Greening the Electrical Grid - part 1

Ok, so Al Gore wants the electrical grid to be 100% Renewable within 10 years. What are the options?

Renewable options include:

Water - hydro electric dams, tidal current, ocean waves

Wind - farms of wind turbines

Biomass - natural gas from composing manure and other waste products

Solar - photovoltaic, thermal

What’s NOT renewable? - fossil fuels (diesel, gasoline), coal, natural gas, nuclear.

What’s Questionable? - ethanol and bio-diesel. These two fuels, and possibly biomass gases,  may be considered renewable but they still produce carbon dioxide when consumed. If manufactured correctly, using cellulosic ethanol or algae bio-diesel, they can produce much more energy when consumed, than required in their production. The carbon dioxide that is released on their consumption is also “recycled” during their production, thus stored carbon (fossil fuel) is not added to the atmosphere.

Nuclear power is also a toss-up in the minds of many people. On the positive side, it does not produce greenhouse gases. On the negative side, the radioactive waste is a huge concern.

In part 1, let’s look further at Solar Thermal Electrical Production.

Solar Thermal Electrical Production

Most of the world’s prime solar thermal sites are located around the equator. The following diagram indicates the prime locations for thermal plants:

 

 The most promising solar thermal technology is Solar Thermal Parabolic Trough.  Parabolic trough power plants consist of numerous trough-shaped parabolic mirrors that concentrate sunlight onto receivers. This heats a fluid that transfers the heat back to an electrical generator that makes electricity.

Several of these power plants are inuse today. With advanced heat storage systems, these power plants can provide power 24 hours a day, 365 days a year.

Once built, a thermal parabolic trough power plant continues to produce electricity at a very low cost (3 cents/kwh).

More information on Solar Thermal Power Plants is available here: Solar Thermal Power Plants

A second form of solar thermal electrical power is via Dish/Engine Systems.These systems use a dish of mirrors to focus the sun’s heat on a Sterling Engine. Though each individual system produces a small amount of electricity, thousands of dishes can be setup to create power plants that generate gigawatts of power.

A third solar thermal system is called Power Towers. These plants use a couple thousand mirrors to focus the sun’s heat onto a central tower. Solar One and Solar Two in the Mojave Desert, was a demo projected that created 10 MW of power. A new production system called Solar Tres is presently being constructed in Spain, which will produce 17 MW of power, and will run 24 hours per day.

For more information on these 3 types of Solar Thermal Power plants, please see: Solar Thermal Power Plants

Stumble it!

Filed under: Go Green