Sunny days for Canadian solar power

The need for energy is growing, and rather than prospecting under the ground for more coal and oil to meet the demand, more and more Canadian companies are taking a serious look at the skies and seeing a golden opportunity in the sun's rays.

The dawn of large-scale solar energy is rising first over Ontario, judging by the deluge of applications the Ontario government has been receiving for new solar power projects. The industry was recently given a boost when a neighbour to OptiSolar Farms Canada's proposed solar farm megaproject in Sarnia, Ont., withdrew an objection that had been filed with the Ontario Municipal Board.

The OptiSolar Farms Canada project will be the largest approved solar energy farm in North America. When fully built in five segments of 10 megawatt (MW) arrays, the solar farm in Sarnia on 365 hectares will provide 50MW of electricity from photovoltaic panels angled south toward the path of the sun. One megawatt of power can supply about 400 average homes.

But bragging rights for the first shovel to break ground on a utility-scale solar project went to joint venture partners SkyPower Corp., a Lehman Brothers Company, and SunEdison Canada when the pair started construction on April 22 of "First Light," a 19MW solar park on 121 hectares in the Township of Stone Mills in Eastern Ontario.

What both these projects and others have in common is the support of the Ontario Power Authority's (OPA) Renewable Energy Standard Offer Program.

The OPA set a contract price of 42 cents per kilowatt hour (1,000 kilowatts equal a megawatt) for photovoltaic solar power through the Standard Offer Program, much higher than the going rate for power generated by others means. By contrast, for example, wind and marine energy generation is paid at 11cents and biomass (plant material and animal waste) at 14.5 cents per kilowatt hour.

Since it started taking applications in November 2006, the Renewable Energy Standard Offer Program has exceeded its modest 10-year target of adding 1,000 megawatts of new power generation from wind, solar, marine and biomass energy. Tim Taylor, a spokesperson for the OPA, says the volume of applications was unexpected.

"We blew through our forecast in a year," says Taylor. "But solar really surprised us."

As of April 2008, the OPA had received 188 applications to provide 420 MW of solar power. Solar made up about one-third of the applications to generate 1,300 MW of renewable power.

The OPA announced last week a plan to conduct a program review of the Renewable Energy Standard Offer Program. These include a requirement that proponents meet certain interim project deadlines. The plan also restricts larger proponents to a single 10 MW project per transformer station and places a 50 MW restriction on the amount of solar power any proponent can develop at any one time.

Making solar power economical

Solar advocates say experience in other countries show that government subsidies provide incentives to attract solar power developers and drive down manufacturing costs. The changes to the Renewable Energy Standard Offer Program radically alter the program for larger developers like OptiSolar and Sun Edison.

Professor Tarlochan Sidhu is chair of the University of Western Ontario department of Electrical and Computer Engineering, and Hydro One Chair in Power Systems Engineering. He says the OPA should not have been surprised that Canada's fledgling solar industry responded in earnest to its incentive program, based on the response other countries have had to similar programs.

"In Germany, there are a lot of government incentives and the industry is very well established," he says.

The trick is making solar power into a viable source of energy in a country like Canada where the amount of sunshine dwindles during winter months. Germany is a cold-climate country that has made solar power work, and engineers at the University of Western Ontario studied the German solar power industry, and those of other countries in sunnier climes, in order to build a Canadian model that made economic sense.

Sidhu says the size of the installation directly affects productivity, and larger plants tend to be more cost efficient. It takes roughly $1 to produce 1KW hourof energy from a small 2 KW plant the average-sized solar installation at a private home. The cost drops to 40 cents to produce 1KW hourof power from a 1MW photovoltaic plant.

"Considering our sun, the minimum size where solar can break even is one megawatt," says Sidhu. "The cost to produce energy per kilowatt hour is almost half as efficient as in a place like California."

Technological challenges

Operating solar power stations is only part of the equation for the growing Canadian solar industry. The rapid growth of alternative energy generation has led to invigorated research opportunities in power engineering.

Photovoltaic energy is the conversion of the photons in sunlight using photovoltaic cells. These cells, arranged into solar panels, are usually made from semiconductors such as silicon that absorb photons and produce electrons. The electricity generated by this process in photovoltaic cells is multiplied across solar panels in direct current (DC) - an electric current flowing in one direction only.

To make the photovoltaic energy grid-friendly, it must be converted by an inverter from DC to alternating current (AC) - the electricity that powers home appliances in 120 or 240 volts. Sidhu says the inverter technology and ensuring there is easy access to feed power into the grid can be an expensive part of a solar power project. Sidhu says 15 to 20 years ago, there was a perception among experts in electricity transmission and distribution that everything they needed in order to operate efficiently was already known. Ontario's blackout of 2003 changed that.

He says Western saw this field as an opportunity to build Canada's foremost power systems engineering group. They teamed with the University of Waterloo to win a $6 million grant in February 2008 from the Ontario Centres of Excellence program to develop efficient technologies to convert solar energy to electricity, and to produce weather-predicting software that would help engineers design more efficient solar-energy producing systems.

Sidhu says the key challenges in renewable power like solar are in the control, protection and operation of the interconnections to the existing electric power grid. For example, allowing homeowners with solar panels on their roofs to pipe power into the grid when it's not needed by the home sounds like a great idea, but it's a challenge for hydro utilities.

"The grid has to be ready to accept this power, and the grid is very centralized - it was not designed for small generators of power," Sidhu says.

He adds that small generators make the grid vulnerable because the amount of power they supply is inconsistent. Solar power is usually available on hot summer days precisely when demand and price for electricity hits its zenith, but the downside to solar, of course, is that the energy depends on how much the sun is shining, and the flow disappears at sunset every night.

"This is not well-behaved power - it's like the Wild West," says Sidhu, adding that this is why utilities like Hydro One are reluctant to sign up smaller power providers.

Sidhu says Western has already worked with Hydro One to connect the larger wind farms and understands the technical challenges of solar power. He thinks the answer to distributing power from renewable sources is the concept of micro-grids, where energy is produced and used locally rather than fed back to the massive main grid.

"There is already a demonstration site in British Columbia with General Electric," he says. "Micro-grids can provide control, protection and efficiency."

While experts deliberate over how to get the power into the electrical grid, there's general agreement that the future of solar power in Canada looks bright. As the commercial interest in solar power grows, solar farms will likely become a more common site in the Canadian countryside as fields full of photovoltaic panels are planted to harvest emissions-free energy.

The author is a Canadian freelance writer.