Tesla Solar Roof V3 Review – Is It Worth It? Cut The Hype

Is the Tesla solar glass roof worth it - featured image

We are going to address three questions:

  • number one what is the efficiency of the Tesla solar glass v3
  • number two how Tesla’s roof tiles have evolved and
  • number three with the lower price for the v3 how do they now compare against normal solar PV installations?

There were a lot of comments asking about the efficiency of the third iteration of the Tesla solar glass, so here are the details.

The Tesla solar roof Version 3 is more expensive per watt compared to a conventional solar panel installation – 6/7 dollars per watt compared to 2.5 to 4 dollars. The Tesla solar roof is worth it if the installation is done on a new build, when the solar tiles are installed instead of the regular roof tiles.

How Did The Tesla Solar Roof Develop?

Tesla has been in partnership with Panasonic, which has helped them to develop both their battery technology and their solar panels.

In fact, Solar City’s Model S C 325 panel was the same as Panasonic HID 325. It was just rebranded as Solar City and now it will be rebranded as Tesla. The solar cells used in these panels are also used in the solar glass V3. These solar cells are based on Panasonic’s HIT technology, which stands for hetero-junction with intrinsic thin layer, with the added two thin layers of amorphous silicon that surround the crystalline silicon.

There are more levels of net to capture the energy, therefore resulting in the higher performance of these cells in comparison to standard crystalline silicon cells in the market. The efficiency of energy conversion per unit area of the HIT solar cell is a remarkable 22.5 two percent.

At the panel level it drops down to 19.4 percent, which is still high in the list of top panels. Note that the efficiency of the panels is always lower than the cells, because of the presence of structural elements and gaps between the cell.

How efficient are the Tesla solar roof tile solar cells?

With the knowledge of solar cells let’s go on to calculate the efficiency of the v3 solar glass. As you can see the larger tile is 45 by 15 inch, but there is an area in which the tile is to be overlapped by the surrounding tile. The solar cell size is approximately 5 by 5 inch. Now there are different sizes of the solar glass tiles.

There are smaller ones with just 2 solar cells for tight spaces and there are larger tiles with 16 solar cells. Some tiles don’t contain any solar cells at all. They are the ones to be put on the borders or the corners and can be cut to shape.

Tesla solar roof - is it worth it?
Is the Tesla V3 solar roof worth the money? Photo courtesy PV-Magazine-USA.com

The efficiency of the large tile per unit area comes out to be 12.45 percent when viewed in isolation, whereas if we take into account the overlapping areas of the surrounding tiles, then the efficiency per unit area increases to around 14.61 percent.

The efficiency of the smaller tile with two solar cells is less than 10 percent. With these numbers we can estimate the amount of maximum power that we can generate for a given roof.

How much power can the Tesla solar roof deliver?

For example, if there’s a roof of 32 square meters then with the Tesla solar glass we will be able to generate not more than 4.9 kilowatts of maximum power. Now let’s turn our focus to how the Tesla roof tiles have evolved.

In 2016, when Tesla launched their first version of the solar tiles, they had produced something that was aesthetically far superior than any other product in the market. However, in terms of cost and practicality it had a lot to be desired.

The installation cost of over a hundred thousand dollars have been reported in some cases and it took a couple of weeks to get the system up and running, even with 10 to 15 people involved in the installation. The problem was the intricate connections as each tile had to be wired individually. Tesla had to go back to the drawing board.

In the next version they started producing pre-wired modules in which there were stacks of three normal sized tiles. This approach brought down the installation time and cost. In the version three, Tesla has gone for larger tiles.

By kind permission Synergy Files

There are tiles which house 16 solar cells for almost 54 watts of power. The v3 compared to the v2 has even lower components, lesser sub assemblies and lower installation times. This also translates to lower cost to the customer.

Reports have suggested that the prices have come down by 40% compared to the previous version. Now let’s address the third question, which was how does Tesla solar glass v3 compare with normal solar PV installations?

As far as the aesthetics are concerned, there’s nothing in the market that can match the v3 solar glass. It is also durable, being able to withstand 2 inch diameter chunks of hail stone. The efficiency is lower compared to conventional PV.

It is only 14.61 percent efficient but that shortcoming is overcome by better form factor on the roof. That is, you can have more area covered on the roof by the solar glass than the normal panels. This makes up for the lower efficiency value.

However, there is one other factor that should be considered. It is the reason why there will be 10 percent lower electricity units generated by the glass roof when compared to the normal panels. It is the transmittance of the glass material that is used in the solar tiles.

You must have noted that the solar cells in the solar glass are only visible in a narrow range of angle. As long as the viewing angle is close to perpendicular, you can view the solar cells. At higher angles from the normal the solar cells are not visible.

This is done to make the tiles look like normal roof when viewed from the ground. A higher refractive index glass is used by Tesla. The disadvantage this brings is that the incident solar radiation received by the tiles at higher angles is not converted into electricity, so when the Sun is either too high or is close to the horizon, the solar glass is unable to utilize the light effectively.

It cannot also utilize sky reflected radiation that is coming from higher angles. This results in 10% less for you at the end of the day compared to normal PV. If your roof installation is purely for aesthetics, then solar glass is your go-to option.

How much is tesla solar glass roof?

If, however, you’re on a budget and would like more value for your money in terms of electricity units produced, then normal PV installation is your best choice. Interestingly Tesla offers both systems. In fact, in most cases for the same amount of money the customers can get an additional power wall if they go for Tesla’s normal solar PV installation.

If the house is a new build and roofing needs to be done, then the solar glass gives more value. This is because you save on the roof tiles. As the price has come down for v3 solar glass, it can actually save you money compared to normal tiles.

For quick price estimates one could use the price per watt for solar glass of 6 to 7 dollars per watt compared to normal PV installation, which is 2.5 to 4 dollars per watt.

The prices here are not just for the PV panels but for the total system, which includes the cost for all components, like inverters, wiring and also the installation cost. To sum it up, for retrofits conventional PV still remains your best option.

Related Questions

How much is tesla solar glass roof?

A Tesla solar glass roof costs in the region of 6 to 7 dollars per watt, which includes all components, wiring and the labor for installation.

Is a tesla solar roof worth it?

A Tesla solar roof is worth it for a new house build, where the solar tiles are fitted instead of regular roof tiles.

Does tesla solar offer financing?

Tesla has several financing options, but the easiest and most cost-effective way to finance is by line-of-credit loans on your property.

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