These technologies are can be separated into three main categories (Alternative Energy):
Wave Energy Converters: These systems extract the power of ocean waves and convert it into electricity. Typically, these systems use either a water column or some type of surface or just-below-surface buoy to capture the wave power. In addition to oceans, some lakes may offer sufficient wave activity to support wave energy converter technology. (Alternative Energy).
Ocean Thermal Energy Conversion (OTEC): OTEC generates electricity through the temperature differential in warmer surface water and colder deep water. Of ocean technologies, OTEC has the most limited applicability in the United States because it requires a 40-degree temperature differential that is typically available in locations like Hawaii and other more tropical climates (Alternative Energy).
Offshore Wind: Offshore wind projects take advantage of the vast wind resources available across oceans and large water bodies. Out at sea, winds blow freely, unobstructed by any buildings or other structures. Moreover, winds over oceans are stronger than most onshore, thus allowing for wind projects with capacity factors of as much as 65%, in contrast to the 35-40% achieved onshore (Alternative Energy).
Pros of Wave Energy
Wave energy is predictable since they are caused by the gravitational pull of the moon. And the tides can be predicted; they occur every day, virtually on schedule, twice every 24 hours.
The tides ebb and flow, and this is caused by the gravitational pull of the moon, and to a lesser degree the sun, on the earth. This means any shortage in supply can be prevented, and these shortages can cause brownouts and blackouts because there is too much demand. Tidal power pros and cons should be carefully considered against every other alternate renewable energy source, as well as all the fossil fuels, so that the best choice can be made. Another benefit of tidal/wave energy is the fact that this process does not emit greenhouse gases or particle pollution, which fossil fuels like oil and coal do, which can have a devastating effect on the environment and all living things on the planet. There is no mining or drilling involved either, which can rip up large chunks of the earth or poison the seas (Hydro Energy).
Cons of Wave Energy
One of the tidal/wave power cons when this energy source is compared to solar power is that tidal power plants must be located in a very specific location, one that meets all of the needed requirements. There must be a significant tidal flow of water through the area to turn the equipment. Nova Scotia and France are the two countries which have successfully developed and built these facilities so far (Hydro Energy).
Wave/tidal energy can lead to the relocation or destruction of habitats for wild life. And it can only be used where tidal/wave flow and energy are available. Therefore inland locations are not viable, and there are limited locations along the oceans that are ideal for the volume of wave/tidal flow.
Maintenance is extensive and costly because of the salt problems. Salt resistant parts are required and are also expensive. Some of the technology disrupts the movement of marine animals and can disrupt and even destroy fish. Serious problems could be created for the local ecosystem.
Germany's Natural Resources and Renewable Energy
Germany is a major success story for renewable energy. Its goal is to be 100% renewable- energy-powered by the year 2050. It has already made major strides in that direction.
The country is utilizing an integrated approach to utilizing its current natural resources with greater efficiency while working steadily on every type of renewable energy it can get its hands on. Germany is also spending tens of millions on research and development of green technology (Burgermeister).
"It's ambitious, but Germany can be running on renewable energy by 2050 if there is the political will," said David Wortmann, Director of Renewable Energy and Resources at Germany Trade and Invest, a government body supporting the country's renewable energy sector. (Burgermeister).
By 2020 the country plans on renewable energy supplying 33% of its needs. That sounds impossible if not for the fact that, in 2008, Germany renewable energy consumption as a percentage of the total was 7.3%. No other European country, or the U.S. is anywhere close.
The integrated plan involving reduction of current dependency plus the incorporation of renewables includes the construction of a smart electric grid which will cut energy consumption by almost 30% by 2030. That alone will cut billions from the current energy imports. Making optimal use of Germany's natural wind resources concentrated along the northern coastlines, huge offshore wind parks, placed in the North Sea, should have the capacity to generate as much as 10,000 MW, feeding electricity into a smart national grid able to transport the energy from the north and east of the country or from the south and west with optimal efficiency using high voltage direct current. Within 12 years, 30% of Germany's electric consumption will be coming from renewable energy, with wind contributing 15%, hydropower 4%, and by 2015 solar power is expected to be affordable enough to become commercially viable (Burgermeister).
"The technical capacity is available for the country to switch over to green energy, so it is a question of political will and the right regulatory framework. The costs are acceptable and they need to be seen against the huge costs that will result if Germany fails to take action to cut its carbon emissions," he said. He said that Germany plans to use all the renewable energy sources at its disposal -- wind, solar, geothermal, hydropower and biomass -- in an optimal mix.
With new research institutes and projects constantly being launched across Germany, many more breakthroughs can be expected, helping Germany to become the world's first green energy economy (Burgermeister).
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