Ask a Solar Expert: High Efficiency Solar Panels from Bella Energy on Vimeo.

Transcript of Ask a Solar Expert Video:

What are high efficiency solar panels?

In short, one would really only need to consider a high efficiency panel if they had a production goal, or a system size goal that could not be achieved with they space they have on their roof.

The long story is, a watt is a watt. (a watt is a unit of power) A watt coming off of or out of a high efficiency solar panel is identical to a watt coming off a standard efficiency panel. There is no difference to your house, your electric bill, to the offset in your electric bill… its all a watt. So, a high efficiency panel will allow you to achieve a given system size in less area.

Essentially if you can achieve your production goal, or your system size goal, with you roof space you have using standard efficiency panels you should do so. Because it will be cheaper out of pocket and have a short payback and a better return on investment.

What brands of high efficiency solar panels are there?

If you are in a scenario, whether residential or business, where you need to look at high efficiency panels in order to achieve your production or system size goal. There are essentially only two companies that make high efficiency panels, one is Sanyo and one is SunPower. In lab conditions SunPowers have a slightly higher efficiency than Sanyos. However, in real life situations in an area like Colorado where we have high heat, Sanyos, watt per watt, will actually give you higher kilowatt hour production per year per watt than a SunPower. The reason is two fold. Number one, when Sanyo comes out of the factory the rating (variance) on that panel is minus zero and plus 5 percent. Sunpower, good panel, but comes out of the factory at minus five percent up to plus five percent. So what that means is if you buy a 210 watt Sanyo panel, that panels has the potential to produce that or five percent better but no worse. SunPower ,if you bought a 235 watt panel, again with the comparisons based on watts per square foot, as the 235 watt panel is larger than a Sanyo 210. So don’t be fooled by the numbers look at how many watts per square foot. Anyways the SunPower panel will produce anywhere from five percent less than 235 watts to five percent more than 235 watts. The second reason and way that a Sanyo panel will produce more kilowatt hours per watt per year here (Colorado) is that the Sanyo cell is a hybrid technology. There is a amorphous thin-film that is wrapped around the silicon cell, which translates to the ability to maintain higher voltage in higher heat. So three, four, five months a year, with that hybrid technology the Sanyo will be able to produce betterthan the SunPower. Overall, a watt of Sanyo will produce more in Colorado than a watt of SunPower.

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