Sat, Mar 09, 2013 - Page 8 News List

Biogas a viable energy alternative

By Du Yu 杜宇

A lot of heated debate has centered on whether a referendum on the construction of the Fourth Nuclear Power Plant in Gongliao District (貢寮), New Taipei City (新北市), should be expressed in positive or negative terms. The public wants to know whether there are any alternatives, given the high risks involved with nuclear power.

Unfortunately, the government and the opposition have not been able to provide the public with the information it needs. Each has stuck to its own guns and no consensus has been reached. The debate will undoubtedly continue even after the referendum, sowing the seeds of further social conflict.

The nation imports more than 99 percent of its energy supplies and, as a result, fluctuations in world oil prices have a huge effect on the domestic economy. The public is still reeling from last year’s twin hikes in fuel and electricity prices.

Countries around the world are working hard to promote the research and development of renewable energy sources, such as solar, wind, hydroelectric, tidal, biomass and ocean thermal energy conversion. They are doing this because renewable energy resources are unlimited and widely available, and create a smaller carbon footprint.

Taiwan has a low usage rate of renewable energy, accounting for less than 1 percent of its total energy supply. The nation needs to develop renewable energy more aggressively, but should focus on one that fits its situation.

Biogas — a technology that uses biomass to produce electricity, is environmentally friendly and conserves energy — is a good example.

It involves taking huge amounts of agricultural organic waste, human and animal excrement, hay and household trash, and then, using anaerobic fermentation, turning these into biogas to power generators and produce electricity. The energy produced can provide electricity for homes, thereby cutting down energy consumption. It also solves the problem of pollution on farms due to the waste that is a by-product from livestock and poultry.

Compared with wind and solar power, biogas has many advantages, including convenience, as it is less affected by weather and environmental factors, and is cheaper to set up.

Research shows that a small wind power device costs three to four times more than a small biogas power generator that yields the same amount of power, while a solar power device is more than 22 times more expensive. The costs associated with biogas are mainly decided by things like the equipment used, gas surplus, gas production rate, the rate of electricity self-sufficiency and the materials used.

Germany is not only a world leader in environmental protection, it is also one of the most successful when it comes to biogas development.

Most German livestock breeders have biogas installations to turn large amounts of organic waste — one 500kg cow can produce 45kg of organic fertilizer daily — into electricity and thermal energy, as well as low-priced, high-quality fertilizer that can be used in place of petrochemical fertilizer, thereby reducing greenhouse gas emissions.

By doing so, farmers can satisfy their own electricity and heating needs, while the surplus power can be sold to the government in exchange for renewable energy subsidies. The Taiwanese government would do well to take a closer look at the German model. Animal husbandry is an important part of the nation’s agricultural industry, with average annual gross production exceeding NT$100 billion (US$3.4 billion), making it an important source of income in rural areas.

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