Robert Ashton warns that government may be happy to incentivise investors to fund emerging markets, like social impact bonds, for a time, but they can swiftly change their mind.

I think I've told you before about my two wind turbines.  They are something of a local landmark; their 15m masts emerge from the trees behind my home. They make my place easy for visitors to find and more importantly, provide around half of the electricity we consume. And best of all, they cost me nothing to install.

Windcrop, the company that provided the turbines was launched in 2009 by John Moore, a talented engineer who left Lotus cars to set the venture up. I was pleased to be one of the first to buy in (or rather not to buy, but to benefit!)

The business model was simple. City investors fund the installation and maintenance of a growing fleet of turbines. Landowners get free electricity and the investors get their return from the government generation and feed-in tariffs. Delightfully, what the turbines actually feed in to the grid is not metered. The assumption is made that 50 per cent goes that way, so for the investors, it's a cut and dried case. Providing, that is, that the wind keeps blowing!

The business model proved popular; quite a few local farmers called me to ask me what the catch was. To date the company has installed 500 turbines in East Anglia, Yorkshire and Cornwall. You might say it's a success story; the kind of green entrepreneurship the government wants to see. But as of last week, you'd be wrong.

You see Windcrop has gone bust. That means 40 people have lost their jobs and I suspect the founder has lost rather more money than he would have liked. The company had won a number of awards and was in the view of many, a real success story. So what went wrong?

Well according to press coverage, the investors lined up for the next round of funding pulled out. Not because they doubted the talent or track record of the team. Not because they doubted the integrity of the business model, because turbines were only sited where meteorological data showed that wind yields were good.

No - the investors, it seems, withdrew because of uncertainties about the government tariffs from which their return would be derived. In other words, it was not the amount of wind the turbines could harvest, but anxieties about the income from government they would generate.

For me there are two very clear messages here. The first is that no business can ever totally rely on future government funding. Yes, it can be done in the short term, but just as politics changes, so too do the various initiatives and campaigns they seek to have delivered. In truth no business-owner can truly sleep comfortably at night if they have only one customer.

The second point is for me more significant. I can understand how government tariffs can pump-prime emerging industry sectors. I can also understand how as that new industry grows, the economies of scale mean costs come down. That means incentives can also be reduced. But sometimes, in my view, government worries too much about letting entrepreneurs profit too much. After all, people like Windcrop's John Moore stake cash, career and reputation on delivering the renewable power generation we all want to see.

Wind is just one example, social impact bonds are another. It's not good enough for government to enable the first puff of success, they have to follow through with sufficient commitment to enable growth to continue.