No, not HS2, the garden bridge, the estuary airport nor the road bridge to Northern Ireland. It is heat pumps.
We need a minimum of 600,000 installations by 2028 for them to have any effect, so says the government, that's 120,000 every year from now on. In 2020 the UK installed 37,000 and they came with a £5,000 bribe. Current uptake is 3.7 per 10,000 households.
People are just not convinced by them, the disruption, the new radiators and pipework, the redecoration nor the pay-back costs and time it takes. Most of us live in larger towns and cities and the overwhelming majority of their housing is not suitable for heat pumps. The take-up there is only 1.7 per 10,000.
A far better scheme would have been to install solar panels connected to a well lagged hot water tank with any extra electricity routed to a storage battery. Millions of households could have taken part, and in a short time.