IMAGINE living in an era of rampant innovation where renewable power provides potentially endless energy for everyone on Earth at levels of demand higher than those today. Imagine solar photovoltaïc (PV) cells so efficient that they could provide all the nation's electricity demand even in a cloudy place like the UK. Fanciful?
    Not according to two of the world's most powerful oil companies. Scenario planners at Shell have calculated that renewable energy holds the potential to power a future world of 10 billion people with ease. In Shell's scenarios, solar energy dominates the mix, and small wonder, because over at BP experts have calculated that even in the cloudy, electricity-profligate UK, covering all suitable roofs with solar PV of existing efficiency would provide more electricity than the country presently uses.
    PV cells are becoming more efficient all the time. You could store the energy they provide in advanced batteries, or by making hydrogen for fuel cells of the kind car manufacturers are developing. Yet many commentators still recite the mantras that underpin the planet wrecking energy status-quo. Solar PV is simply too expensive, they say.
    This argument assumes an economic frame of reference that compares the price of power from PV, which has virtually no distribution costs, with the current wholesale price of power from greenhouse-boosting sources. This is an economic frame of reference that ignores the value of PV panels as a building material in its own right, and more significantly places a value of zero on our children's future. It is the economics of the madhouse - but as it’s the basis of most economist’s calculations, let's use it anyway.
    In fact, most off-grid PV solutions are already "economic" on this basis, and so are rnany grid-connected applications. The off-grid applications, including street furniture, telecoms infrastructure and some housing, are economic because they cost less to power by PV and batteries than it costs to extend the grid. In almost all homes in the developing world, PV is cheaper than the other energy-supply alternatives, including candles and kerosene, and hundreds of millions of homes could be lit given appropriate channels of distribution and credit.
    The currently "economic" grid connected applications are those involving cladding or roofing materials. PV cladding costs less than prestige cladding. Why build a functionless facade when you can build a cheaper and equally attractive PV one that gives you decades of electricity for free?
    The "too expensive" argument also ignores the fact that as manufacturers scale up production, prices - already falling fast- will fall further. I have seen business plans for large PV manufacturing plants that will allow generation of "competitive" electricity in most markets. Such plants could be built in just a few years and be abundant within the decade.
    PV is a classic example of a disruptive technology, capable of invading the trillion dollar global energy market with the same speed that personal computers invaded the mainframe market. Companies tend not to spot such invasions of their core markets. Horse traders laughed at the first automobiles, shortly before going out of business. IBM failed to realise that the mainframe was underthreat until late in the day. In fact, never in the history of commerce has a company with core interests in the threatened area commercialised the disruptive invader.
    In this case, the threatened area involves the fossil fuels. Shell and BP, despite their scenario planners and the green mood music in their television ads, cannot be relied on to commercialise PV at the speed society needs. Indeed, the oil companies are still aiming to increase the amount of oil and gas they sell, not cut it.
    The Germans and the Japanese have spotted the coming business revolution and are scaling up their domestic PV industries fast. Investors are responding: specialist funds for renewable energy and PV have recently been set up in these countries. In the case of the solar PV market, Japanese government funding will result in 370.000 solar roofs by 2005, on current trends. In Germany there will be 140.000. In the UK, there will be fewer than 2000.
    A solar revolution would bring huge benefits to society. It would have a multiplier effect on other smart technology sectors. Moreover, solar PV is a democratising technology that is immensely popular where the public understands its potential. When your home is your power plant, generating electricity for your appliances and hydrogen for your heating and car, you no longer need to rely on utilities or oil companies. With storage, you can cut out the power cuts. What's more, you and the big retailers alike will be earning cash on the side trading your green electricity for top dollar in the carton markets.
    Oh, and by theway, you will be helping to save the world as you do it.

(*) Jeremy Legget is Chief Executive of the UK’s largest solar eletric solutions company, Solar Century, and a founding director of the world's first private equity fund for renewable energy.