The UK Green Investment Bank used a little state money to crowd in private capital

Green infrastructure projects were profitable over the long run but carried risk no private investor would take first.

The UK Green Investment Bank invested public money commercially in such projects rather than giving grants.

By taking hard first positions it de-risked projects and attracted private co-investment.

A £1.6bn of direct investment had mobilised £5.6bn of private capital by mid-2015.

Do the first deal so private money follows

Investing, not granting, keeps commercial discipline and returns.

Going first reduces the risk that blocks private capital.

Co-investment multiplies the public money rather than substituting for it.

Demonstrated returns made follow-on projects self-financing.

When a market refuses to start, a patient co-investor that goes first and proves the return can bring private capital in behind it.

By 2017 the bank had committed about £3.5bn across roughly 100 projects and mobilised further private capital. It was sold to Macquarie for £2.3bn, returning taxpayer funding with a gain of around £186m.