Solar cell roofs made from solar shingles or solar panels are increasingly being incorporated into the construction of new residential and commercial buildings. In many areas, people choose to replace their conventional roof with a solar roof when it comes time for maintenance. And most of these people would tell you that the long-term value, or the short-term increase in resale interest, made it worth it.
A solar cell roof is called an “integrated building”, also known by the more comprehensive name “building integrated photovoltaic” (BIPV). BIPV suggests that it would have needed that part of the structure built anyway, and has chosen to use material that will also serve to generate power via solar power. The first advantage of solar cell roof tiles or panels is obvious: part of the initial cost is paid for by reducing the overall material and labor costs involved in construction. The second advantage is that the BIPV does not stand out, it is a normal and expected part of the design and structure of the building. These two advantages often make bipv solar roofs the clear choice over rooftop wind turbines, overhead solar panels, and backyard windmills, which stand out and cost much more to build and install.
In some parts of the world, often thanks to government subsidies, many new homes are being built with solar roofs. Until recently, this was not the case in the US, UK, and much of Europe because the cost remained prohibitive. However, with the invention of what is called “thin-film solar technology,” solar roof tiles, panels, and shingles have become easier to manufacture and work with, and are much more aesthetically pleasing. This technology is best for sloped roofs where shingles or small tiles are the norm. Large flat roofs, like the tops of many commercial buildings, can have a giant layer of solar film or large integrated panels.
Solar cell rooftops can be connected in two ways: on-grid and off-grid. Off-grid solar power means you’ll be using the power you get from solar panels and not connected to the power company at all or connected in a completely parallel and unrelated way. Off-grid applications may be appropriate for homes that are far from power lines but receive enough sunlight to be fully solar, homes with combined systems with other renewable energy systems, or homes in locations that receive little sunlight, so it is unlikely that the solar power generated would ever be more than what the house requires. Grid-tied systems are connected to your conventional electrical supply, and when the solar energy system generates more electricity than it needs, it actually sells it to the power company. Your meter literally spins backwards and you may get a zero bill or even a check in the mail instead of a bill.
There is some debate among real estate developers, but the general rule of thumb is that any renewable energy source for the country of origin is turned off if it pays back its original installation investment in ten years or less through energy savings. The invention and perfection of thin-film sunroofs has brought us rapidly approaching that comeback, and possibly even surpassing it depending on where you live.
There are four things to keep in mind when looking at a solar cell roof:
1. How much sun does your area get each year, regardless of the outside temperature?
2. Which way does your ceiling face? Ideally it should face east/west if it is a sloped roof.
3. What is the current and projected cost of electricity where you are located?
4. What is the general attitude of home buyers in your area towards renewable energy (especially if you could sell your house in 10 years)?
If you choose a solar cell roof for your home or business, you’ll likely be pleasantly surprised at the efficiency, cost, and savings associated with BIPV.