There are moments when you can glimpse what the future will look like and I had one of those last Friday.
You might not necessarily associate such a revelation with sewage, but in this case it’s true. I was visiting Knostrop in Leeds where Yorkshire Water has its biggest sewage treatment works. If we’re honest, we probably don’t give much thought to what happens after we flush the loo, but Yorkshire Water has to deal with the business end, so to speak. Sewage treatment consists of separating out the solids from the liquids and cleaning up the liquid so that it’s clean enough to put back in the river. The remaining task is to deal with the solid waste.
What Yorkshire Water used to do was to incinerate it – which was bad for the environment because of the CO2 it produced – and then put the residual ash into landfill. But a revolution has now taken place and thanks to a huge investment, the solid waste is now put into big tanks where it produces biogas – as our wonderful guide explained, it’s a bit like the workings of a cow’s stomach. The biogas is then stored in a white container that looks like a giant golf ball from where it is drawn off to generate electricity. Dealing with sewage uses a lot of energy and this new system will produce about 55% of the electricity that Yorkshire Water needs to power the huge Knostrop site. What’s more, the waste that’s left behind will now go to farmers to be used as a fertiliser. It’s a change from an unsustainable process to a sustainable one.
So, how does this fit it in to the huge challenge the world faces in preventing dangerous climate change? In Parliament we recently agreed a new legal target to make the UK net zero carbon by 2050. It’s a big task and, in truth, we need to get there sooner than that, but it is by practical steps such as the one we saw at Knostrop last week that we will get there.
But there are lots of other steps we need to take. Moving away, for example, from petrol and diesel cars to vehicles powered by renewable electricity or hydrogen. This will bring two enormous benefits – getting rid of C02 emissions and hugely improving air quality in our towns and cities.
And changing the way in which we heat our homes and cook. About 80% of homes rely on gas for one or the other but that will have to change because of the CO2 they produce. Again, electricity or hydrogen are likely to be the alternatives, combined with much better insulated homes.
In many ways, making these changes actually happen can seem rather daunting, and yet if Yorkshire Water had said to itself 20 or 30 years ago that it would have been able to reduce its CO2 emissions so significantly in a decade, it might have seemed far-fetched and impossible. It isn’t. It’s happening. And it’s through lots of other bold and imaginative steps like this one that we will get to that zero carbon future we know we must achieve.