It is no surprise that makers of solar panels are going broke all over the world. But the key problem is not just a flood of cheap Chinese panels or the slashing of "feed-in" bribes.

Solar energy is useful for growing crops and timber, evaporating sea water to produce salt, drying clothes, heating domestic water and powering remote locations and portable equipment. Some people may also choose to use solar panels to run their air conditioner on a hot day. Everyone should be free to use solar, but not at the expense of taxpayers or other consumers.

But for generating continuous mains power, solar is a green toy. In clear sunny weather, the electricity generated from solar panels varies from zero at midnight to a modest maximum at midday, providing there is no dust on the panel. On a cloudy day, output varies from negligible to none. In all cases complete reliable backup generation is required.

Solar power is a high cost way of generating an intermittent and variable supply of electricity from a very dilute source while sterilising a large area of land.

The solar industry is only efficient at one thing - extracting unearned profits from tax payers and other electricity consumers.

As the growing global austerity starts to bite, all such frippery will evaporate.

The sagging market for solar panels is merely heralding that emerging reality.