"In the winter, will the solar cells be able to power the heating elements in the panels?
We designed our panels so the heaters are driven by the grid and not by the solar cells - the systems are independent of one another. This is because the heaters and LEDs have to work at night, when the solar cells are incapable of producing power.
Currently, the full size hexagons are 36-watt solar panels, with 69-percent surface coverage by solar cells. This will become 52-watts when we cover the whole surface when we go into production. When we add piezoelectric, they'll be capable of producing even more power. Also, as the efficiency of solar cells increase, more power will be converted.
We tested the heaters over the winter with a DC power supply that provided them with 72-watts. This was an overkill and made the surface warm to the touch on most winter days. We still need to experiment with different voltages at different temperatures, to determine the minimum amount of power required to keep the surface above freezing. Remember, they don't have to heat up to 85 degrees like the defroster wire in the windows of your car: they only have to keep the surface warm enough to prevent snow/ice accumulation (35 degrees?).
The heaters will use more power than the panels can make at night or on overcast days, but keep in mind that the heaters will only be on when they are needed. It can be five below zero, but unless there is precipitation or snow drifts, there's no need to activate the heaters.
The amount of power a panel produces depends on the amount of sunlight. The amount of power required by the heaters depends on the temperature and the precipitation. Those who live in the northern climates will have to determine if the added safety and the elimination of snow plows, shoveling and road chemicals are worth the investment.
There will be some northern latitude after which it may not be worth it. On the other hand, it's hard to put a monetary value on all of the ways winter could be made more pleasant with heated roads! Each community, business owner and homeowner can make that decision for themselves. Once we are manufacturing, we envision a team of employees whose job it will be to evaluate sites for prospective customers and provide data to enable them to make the decision that is right for them.
Those in warm climates won't need the heating feature."