Geothermal Energy

image via: lydurs

What is It?

In California it is 5% of our overall energy, in El Salvador it is 25% of their energy use. Idaho and Iceland use it to heat their buildings and keep homes cool or warm. Geothermal energy is gathered from underground, about 33,000 feet underground and has 50,000 times more energy then our natural gasses. But we don’t have to go 33,000 feet underground to get this energy. In hotspots the earth’s crust is thin enough to let heat out. Most of the midwest, and especially Nevada is filled with hotspots. Also, most of Louisiana and Southeast Texas.

How do we get it?

There are three forms of geothermal plants, dry steam, flash steam, and the binary cycle plant. In genereal these plants use the natural process of “hydrothermal convection” to capture the steam. Hydrothermal convection is when the cooler water gets soaked into the earth and than rises back up in a much hotter temperature. These plants drill holes into the existing hot rock surrounding the area in order to capture it. So, what is the difference between the three and which one do we know is to be used? In dry steam poweplant, the original and most commonly used plants the steam goes into a turbine, this allows the turbine to run off the steam and not any fossil fuels. The steam is gathered through a drill, into the turbine, then into a generator. The largest plant of geothermal energy uses this process, in our own state it is called The Geysers in Northern California. But this process disperses a lot of steam into the air, as well with some air pollutants.

The second form used is the Flash Steam Power Plants, this system uses the hydrothermal fluids. These fluids are rushed into a tank called the flash tank, the tank is at a lower pressure so this causes some of the fluids to immediately flash into vapor then run through a turbine and goes through the same process as the previous plant, but with this plant you can add another flash tank and gather even more energy.

The most modern of them all is the Binary Cycle Power Plants, this is a closed system so almost nothing goes into the earth’s atmosphere! Hydrothermal fluids and moderate fluids with lower boiling points are gathered through the drill, then they are passed to the heat exchanger, the hotter fluids cause the more moderate fluids to vapor or flash. Then the rest goes into the turbines, and then the generators.

In an area that may not provide as many hydrothermal fluids, the binary cycle power plant would be ideal since it can combine the two.

If this became a major energy source that would most likely be the most common, it emits no pollutants and doesn’t have to be in only an intense hot spot. The resources of geothermal energy are basically endless, it comes from hot water resevoirs, the magma, and hot dry rock. The heat from our earth’s crust will always be there so it would be ideal to run off this alternative and stop the fossil fuels. As long as we accept and produce the technology to gather this energy then this can become a very important source of our energy and wouldn’t just take up 5% of California’s energy, but increase and help our whole nation.

Solar Energy

image via: rob

How does it work?

We all know what solar energy is, but how do we get it to light up our homes and run our electronics? You would think with all the sunlight in the world all of us would be living off the sun’s energy. The sunlight in twenty days can match all the energy reserves we have here on earth. A somewhat obvious was to light up our homes is by simple desgin, clear windows up top can light a whole living room. I recall living in an apartment that had these skylights and we never had to use a light, until nigh time of course. I think this would be ideal for offices and would really cut down electricity, seeing as offices are most only used till the late afternoon. But then there is the more expensive, but only one time expense for your home. Solar panels or Solar Heat Collectors, these are the most common we see on rooftops and such. But these can only power cooling systems, an example of this system would be desiccant evaporators. The hot air is seprated from the cooler air, and the hot air is realeased. Another process to power our air conditioners, even refrigerators is an absorption chiller.

Photovolatics

This was discovered in 1839 by a French scientist, he discovered that certain materials when struck by light caused a spark of electricity. By the 1950’s this theory was put to the test and ended up powering many satelites! It is basically two layers of silicon, but with additives. The bottom layer with a boron addition and the top layer with phosphorus. These two make two opposite charges, like a battery! With a circuit and sun light the electricity can be carried through the circuit give the owner of this cell its own electricity!

In the Future

Many states, specifically California have come to realize the importance of this renewable energy. In 2006 the California Solar Initiative was approved which dedicated billions to solar research and provides over a million homes with solar panels on their roofs! Many states promote this with tax incentives and even the federal government has been said to pay up to thirty percent tax credits for the purchase and installation! The only problem is, it is an expensive buy and installation, but it is only at one time. It reduces your monthly bills, and proves a huge savings by the end of the year.

Wind Energy

image via: pbo31

How does wind turn into electricity?

When I was young and driving up to San Francisco I remember seeing thousands of windmills and I didn’t understand why, when I asked my parents what it was for they said electricity. I simply couldn’t understand how that windmill could light up a home. Wind electricity prices have dropped very much over the years about 4-6 cents per kWh now a days, but these wind turbines have risen in price. These wind turbines are those simple windmills you see on the way to San Francisco, but behind the simplicity a lot is at work. For AC electricity it is somewhat simple, but for electricity elsewhere, the wind has to be at a certain rate in order to achieve electricity. Since winds change, so does the gearbox behind the blades inside the “tower” the blades are connected to. It is suggested to use a gearbox that varies because a slow one can come to a stand still during slow winds, and a fast one could alter equipment. You cannot just get any windmill but a specific wind turbine, the blades are especially made to capture the winds kinetic energy. For these wind turbines, placement is everything, putting it in a place with no wind would make it virtually useless.

Overall, all of three of these alternatives would be fantastic for our nation. Sadly all three of these are in the other category, and in totaly only 5% of our nations energy is used through these alternatives. All these of these alternatives have endless resources, but not everyone can pay that big lump sum at the time to get this technology even with tax incentives. In order for us to stop depending on coal which is 52% of our nation’s energy use we would have to make this technology more affordable and available. Once that happens we can easily use all these abundant resources!