Dal researcher wants to lower the cost of solar cell tech
Dal prof wants printed solar cells in homes
November 26, 2014, 3:46 PM AST
Last updated November 26, 2014, 4:35 PM AST
For Dalhousie professor Ian Hill, the remaining challenge in the next generation of solar cell technology is not the manufacturing — but to make the production of solar generated electricity more affordable.
He’s been working in the organic electronics field for 16 years and transitioned to focusing on solar cells about six years ago.
What’s out there now
Most solar cells on the market are silicon, which Hill describes as “rigid wafers of very pure crystal.” However, silicane is energy-intensive to make. The more energy it takes to create a substance, the more wasteful it is.
When a large panel of the silicon is produced, it’s then cut into thinner wafers, which are known as solar panels. These are then mounted onto roofs that are wired into a house’s power system.
It’s become cheaper to produce silicon solar cells in the last decade and they now have a life expectancy of more than 20 years.
It’s the cost of installing the cells into the home that is still expensive. While it costs about 63 cents per watt to make the cell, it takes $6.50 per watt to install it, Hill explains. The cells makes up about 10 per cent of the total cost.
“There’s little to gain from actually making a cheaper cell […]. The problem is all the other costs,” Hill says. “The question is how can you design a system which eliminates those excess costs.” This is why he’s researching the potential of the printed solar cell.
At the moment, solar cell panels are purchased and then lugged up onto the roof of a house. Hill’s working on a system where the solar cells are already in the product. They could be painted onto the window or the facade of the house and worked into the house’s internal system, cutting out the extra costs of installation.
The solar cells could be coated directly onto a material that could be put onto the window. Homes would also have to be intelligently designed to integrate the solar cells’ technology
The new technology isn’t near that point yet, Hill says. Efficiency and lifespan are the benchmarks researchers need to hit for the material to be considered viable.
Hill is aiming for his solar cells to have a lifespan of 20 to 25 years, as silicon has. After all, windows and roofs on a house need to be replaced after 20 years or so. It would be pointless to develop a product that couldn’t keep up with these items, he says.
“You don’t ever want to replace them except when you have to replace the items they’re integrated with. You have to match that lifetime,” Hill says.
Coming to a store near you
The silicon panels bought in stores are between 15 to 18 per cent energy efficient.
Hill says that a product needs to be more than 10 per cent efficient before it’s considered commercially viable. Organic solar cells have reached 11 to 12 per cent. A decade ago they were only one to two per cent. The advances in technology are getting what Hill calls “commercially interesting.”
He’s also been looking into perovskite, which has shown even better results in the lab. Hill says the lab the tests have shown an average of 15 per cent efficiency.
Hill says “small-scale things are already starting to be out there. You’ll see more in the five years time frame,” but 10 years is more realistic.
Similar technology is already available in stores, such as backpacks that have solar cells built in. The cells aren’t being printed onto objects, but it’s closer to having solar cells incorporated into the design.
The product Hill’s working on isn’t something that can be found in an aisle at Canadian Tire yet, but one day it could be.
Hill’s solar cells need to be cost efficient. People might say they’ll buy this product even if it does cost a bit more in the name of being environmental, but Hill is skeptical.
“We have to drive the costs of these technologies down to the point where people will adopt them,” Hill says.
“Once we do that, then the days of fossil fuels will be numbered.”