Cleantech investors often talk about the quest for the ‘Google of energy’. But for some, it could just be that the future is already here, it's just not evenly distributed yet, as William Gibson would say.

Solar advocates already believe they've picked the winner. No surprise there. But faith in their technology is backed by some of the brightest brains in science, and not necessarily those academically linked to solar research.

Earlier this month, I had the good fortune to hear engineer, inventor, futurist and now-Google employee, Ray Kurzweil, speak at Berkeley University. Judging by the rapt attention of the audience, Kurzweil attracts devotees to his worldview of life-extending nutrition, artificial intelligence and the merging of the human mind with machines.

During his note-free two hours on stage without a single "um, er, ah" or seeming pause for breath, Kurzweil took the audience on a fantastic voyage on the impact of exponential versus linear growth in technology.

"History shows us that technological change is exponential, but we humans with our common sense intuit a more linear view," he said.

"If we take 30 steps we get to 30 steps in a linear path," he said. "If we take 30 steps exponentially, we get to a billion in 30 steps."

Picking up his iPhone, Kurzweil indicated that this was a computer billions of times more powerful and a trillion times cheaper by processing power than the computers he had worked on at MIT when he was a student in the 1960s.

Solar, said Kurzweil, was another technology that could benefit from this law of accelerating returns, if it wasn't already doing so with the precipitous decline in module prices.

But to check whether Kurzweil is on the right curve, it's time to go back to the future.

Kurzweil has already worked on solar energy with Google co-founder Larry Page as part of a panel of experts convened by the National Academy of Engineers in 2008, light years ago in the solar industry.

"There's a lot of available solar energy," said Kurzweil at that time. "We have 10,000 times more than we need. If we captured one part in 10,000, and that's feasible, we could meet 100% of our energy needsl; we can create solar farms on a very tiny fraction of the land, 20%-30% of the land in the United States is unusable desert.

"Larry Page and I are convinced that within five years we will reach a tipping point where energy from solar will be less expensive per watt than from coal and oil."

At that time, solar panel prices were $3.25 per watt, then soon dropped off a cliff. In fact, Paula Mints' slide (see caption 2) doesn't look a million miles away from one of Kurzweil's exponential graphs.

Kurzweil came closer to the truth when he talked about volume. In 2008, installed PV capacity was around 16GW, compared with around 104GW today.

"We also see an exponential progression in the use of solar energy," he has predicted. "It is doubling now every two years. Doubling every two years means multiplying by 1,000 in 20 years. At that rate we'll meet 100% of our energy needs in 20 years."

Since around one-third of that 104GW installed capacity is in Germany and China is only really getting going, Kurzweil's forecasts don't look too far-fetched.

Despite these glitches (or S curves) on his graph, Kurzweill still believes that a "doubling every two years means it’s only eight more doublings before it meets 100% of the world’s energy needs."

That takes us to about 2027, close to his predictions in 2008.

Kurzweil is now Google's director of engineering tasked with a project to "create" a mind. But with Google's investments in renewables at a substantial $1 billion and its co-founder an exponent of 10x growth objectives, it's not too much of a stretch to imagine some synergistic impact for solar now that Kurzweil is clocking on at the Googleplex.

Kurzweil has his critics, that's for sure. Miguel Nicolelis, a neuroscientist at Duke University, is at least one who dismisses Kurzweil's prediction that computers will replicate the human brain.

There is a will to want Kurzweil to continue to get his predictions right. After all, who wouldn't want their own human "memory" to be backed up on a computer (no more 'where did I put my keys?) or have their mind connected to the cloud to access collective human knowledge without a Google search?

Twelve years ago, Kurzweil was predicting that "within a few decades, machine intelligence will surpass human intelligence, leading to The Singularity — technological change so rapid and profound it represents a rupture in the fabric of human history."

We might still be waiting for Singularity to occur in the energy industry. But if Kurzweil is right, thanks to the booming cloud and clout of IT, PV may indeed become the Google of the energy industry. Perhaps a "rupture in the fabric of human history" starts with a tiny tear.