Solar power

Photo by Randy Montoya

You know the expression “the sky’s the limit.” With solar power, that’s literally true – and Canada has a lot of sky. It’s surprising, then, that Canada has been somewhat slow to embrace solar as a viable energy source.

There are positive signs this is changing.

Take Calgary – according to the Environment Canada, the country’s sunniest major metropolitan centre, at 333 days of sun per year. Until August 2008, residents who wished to install solar panels had to apply for development permits. That doesn’t sound too bad on the surface, but the permits cost $3,000 and approval took weeks. The lethal combination of extra cost and significant delay effectively killed not a few prospective solar projects.

Ending the permit requirement for solar panels happened concurrently with Alberta’s provincial government passing a new law. Alberta’s electrical utilities are now required to compensate customers for the surplus power they produce (from solar or any other source). Suddenly, Albertans – and especially Calgarians – found it cheaper, less time-consuming, and more rewarding to install solar panels.

That’s no mere drop in the bucket, and representative of the shifting mood and increasing opportunities for solar across the country.

As of late 2008, the solar power industry was growing annually by 30 to 40 per cent. This is a timely trend; experts say new technologies on the verge of being ready for the market are about to make solar power lighter, cheaper and more efficient.

Until fairly recently, solar powered electricity, or photovoltaic, was prohibitively expensive. It only made economic sense in remote locations where transmission and construction costs made hooking up to the grid a pricey proposition. Solar heating (also called solar thermal) was cheaper and thus much more widespread.

What makes solar power so expensive? In short, the necessary raw materials, and inefficient technology.

First, the raw materials. Whether photovoltaic or thermal, solar panels are primarily made of silicon. Silicon is costly stuff – or, at least, it used to be. A couple of years ago, The Economist famously predicted solar technology would remain expensive until the price of silicon falls. And lo, it has.

New Energy Finance, a London-based energy analysis and research firm, predicted silicon prices would fall over 70 per cent by 2015. That’s on top of the 40 per cent it fell from 2006 to 2008. This has real impact on the price of solar power. In the US, a one-watt solar cell cost $50 in 1980. It’s currently just under $3.

That would be impressive enough, even if “conventional” electricity remained cheap in Canada – but it’s not. Costs are rising across the board, just as solar is getting cheap. “Grid parity” (where solar costs the same per kilowatt hour as conventional electricity) is a term often used in green energy circles, most often in the form of misty-eyed dreaming. Suddenly, it’s just over the horizon – five years in some European markets, say experts. It’ll take longer in Canada, but if current trends continue, it will come just the same.

Second, technology. Until very recently, generating electricity from solar panels was extraordinarily inefficient. In 1984, a particular new solar energy system achieved a sunlight-to-energy efficiency rate of 29.4 per cent. In other words, more than 70 per cent of the solar heat collected was simply waste. That record rate stood for 24 years – an amazing span of time in the tech world.

In January 2008, that record finally fell. New Mexico-based Sandia National Laboratories tested its new Serial #3 solar dish, and achieved a 31.25 per cent conversion rate. While Sandia happily admits it was an extraordinarily bright and sunny day, the real story was the new solar panel design.

While the device defies quick verbal description, here’s a capsule summary. 82 mirrors are set up to create a dish shape, which has the effect of focusing the light into an intense, hot, beam. Ever watch kids fry ants with a magnifying glass? Same concept.

Electricity is generated by focusing the beam onto a receiver and engine, which is filled with hydrogen. The design is efficiency itself, as the mirrors transmit 94 per cent of the available sunlight to the engine. As the gas heats and cools, the pressure drives pistons, which drives a generator.

You might be wondering if that’s truly a big deal – we’re talking about less than two percentage points here. Well, those add up in a hurry. In a 2.5 hour test, the Sandia facility generated 26.75 kilowatts of juice. Two percentage points’ difference means half a kilowatt – or about the total energy generated by a small solar cell unit.

Improvements aren’t just coming from improvements on existing designs, though. Researchers at UC Santa Cruz have been developing a handful of techniques for nanotechnology solar cells. When tested, they delivered a higher-than-expected conversion rate. In the UK, a researcher is exploring ways to design hybrid solar cells – combining organic and inorganic conductors – which may allow for higher conversion rates.

What do these developments mean for Canada? After all, it’s a nation blessed with natural resources that already enjoys some of the world’s lowest energy costs. Canada has traditionally and continues to see solar as a contributor; part of the national energy puzzle, but not an overarching cure-all.

Currently, about 20 per cent of all Canadian energy use is residential. While installing solar cells can put a dent in energy bills, that’s about the limit. Under current costs replacing a typical furnace with a solar system would cost between $15,000 and $30,000. It would eventually pay for itself – eventually. Natural Resources Canada says a 100 per cent solar-powered home becomes a good investment after 30 to 40 years of continuous use.

That has created a vicious circle; Canadians have avoided solar because of high prices, and constant assurances that costs would and will eventually come down – so why pony up now for a system predicted to be soon obsolete?

It’s a reasonable concern. As such, Canada’s residential solar industry has concentrated on niches. First and foremost, water.

17 per cent of Canadian residential energy is consumed in the act of heating water. Nearly 10 per cent of Canadian homes have outdoor swimming pools. Heating an average-sized pool – even in the heat of summer – is actually more energy-intensive than heating a home in winter.

The solution? Solar panels, of course. It already heats about a tenth of the nation’s pools, and a modest $600 system makes a significant difference in energy consumption and bills. The reason is that solar heating is vastly more efficient than photovoltaic electricity.

It’s an exciting time for solar energy. The future’s so bright, it’s gotta wear shades.