In the latest BERR document on renewable energy, currently going through its consultation phase, there is the suggestion that the least expensive option to deliver the UK’s 2020 renewable energy goals lies with bioenergy (energy produced from the direct or indirect combustion of biomass material such as energy crops, wood and waste and biogas) delivering electricity and heat.

Clearly, BERR is not suggesting that the UK relies on cereals and edible oils to generate electricity as well as transport fuels – this debate still has a long way to go – but is focussing on new energy crops, some to be grown in the UK and some to be imported, that will not compete with food production.

One major reason for a focus on biomass fuelled power stations is that they can produce around three times more energy than a wind farm for the same amount of generating capacity.  It is also reliable and constant and can be scaled up or down to meet consumer demand.

The government is clearly recognising the benefits of biomass and is proposing changes to its Renewable Obligation Certificate programme to further increase the value of energy that is generated from biomass sources.

With the current delays in commencing the replacement programme for the UK’s nuclear power stations, such support for biomass fuelled power stations that can be constructed within a three year time frame and help overcome the current probability of electricity shortages in the UK by 2015 is more than welcome.

When the world’s biggest biomass plant goes online in Port Talbot at the end of the current decade, it will generate 350 megawatts and contribute 70% of the Welsh Assembly’s 2010 renewable electricity target.
The £400 million project, given government approval in November, will be fuelled by wood chips from renewable sources in the US and Canada and will generate enough electricity to power one in every two homes in Wales.
The project, from London based Prenergy Power will produce base-load electricity 24/7 for a period of 25 years.

Dream or Reality?

The world consumption of fossil fuel is currently 84 million barrels a day and set to increase steadily as the populations of China and India take to the roads in ever increasing numbers. Assuming there is no slowdown, the known oil reserves in the ground will last for 40 years or so. The most optimistic bio fuels programme, promoted by the EU, suggests we may be able to replace 20% of our oil needs by 2020. So is it just a dream that we will be able to fully replace fossil fuel in the next half century?

There is a growing body of opinion that believes it is possible but who or what will lead the charge? Will it be wood, cereals, rapeseed? No. A lot of smart money is going behind algae, yes, that same green slime to be found in village ponds and sewage farms.

A massive body of research was undertaken in the United States during the 1980’s and 90’s by the Office of Fuels Development. Known as the ‘Aquatic Species Programme’ it focused on investigating whether high-oil varieties of algae can be grown specifically for bio-diesel production. The research was halted due to budget cuts with the US putting its available money behind development of bio ethanol. However, before it stopped, the research programme indicated that 7.5 billion gallons of bio-diesel could be produced on 500,000 acres covered by algae ponds, shallow salt water pools that the research had used for growing the algae. Given that current US transport fuel consumption is the equivalent of 140 billion gallons of bio-diesel each year, the original research suggested that an area of up to 30 million acres would be needed to grow sufficient algae to completely replace fossil fuel for US transport use. This sounds like an enormous area but to put it in perspective, the US has 2.3 billion acres of land of which 450 million acres is used to grow crops and 580 million acres is used for grassland pasture.

Today, a number of major companies and institutions are addressing the questions raised, but not answered, by the original algae research. These are primarily; how to encourage the growth of high oil algae, overcoming its vulnerability to temperature variations and avoiding high evaporation losses. Once these issues are resolved, the huge advantage of algae over other vegetable oil feedstocks is that it is capable of producing up to 40 times the volume of oil per acre than crops such as rapeseed, sunflower or soya. A lot of the current research work involves the use of photobioreactors and is linked to other processes such as waste stream treatment and power plant emissions reduction (algae actually feeds on CO₂). 

Michael Briggs of the University of New Hampshire has calculated that the cost of building the less efficient algae farms in the US to replace fossil fuel entirely would be in the region of $300 billion and the operating costs per year around $46 billion. This equates to the $100 billion plus spent each year by the US on foreign oil and takes no account of the money spent on policing those areas of the world, particularly the Middle East, that the US is dependent on and that are vulnerable to terrorist attacks.

So, can the dream of replacing fossil fuel with a more environmentally friendly alternative actually become a reality? Watch this space.