Meet The Giant Heat Pumps Replacing Coal

Imagine a pipe you could walk through, swallowing 10,000 litres of river water every second to heat homes. That’s the scale of a new project in Mannheim, Germany, where energy firm MVV is fitting a former coal site with enormous heat pumps to feed a district heating network. The plan calls for two massive units, each rated at 82.5MW, and the project is described as having roughly 162MW of capacity. Together they should be able to supply heat for around 40,000 homes. Work is due to start next year and MVV expects the system to be up and running in the winter of 2028–29. These machines don’t burn anything. They extract warmth from the Rhine, amplify it using industrial-scale compressors borrowed from the oil and gas world, and push hot water into pipes that serve entire neighbourhoods. MVV will use 2m-diameter intake pipes and a multi-stage filter to keep fish out; modelling suggests the river’s average temperature would shift by less than 0.1C. Big as Mannheim is, it’s not unique. Everllence (formerly MAN Energy Solutions) is building a 176MW plant in Aalborg, Denmark, made from four 44MW modules and due in 2027. That system will cover nearly a third of the town’s heat needs and will be paired with giant hot-water tanks — each holding 200,000 cubic metres — so heat can be stored and used when electricity is expensive. There are trade-offs. The Mannheim installation carries a hefty price tag — about €200m — and equipment costs at Everllence come in around €500,000 per MW, not counting buildings and pipework. Still, the prize is flexibility. Large heat pumps can multiply each kilowatt-hour of electricity into several kilowatt-hours of heat, and when paired with storage or electric boilers they can help balance renewable power on the grid. Cities are adapting different approaches. Helsinki has rebuilt a 1,400km district heating network linking almost 90% of buildings, combining heat pumps with biomass and electric boilers; engineers there found the nearby sea was too shallow to supply enough heat without a very long tunnel. In the UK, schemes are smaller so far — Exeter’s network will be about 12MW using three 4MW heat pumps, with the first unit planned for 2028 — but researchers say Britain has untapped opportunity. Minewater, abandoned industrial sites and rural areas with room for storage tanks are prime candidates for larger systems. What unites these projects is a pragmatic reuse of existing infrastructure: grid connections, waterfront sites and skilled labour from the fossil era are being retooled to keep homes warm — but with far less carbon. --- Managing your business finances? TaxAce provides smart online accountancy services for UK businesses with flexible monthly plans. Image and reporting: https://www.bbc.co.uk | Read original article