One of the most exciting developments in the residential solar industry has been the development of “solar shingles”. These shingles are smaller, thinner versions of the standard solar panel. The idea is you can have these solar shingles installed in place of your old shingles or roof tiles. But do they really work out well for homeowners?
Solar shingles are a relatively new technology. Manufacturers and installers are still working out the kinks, but the basic technology is pretty sound. If you are interested in solar shingles for your home there are four substantial advantages and four drawbacks to keep in mind.
Solar Shingles could be a real game-changer for homeowners who want to take advantage of solar power. Unlike traditional solar panels that you install on racks above the roof, solar shingles can become part of the roof itself. Potentially you can get all the power of solar panels in a system that is a lot more appealing to the eye.
What is a Solar Shingle?
“Solar shingles” act like a solar panel. At the heart of both are “cells”, wafers of semiconducting material that create an electric current when they are exposed to light. The distinction is that an individual solar shingle is smaller and thinner.
Solar shingles are designed to fit together much like traditional roofing shingles, and have a similar appearance. Depending on the make and model, they could conceivably be fit in among standard asphalt shingles. They are designed to take the place of standard shingles, protecting the roof structure from the elements while generating electricity.
There are also “Solar Tiles” that can be used in tile roofs. Solar shingles and solar tiles are referred to as “Building-Integrated Photovoltaics” (BIPVs) and they have similar performance. Solar shingles are more common, so this article will treat them both as “solar shingles.”
Solar shingles (and tiles) are more likely to be based on thin-film solar cells, meaning the glass and metal frame of a solar panel will be replaced with a durable, flexible glass coating, but inside the actual solar cells — the part that converts light into electricity — will essentially be the same that you would find in a solar panel.
Solar Shingles: The Pros
1. Cheap, Green Electricity
The number one reason to install any sort of solar power system is the same whether you use the more established solar panels or the newer BIPVs. Adding solar power equipment allows you to generate electrical power on your own, reducing your dependence on the grid.
You can use tax incentives to reduce the cost of installing solar power, and then operate your home on solar power as long as the sun shines. With battery backup, you can even use solar power well after the sun has set.
Solar power is the greenest, most sustainable power there is. If you are at all concerned about global climate change, solar panels do not emit any gases, and unlike nuclear power they do not create radioactive waste. Your home can run on sunlight.
2. Solar Shingles Are Integrated into Your Roof
Solar shingles and solar tiles don’t go up on top of your roof; they become a part of your roof. In other words, the solar shingles take the place of your asphalt shingles or slate, and solar tiles take the place of the stone or cement tiles.
Solar shingles are designed to be every bit as durable as solar panels. They stand up under wind, heavy rains, and golf-ball-sized hail.
With solar shingles, your roof structure is a lot simpler than it would be if you had a standard roof and solar panels above them — you can dispense with the mounting brackets. Having fewer parts means having fewer things that can break. It also means that if you are thinking about going solar and are ready to replace your current roof, you can replace that old roof with solar shingles and turn two projects into one.
3. Solar Shingles Are Attractive
Economically solar panels might be very practical, but aesthetically they often leave a lot to be desired. The mass of solar panels will break up the roof’s appearance, and depending on the architectural style the appearance could be jarring. The effect isn’t so bad with a modernistic or functional look, but solar panels can clash with an old-fashioned or rustic exterior.
The difference between solar panels and solar shingles is very striking. Solar tiles and shingles in general have a much less prominent profile. Whatever style of roof you have, BIPV’s will at minimum preserve the overall shape of the roof. Even if they are distinct from the rest of the roof material, the effect is much less glaring.
And progress has been made in creating solar shingles that mimic the look of traditional roofing materials. From the ground level at least the appearance can be pretty impressive. Tesla in particular has created solar shingles that are difficult to distinguish from many traditional roof types, including asphalt shingles or even slate.
The technology behind these shingles is pretty clever. Solar shingle makers have learned they can use the light-bending properties of glass to make shingles that appear to have a particular color and texture from one angle — that would be the perspective of the pedestrian walking up to your home — while they are transparent from above, where the sunlight that powers your solar cells comes from.
There is a tradeoff. Someone viewing your home from a tall building nearby will see through the glass and recognize the solar shingles for what they are. But for guests in your yard or neighbors walking past your home can look as appealing as ever.
