When the Tesla Solar roof was first announced by Elon Musk and his team, they made a very bold claim that their solar roof would cost the same as a traditional roof. After some simple calculations by The Motley Fool, it is apparent that this won't be the case.

Musk's confidence comes from his acquisition of Solar City where he served on the board for many years, however, after looking at the math, it is hard to imagine the Tesla Solar roof will be as affordable as Tesla claims (the technology is new, unproven, and still without a field test).

The Cost of the New Tesla Solar Roof

Travis Hoium of Motley Fool recently wrote a fantastic article explaining the actual cost of the Tesla Solar roof. If you want to deep dive into costs, you can read his article here. Our article will serve as a summary of his piece of the Tesla Solar roof.

No one can deny Tesla's incredibly talented PR team and their ability to promote a new product. It is important however to address the "traditional roof" Elon Musk and Tesla use in their claims. When Musk refers to a traditional roof, he is referencing ceramic or concrete tile roofs. So, what’s the problem here?

According to a recent publication, these roof types are the most expensive roofs on the market and makeup ONLY 13% of the US housing market. Ceramic or concrete tiles aside, the roof that makes up roughly 50% of roofs in America are asphalt shingles. These roofs, unfortunately for Tesla, are SIGNIFICANTLY CHEAPER (25% to 200% less) than the ceramic/concrete tiles and there is no way the Tesla solar roof can compete with this roof style when it comes to cost. Let's look at Travis Hoium's explanation:

"Based on the data sheet from a solar panel that has similar efficiency to what Tesla claims for the Silevo panels, you can fit about 19.6 watts of solar cells in a square foot. The best-case scenario for a Silevo solar cell (not the whole solar roof, but just the cell) is a cost of about $0.30 per watt, based on the price of solar cells today. That means a square of solar cells would cost about $588 before we even consider the cost of manufacturing the roof tile, installing the tiles, wiring to connect tiles, the inverter, and other components and costs that go into roofing and solar systems.

If we just use SolarCity's installed cost of about $3 per watt, we get an even more alarming cost of $5,880 per square. And I can't imagine the solar roof will be easier to install than a standard solar system, so this is probably a better ballpark figure to use."

The Future of the Tesla Solar Roof

It seems once again that the Tesla PR team did an incredible job promoting the new Tesla Solar roof, but their claims are terribly misleading. The claim that their solar roof will cost the same as a traditional roof is based off the most expensive, least conventional roofs in the United States housing market. The roll out of solar roofs by the Tesla Solar program will be a new, more complex challenge than the roll out of their electric vehicles. There is no denying the aesthetics and innovation behind these solar roofs. They are a beautiful product. Beauty aside, efficiency, cost, and even the ability to manufacture are still massive question marks.