5 things you always wanted to know about bioenergy, but were too afraid to ask

To begin with, what is bioenergy?

Bioenergy involves the use of organic (very often plant-based) materials to generate energy for heat, electricity and transport. In some cases, bioenergy provides emissions reductions compared to fossil fuels, thereby helping to tackle climate change. In other cases it doesn’t result in these savings, or even increases emissions, and it can also pose risks to wildlife.

That’s why RSPB is joining other environmental organisations across the world today in calling for bioenergy that protects wildlife, forests and the climate, and for risky practices to be brought to an end.

But what role does bioenergy play in our energy system, why does it pose risks, and which kinds of bioenergy can help wildlife?

1. In the UK, in terms of renewable energy (heat and electricity) input bioenergy contributes 71%, compared to 29% from solar and wind. This includes types of materials such as ‘plant biomass’, ‘domestic wood’, ‘sewage gas’ and ‘transport biofuels’. It’s important to note that this is the input of energy. When it comes to the energy used by consumers (the energy output), bioenergy was responsible for just over one third of renewable electricity.

2. Bioenergy is made from all sorts of materials, from maize crops to animal sludge, to hardwood trees cut down abroad and turned into wood pellets. It is used for heat, electricity and transport in the form of a gas, a solid or a liquid. In 2015 the UK imported 2.7 million oven dried tonnes of wood from North America, which is used predominantly in power plants, and used 370 million litres of biofuels for vehicles (made mostly from used cooking oil and sugar beet), just under 3% of all the fuels used for vehicles in the UK.

3. Bioenergy can help wildlife. In the UK, many of our broadleaf woodlands have fallen out of management which can affect woodland wildlife like fritillary butterflies. While carbon risks of using trees for energy would need to be carefully managed, brining these woodlands back into management could provide a useful way of helping declining woodland species. The RSPB has successfully trialled the use of material from its own nature reserves, such as our reedbeds, as a bioenergy material.

4. But some kinds of bioenergy can pose risks to wildlife. The use of trees or crops to generate energy relies in many cases on the availability of land.  In April this year I travelled to the southeastern United States. Millions of tonnes of wood pellets are produced there every year and shipped to Europe, including the UK, to be used for energy. I saw the impacts this is having on some of the incredible forests there, which are being logged to produce pellets. I saw with my own eyes the bald eagles, turtles, great blue herons and egrets that live in some of these magnificent wetland forests.

A clearcut in a wetland hardwood forest in the southeastern USA, that has been cut down and turned into wood pellets to be used for energy in the UK; credit: Matt Adam Williams

5. It can be worse for the climate to use bioenergy than to use fossil fuels. Burning trees for energy releases carbon dioxide straight into the atmosphere. Because wood is less energy dense than coal, more carbon dioxide is released than by fossil fuels. This carbon dioxide might eventually be recaptured by new trees, but this can take years, decades or even longer, and we should be reducing emissions right now. The Department of Energy and Climate Change science team produced a detailed analysis of this a couple of years ago reaching this conclusion, and we also produced our own report. In fact, evidence suggests that using whole trees can be up to three times worse for the climate than coal even forty years later. We have long been asking decision-makers to introduce new regulations to reduce these risks, and to stop counting bioenergy as 'zero carbon' when it so clearly isn't.

If you would like to find out even more about bioenergy, this recent piece by New Scientist may be of interest. And prominent climate change campaigner Bill McKibben also recently wrote this piece.

Our friends at the Natural Resources Defense Council have published a report this week on why other kinds of renewable energy can be more cost effective than bioenergy too.

Calling for support for sustainable bioenergy was one of the ten recommendations in our recent Energy Vision report, setting out how the UK could meet its carbon reduction targets using renewable energy in harmony with nature. You can read the report here.