Mercifully steered away from a gut-related photo

By Michael Morrison

In China and parts of the Middle East it can be considered rude not to leave a few food scraps on your plate at the end of a meal, as otherwise it suggests that the amount given was insufficient. Thankfully most of the Western Hemisphere favours the ‘shovel it all down to show your appreciation’ approach to portion control though, so we clearly don’t have to worry about wasting food…

Or do we?

Here in Scotland, Food waste alone costs the average household £430 a year, mainly through over-zealous portion sizes, inefficient grocery shopping and a general disorganisation when it comes to planning our meals.

But of course it’s not just a domestic problem: supermarkets have been coming under increasing pressure to tighten their belts in an effort to reign in the £17bn worth of food binned each year. Curiously though, by emulating the human body itself we might be able to turn the tide on wasting our country’s abundance of food.

Scottish Water Horizons are just one company with a focus on finding new and creative ways to encourage renewable growth, and we like them so much we give them our rubbish. David Weber spoke to Energy Saving Trust to explain how the food waste from our Scottish office is turned into energy and fed into the national grid – via their £7million recycling facility in Deerdykes, Lanarkshire.

Our anaerobic digestion plant handles up to 30,000 tonnes of food waste and organic matter each year, generating up to 1MW of renewable electricity” said David, who is clearly passionate about the role Deerdykes plays in meeting Scotland’s Zero Waste target. But how exactly are our apple cores, sodden teabags and coffee granules turned into electricity? Like I said, the answer is obvious – it’s inside every one of us.

The company first collects food waste from all over the central-belt and feed it into a vast air pressurised shed: “You can stand right next to it and not smell a thing” David enthuses. “But take the lid of? No thanks.

This is where the organic matter starts to naturally breakdown, before it goes through an industrial macerator and an interestingly-named ‘turbo-dissolver’. By this point it’s pretty much a primal soup. The sludge gets filtered to make sure no plastics or metals have snuck into the mix, before being sterilised and poured into a huge digestion tank. Naturally, methane is produced and captured (enough to heat 2,000 homes per go) and this completes the lifecycle of our food waste. The similarity to the human digestion process is no coincidence – if it aint broke, why fix it?

To really go full circle though, the company collect the organic bi-product and sell it to farmers as high-grade fertiliser, but only after the digestate meets the Water & Resources Action Programme-developed PAS 110 standard. From here, the food cycle starts all over again.

Though food waste collection isn’t quite operating on a domestic level yet, there are still plenty of ways that technology can help to cut down the amount of food we needlessly throw away. ZeroWaste, who lead the way in helping Scotland’s homes and businesses reduce waste, released a very handy smart-phone app in 2010 which lets savvy shoppers easily manage how much food they buy and even helps to use up whatever seemingly disparate ingredients lurk in their kitchen cupboards, by way of an instant recipe generator. We’ve also got some waste-whacking tips of our own right here.