What are farmers doing to produce renewable energy?
Farmland has been used for both food and energy production for hundreds of years. Today, nearly 40% of farmers and growers are using the sun, wind, farm by-products and energy crops to produce electricity and heat for use on farm.
Two of the most used renewable technologies on British farms are solar PV panels for electricity and heat generation from biomass.
Farmers have a long history of using the sun’s energy to grow and dry crops. The development of solar power technology (often referred to as photovoltaics or solar PV) means light energy can also be captured to produce an electric current.
PV panels or modules can work for a long time (up to 40-50 years) and require very little maintenance. Solar PV is regarded by many experts as one of the most environmentally-friendly renewable energy technologies.
Many farmers have installed solar panels on their buildings and land. There are three main ways solar panels can be installed:
- PV panels mounted on top of existing roofs or integrated into new roofs and buildings
- Ground-mounted panels in unplanted areas – for example around the edges of fields
- Large arrays of panels across entire fields
Anaerobic digestion (AD) is the controlled breakdown of organic material in a closed ‘digester’ vessel. Anaerobic means ‘without air’, as opposed to composting, which takes place in the presence of air.
After 20 to 60 days, depending on the configuration and internal temperature of the digester, a methane-rich ‘biogas’ is produced. This gas is used for electricity and heat generation, and may also be upgraded for other applications. Another product of the AD process is an odour-free ‘digestate’ which can be spread on farmland as a fertiliser.
Material suitable for the AD process includes:
- Animal manure and slurry
- Energy crops such as maize or ryegrass silage and fodder beet
- Food processing by-products
- Food waste from retailers
- Biodegradable household waste