The hidden power of leftovers: consuming renewable energy.

I love eating, although my relationship with food hasn’t always been that healthy. When I finally saw the light and lost a heap of blubber ─ and kept it off ─ I grasped the notion of portion control and took an avid interest in what I actually put in my gob. As part of this awakening – in which I successfully reversed type 2 diabetes – I began to prepare food from scratch using healthy ingredients; however, before you picture me as some sort of budding Gordon Ramsey, let me be frank with you ─ I can prepare a wicked soup and that’s about the height of my gastronomic skills.

My soup maker is the magical technical cauldron that manages the whole preparation process. All I have to do is chop up my raw materials and bung them in with a stock cube and water, chucking a minimal amount away into the food waste caddy – a relatively new addition to the Kitchenalia range that apparently makes me an environmentalist. A member of the green team. But what did I really know about this movement and how had my leftovers surreptitiously occupied such a special temporary resting place on the worktop? As I slurped my soup, I pondered the gap in my knowledge and wondered what the onward journey of my scraps entailed and how this reasonably small gesture was helping the planet…

The next day I visited my mate Kiran who was toiling away on his impressive allotment ─ a veritable cornucopia of vegetables nurtured from seeds. Happening to mention my love affair with soup, he offered up some of his harvest festival and within moments I had my bounty: climbing French beans, beetroot, spinach, Swiss chard, courgettes, and purple basil for flavouring. Hotfooting it home I chopped it all up, and put it in my meal making marvel, placing the minimal spoil to one side. On this occasion I felt rebellious and selected the hitherto untried “chunky” setting, resulting in a pretty heavy-duty broth. Nonetheless it was gorgeous, and I gobbled down my portion-controlled bowl full – freezing enough to feed the rest of the street too. As I did so, I realised my sense of discovery wasn’t just the unique taste of my exquisite lumpy scarlet creation but the first base on my eco-friendly expedition.

Placing the food debris in a liner (on this occasion a used bread bag) before putting it in the outside caddy I was poised – awaiting the subsequent collection by Bracknell Forest Council. Would it be Dame Foodie, Binderella, Truck Norris, Hank Marvin, or The Food Dude ─ the fleet of food waste vehicles named following an imaginative branding competition which earned the respect of Dame Judie Dench (or fictional M to James Bond and the rest at MI5). Back in the world of reality I bade farewell to my excess and continued my expedition to the next significant part of this voyage of enlightenment – Wallingford Anaerobic Digester Facility in leafy Oxfordshire ─ on a crisp, chilly, slightly misty morning reminiscent of a scene from my favourite Sherlock Holmes tale: Hound of the Baskervilles.

Meeting my effervescent guide Debs Barnacle (aka my Doctor Watson), Severn Trent Green Power Client Liaison Manager, in the carpark, she handed me a reflective jacket and placed the comprehensive operations into a narrative that even I could understand: “It basically replicates your stomach.” As the soft breeze bathed me in an odour that reminded me of the final process of emptying mine, I was cognisant that this plant was in the business of processing food waste and a healthy whiff of rotting fodder was part and parcel of this special eco-empire. Debs continued as a huge lorry containing around twenty-six tonnes of food waste rattled into the compound, “Each vehicle is individually weighed on the weighbridge before entering the main reception area.” I was astonished to learn that the ultimate energy transfer of this modest complex generated enough electricity to power almost five thousand homes. Alongside this incredible output was the production of fertiliser that was subsequently whisked away to nourish the growth of more sustenance for the human food chain. I had yet to set foot within the main processing plant and already I was gobsmacked at the ingenuity that transforms discarded grub into energy alongside nurturing more food supplies.

Once inside and acclimatising quickly to the assault on my delicate masculine nostrils, I was surprised at how low-tech the machinery looked, with an almost Heath Robinson feel about it. The reception bunker – with a mighty eighty tonne capacity – housed the familiar food waste bags, where my soup remnants would have inevitably ended up. Debs explained the onward transmission into an impressive Archimedes screw which pushed the contents towards a hammer mill that bashed the waste to a pulp before traversing the next phase ─ the separation of the plastic food bags and contents. At this juncture the mineral waste was collected – to be processed in another plant to create, amongst other things, products for the construction industry – whilst the green matter was latterly mixed with waste fats and oils to create an authentic witch’s brew. Unsurprisingly there is around a forty-percent uplift in food waste in January as Brits celebrate the biggest food fest of the year in December ─ Christmas ─ and subsequently dispose of the excess of their overly optimistic food haul.

Three huge pasteurisation tanks dominate the opposite side of the hanger and Debs outlined the chemical process that turns some of the food waste sludge into fertiliser whilst eliminating any potential biohazards. An ongoing partnership with the University from my home city and centre of the known universe (in my humble opinion anyway), Nottingham, provides the ongoing research and development process that will always keep this facility and the broader Green Power business at the cutting edge of sustainable energy technology.

Venturing outside, the immediate vicinity was overshadowed by five huge concrete digesters – the powerhouse of the energy operations – where the bio slush was stirred and warmed by recycled heat from the plant to create methane gas which is injected into two turbine engines. Here the magic of energy transfer creates electricity, with the overall journey from caddy bag to the National Grid taking around ninety days. My food waste contributed to this miracle of renewable energy, and I felt a sudden pang of pride in that I had finally realised my green credentials and now better understood the concept of this extraordinary process – the only credible approach to our future energy security and the obvious need to wean us all off more damaging fossil fuels.

As we walked back to our initial rendezvous point my pragmatic partner on this journey of discovery provided the final persuasive proof: “Anything that is destined for your gob can go into the food bin and be turned into power!”

Elementary my dear Doctor Watson!

© Ian Kirke 2022 & all uncredited photographs.
@ianjkirke