eco otaku

Its getting quite cold here in Japan and unless your keen on skiing, the best thing to do in winter is to head to an Izakaya, a Japanese style bar where you can chat to friends over a warm sake. One such conversation on the weekend that has just passed was a discussion on how the world is to cope with the growing demands of energy in the wake of global warming. My friend was largely unaware of sustainable energy sources such as solar, wind, geothermal, wave power and hydro, so I thought I would give a small overview of the alternatives to fossil fuels. By sustainable energy, I was referring to energy that is renewable, and therefore truly sustainable.  

Solar

Solar used to generate electricity can be used to power a house, heating, cooling, machinery, anything really. Solar power is harnessed in two main ways, solar-thermal, and Photovoltaic.

Photovoltaic solar power is the dark panels that can be seen on roofs of houses or attached to concept cars or even some calculators. These panels a made up of silicone cells, a product of sand that is able to harness electricity. Each panel has two layers of silicone cells, one side that is positive, the other that is negative. When light is shined on the cells, the electric field between the two layers of cells causes electricity to flow. The system is dependent on light not sun, so even days when its entirely cloudy, electricity can be generated from glare from the clouds.

Solarthermal is a little different and more suited to an industrial style of harnessing energy. Through this process, sunlight is directed to a single area using mirrors where it creates steam that powers fans that generate the electricity.

Wind

Wind energy is harnessed by large turbines that are positioned in valleys or areas that encounter continuous wind currents. While not the only design, the most common is a three blade that when spinning generates electricity with the help of the magnets and copper wise inside the turbine.

According to a report, The Global Wing Energy Outlook 2006, wind energy could make up to 1/3 (34 percent)  of the worlds energy by 2050 and if wind energy is harnessed to this effect, it would be able to  remove up to 113 billion tons of CO2 from the atmosphere. In China for instance, development of wind turbines is increasing rapidly. It has been suggested by Professors from Harvard and Beijing’s Tsinghua University that wind could power all of China until 2030. Peter Farley of Technology Review says;

China has doubled its installed wind power capacity every year for the past five, and is on pace this year to supplant the United States as the world’s largest market for new installations. But researchers from Harvard University and Beijing’s Tsinghua University suggest that the Chinese wind power industry has hardly begun to tap its potential.

Geothermal

Geothermal is actually just what its name suggests, earth heat. The core of the earth is extremely hot. Large wells at about 1.5kms below the surface boil water and other liquids to generate large amounts of steam which is channeled into large turbines that harness the electricity. According to Greenpeace, geothermal is a great resource that is largely untapped.

Geothermal power generation causes virtually no pollution or greenhouse gas emissions. It’s also quiet, and extremely reliable. Geothermal power plants produce electricity about 90 percent of the time, compared to 65-75 percent for fossil fuel power plants.

Unfortunately, even in many countries with abundant geothermal reserves, this proven renewable energy source is being massively under utilized.

Wave Energy

Tidal power is somewhat similar to wind turbines, but instead the turbines are positioned underwater in channels that can maximise the power and kinetic energy transfer from the tides. Seawater is actually 800 times more dense than air, this means that a turbine is far more efficient than a wind turbine. Its also been suggested that while fossil fuel energy efficiency is rated at a maximum of 30 percent, tidal efficiency is 80 percent. Time magazine says;

With 70% of the earth’s surface covered by the restless tides and currents of the oceans, the idea of harnessing that movement to serve the planet’s energy needs is too tempting to ignore.

Hydro Power

By using a dam, water is released and channeled through large turbines that generate large amounts of electricity. While hydro is a renewable source of energy, it can have quite potentially harmful effects on the plant and animal life at either end of the cycle.

The best thing about these sources of energy, once they are up and running, the energy they produce is free and renewable. It really makes you think why so much is invested into fossil fuels when there are already sustainable sources of energy that are also alot more efficient. Australia in particular has some great sources of solar and wind but is far from the leader in the industry.

http://solarpowernotes.com/renewable-energy/tidal-energy/tidal-energy.html

http://www.technologyreview.com/energy/23460/page1/

http://www.greenpeace.org/international/campaigns/climate-change/solutions/geothermal

http://www.greenenergyhelpfiles.com/electrokinetics.htm

Interesting video about tidal (wave) power