Dave Gerwing is the president and founder of Menova Energy Inc., a private Ottawa-based clean-tech startup that boasts Nike, the University of Michigan and Wal-Mart Canada as clients. Menova manufactures the Power-Spar, a solar concentrator that, it claims, can deliver both solar thermal energy for heat and air conditioning, and renewable solar electricity at a rate that is better than grid parity — 10¢ a kilowatt hour (when amortized over approximately 25 years). Gerwing spoke with Rachel Pulfer about why he jumped into clean-tech, what it’s like to work with Wal-Mart and why securing VC financing is a waste of time.
The Great Recession has not been kind to tech startups. How’s Menova doing now?
We have reseller agreements in Canada, the southwest U.S., Spain, Italy, Greece, Oman, France and Saudi Arabia. We just put units on the top of Nike’s corporate headquarters in Portland, Ore. We’re working with Wal-Mart to install Power-Spar units on top of a big-box store in Ontario. And we’re hiring.
How does Menova’s technology work?
We use photovoltaic cells to make solid-state electricity directly without steam, and then we take the parasitic heat off and funnel it to a solar thermal air conditioning or heating system.
The actual Power-Spar is a series of 64 parabolic concentrating mirrors, each measuring 30 by 117 inches, sitting in a ring-like formation and mounted on a tracker that tracks the movement of the sun. We concentrate the sun into receiver heads that hold the solar cells. These are raised 23 feet higher than the trackers. And we pump off the heat with a mixture of water and propylene glycol.
We use a concentrating solar cell instead of silicon. Silicon cells can only take 20 to 50 suns on them. [A sun is a unit that measures the concentration of regular sunlight.] We use a thousand suns.
The cells we use are the same as those on the satellite circling the planet Mercury. These cells convert 35% of the sunlight shining on them. Traditional cells have efficiencies of up to 21%.
What are the current challenges?
When it’s really sunny, we don’t need all the energy we produce. However, the sun only shines four to six hours a day — and we have to produce energy for 18 to 20 hours a day. That presents an issue of storage. Right now, we’re using tanks of water to provide daytime energy storage. But we are working on a technology using algae that we believe will allow us to store light energy through photosynthesis to create a kind of bio-battery.
You claim the Power-Spar is able to supply electricity at 4¢ a kilowatt hour. In theory, that makes your technology competitive with coal. Is this in fact accurate?
It depends on how much the sun shines, and what your amortization period is. If we amortize the upfront costs over 25 years, and we include the value of the thermal energy, we can get to 3¢- to 4¢-a-kilowatt-hour power.
How did you start working on this?
I got caught in the ice storm with my five-month-old son, Josh: 12 days of no heat and power. It was a taste of life without electrons. For me, it was one of those epiphany moments. I was like: this could happen. At the time, I was working with engineers who had the basic skills that go into concentrators. So it all came together.
What’s it like to work with Wal-Mart?
They’re the most lucid group we’ve ever worked with. Any meeting you go to with Wal-Mart World, they have the metrics written up on the board. You should have this rate of return. You should reduce energy use by this much in new stores and this much in existing stores, and you should have this much reduction compared to status quo. And it is always the same. If you meet these objectives you will be a supplier. If not, there’s the door.
How did you start working with them?
Their then president Lee Scott was touting their green plan online, so we sent one of our big-game-hunter salesmen after him, and he landed some meetings.
Any advice for other clean-tech startups?
Find a good partner. We partnered with Woodbine Tool & Die — an auto-parts supplier — and they have been great. They’ve really helped us weather the recession. Also, don’t push the venture capital button. We did private placements and got the bulk of our early-stage financing from family and friends.
Why has this worked for you?
First of all, VC in Canada has not made money for the past five years. It also tends to distort your development. You develop fast, but because you’re making decisions so quickly, you usually develop the wrong thing.