that of non-renewable sources. A range of barriers hamper the widespread deployment of renewable energy technologies.