Tesla’s Solar Roof and the Future of Distributed Generation


With the Tesla “solar roof” announcement dominating headlines this week, rooftop solar is once again making news. While reactions have ranged from excited to skeptical, we appreciate the company’s interest in combining onsite power generation with a sleek look. Any advancement in solar technology is good for our industry, and we should all be excited about where solar is heading. But beyond the beautiful aesthetics, the unveiling brought to light another, more important trend: Distributed generation has hit the mainstream.

According to a report by Deutsche Bank, solar is in the process of hitting “grid parity” in a majority of states and international markets. Last year, the International Energy Agency estimated that half a million solar panels were installed every day, for a total of 177 GW of capacity worldwide. When you contemplate these numbers, it’s hard to argue against the fact that the solar energy revolution is underway.

Image: Screenshot via Tesla.com

Image: Screenshot via Tesla.com

Lost in Tesla’s announcement is the fact that solar tiles have actually been around for more than a decade. However, until now, they have been too expensive to be anything but a niche product. Based on the industry’s dramatic growth to date, driven by falling costs, the conditions may be right for Tesla to gain traction where other companies have failed.

Consumers consider aesthetics in every decision, and while some make decisions based on a desire to be and look “green” — as standard roof top solar undoubtedly does — many more would rather not mess with their home’s appearance in a desire to save what can be a somewhat marginal (10–25%) amount off their energy bill. To the degree a product like Tesla’s can do both — save money and meet aesthetic tastes — they could have a winner,

That’s not to say it won’t be without challenges. Though Elon Musk stated a 2% decrease in production between typical solar panels and his tiles, we would expect otherwise. Take a typical solar panel and a solar tile, and put the two under direct sunlight, and we wouldn’t be surprised if that figure were correct. But what matters a lot more is the solar production — measured as the “kilowatt hour per kilowatt peak”, which measures how much actual energy will be generated per kilowatt of solar capacity. And here, those solar tiles are going to fall far short of typical solar.

Why do we say that? It’s actually quite simple. Rooftop solar panels are carefully situated for maximum solar production. Those tiles — they need to be everywhere. They are on all surfaces of the roof, no matter which direction they face, and no matter how the roof is pitched or what areas may be shaded. On this basis, we would expect that drop in energy to exceed 25%, and in some cases could be as large as 50%.

The product will quite possibly have other issues as well. Roofers and other contractors are used to being able to walk on roofs when performing maintenance; but solar panels cannot be walked on, which is why engineers designate “maintenance rows” in typical solar designs. As solar panels need periodic cleaning, buildup of grime on a tiled roof could present challenges. We don’t claim for a minute that these issues are insurmountable, but only that there are still challenges to be solved that will have real costs attached to them.

At the end of the day, solar has become so cost-effective that applications like these get quite interesting. We believe that in the coming months and years, solution providers will expand market share by leveraging the new low cost of solar while expanding the solutions outward to do more, while still lowering energy costs.

So, no matter how you look at the trends, one thing remains clear: Distributed solar is well on its way to becoming the predominant energy source for a majority of people around the world. At UGE, we know that cheaper, cleaner energy will always be in fashion. Let us help you get there.