This group brings together the best thinkers on energy and climate. Join us for smart, insightful posts and conversations about where the energy industry is and where it is going.

Post

The Limits of Biomass: UK Energy Needs

A simple thought experiment. What if instead of building the 3.2 GW Hinkley C nuclear power station, the UK built a biomass plant instead? We would need to do two things: build the power plant and gather up the biomass for the plant. The first is not a major problem. Land requirements for a biomass aren’t too bad. The latter on the other hand is a problem, and not a mild one.

As Vaclav Smil points out:

Even with an intensively cultivated plantation of fast-growing trees, a wood-burning electricity generation plant would not have power densities higher than 0.6 W/m2, and for most operations the rate would be below 0.5 W/m²

Wind farms have a power density of roughly 2.5 W/m², or about 5 times greater than biomass. As I showed in an earlier post an offshore wind farm would have to be something close to 1,200 km² to provide as much power as Hinkley C.. So, a back of the envelope calculation would indicate that our biomass plant would need to be about 6,000 km², or more accurately 5,200 km² assuming a power density of 0.5 W/m². The United Kingdom has a surface area of 243,610 km², so this would already be taking up slightly over 2% of the UK’s land surface, and this is to provide only about 7% of the UK’s electricity.

What if we expanded biomass to provide all of the UK’s electricity? UK electricity demand averages about 40.6 GW throughout the year (source). To meet this we would need biomass plantations to cover about 81,000 km², essentially one third of the UK (or more likely somewhere else)). To put this in perspective only 12% of the UK is currently forested. The island of Ireland has a total surface area of just over 81,000 square km², so the map below will give you a good idea of just how much land is needed to supply all of the UK’s electricity from biomass. So, it is quite clear that there are some sharp limits on how much electricity you can get from biomass.

ireland - Google Maps

 

Robert Wilson's picture

Thank Robert for the Post!

Energy Central contributors share their experience and insights for the benefit of other Members (like you). Please show them your appreciation by leaving a comment, 'liking' this post, or following this Member.

Discussions

Nathan Wilson's picture
Nathan Wilson on Mar 28, 2013 7:45 am GMT

Before assessing the amount of land available for biomass for electricity, it should be remembered that in a non-fossil-fuel powered society,  biofuels must also replace much of the oil used in transportation:

- all that is used for aviation (since hydrocarbon fuels are the only ones that can power transcontinental airplanes),

- whatever fraction of cars, trucks, trains, and boats that won't transition to batteries, hydrogen, or ammonia fuel.

 

Also, it is often suggest that biomass powered electric plants be used as low capacity factor backup plants for a mostly solar+wind system.  That would save wood and land, but note that according to the US EIA, a biomass plant has a capital cost of 3.2 times that of an equivalent combined cycle natural gas plant, which makes biomass much less attractive in this application than the levelized cost suggests.

Get Published - Build a Following

The Energy Central Power Industry Network is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other.

If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.

                 Learn more about posting on Energy Central »