As Kermit the Frog observed, it’s not easy being green. Royal Dutch Shell and Anglo American on Tuesday became the latest natural resources companies to shelve a clean energy scheme. Their joint A$5bn project in Australia to convert coal into liquid fuels may go ahead, eventually, but not with development costs this high and an oil price this low.

The about-turn caps a miserable year for alt-energy enthusiasts. The WilderHill New Energy index is down almost two-thirds this year, erasing all the gains, and more, of the past three years. Banks are refusing debt finance and equity markets have shut up shop. Global IPO volume for hydro, wind, solar and biofuel companies is under $4bn in the year to date, according to Dealogic – down from $14bn in 2007. Private equity is only partially bridging the shortfall.