Today we have announced successful completion of G59 (first electricity supply to grid) at our two latest Anaerobic Digestion (AD) facilities; securing their tariffs for the next 20 years. The two new plants in South Wales and North London will strengthen the network of food waste facilities that Agrivert operate to a total of 5, increasing our total food waste recycling capacity to 250,000 tonnes per annum and our geographical coverage to span Hertfordshire, London and the South East, Oxfordshire and South Wales.
Using food wastes produced by local householders, food manufacturers and retailers we produce a total of 13 MW of renewable electricity which is enough to power approximately 25,000 local homes.
This was a particularly complex year of construction for the business as we simultaneously delivered the construction of our own 2 new facilities, alongside the build of a second AD plant for Severn Trent Water (having built Severn Trent’s first food AD facility at Coleshill in 2014).
Recent changes to government policy on renewable energy tariffs meant that all 3 facilities were under pressure to complete construction and achieve G59 in record timing in order to secure any ‘feed-in tariff’ (FIT) subsidies. In previous years, a business missing a G59 deadline to secure FITs would have suffered a reduction in the amount of tariff that they were eligible to claim. However the government has proposed effectively ending the FIT scheme for any plant producing more than 1MW. The impact of missing the G59 deadline for larger plants is the loss of the right to claim any subsidies making a plant financially unviable.
Instead the Renewable Heat Incentive (RHI) scheme will cover any new facilities that are built over 1MW in the future. RHI remains viable for gas to grid projects, yet the National Grid provides no guarantees to offtake the gas produced by a plant, thus significantly increasing the level of risk involved and making securing investment far more challenging.
Our new South Wales and North London facilities will provide a cost effective and sustainable outlet for up to 100,000 tonnes of food waste each year, powering 12,000 homes with the electricity produced. Furthermore the nutrient-rich biofertilisers produced by each plant will be used to benefit the surrounding agricultural land in place of petro-chemical derived fertilisers.
Alexander Maddan, CEO Agrivert said, “I am delighted to see us mark our success on this important milestone for the industry and secure the future of our latest AD plants. These facilities are likely to be the last of only a handful of food waste AD plants that remain to be built in the UK under the FIT scheme. Our construction and engineering team have demonstrated tremendous commitment through a busy period; managing 3 separate AD build projects and delivering this latest pair in a record 9 months construction period. Both plants will provide a stable and truly sustainable food waste solution to local communities and businesses alike and we look forward to opening the gates in the coming weeks.”
The chance of being struck by lightning is calculated as a one in 30,000 year event. Having been recently hit, Agrivert is pleased to report that we have survived without any injuries or damage to our local environment. So what happened and what lessons can be learnt?
At 5.20pm Thursday 16th June 2016 our Wallingford AD facility suffered a direct lightning hit during an aggressive storm. It instantly ignited c.1200m3 of flammable gas stored in the roof creating a spectacular 45 metre flare which was captured on camera by a local resident who was filming the storm (BBC News footage). This burnt out quickly leaving smaller fires burning until the roof membrane had burnt out. All were extinct by the time the fire brigade arrived 15 minutes later.
The remaining digesters were still producing approx. 1000m3 of gas/hour, so continuing to consume this was the safest course of action. Once explained, the fire brigade teams agreed to restart the engines which had tripped out during the event.
Benefiting from more digesters than the industry average, we isolated tank 3, whilst using the others to help the site to keep operating. One of the isolation valves were heat damaged resulting in a slight gas leak which we sealed this within 3 hours; most of which were spent sourcing appropriate parts which we didn’t hold in stock.
We ordered a new roof immediately, using the remaining 3 tanks to process normal feedstock volumes whilst we awaited its arrival. Normal waste acceptance was resumed the morning after the strike and we were back up to our usual 97% power output just 24 hours later. By day 14 repairs were completed and we are back to usual operating standards.
We draw two significant lessons:
- Our extensive emergency plans are written for an internal audience. Simplifying these for an external audience could have expedited handovers to the fire crews and between their shifts/brigades.
- A more comprehensive array of seals in our stocks would have been an inexpensive way to expedite our recovery.
We are now reviewing lightning risk assessments at all sites but this is complex and there are various approaches to protecting a plant. In addition, on this occasion, the fire brigade’s opinion was that the lightning bolt missed 2 nearby taller metallic conductors due to the sheer volume of atmospheric water providing a conduit to the top of our digester roof; demonstrating that the incident was largely unavoidable regardless of the type of protection we had in place.
In summary, whilst this was not a welcomed test, the experience has proved that our emergency procedures work well and our plants can remain safe and resilient; keeping our staff, the environment and the local community safe whilst providing continuity of waste acceptance and maintaining healthy power production in even the most unexpected of circumstances.
“I am very pleased with the outcome of what could have been a far more serious incident. Our staff performed fantastically, our customers, neighbours and regulators are happy and this can now become a great case study demonstrating the resilience of our plants” Alexander Maddan, Chief Executive.
Our West London AD facility was recognised as the industry’s “Best food waste AD plant” for a second year running and our dedicated operations and maintenance team was awarded “AD team of the year”.
According to Ofgem data, our three AD plants are the top performing food waste plants in the UK. Over the past year each site consistently achieved over 96%+ efficiency in power generation (% of base load capacity). This compares with an industry average of 71%. All three sites combined have an availability rate of 99.9%, with just one of the facilities being unable to accept waste for an afternoon over its 5 years of operation. This level of plant performance is due to Agrivert’s well-designed and resilient plants combined with the dedicated and experienced team that ensure the seamless running of the plants.
Agrivert’s next phase of growth will see a further 2 plants added to our infrastructure portfolio; North London AD (London Colney) and Stormy Down AD (Bridgend in Wales). Both plants will be open to accept food waste deliveries in the last quarter of 2016, adding a further 100,000 tonnes to our annual food wast processing capacity.
“We are delighted our performance has been recognised by wider industry and we look forward to showcasing our next phase of growth in the coming months”. Harry Waters, Commercial Director.