Forecasting the future of solar power

Karin Hinzer and Mark Yandt

“Building owners who invest in solar equipment want to know how much money is going to come back.”

– Karin Hinzer

Take out a loan for a car or a house, and there is all manner of independent, reliable information to tell the lender how much your purchase should be worth. Go looking for money to put up solar panels on your house, however, and accurate information is sorely lacking.

The technology itself is very well known; in fact, the operational efficiency and affordability of solar power has never been better. The more critical question is how well this technology performs in practice or, more specifically, how it works as part of an integrated solar system and under climatic conditions that can change drastically from location to location. Like the depreciation of an automobile or assessed value of real estate, the ongoing performance of solar panels is an essential part of understanding what kind of investment they represent.

“Building owners who invest in solar equipment want to know how much money is going to come back,” says Karin Hinzer, a professor at the School of Electrical Engineering and Computer Science who has spent much of her career at the cutting edge of nanotechnology and the design of advanced photovoltaic cells, which convert solar energy into electricity.

Joan Haysom, a senior researcher who works with Hinzer at the SUNLAB, the University’s solar research facility, knows first-hand how imprecise performance estimates can be. She has had solar systems installed at her home and for the Ottawa Renewable Energy Cooperative.

“It was relatively challenging to know if performance estimates were accurate,” she says, recalling the discussion over how long it might take for this investment to pay for itself. She estimates it will take about seven years for her house, but concedes that the whole project is something of an experiment, with the actual return depending on the vagaries of the region’s weather, including the effects of snow.

Despite such uncertainties, “it will be economically viable in the near future for solar generation to be integrated into a building’s electrical system,” says Haysom. “Solar energy installations can be ideal for reducing a building’s electricity bills because they generate power during the day, when electricity consumption is at its peak and is most expensive. But standardized performance estimates will be required for mainstream adoption.” With that challenge in mind, Haysom and electrical engineering doctoral student Mark Yandt have undertaken a project with Hydro Ottawa that should help reassure bankers, homeowners and other interested parties.

“To be able to determine your system performance, you need local data,” explains Yandt, adding that it is crucial to know everything about the light that is hitting solar panels while they are working. To that end, Hydro Ottawa has provided several years’ worth of power generation details for its seven solar installations on the local power grid, which he and Haysom are combining with meteorological records of sunlight for the same period.

By marrying these two databases, the researchers should be able to pin down how well each of these installations has performed, including the value of each investment relative to the changing cost of electricity over the course of a year. Their findings will also suggest how such installations should be outfitted for this kind of monitoring, so that in the future the necessary information can be collected as a matter of course, creating the same kind of reference documents now used for investments like cars or houses.

“We’ll be able to make a strong and grounded recommendation about what needs to be monitored at each system,” says Yandt, “or how long we need to be monitoring in order to get a good assessment of how it’s performing and how different design parameters affect that performance.”

Such insights were among Karin Hinzer’s motivations for founding the SUNLAB in 2007, where innovative approaches to achieving solar power generation with unprecedented levels of efficiency have been developed. The SUNLAB has built partnerships with other universities, government agencies and private companies, particularly Toronto-based Morgan Solar, which has helped set up local solar test sites that Hinzer’s team has been monitoring for the past few years.

This latest collaboration with Hydro Ottawa adds a further dimension to these initiatives, which the company is pleased to support.

“It’s an opportunity for us to learn what’s to come, in terms of technology and understanding the use of that technology,” says Hydro Ottawa strategic planning engineer Raed Abdullah. “And it’s also good for the academics to learn what the real-life situation is like, what’s needed now.” Most importantly, the partnership is about moving an alternative source of energy into the mainstream.

 

by Tim Lougheed

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