4. Less Controversy with Historic Buildings or Home Owners Associations
Solar shingles could go a long way toward making it easier for solar power enthusiasts to get along with their neighbors. If you live in an area with a homeowners association (HOA) you will probably need to get their approval before making any significant change to the appearance of your home. And because solar panels clash with many home designs, that approval isn’t always a given.
A similar issue can come up if your home has some historical or architectural significance. Preservationists will understand that technology changes, but they will want to keep as much of the original appearance as is possible.
With solar shingles, there’s a much better chance that you can design a solar power system that preserves the look of your home and keeps up the overall beauty of your neighborhood. Even if you can’t find an exact match, there is a much better chance you can design a solar power system that your neighbors will find acceptable.
1. New Technology
The basic principles behind solar shingles are fairly well established. The prototypes have been tested. The technology works. But solar shingles are still relatively new. There are still some kinks to be worked out. That can cause problems for homeowners.
On a square foot basis, solar shingles are not quite on par with solar panels. The difference is not crippling but it is significant, around 15% lower wattage per square foot.
Engineers have honed in on a cause and are working on solutions. The chief problem seems to be air circulation. Traditional solar panels are set up on racks above the roof, so air circulates below them, cooling the panels off. But solar shingles are fixed firmly into the roof. They get less air circulation and heat up more. The heat makes the shingles a bit less efficient at converting light into electricity.
Because solar shingles are so new, many construction and electrical contractors are not familiar with them. Depending on where you live you may find it difficult to find an installer who can put your solar shingles up or wire them together.
In extreme cases, it may not be possible to get the make and model of solar shingles you want up on your roof. Tesla in particular has had difficulties with rolling out its solar roof, and has even refunded deposits made by some of its customers because it is unable to arrange for installation.
This should become less and less of a problem as time goes by and more contractors are trained on solar shingle installations. But for now this is a significant hurdle for homeowners who want the combination of green power and attractive aesthetics that solar panels can provide.
2. Fewer Make and Model Choices
Currently only about half a dozen manufacturers are offering solar shingles in the North American market. By contrast, there are around 20 makers of full-sized solar panels. This means there are fewer choices for consumers.
This could cramp your style if you (or your local HOA) are particularly fussy. As things stand now even if you have found a contractor who is well-versed in solar shingle installation, you may have trouble finding a shingle that really matches up just so with your design and color scheme.
This will likely change as more companies develop solar shingle technologies and bring their own offerings to the public. As long as you are not overly particular about texture or coloring you should be able to find a shingle that fits in reasonably well with your home. But for the time being there is no guarantee you will be able to get an exact match.
Solar shingles are not cheap. They are new technology that require specialized materials and methods to make. The shingles are smaller but you need more of them to cover the same area or to get the same amount of power. Electricians and roofers are unfamiliar with them as well, which can drive up the cost of installation.
Overall, installing solar shingles or tiles instead of the more familiar solar panels can double the overall cost of installing a solar power system. That can go up to a factor of six if your roof is especially large or complicated.
This is partly a consequence of solar shingles being new. As more companies enter the field competition and new manufacturing techniques should bring lower prices. But solar shingles will probably always be a bit more expensive than panels. Their smaller size means there will be more units that need to be wired up in order to produce the same amount of electricity.
4. Not Practical for Every Home
Solar shingles will not work on every home. Because the shingles are integrated into your roof, they will point in the direction that your roof points, and the angle will be determined by the pitch of your roof.
Whether you install solar panels or shingles, to get the most power from your solar power system you want sunlight to fall directly on your panels as long as possible. That means you want your panels pointed more or less due south, and tilted at the right angle (typically around 45 degrees, though that varies according to your latitude.
With solar panels, if your home isn’t oriented very well toward the sun, or your roof pitch is a little too steep or too flat, you can use the rigging on top of your roof to compensate. If you’re really committed to solar power you can even set up a “tracking” system that moves your panels throughout the day to match the sun’s position.
None of that is possible with solar shingles. If you don’t have a decent-sized part of your roof facing south, or you have an extremely steep or flat roof, odds are solar shingles will not work for you.
Building Integrated Photovoltaics — Solar shingles and solar tiles — are a major step forward in solar power technology. In time they could make it easier to install solar power in millions of homes. They can make solar power a lot easier on the eye.
The technology is still relatively new: new enough that choices are limited, prices are a bit stiff, and installers face a learning curve. The technology is sound, however, and the difficulties are the sort that should be overcome with time. The future for this technology is bright.