A new study by Scottish Water Horizons for Scottish Renewables makes a kind of obvious if a little yucky suggestion. Why don’t we recycle the heat from wastewater and sewage? Currently, it all gets lost in the recycling process. By recovering this energy, the group claim dramatically:
‘Scotland’s sewers could contain enough natural heat to warm Glasgow for more than 15 years.’
I take it that they mean the current quantity of sewage could do that so if we keep up our efforts, the supply is infinite?
The water and sewage we flush away contains huge amounts of thermal energy. Every day Scots flush away 921 litres of wastewater and sewage. The temperature in sewers is often as high as 21 degrees C. Further, this method would mean preventing 10 000 tonnes of CO2 from entering the atmosphere.
Add this to the renewables and oil/gas boom and it’s hard to see what we do with it all. Sell it?