It is virtually 6,500 kilometers (four,000 miles) from the surface to the center of the Earth, and the deeper you go, the hotter it gets. The outer layer, the crust, is 3 to 35 miles thick and insulates us from the hot interior.
Outside of the seasonal variations, the geothermal gradient of temperatures via the crust is 25-30 °C (45-54 °F) per kilometer of depth in most of the planet. The conductive heat flux averages .1 MW/km2. These values are considerably greater close to tectonic plate boundaries where the crust is thinner. They could be further augmented by fluid circulation, either by means of magma conduits, hot springs, hydrothermal circulation or a mixture of these.
Solar hot water makes an critical contribution in quite a few countries, most notably in China, which now has 70 % of the worldwide total (180 GWth). Most of these systems are installed on multi-family apartment buildings and meet a portion of the hot water demands of an estimated 50-60 million households in China. Worldwide, total installed solar water heating systems meet a portion of the water heating needs of over 70 million households. The use of biomass for heating continues to grow as well. In Sweden, national use of biomass energy has surpassed that of oil. Direct geothermal for heating is also increasing quickly.
Hueso has been attempting to capitalize on that momentum, meeting Wednesday with representatives from Gov. Jerry Brown’s office and a number of state agencies to discuss non-legislative actions that could bolster the state’s geothermal sector. One particular of the actions they discussed, Hueso said, was encouraging the federal government and the state’s Department of Water Resources to procure much more geothermal power.
Renewable sources are these that are constantly accessible and not anticipated to run out. The definition of renewable energy varies from state to state below RPS mandates. Biofuels like ethanol, biomass like wood and yard waste, landfill gas like methane captured from trash dumps, solar, wind and hydroelectric power regarded renewable power in all fifty states. Geothermal is classified as an eligible technologies in most states.