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In a number of regions, due to low insolation, it is impractical to install a full-fledged solar power plant. However, you can provide such needs as lighting or the uninterrupted operation of a circulation pump: talk about modern roofing that generates electricity.
What is photovoltaic roof tiles
The solar cell does not have to be a panel or film form factor. In 2005, under the Powerhouse brand, the first prototype of a photovoltaic converter was presented, at the same time serving as a protective roof covering. And although the concept itself aroused genuine interest, solar tiles did not receive rapid development. However, over time, the development of production technology made it possible to reduce the cost and make the product large enough to appear on the wide market..
The main feature of photovoltaic shingles is the rejection of traditional roofing. While standard solar panels do not provide protection from precipitation, wind and mechanical stress, the tiles serve as a full-fledged coating with a very attractive and original appearance. In addition, there is no need for a special installation system: the tiles are attached to the standard battens without additional substructures..
The structure of FG shingles may differ depending on the manufacturer. There are coatings in the form of rigid tiles or panels, flexible shingles and stamped sheets. Most often, the phenomenon of the photoelectric effect is achieved through the introduction of flexible energy cells, similar in design to film batteries. Also patented is the technology of deposition of amorphous silicon in several layers and coating with compounds of rare metals. The last two types of tiles have a conversion coefficient comparable to crystal panels – about 20%, which ensures generation of up to 200 W / h per sq. m of coverage area.
Photovoltaic shingles have a high density of energy-releasing elements and allow using the entire roof area, while a standard solar installation always has gaps in the form of frames or indents from the edge of the slope. The special optical properties of the protective transparent coating also play a role: in modern tiles, it acts as a camera trap and efficiently absorbs rays with a small angle of incidence, which supports generation in the morning and evening hours..
Leading manufacturers and brands
CertainTeed Solar is one of the oldest representatives in the industry. These shingles are essentially ordinary solar panels equipped with waterproof docking locks. The coating is characterized by the lowest performance indicator – about 50 W / m2. At the same time, the selling price for shingles is one of the most democratic, and its protective and operational properties are at the level of the best manufacturers of roofing, which, in fact, CertainTeed is. It will be possible to purchase products from the USA only by ordering a turnkey installation from a company that has access to foreign suppliers, because this tile cannot be found on the open sale.
SolteQ is a German manufacturer of panels consisting of a set of standard polycrystalline elements placed on a rigid substrate and coated with a durable compound with special optical properties. The configuration of the panels is such that they fit without problems on a continuous crate with an overlap. They do not have outstanding strength, however, in the absence of passing loads, they can be operated for about 50 years in most climatic zones.
Tegola is one of the most popular suppliers of solar tiles in the CIS. Tegosolar is a coating with a soft bitumen backing on which a flexible thin-film photocell is placed. Like ordinary bituminous shingles, it is laid on a lining carpet, at low slope angles and on a flat roof, shingles are fused onto a Euro-ruberoid substrate. Unlike rigid elements, flexible shingles have a reduced energy release, but at the same time they are affordable and durable.
Tesla Solar Roof is a promising development of Solar City, the largest solar panel supplier in California. Despite the release of the third version of the tile, the introduction of the product to the international market is still only in the plans. At the same time, the production capacity is constantly growing, which means that it will be possible to evaluate the efficiency of Tesla tiles in the Russian climate in the foreseeable future. Solar Roof is interesting for its technical features, since it is a whole technological complex, which is based on a lithium battery, an inverter and a charging unit, placed in a single case with an attractive design. The photocells themselves use standard polycrystalline, but the form factor of the tile is remarkable: small flakes that allow you to occupy as large a roof area as possible and thereby level the difference in electricity production in comparison with standard panels.
Solar Frontier, a Japanese competitor to Tesla, offers a product that rivals, and in some respects even surpasses, the products of American innovators. The shingles were developed in the shortest possible time and with complete disregard for the design component of the project, resulting in a coating of less thickness and weight, while the power generation is the highest among analogues. Unlike Solar Roof, Japanese roof tiles are available in the CIS market and are the main competitors to SolteQ and Tegosolar. It is a panel of a fairly large format – each with an area of about 1 m2, which fit seamlessly.
Installation features
Each individual sample of solar tiles has its own installation instructions, which differ in the method of joining the elements of the coating, their fastening and assembly of electrical circuits. And yet, the main differences lie in the format of the covering elements, we will consider them on two specific examples of working with flexible and rigid tiles..
Tegosolar – the installation of the tiles is carried out on a solid lath covered with a lining carpet with a vulcanizing layer on the surface. These materials differ from standard underlay carpets in that the surface is designed for overlaying subsequent layers. Thus, instead of branded linings, you can use standard Euro-roofing material and other materials with comparable water resistance..
Laying of flexible shingles is carried out on a strict grid without displacement of elements in rows. The fastening process is extremely simple: first, the shingles are laid in place, joining with the neighboring ones. First, it is necessary to install the cable duct fastening elements on the edges and remove the protective film. After that, the free edge must be lifted and the surface of the substrate must be melted with a gas burner. When the entire contact area is ready for gluing, the raised edge of the tile must be lowered and carefully pressed against the substrate, avoiding divergence of the joints. For good bonding, both surfaces must be dry and clean..
Electrical installation consists in connecting each element to an insulated current-carrying bus laid along the vertical joints. To do this, each shingle has a pair of wires with connectors that can be used for both parallel and mixed connection, depending on the topology of the electrical circuits. After making the connections and laying the conductors, the tray is closed with a protective cover.
SolteQ – rigid tiles are mechanically fixed, for which the panel structure can provide holes for through fastening or click-system elements on the back. The key difference between the installation process is a significant reduction in electrical installation: the panels are connected to each other by contact terminals located at the joints, and their integration into a common network is performed under the ridge, wind or cornice cover.
A suitable base for the installation of rigid tiles can be a sparse sheathing. However, its pitch must correspond to the tile format, while a counter-grill and a hydro-barrier are required. For cold roofs, most woven materials or a micro-perforated film are suitable; for insulated roofs, a hydro-barrier should be selected taking into account the required vapor permeability.
Can you provide more information on the application prospects of photovoltaic roof tiles? Also, I am curious about the installation process and any specific features that need to be considered.