What goes in must come out…
Because anaerobic digestion (AD) is a closed system all the inputs and outputs can be accounted for. A mass and energy balance can therefore be calculated for any AD system.
What this means is that if you put in all of the UK’s domestic food waste this would generate enough electricity for 350,000 households.
Another way to look at it is to see one household’s electricity consumption (0.5kW of continuous electricity generation) being generated from 6-8m3 per day of biogas. This in turn would come from;
- manure from 5 dairy cows
- sewage sludge from 100 households
- kitchen waste from 75 households
Biogas, a Renewable Energy
Government continues to promote energy from renewable sources and as the market opens up for “green” electricity, biogas becomes a valuable commodity. Biogas from anaerobic digestion (AD) offers a great potential for providing electricity, heat and transportation fuel.
In addition to simply generating renewable electricity localised production means a reduction in transmission losses and strengthening of the national grid.
By replacing fossil fuels such as coal and oil, biogas can reduce the pollution causing climate change and acid rain. As a carbon neutral process, AD lowers the levels of carbon dioxide in the atmosphere.
There is great potential to generate revenue from the AD of organic wastes. Using all agricultural waste produced there is the capacity to generate twice the energy requirement of the agricultural sector. At current renewable energy electricity market prices, there is an opportunity to make £10 to £20 from only one tonne of organic waste.