UN Sustainable Development Goal 7: Ensure access to affordable, reliable, sustainable and modern energy for all
How biogas contributes to the above goal:
- Peak Fossil Fuel: Globally, approximately 80% of energy is still produced from fossil fuels (International Energy Agency, 2015). With Peak Oil production expected to be reached in the next decade, finding alternative, sustainable sources of energy has become imperative. Anaerobic digestion can play a part in filling the gap by utilising waste-derived biogas to produce energy (electricity, heating, cooling, transport).
- Substituting fossil fuels for heat: Both residential and industrial establishments rely on natural gas or oil to meet their heat requirement. Upgraded biogas produced from waste, which has similar properties to natural gas, can support this requirement and reduce dependence on fossil fuels.
- Substituting vehicular fuel: Biogas upgraded to compressed or liquefied biomethane can be used to fuel natural gas vehicles like automobiles, heavy goods vehicles (HGVs) and buses. As of 2015, there are an estimated 22 million natural gas vehicles on the road that can be switched to biomethane without needing modifications (NGV Journal, 2015).
- Decentralisation of energy: Anaerobic digestion offers an opportunity for decentralisation and democratisation of energy generation. Rural and remote communities which are not connected to the electricity and gas grids are able to produce their own from the waste and the agricultural residues that they produce and can become energy self-sufficient.
- Energy available when it is needed: Anaerobic digestion, once started and stabilised, produces biogas on a continuous basis independently of external environmental factors such as the sun shining or the wind blowing. Biogas when not required can be stored within the digester, in a small scale gas holder or injected into an existing gas grid. It can therefore be used to fulfil baseload as well as peak energy requirements in tandem with other energy producing technologies.
Rainbarrow Farm Anaerobic Digestion Plant, Poundbury, Dorset, UK
- Digests maize and grass silage, potato waste, food waste including chocolate and muesli
- Exports enough biomethane to the gas grid to fulfil annual heat requirement of 3,200 new build houses
- Generates electricity to cover parasitic load as well as export to the electricity grid
- Replaces inorganic fertilisers on the neighbouring farms growing the feedstock.
Linkoping Biogas Plant, Sweden
- Digests abattoir, industrial organic waste, manure from pigs and cattle and some household waste
- The biogas produced is upgraded to be used as vehicular fuel for:
- 64 public transport buses
- 12 public filling stations for private cars, taxis and distribution vehicles from different companies.
- World’s first biogas train run between Linkoping and Vastervik, Sweden
- Resultant emissions reduction from 4.7 million m3 of upgraded biogas is estimated at 9,000 tonnes CO2 eq. per year.
- The digestate biofertiliser produced is certified according to the Swedish certification system SPCR 120 and recycled to 17 nearby farms.