PV Gap

Gail Said:

Explain each of the following alternative thermal energy sources: Solar, Wind, Hydro, Compost, Geothermal.?

We Answered:

Geothermal and solar are the only "thermal energy sources".

Geothermal works by generating electricity from heat deep underground, usually near active volcanoes. Water is pumped down, then turned to steam which comes back up and drives a turbine.
http://en.wikipedia.org/wiki/Geothermal_…

There are solar thermal power plants out there, but they are not very common and this is usually not the technology people mean when they say "solar" energy. Most of these applications involve using large mirrors to concentrate solar energy, and heat up water to drive a turbine.
http://en.wikipedia.org/wiki/Solar_power…

Solar energy (photovoltaic) turns solar radiation into electricity; photons of light knock loose electrons of silicon, which form an electric current (all a current really is is a flow of electrons.) This is the standard meaning of "solar energy" and "solar panel".
http://en.wikipedia.org/wiki/Photovoltai…

Wind and hydro have nothing to do with thermal energy; composting is not an energy source, it's a fertilizer.
http://en.wikipedia.org/wiki/Compost

Oscar Said:

Is thermal solar energy cheap...?

We Answered:

Thermal energy is the cheapest...

uses

-solar cooking
-radiation
-solar panels
-solar furnace

etc..

Lisa Said:

how solar energy use in thermal generation?

We Answered:

usually solar energy is used to heat water(or any other liquid with heat transfer characteristics)

so for example ,solar thermal power plants,they use sun to heat the water till it becomes steam under high pressure to turn on turbines which generate electricity.

Also thermal water heaters in homes use the same idea where sometimes vacuum tubes are used where water passes through them,These tubes are designed such that they absorb the solar energy (photons with energy transformed to heat) but in the mean time they dont dissipate heat back to atmosphere

Melissa Said:

What's solar thermal energy?

We Answered:

According to Ask.com~Solar thermal energy refers to harnessing the sun's light to produce heat.

Maria Said:

Estimate the temperature Earth's surface will need to attain in order to radiate that much thermal energy. ?

We Answered:

The 4th root of 3000 is 7.4, so about 7.4 times 300K, or 2200 K.