An introduction to energy crops.

Energy crops are crops which are grown for their Biomass (biological matter) and produce renewable energy for heat, electricity and transport fuel.

An increasing number of farmers are now growing energy crops, some have even set up their own company ReGro to help them manage the process.

Biomass or energy crops can generally be divided into two main areas:

BioEnergy - crops grown for power generation.
- Willow Page
BioFuel - crops grown to produce fuel for vehicles
- Biofuel Page

Bioenergy.

These are crops grown for power or heat generation and include:

Short rotation coppice.

This consists of willow or poplar species which are harvested to produce wood chips or billets. These are then burnt to produce heat or electricity. They are harvested every 3-4 years.

Miscanthus (Elephant Grass)

This is similar to bamboo and is very fast growing. Harvested annually the chopped crop can be burnt to produce heat and electricity.

Whole crop silages

Maize and other whole crop silages can be converted by anaerobic digestion into a biogas that can be used to produce electricity and heat.

Biofuels.

These are crops grown for transport fuels:

Oilseed rape

Oilseed rape is grown for the production of biodiesel. Biodiesel is a natural replacement for mineral diesel. Normally biodiesel and mineral diesel are mixed to produce a blend.

Cereal Crops

Wheat and other cereal crops can be grown for the production of bioethanol that can be blended with petrol.

Sugar beet

Sugar Beet can be grown for the production of bioethanol and biobutanol, both being blended with petrol.

The uptake of some of these crops has been very low in the UK, despite much meia and political interest and even criticism from some. One of the main arguments against being that the world cannot grow enough food, so using some of the land to grow fuel is not appropriate

Despite media and political interest, the use of energy crops in the UK remains in its infancy and far behind that of many other countries. However, energy cropping in agriculture is just a part of the bigger biomass picture. Biomass is also derived from forest residues and wastes (straws, slurries, sewage, food etc), all of which can be used to produce bioenergy. The EU estimates that by 2010 around 60% of EU bioenergy will be produced from waste with agriculture and forestry producing about 20% each. However, over the following decades most of the increase in bioenergy production will come from agriculture with energy crops playing an increasingly important role on farm.

Although energy cropping is often regarded as a new activity, it should not be forgotten that for most of the past 6000 years, coppicing provided our ancestors with a sustainable source of wood for heat. It is only in the last two centuries with the adoption of cheaper and more convenient alternatives that the sustainable practice of coppicing has been displaced.