From Waste to Wattage
Cenin are delighted to have Severn Trent Green Power’s anaerobic digestion plant based at Parc Stormy. It is the first AD plant of its type in Wales, enabling local food waste to be turned into electricity and fertilizer as part of a circular economy.
The plant, under its original ownership by Agrivert, was opened by First Minister of Wales, Carwyn Jones, on the 2nd December 2016. The facility takes in organic wastes such as food waste and surplus crops from the local communities and farms and turns them into bio-gas to power a 3MW electrical generator. Organic waste like this would previously go to landfill where it would decay and release harmful greenhouse gases. Instead, bacteria in the AD tanks break down the food waste producing gas and an organic digestate liquid fertilizer . AD is a very reliable renewable energy source because it is not weather dependent, therefore the generator produces a constant 3MW of electricity 24 hours a day, 365 days of the year, which is enough to power 5900 homes. The generator has a large air cooling system. Instead of just releasing all that heat into the sky, waste heat is piped to Cenin’s minerals drying building to be used in low-carbon cement production.
The only bi-product is an organic digestate liquid fertiliser which is spread on our neighbour’s 3000 acre farm. Richard Anthony, the farmer, has achieved excellent yields and no longer uses fossil based fertilisers. Some crops are grown as backup feed to balance the pH levels in the AD tanks, and others for food, thus completing the circle of sustainable production.
AD Plant Key Facts
• Construction time: 9 months
• Commissioned: September 2016
• Achieved 90% power: November 2016
• Design power output: 3MWe (2 x Jenbacher 420 engines)
• Facility footprint: 2.8 hectares
• Waste input: solid, liquid, packaged and unpackaged food waste
• Digestion retention time: circa 75 days
• ABPR certified
• PAS110 approved process
• Digesters: 4 x 5,800m3 tanks
• Digestate storage: 1 x 5,800m3 tank and 20,000m3 off-site lagoon
Our neighboring farmer Richard Anthony has state of the art equipment to pump and spread the liquid digestate directly to the roots of his crops. The liquid digestate is pumped from the holding lagoon to the spreader, where it is fed through tubes to the base of the plants. The tractor uses GPS to position the spreading accurately so that no area of the field is missed or done twice. The rye crop planted this year looks lush and healthy, please click on the photos below for a more detailed image.