Energy consumption on farms
Running and maintaining a farm is a lot of work that often requires the use of heavy machinery, electricity or large amounts of water. How can we reduce the emissions from these activities?
In comparison to the emissions of CH4 and N2O, the emissions of CO2 from the farming industry are low compared to other sectors. In the UK, agriculture accounts for only 1.1% of the CO2 emissions. However, there are number of mitigation options, many of which can be applied outside of agriculture, too.
Figure 1: Solar panels on a cow shed in Switzerland. © Marie Dittmann.
The largest proportion of electricity is still created by the burning of fossil fuels, thereby emitting CO2, but there are ways to create electricity in a sustainable way.
- Photovoltaic: Using the power of the sun to create electricity is effective and sustainable and fitting solar panels to the roof also provides insulation from solar radiation. Solar panels work in direct sunlight but also create electricity on a cloudy day. Some small scale solar panels can also be used to power electric fencing or water pumps, and even serve as shade for animals in the fields.
In the last few years, as technology progresses, solar panels have become cheaper. If the power generated exceeds the need of the farm, the additional electricity created by the solar panels can be fed back to the grid and used by others, which the farmer will receive a payback for.
- Wind power: Although less common on a small scale, it is possible to create electricity from wind using turbines. However, setting up these systems is not as straight forward as solar panels and there is some public objection to wind turbines. As with solar panels, unused electricity can be fed into the grid.
Farming generally requires a lot of water – a resource that is likely to become more scarce in some regions in the future. Solutions for conserving and heating water both mitigate GHG emissions and save money.
Rainwater collection: This reduces the water bill and, on a small scale, water that is collected does not add to flooding caused by extreme rainfalls, which are likely to rise because of climate change.
Solar heating: Technologies are available that use energy from the sun to heat water. Generally water is pumped through a panel or tube installed on the roof, for heating before it’s pumped back into the hot water tank.
Counter flow systems: Milk leaves the udder at almost body temperature and needs to be cooled down quickly to prevent bacterial growth. Some modern counter flow systems work by milk and water (although physically separated) flowing past each other in opposite directions. This not only rapidly cools the milk, it also warms up the water.
From the sowing of the forage to the stacking of the milk in the shelf of your local shop, heavy machinery and transportation generates CO2 emissions. Think of all the machines and vehicles that are needed to sow the seed, spread fertiliser, harvest, ensile forage, feed the animals, muck out the shed, and transport the product. Here are some options that can help to cut down fuel consumption:
Efficient engines and transport routes.
Machinery run on methane produced in anaerobic digesters.
Biofuel: methane, ethanol, diesel and butanol can all be produced from waste biomass and used to power equipment. Although biofuel has gained a bad reputation in recent years because it can be associated with deforestation, biofuel can also be created by turning waste into fuel.
Figure2: The green structures are large digesters the approximate size of a two to three storey building. The pulverised food waste is broken down in these over a period of approximately three months to create digestate (liquid fertiliser) and methane (burnt to make electricity). © University of Reading sustainability team.
Inefficient heating systems within houses are responsible for using considerable amounts of fossil fuels, which result in the emission of CO2. The amount of fossil fuels burnt for heating could be reduced drastically by improving the insulation of buildings.
Efficient wood burners to heat a house could be considered carbon neutral - provided that trees and woody plants harvested for firewood are replaced with new ones which ensure the uptake of CO2 from the atmosphere.
Using wood to cook and heat can create problems in some developing countries though, when the wood is harvested directly from natural ecosystems and precious forests. In Madagascar, a project promotes the use of energy efficient wood stoves, which save about 60-80% of the firewood, reducing deforestation yet still providing renewable energy for the locals. You can read more about this project on the Chances for Nature website.
References and further reading:
- Bardi, U., El Asmar, T., & Lavacchi, A. (2013). Turning electricity into food: the role of renewable energy in the future of agriculture. Journal of Cleaner Production, 53, 224-231.
- Brudermann, T., Reinsberger, K., Orthofer, A., Kislinger, M., & Posch, A. (2013). Photovoltaics in agriculture: A case study on decision making of farmers. Energy Policy, 61, 96-103.
- Panwar, N. L., Kaushik, S. C., & Kothari, S. (2011). Role of renewable energy sources in environmental protection: a review. Renewable and Sustainable Energy Reviews, 15(3), 1513-1524.
- Edenhofer, O., Pichs-Madruga, R., Sokona, Y., Seyboth, K., Matschoss, P., Kadner, S., Zwickel, T., Eickemeier, P., Hansen, G., Schlömer, S. & von Stechow, C., (2011). IPCC special report on renewable energy sources and climate change mitigation. Prepared By Working Group III of the Intergovernmental Panel on Climate Change
- Ecological Stoves in Madagascar on the Chances for Nature website.
© University of Reading