== Solar power ==
Uncaptured solar energy can convert itself to wind and wave energy, and of course warm the atmosphere. Large scale solar collection systems are few. One experimental version generated enough power from stored heat collected in a large "ball" containing salt heated to the melting point that they could have generated enough power for a small city a few hours after dark. Larger scale under ground storage was not mentioned.Solar electric panel are presently over the 10% efficiency point. They actually are more efficient on cold days.
== Wind power ==
Wind power systems tend to work best, and so most cost effective, where the wind is often at 30 miles per hour, or so.
== Biomass ==
There are reports that it's possible to convert carbohydrates directly to hydrocarbons (Huber et al., Production of Liquid Alkanes by Aqueous-Phase Processing of Biomass-Derived Carbohydrates, Science 3 June 2005: 1446-1450)
== Wave power ==
A very conservative estimate of the amount of energy that could be captured from a 6 feet wave across its length and 100 feet wide is 100,000 watts. The north-west Pacific is often considered a storm generator and high wave are not uncommon. (Kayaks are the favored form of water transport by the natives.) A sea mount nearing the surface off the coast of California is noted as a shipping hazard due to its high waves.
== Tidal power ==
There are places in the world, particularly as one get farther from the equator, where tidal extremes are very significant. The west shore of the Korean peninsula and Norway's fiords are noted for the effect.
== Geothermal power ==
The Earth's interior has a radioactive source that some figure is generating the equivalent of 10,000 atomic power plants. Scientists have noted by monitoring the speed and intensity of earthquake energy propagating through the earth that it tends to rise in plumes coming up through the mantle and sometimes penetrating the surface to generate volcanoes and sometimes form islands like Hawaii. They can note this because some forms of earthquake energy does not like to propagate through molten material.