At first glance, solar tiles are hardly distinguishable from conventional tiles. They can be a dark sheet that imitates homogeneous slate sheets, but they are also designed as Roman tiles, those with a curved mould with flat sides and reddish tones. This aesthetic camouflage means that at first glance it is not easy to tell that these tiles are capable of producing solar energy.
Aesthetics are a big advantage over traditional panels. Unlike bulky photovoltaic panels that are placed on roofs, solar tiles blend seamlessly into the design of the home. This makes them an attractive option for many homeowners who value the visual impact of their roofs. Although aesthetics may seem like a trivial factor, this detail could be key to more homes opting for solar tiles in the coming years.
Tesla's push into the solar roof tile market
The impact of a company like Tesla on the solar roof tile market has been remarkable. In October 2016, Tesla, led by Elon Musk, introduced its solar roof tile offering at an event that had a Hollywood-like atmosphere. What was striking was not just the technology, but the aesthetic integration. No one in the audience had noticed that the homes at the event included solar roof tiles until Musk mentioned it. This approach broke with the traditional image of visible, bulky solar panels.
Juan Monjo, professor at the UPM, highlights that Tesla's innovation lies in the use of resistant glass on the outside, followed by a coloured element that allows light to pass through. Beneath this structure is the photovoltaic cell. This technology makes it possible to create tiles that are no longer necessarily black, but can have the appearance of slate or traditional tiles, maintaining the photovoltaic functionality without affecting the aesthetics.
Solar tiles: a growing market
While Tesla has revived interest in solar shingles, it is not a new technology. They have been in production for over a decade, although demand has grown exponentially in recent years. Manufacturer SunTegra, for example, has seen 300% growth in just six months. This, according to its CEO, Oliver Koehler, is because many people find conventional panels difficult to integrate into a home's design.
Solar tiles offer an aesthetic solution that blends seamlessly into homes without compromising too much on energy efficiency. Although they are slightly less efficient than panels, with a 15% efficiency, their discretion and customisability make them an attractive option for many homeowners.
European manufacturers are also experimenting with these solutions. Swedish company SolTech Energy, for example, is developing solar tiles that can be fully integrated into the structure of homes, representing a growing trend in the world of renewable energy. Solar tiles like SolTech's not only capture energy, but also help with the thermal efficiency of homes.
Energy savings from solar tiles
One of the main reasons to invest in solar shingles is energy savings. According to SunTegra, a 5 kW system would cover approximately 37 square feet and cost between $16.000 and $20.000, installed. The amount of energy produced will depend on geographic location. In sunny places like California, 1,5 to 1,7 kWh can be generated annually per installed watt. In less sunny areas, like New York, output drops to 1,2 to 1,3 kWh.
To give a practical example, if we multiply 5.000 watts by 1,5 kWh, we get 7.500 kWh per year. This energy saving is significant, considering that the average energy consumption of a Spanish home is approximately 10.000 kWh annually. Therefore, solar tiles could cover most of the energy needs of a home.
The environmental impact is also considerable. According to the U.S. Environmental Protection Agency, generating 7.500 kWh annually with solar energy would avoid the emission of 5,3 metric tons of CO2, which is equivalent to traveling more than 20.000 kilometers in a car.
Regulatory and economic challenges in Spain
Self-consumption regulations in Spain have been a major obstacle to the adoption of solar tiles. Currently, legislation does not allow users to be compensated for any excess energy they may generate and feed into the grid. For many families, this means that the investment must also include the cost of batteries, which can exceed $4.000, to store the excess energy.
Another factor that deters some consumers is the price of solar shingles compared to conventional shingles. Solar shingles are about five times more expensive. However, the price per watt of these shingles is approaching that of traditional solar panels, which can make them an attractive option in certain cases.
The future of solar roofs?
Although solar shingles are still in an evolutionary phase, their potential is enormous. Monjo notes that we are still in the “prehistory” of this technology, as is the case with traditional photovoltaic panels. However, there is reason for optimism. As research into materials and photovoltaic technology advances, solar shingles are likely to become more efficient and less expensive.
Although still less efficient than conventional solar panels, solar shingles undoubtedly represent an attractive solution for those looking to improve the energy efficiency of their homes without compromising aesthetics. The industry is looking towards sustainability and the integration of energy solutions that not only save energy but also blend in with the architectural design of homes and other buildings. The coming years could see considerable growth in the adoption of this technology, especially in the area of single-family homes.