There are amazing options available for building integrated photovoltaic installations. We will cover from the most expensive to the more affordable options and we will not be limiting ourselves to solar roof tiles alone.
Photovoltaics that are integrated into the fabric of the building look pleasing to the eye and can actually increase the value of your property by more than 5%. Before we explore the various options let me clarify one thing.
If you have a limited roof space and a limited budget, and you want to maximize the energy generation then the normal solar PV installation is your best bet in most cases. However, if aesthetics mean something to you then there are quite a few options that can benefit you depending upon your budget.
What is meant by integrated photovoltaics?
We will go from exploring the most expensive to the lowest cost alternatives. We have the following options for BIPV or building integrated photovoltaics.
- One – we have solar roof shingles or roof tiles
- Two – we have the flexible solar laminates
- Three – we have roof integrated photovoltaic systems
- Four – we have the transparent solar glass
When exploring BIPV prices we normally get quotations for per square foot of installation but please bear in mind that BIPV elements are not the most efficient. They require a lot of area and run at hotter than normal temperatures, so it would be much better to look at the price per watt to get the best estimate of your payback time.
The prices mentioned here will not include the other components, such as inverters, wiring and batteries, etc. Let’s start with solar roof tiles. Now contrary to popular belief solar roof tiles have been around for a long time.
They were however brought to the attention of the masses when Tesla put their weight behind them in late 2016. Elon Musk mentioned that the cost of a roof using Tesla roof tiles should be less than your normal roof with a conventional solar installation. In reality though, it is not the case. It can actually cost a lot more.
What is building integrated photovoltaics?
This depends upon the type of roof being replaced as well. Asphalt tiles will be the most expensive to replace with Tesla solar roof tiles. On the other hand, in the case of replacing slate tiles, it makes a little more economic sense.
Tesla roof tiles at present will only appeal to the luxury end of the market. Besides Tesla there are three other players who have been in the solar roof tile market for a long time. These companies are Sun Tegra, CertainTeed an RGS.
Building integrated photovoltaics cost
With the cost of installation added, Tesla roof tiles would cost about $22 per square foot, while Dow Powerhouse tiles cost about $11 per square foot. In terms of price per watt, we’re looking at $8 per watt for Tesla roof tiles and around $4 per watt for other brands.
There are some Chinese alternatives but the product quality is far inferior. They don’t look as aesthetically pleasing and the discount is only that of 30% compared to Tesla. Having broadly covered solar roof tiles, let’s switch to some of the cheaper alternatives.
If you have a metallic roof, or are thinking of getting one, then you can bag yourself a PV system at a much lower price. There are flexible solar laminates available that you can simply stick to your box-profile metallic roof sheets.
An integrated photovoltaic system – DIY?
You can either stick the panels yourself to your existing roof using adhesive kits that are freely available or you can purchase roofing sheets with flexible panels already attached, such as the ones available from Marcegalya.
I can cost you around 1.5 dollars per watt to 3 dollars per watt, depending upon the size of your installation and flexible panel band that you choose. There are a number of suppliers providing flexible solar panels.
The thin film amorphous silicon panels are very low efficiency and would require a very high covered area on the roof for a certain amount of output. On the other hand, the thin film CIGS panels provide a higher efficiency and also better performance, even when they get hot.
It’s best to avoid amorphous silicon panels and pay a little bit extra for CIGS panels. There are certain Chinese brand that also sell flexible panels, which can bring down the cost to $1.00 per watt, and even lower if purchased in bulk.
Integrated photovoltaic roof
Number three is roof integrated PV system. The idea here is to take the conventional solar installation and use it in place of roof slates, rather than attaching in front of them. For retrofits and even for new builds, this is the best option which looks totally non obtrusive and maintains a low profile.
In fact, a well-fitted installation blends into your roof seamlessly. There is no need of putting metal brackets to hold your PV panels in place and therefore no penetration into the tiles is needed that could result in tracking later on.
It does require specialist installers. The overall cost is only slightly more than the cost of your normal PV installation. You can use your conventional panel with weatherproof mounts and lining membrane, or you can buy panels that are specifically designed for a roof integrated system.
Depending upon the type of panels and the storage, you can achieve costs of around $1 to $2 per watt. We have covered the roofing options – we will now look at another important BIPV element, which is the solar glass.
Integrated photovoltaic solar glass
Solar glass can be used in windows, conservatories and facades. It can let in sunlight and at the same time generate electricity. A variety of options are available in solar glass. You can have glass with opaque solar cells partially covering the overall area.
You can also have semi-transparent and near transparent solar glass, but these options are a little more expensive. The glass with opaque solar cells can be purchased for around 1.3 dollars per watt, if you buy above 300 watt capacity.
For transparent solar glass there are two popular suppliers, which are namely Onyx Solar and Polysolar. Their products cost around two dollars per watt. For example, a one meter square glass with greyish tint and a peak conversion efficiency of 15% is sold for $300 by Polysolar. It can generate 150 watts of power during peak times.
What is solar paint?
Another exciting product that is on the horizon is solar paint. With it you can paint any wall and convert it into a solar panel. This paint however requires both moisture and sunlight for operation. It’s still early days and a minimum of five years has been cited for this technology to commercialize.
One common disadvantage of all BIPV components is that they are not installed at the best angle to maximize the output but they do generate something which is better than nothing.
Please note that you might be eligible for grants and discount offered by your local council. This can bring down the cost of your PV system substantially. In addition, you’re more likely to get permission if you live in an area where home renovation or refurbishment requires approval from a local body, if you go for a building integrated PV installation rather than a normal one.