Energy and Construction - Clima2007

Lois Said:

What is the difference between thermal and solar energy?

We Answered:

Solar energy is energy from the sun.

There are many forms of energy.
- Plants use photosysthesis to convert solar energy into chemical energy.
- Solar cells convert solar energy into electricity.
- Evaporated and condensed water, thermals, and winds convert solar energy to mechanical energy.
- Copper flashing, like most things sitting out in the sun, convert solar energy to heat.

So, its solar energy until it is absorbed by the copper, then it is thermal energy (heat).

Edit: I know 2 ways to convert thermal energy to electrical. First is a thermoelectric generator. These tend to be costly, delicate, and have low efficiency. Check out the links below the article, especially the HZ-14 one: http://en.wikipedia.org/wiki/Thermoelect…

2nd way is to use an engine or turbine. Concentrating sunlight with mirrors onto a small boiler creates high pressure steam. It is used in a turbine to make electricity. Some experimental units have actually been deployed by utility companies in sunny areas. While they depend on government subsidies, with enough emprovement, the technologies may stand on their own. You can also use solar energy to heat air or other working fluid inside an engine to convert the thermal energy to mechanical motion that drives an electrical generator. The most efficient such engine is called a carnot engine, which is unfortunately impractical to make economically.

Finally, things like windmills and waterpower actually convert solar to mechanical power, which is then used to drive generators. These are actually variations of the 2nd point.

BTW, if you're asking how to make a simple solar cell from copper, see link: http://answers.yahoo.com/question/index;…

Stanley Said:

What are potential salts used for storing solar thermal energy?

We Answered:

Any salt can be used but a mix of sodium and potassium nitrate is best used commercially (otherwise used as a fertiliser)

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Tommy Said:

Where to buy a personal Solar Thermal Energy device?

We Answered:

Make one man. Its called a parabolic trough, and is basically just a big curved mirror with a tube placed where the sun is concentrated. The tube is surrounded by a second transparent tube that acts as a kind of greenhouse. You can use it to heat your water or if you make a good one, to drive a little turbine.....

Franklin Said:

Solar Thermal Energy use in the Great Lakes area?

We Answered:

The world's largest laundromat in Chicago uses solar thermal to heat its water. http://www.worldslargestlaundry.com/sola…

You just missed the annual solar tour in October, here's a summary of some of the locations in Michigan http://www.michigan.gov/documents/dleg/A…

Here's a company that provides solar water heating and solar space heating in Michigan and has great examples on their site. http://www.by-solar.com/index.html

I'm in New England, we have similar weather, and I have a solar air heater and am installing solar water heating to heat my radiant floors. http://www.altestore.com/gallery/Amy-Bea…

Margaret Said:

Does anybody have any info on thermal energy/solar energy, and how it realates to seasons?

We Answered:

The earth rotates on an axis. In the summer, your hemisphere is tilted towards the sun. This results in longer days, and the sunlight hitting the earth more straight on.

In the winter, your hemisphere is tilted away from the sun. This results in shorter days, and the light hits the earth at a greater angle. More light is reflected off the atmosphere and off the earth itself, which contributes to less heat absorbed. Also, the same area of sunlight is spread over a greater area (like shining a torch sideways along the ground), this reduced density of sunlight on the earth also means less heat is absorbed.

The seasons are more distinct further from the equator where the tilt has more of an effect. On the equator, there are actually 2 longest and 2 shortest days each year and less distinct seasons, as when the earth is on either side of the sun (during autumn/spring seasons) the sun is directly above the equator, no matter which side of the sun the earth is on.

Tracey Said:

What are some current places where Solar energy thermal (heat) is being used?

We Answered:

Solar thermal can be used to generate electricity in large power plants, or can be used to capture heat for water and space heating. Here's a good site on solar thermal electricity, http://www.ecoworld.com/energy-fuels/sol… I'm using solar thermal in New England to heat my domestic water for showers and washing, as well as to heat my house. Here's a description of it, http://www.altestore.com/gallery/Amy-Bea… It can be used to heat the water for radiant floors, or heat the air in forced hot air systems.

Solar thermal is used all around the world. China is the largest user of solar water heating, with Japan, Germany, Israel all closer behind. It is now required by law in Hawaii for new construction to install slar water heating, since it saves so much power instead of using electricity to heat water.

Gertrude Said:

Solar energy (thermal and photo voltaic) Differences between the conditions in North and South Europe?

We Answered:

There are maps to show how much solar energy is available on average per day for the planet. Solar energy return is also dependent on tracking the sun. Tracking can be applied on solar thermal and photovoltaic. Solar thermal is more economical when scaled up in MW. Solar thermal can also provide night time energy using salt ponds for heat storage.