** Update: As of May 1st, 2020, the cost of Tesla solar roof tiles is 30.77 $CAD per square foot (before taxes). For a standard 1800 square foot roof, the total cost would be 55 386 $CAD (before taxes). This cost is based on a roof made of 35 percent solar tiles. **
Tesla’s solar roof tiles will soon make us rethink our perception of solar installations forever, but at what cost?
When you imagine installing on a roof, it is probably with conventional solar panels attached to an aluminum structure. Tesla is now looking to change your thinking with their new product, which is both a roof tile and a solar panel.
Although technically not shingles, these solar tiles from Tesla and Solarcity, look like traditional shingles and work very well with the house. They are not to be confused with the low-profile panels recently introduced by Tesla; these are real panels designed to cover the shingles to conceal the fixing hardware.
Elon Musk said in October 2016 that the cost would be comparable to that of a typical roof. Talking to investors in November 2016, he said: “… would you like to have a roof that looks better, lasts twice as long, costs less, and moreover, generates electricity?” He justifies that the cost would be lower when we combine the cost of a traditional roof and the projected savings on electricity services. But the fact remains that there are still skeptics who are not convinced that this is feasible.
Tom Werner, President of SunPower (a SolarCity competitor), explains why the implementation of the solar shingles failed: they overheated due to a nonsufficient spacing. The spacing between the roof and conventional solar panels, on the other hand, provided adequate ventilation, thereby avoiding overheating.
An important concern: what did Musk mean when he said that the cost of his shingles would be comparable to that of a “normal roof.” He had to specify that he was talking about the prices of ceramic and concrete tiles, which are quite expensive, between $ 400 and $ 2,000 per 100 square feet. However, a normal asphalt shingle roof costs an average of $ 90 per 100 square feet. All this to say that the final cost, without specifying what kind of roof we are comparing, is likely to be much higher.
1. Motley Fool
A columnist for Motley Fool has made calculations to predict how solar shingles compare to a traditional roof. He estimates that based on a manufacturing cost of $ 0.30 per shingle (equivalent to $ 588 per 100 square feet) is comparable to ceramic or concrete tiles. But be aware that the installation costs are extra: Tesla says that the cost price is $ 3 per watt installed (meaning $ 5880 per 100 square feet or $ 176,400 for a standard 3,000 square feet house.
2. Consumer Reports
… Have developed a calculation including anticipated savings in electricity in order to be competitive with a traditional roof; they determined that a maximum expenditure of $ 73,500 would be necessary in order to be competitive with asphalt shingle roofing, one of the least expensive solutions. According to information provided by roofing installation associations, and assuming an average house with a 3,000 square foot roof, the total cost of this asphalt shingle roof would be approximately $ 20,000. They then added an annual cost invoice of $ 2,000 in their calculation (costs theoretically eliminated by solar shingles), and the life of the shingles being 30 years as stated by Tesla. After thirty years, savings are expected to rise to around $ 60,000. When the Powerwall, which is part of the installation of the electricity storage system for non-solarized moments, and which costs $ 6,500, the savings would be reduced to $ 53,500.
Thus, with a normal asphalt shingle roof costing $ 20,000 and savings of $ 53,500 with solar shingles, the Tesla option should not exceed $ 73,500 to be competitive.
In an interview with Energysage in June 2019, a northern California customer who had a Tesla solar roof installed as well as three Powerwalls gave some details and an overview of the cost of the installation. According to the customer in question, the entire installation cost CAN $ 140 000, which included the complete replacement of its 1,000 square foot roof and three Powerwall 2 (three batteries of 13 kWh autonomy each). Without the Powerwalls, the replacement of the old roof and the addition of the solar roof cost CAN $ 98 000, which comes to CAN $ 98 per square foot. The system has a power of 10 kW and keeps the lights on in the customer’s home without needing the electricity network 80% of the time. Its roof had several obstructions and had a high slope, which drastically inflated the price of its system. It would therefore seem that the price of CAN $ 30.77 is for a roof without obstructions and with a constant and slight slope.
It is important to note that these are estimates only, and do not take geographic variations into account. GreenTech Media also has concerns that not all shingles would be able to produce electricity efficiently due to the sunshine’s variability.
The calculations provided strongly suggest that having a Tesla Solar Roof eliminates the electricity bill entirely, rather than only reducing it. However, the estimates cannot consider variations due to the complexity of the installation compared to that of a traditional solar installation. There are many factors that can significantly affect the total cost of the project.
The Tesla Solar Roof is not a new concept. Other manufacturers have already attempted the production of solar shingles; some have failed, and others are still on the market. One of the products from Dow Chemical’s Powerhouse Solar System only lasted five years; at the time it was the product of choice, but the company end up going bankrupt.
Other companies are continuing to produce and install solar shingles. But it is difficult to find the costs associated with it. It is important to note that the companies listed incorporate solar shingles and tiles with traditional materials, while Tesla’s solar roof tiles are designed to cover the entire roof or even replace it. But Tesla’s competitors are demanding that a large part of the roof be covered with normal shingles (at customer cost) in addition to the price of their systems.
1. Dow Chemical
Even if the company is no longer in business, it is worth looking at it because of cost information. Their Powerhouse system did not cover the entire roof; it came in super shingles that fit well with traditional shingles. Installing 350 Powerhouse shingles would cost more than $ 20,000 and reduce electricity consumption by 40-60%. In a Dow press release, it was announced that “for an additional expense of $ 27,480 above the cost of a traditional roof, you could collect $ 58,640 in energy savings over 25 years, and similarly increase the value of your home by $ 33,000 ”.
The largest company still in operation that offers solar shingles is CertainTeed; it sells its Apollo II system through its accredited installers; this system would only cover a part of your roof. CertainTeed guarantees that you will get 60 watts of energy per solar tile for 25 years. It provides protection against damage created by wind or shocks. CertainTeed estimates that a 350 square foot solar shingle layer would cost approximately $ 20,000, and reduce your electricity bill by 40 to 70%.
SunSlates is a product of Atlantis Energy Systems; a standard set includes 216 slate surfaces covered with solar wrap covering 300 square feet of roof. The company employs experienced installers. The Eternit tiles are very popular in Europe and allow excellent drainage. The costs are quite expensive; $ 13,000 per 100 square feet or $ 39,000 for a standard set. They are higher than CertainTeed’s Apollo II. The Eastern (US) sales manager says his product costs between $ 8 and $ 10 per watt, slightly below estimates of $ 13,000 / $ 39,000. Always cheaper than some of Tesla’s products, it should always be remembered that SunSlates only covers part of the roof.
SunTegra manufactures both solar tiles (which look good with asphalt shingles) and solar tiles (which look good with ceramic roofs). Both products have high efficiencies and their design promotes good ventilation.