Biomass: Biodiesel Electricity
Most forms of biofuel can be used for generating electricity in much the same way that oil, coal and gas are used - through burning. As with fossil-fuel electricity generation, the use of biofuels for electricity also results in carbon emissions. As supporters of biofuel-based electricity will argue, the difference is that these fuels are renewable whilst the standard fuels of oil, coal and gas are not.
Moreover, many of the biofuels generated are taken from sources such as garbage, sewage and waste vegetable oil and are in effect recycling matter which would otherwise have been left to decompose in landfill. Though not entirely environmentally friendly, biofuel-generated electricity is certainly preferable to using precious fossil fuel resources which are rapidly diminishing.
Homes And Businesses
Back-up and small scale electricity generators are becoming increasingly popular in remote areas or in districts where power outages are common. While such generators would once have been powered by standard diesel it is now possible to use biodiesel or to purchase biodiesel-specific generators. In order to make the most of biodiesel's potential many users have installed combined heat and power generators. These generators take biodiesel as the fuel for the engine which not only powers a generator for electricity but which also uses an exhaust gas heat exchanger and heat recovery system to heat internal spaces.
Sometimes referred to as micro co-generators or mini co-generators, these machines can be called upon to produce between 5 and 500 kWe and are suitable for installation in houses and small businesses. The British government has acknowledged the usefulness of Combined Heat and Power (CHP) and has set down a target of at least 10,000 MWe of installed CHP by the year 2010. In doing so they have also established incentives, such as grants, VAT reductions and exemptions from the Climate Change Levy.
Large-scale production of biofuel generated electricity for inclusion into the mains grid is a possibility that has been discussed by a number of governments. Biodiesel presents two key problems in terms of the fuelling of industrial-scale power-plants however.
Firstly, biodiesel is predominately used for automobile fuel and the growing petrol prices will only serve to increase demand for this renewable alternative. Second, biodiesel is presently more expensive than fossil fuels such as oil and coal and cannot be produced in large enough quantities to supply industrial-scale power-plants for undetermined periods.
The solution that many large businesses and governments are investigating is the use of biogas. Biogas can be purified to the quality of natural gas and can be fed through gas lines without the need for extra infrastructure. It also has the potential to be produced in much larger quantities without significant strain on the environment (it can be obtained from garbage and sewage, for instance, or from algae). Whilst biodiesel presents an ideal solution for small-scale electricity generation it would appear that the future for power-plant generation is with biogas.