Poo power: How sewage can help create energy
Did you know that the sewage that we produce each year could be a source of fuel to help power the country? It may sound a bit icky, but the contents of our sewers could prove invaluable.
In recent days, a Welsh project to transform sewage waste into hydrogen fuel has just been awarded £60,000 by Innovate UK, a government-based innovation agency. Under the distinctive name ‘Make Your Poo Work for You’, the project is run by Welsh Water in conjunction with tech company Costain and local authorities in South Wales.
The project takes sewage sludge, a by-product from water treatment, places it in tanks, and allows it to transform into a compost-like substance (biosolids), while also generating quantities of biogas. These gases can be easily converted into hydrogen for fuel, allowing Welsh Water to power their fleet of vehicles.
Cutting their reliance on petrol and diesel in this way could help the water company save an estimated 9,000 tones of carbon being released into the atmosphere
Hydrogen could be viable soon
In 2019, the UK’s Committee for Climate Change (CCC) stated that hydrogen power could be integral in helping the UK achieve net-zero carbon emissions by 2050. The committee published a report, detailing how there was a need to generate a low-carbon industry with the same hydrogen production capacity as existing fleets of gas-powered stations, in order to meet this target.
The benefits of relying on hydrogen as a source of fuel is that, when burnt in a fuel cell, it produces only water. In comparison, hydrocarbons release sulphur and carbon-based compounds. These gases can contribute to climate change and phenomena including acid rain.
Having a renewable resource in the form of hydrogen could be an effective way to power the economy for years to come, provided that the fuel cells themselves use clean electricity to power them. Hydrogen is one of the most abundant elements in the universe, so there’s certainly no limit to the amount of it which could be accessible technically.
Hydrogen could be integrated easily
Clean hydrogen power can be considered something of a space-age way of generating energy. At present, natural gas or methane has a significant share of our energy mix – in 2019, 36 per cent of the energy we consumed came from methane, and existing infrastructure makes it cheap and easy to do so.
Burning methane still produces carbon, even if you try to use natural gas to produce hydrogen. Fortunately, the National Grid is aware of this dilemma, and published an article exploring the potential of carbon capture technology to limit the amounts of carbon emitted, as well as electrolysis.
The National Grid is actively exploring how to ensure the safe transmission of hydrogen through its very own Hydrogen National Transmission System programme (HyNTS). One initiative of this programme is Project Cavendish, in which the Isle of Grain in Kent could be used as a hub for the storage and transportation of hydrogen, to help supply South London.
A technique called ‘hydrogen blending’, in which hydrogen gas is mixed with methane, could be the way the National Grid can allow for a steady transition from natural gas to hydrogen in the long term. That way, the move towards cleaner energy needn’t disrupt supply chains or create an energy crunch point.