Solar Power, Mechatronics and Economics

At the recent Semicon show the big buzz was about the emerging Solar Energy industry. Lots of “new” products, lots of buzz. The big semiconductor machinery manufacturers who view crystalline solar cells as a stimulus to the demand for machinery and silicon have put in a lot of effort. The main goal? Get the cost of the solar cells down to where electricity produced with silicon is comparable to the cost of electricity generated by fossil fuel.

And, in fact, the industry is getting there. The current estimates are that solar power is costing about the same as peak demand consumer power, $.23/kWh. And with the current wave of investment and scale up, something which the semiconductor industry has always done well, there is serious forecasting that the cost of solar electricity will continue to fall.

The mechatronic connection is really interesting. It was something I wasn’t really paying attention to. The solar tracking application. You need 2 axes of motion, elevation and azimuth, to follow the sun in its daily course and maximize the electricity coming out of the solar panel. Most vendors claim up to 40% increase in the amount of electricity generated by solar power. But when you get right down to it, this is a very difficult application to do, because even though the duty cycle is very low, it requires decent accuracy and low cost. A very tough combination.

Some solar trackers use two motors and gear reducers to move 12 or 16 solar panels in a large frame. The typical solar panel is 15″ wide and 48″ long and weighs about 33 to 40 pounds. 12 units would be a payload of 480 pounds. Pretty serious amount of load.

The nice thing is, you can use a lot of gear reduction to make a smaller motor do the job. But on average the systems I have seen add more than $200 per solar panel to the installation. And that’s about half again the cost of the solar panel to begin with. So it really impacts the return on investment for solar power.

And that means we need a better mechatronic solution to do this job at a much lower cost. So we need to run a contest for the best solar tracker. You can do it any way you want, 1 panel system or multi-panel system. There are some new solar energy systems where mirrors are used to create solar concentrators to increase the light density on the surface of the silicon photovoltaic device. But we just have get a better solution out into the marketplace.

See? There really is a mechatronic connection in this solar energy stuff.

Now here’s the hard part: It doesn’t matter how good a job you do on the mechatronic part if we don’t get the government to change its policy on home financing. Currently, none of the green energy technologies qualify for FHA lending. This means that you have to do your solar retrofit for cash. You can’t get a second on your house or roll it into a new home finance package. So you have to come up with $20K- $25K to get a system installed. That’s the reason we don’t have a million home off the grid yet. Write your congressman or woman.