NOTHING GOES TO WASTE
It’s the local landmark that people love to hate; a modern, industrial behemoth soaring up above the coastline. A silent giant, working around the clock to deal with an environmental issue that we’ve all become much more aware of, yet almost no more aware of the processes in action once it leaves our homes: waste.
Despite all of the initial negative press surrounding the building itself, personally, I find the exterior architecture quite appealing - especially given the surrounding industrial structures, which date back to the seventies. It’s a structural-expressionist twist in contrast to the concrete brutalism of the La Collette power station next door, and a breath of fresh air in an industrial area. Quite literally, in fact.
You see, the common misconception about incinerators, and one that I also held until my recent visit to Jersey’s Energy Recovery Facility, is that burning things is bad for the atmosphere. Very bad. In many cases, it is - but if you add a sprinkling of science you can bring the emissions down to staggeringly low levels. In fact, the team working inside this seldom glanced-at building worked relentlessly for two years to attain the ISO 14001 standard for emissions - a stringent and impressive, if not sexy or exciting-sounding achievement that they’re rightfully very proud of. Their hard work isn’t over though, as the facility can only stray outside of the prescribed emissions limits for 60 hours per annum. To put that into context, that means that the operation must remain squeaky-clean for the other 8,700 hours that make up a year. That’s no mean feat when you consider they’re burning anything and everything that can’t be reused or recycled; from household and commercial waste to street-sweepings and even dried sewage!
But what actually happens inside this huge, inside-out looking metal and glass box, you might ask? Fundamentally, the process is quite straightforward. Non-recyclable waste from the island’s homes and businesses is brought here to be burnt, and the heat generated is used to turn water into steam, which in turn passes through a turbine attached to a gigantic alternator (just like the one in your car that keeps the battery charged) and that energy is fed directly into Jersey’s power grid. When operating at its peak, the facility supplies enough power for 7,000 homes - all from incinerating the contents of those black bags that are collected from outside your house and that need to be disposed of by incineration in any case. It’s as straightforward as that, but as much as it sounds simple, the reality is that it’s a very fine balancing act to get right in order to reach peak-efficiency, and that’s all-important when it comes to minimising the use of natural resources and reducing emissions in order to protect the environment.
After your bins have been collected, the waste is taken to the Energy Recovery Facility, tipped, and then shredded to make it burn more easily. It’s stored in the bunker, a 5,000 cubic metre concrete pit capable of holding around 3,000 tonnes of rubbish, before being fed into the incinerators by overhead cranes; their gargantuan grabs feeding up to 7.5 tonnes of waste into each of the two incinerators at the facility every hour. The crane system can be programmed to work autonomously if required, selecting different areas of the bunker with each grab, to mix the waste content up. One incinerator can deal with Jersey’s waste production for around six weeks before the bunker, which is essentially the facility’s fuel tank, would become full. As waste can’t be taken elsewhere in the event of a complete shutdown, unlike in the UK, it’s therefore essential that downtime of each of the incinerators is kept to a minimum. Each can operate independently, which not only ensures resilience but also caters for twice-yearly preventative heavy maintenance. Between the teams operating the plant in shifts around the clock non-stop, every single day of the year, the on-call engineers and their extensive stock of spare parts held to avoid the transport delays we’ve all come to expect from island life though, almost all eventualities are covered.
Inside, the unrelenting hum of machinery is difficult to ignore. Add to that pops of compressed air and the clanging of maintenance staff working away and you soon realise that the interior of this structure belies the silent nature of its shell. At the heart of the furnaces, temperatures soar to over 1,100 Celsius, with extra air being fed in to destroy any volatile gases by increasing the heat levels. Lead, cadmium and mercury vaporises, and any metallic items that have snuck into the waste stream run through the grate inside to separate and collect them for recycling. The fires are self-sustaining once up to temperature, and each furnace is encircled by a labyrinth of thick steel pipes through which water is pumped and turned into steam. The water makes seven passes to maximise the amount of heat extracted, before the 24 tonnes of steam that is produced per hour travels through the turbine housed at the western end of the building at a pressure of 46 BAR, causing it to spin at 6,000 revolutions per minute. The shaft of this turbine is connected to a reduction gearbox and then onto the alternator, which spins at 1,500rpm to create electricity. Enough electricity for 7% of the islands’ requirements, meaning we can import less energy from France.
You can’t just burn anything, create steam, spin an alternator and also help to save the planet though, unfortunately. In order to lower emissions to almost unbelievable levels, a few things are carefully added as required; lime, carbon and urea. The lime, derived from limestone, helps to reduce acidic gases and is re-used a number of times so that nothing is wasted; carbon, which is a by-product of the waste stream in any case, is added to absorb heavy metals in the flue gas; and urea, a fertiliser and organic compound occurring in the human body, is added to split the nasty NOx gases that are a by-product of incineration into nitrogen and oxygen - two of the most abundant gases in the atmosphere.
The ash produced results in just 1.3% carbon, with the other 98.7% of the waste burnt off without so much as a wisp of smoke leaving the chimney that the facility shares with the La Colette power station - a prime consideration when it came to choosing a location for it. Not only does La Collette provide an existing chimney stack, but also a direct hook-up to the power grid and easy access to sea water for cooling the plant, which is returned to the ocean a mere four Celsius warmer.
There are around sixty Energy Recovery Facilities in Great Britain, ours being one of the smallest, and yet the combined emissions from every single one over the course of each year are less than the air pollution caused by the fireworks set off on Guy Fawkes Night in Great Britain alone. Take a moment to think about that.
The ash produced is non-toxic and gets shipped to England for reprocessing, where it is used to displace aggregate in the construction of new roads, thus reducing the amount of fresh material that needs to be mined to meet demands - another environmentally positive knock-on effect.
You may not admire the building’s exterior, but it’s difficult not to admire what happens inside. It’s a delicate balancing act that Ian Williams, the ERF Manager described as ‘like herding cats’, with the close-knit team of talented operators constantly preempting the best course of action in order to generate the most electricity yet the least emissions.
They’re a team who provide an invisible service that’s essential to island life - it’s easy to take their hard work for granted, but you’d soon notice the effects if the infrastructure was removed and your bins couldn’t be emptied. When they’re doing a good job, nobody notices. ‘Boring is good’, Ian told me, because it means that things are going well, but next time you turn on a light switch, put something in the bin or inhale a breath of fresh air, don’t forget what’s happening behind the scenes.
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As featured in issue 162 of Gallery magazine published 1st May 2019. www.gallery.je
Words and images written, shot and edited by Russ Atkinson (not to be reproduced without permission).
