The Sun plays an exceptional role in the life of the Earth. The whole organic world of our planet owes its existence to the Sun. The sun provides us with 10,000 times more free energy than is actually used around the world. Only in the global commercial market, a little less than 85 trillion kWh of energy per year is bought and sold.
"The overarching purpose of Tesla Motors (and the reason I am funding the company) is to help expedite the move from a mine-and-burn hydrocarbon economy towards a solar electric economy, which I believe to be the primary, but not exclusive, sustainable solution."
"Tesla Motors will be co-marketing sustainable energy products from other companies along with the car. For example, among other choices, we will be offering a modestly sized and priced solar panel from SolarCity, a photovoltaics company."
Elon Musk talks about Tesla’s plans at 'Master Plan, Part Deux':
"Create stunning solar roofs with seamlessly integrated battery storage."
All Tesla company actions line up in a logical chain. Today the company has a number of products that can help us switch to renewable energy. Solar panels & roofs, energy storage systems and electric cars can make us independent of fossil energy sources.
All of these “helpers” were developed by Tesla over the years. The company continues to work on improving its products, as evidenced by its new patents.
Tesla Solarglass roof https://t.co/7lw43mL92D— Elon Musk (@elonmusk) October 25, 2019
A PV roof tile ( or solar roof tile) can be a particular type of PV module offering weather protection for the home and a pleasing aesthetic appearance, while also functioning as a PV module to convert solar energy to electricity. The PV roof tile can be shaped like a conventional roof tile and can include one or more solar cells encapsulated between a front cover and a back cover, but typically encloses fewer solar cells than a conventional solar panel.
The front and back covers can be fortified glass or other material that can protect the PV cells from the weather elements. Similar to a conventional PV panel, the PV roof tile can include an encapsulating layer, such as an organic polymer. A lamination process can seal the solar cells between the front and back covers. Like conventional PV panels, electrical interconnections among different roof tiles are needed.
Tesla filed a patent application on June 29, 2018, and it was published on January 2, 2020. This patent is related to interconnecting circuitry among solar roof tiles.
Shows an exemplary configuration of PV roof tiles on a house/Source: Tesla patent
The photovoltaic roof tile module can include a plurality of photovoltaic roof tiles mechanically and electrically coupled to each other. A respective photovoltaic roof tile can include a front glass cover, a back glass cover, and a plurality of photovoltaic structures positioned between the front and back glass covers. The back glass cover can include a glass substrate and a pre-laid circuit electrically coupled to the plurality of photovoltaic structures, and the pre-laid circuit can include a plurality of metallic strips that are attached to and in direct contact with the back glass cover.
Also a respective photovoltaic structure can include a first edge busbar positioned near an edge of a first surface and a second edge busbar positioned near an opposite edge of a second surface. It can further include a bridge electrode configured to couple to an edge busbar of the serially coupled string and the plurality of metallic strips can be attached to the glass substrate or integrated into the glass substrate.
One embodiment can provide a method for fabricating a photovoltaic roof tile module. The fabrication method can include obtaining one or more back glass covers and forming a pre-laid circuit on a respective back glass cover. The pre-laid circuit can include a plurality of metallic strips that are attached to and in direct contact with the back glass cover. The fabrication method further comprises placing a cascaded string of photovoltaic structures on the respective back glass cover such that the pre-laid circuit electrically couples to electrodes of the cascaded string, placing a front encapsulant layer and a front glass cover on top of the cascaded string, and performing a lamination operation to laminate together the front glass cover, the cascaded string, and the back glass cover.
Source: Tesla patent
Solar cells 204 and 206 can be hermetically sealed between top glass cover 202 and backsheet 208, which jointly can protect the solar cells from various weather elements. In the example, metallic tabbing strips 212 can be in contact with the front-side electrodes of solar cell 204 and extend beyond the left edge of glass 202, thereby serving as contact electrodes of a first polarity of the PV roof tile. Tabbing strips 212 can also be in contact with the back of solar cell 206, creating a serial connection between solar cell 204 and solar cell 206. On the other hand, tabbing strips 214 can be in contact with front-side electrodes of solar cell 206 and extend beyond the right edge of glass cover 202, serving as contact electrodes of a second polarity of the PV roof tile.
Process for fabricating a photovoltaic tile module/Source: Tesla patent
This is a flowchart illustrating an exemplary process for fabricating a photovoltaic tile module, according to an embodiment. The photovoltaic tile module can be a single-tile module or a multi-tile module. During fabrication, one or more cascaded strings of photovoltaic strips can be obtained. The photovoltaic strips can be obtained by dividing a standard square or pseudo-square solar cell into multiple pieces, and a string of strips can be formed by cascading multiple strips at the edges. The cascading forms a serial connection among the strips. In some embodiments, each individual solar roof tile may include one string, and each string can include six cascaded strips.
Shows a partial cross-sectional view of a multi-tile module, according to one embodiment/Source: Tesla patent
In FIG. 11, multi-tile module 1100 can include front glass cover 1102, back glass cover 1104, front encapsulant layer 1106, and cascaded strings 1108 and 1110. Multi-tile module 1100 can also include pre-laid circuit 1112 attached to or directly deposited on back cover 1104. As shown in FIG. 11, pre-laid circuit 1112 can electrically couple cascaded strings 1108 and 1110.
Multi-tile module 1100 can also include a junction box 1120 attached to the exterior surface of back cover 1104. To facilitate electrical coupling between wire 1122 within junction box 1120 and pre-laid circuit 1112, in some embodiments, via 1114 can be formed at a desired location on back cover 1104. More specifically, via 1114 can be formed by drilling (e.g., using a physical or chemical method) a relatively small hole (e.g., a few millimeters in diameter) at a desired location followed by filling the hole with electroplated Cu. Metal-to-metal contact can be made between via 1114 and pre-laid circuit 1112. In some embodiment, metal trace 1116 can also be formed on the exterior surface of back cover 1104. Metal trace 1116 can be coupled, simultaneously, to via 1114 and wire 1122, thus facilitating electrical coupling between wire 1122 and pre-laid circuit 1112. FIG. 11 also shows that the portion of wire 1122 outside of junction box 1120 can be protected by jacket 1124 from weather elements.
Tesla CEO Elon Musk forecast that the company’s energy business will eventually be the same size as — or even bigger than — its automotive sector, the latest sign that the company plans to put more time and resources to scaling up its solar and storage products.