Reposted from Science Omega online
As the world’s supply of fossil fuels dwindles, the search for alternative energy sources is vital. Biomass is one such energy source that is being touted as a good alternative to conventional fossil fuels. However, it is not without considerable opposition from those who argue that biomass could do more harm than good in the battle to reduce greenhouse gas emissions.
Biomass is energy created from the burning of biological materials such as plants and non-living things such as biodegradable waste. Anything that is alive or was alive a short time ago can be categorised under biomass, therefore trees, crops, animal and plant waste are all included.
The attraction of biomass in the fight against climate change is that it is carbon neutral. Unlike the fossil fuels, oil, gas and coal, which when burnt add to the net amount of carbon dioxide in the atmosphere, the CO2 that biomass produces when ignited is absorbed from the atmosphere by the crops used to make it, and so the net atmospheric amount is not increased.
“It is clear that for biomass to be part of a zero-carbon energy future, strict safeguards need to be in place to ensure that only sustainable sourcing occurs. “
Currently in the UK there are 20 dedicated biomass power plants that are producing a total of 1,092MW from a variety of sources including poultry waste and woody biomass. There are around another 30 at planning stage with a combined capacity of 5,000MW.
Given that 1MW can sustain 1,000 homes for an hour, that is a significant contribution to the UK energy mix. However like many energy sources, it is also controversial, as there are both advantages and disadvantages.
In recent years numerous organisations have issued warnings about the potential impacts of the mass production of biomass. UK-based organisation Biofuelwatch is currently protesting against plans by Drax power station in Yorkshire to convert half of their coal-fired power station to run on biomass. Whilst in practice this sounds like a green idea, “highly biodiverse forests in North America are already being clear cut to make wood pellets for UK power stations. This will only get worse as the industry expands.”
Biofuelwatch say that communities in South Africa are already losing access to land and water because biodiverse grasslands are being destroyed for monoculture tree plantations, some of which supply Drax.
Drax has the capability to produce 12.5 per cent of its output from renewable and sustainable biomass – the equivalent output of over 700 wind turbines. Drax says that ‘burning biomass at this level saves over two and a half million tonnes of CO2 each year.’
Wood has always served as a fuel source for fires and ovens, however technological advances mean that burning biomass can produce energy for everything from a power plant to an engine.
The advantages are that burning biomass is said to be carbon neutral, in that by growing and then burning it there is no creation of additional carbon monoxide. Biomass products are abundant and renewable; since they come from living sources and life is cyclical, these products potentially never run out, so long as there is something living on earth and someone is there to turn that living thing’s components and waste products into energy.
Another benefit of biomass is that we can use waste and thus reduce landfill to produce energy. However there are concerns that incinerating household waste depresses recycling and wastes resources, releases greenhouse gasses, and is often forced through against strong public opposition. Instead of promoting zero waste, incinerators rely on material for feedstock that should be recycled or composted. Incinerators create toxic emissions and hazardous ash, and therefore pose significant health risks.
It is clear that for biomass to be part of a zero-carbon energy future, strict safeguards need to be in place to ensure that only sustainable sourcing occurs. Otherwise, as the Centre for Alternative Technology’s Freya Stanley-Price points out: “We are getting rid of one environmental problem and replacing it with another.”
Friends of the Earth suggest a number of measures that include keeping the scale of biomass to the size of domestically available resources, using anaerobic digestion for the treatment of food and animal waste and focusing biomass use close to production.
In addition, there must be a joined-up, integrated approach to energy planning that considers the most efficient use of any energy generated and looks forward to managing energy demand.
“There are many things that have to be carefully considered and weighed when determining if biomass energy is a viable alternative energy source,” Stanley-Price says. “In a zero-carbon future we must make sustainable use of trees as fuel, and replant them as we harvest them – creating a continuous carbon cycle. Growing our own fuel also creates jobs and is ideal for strong, local economies.”
Read more: http://www.scienceomega.com/article/1099/burning-issues#ixzz2WBqMeRru