Archive for the ‘solar pv’ tag
Most solar systems are installed on a roof of a house or a building. The exception are solar farms or ground-mounted solar installations, but these are rare, and usually 100% commercial solar systems. The reason most solar systems are installed on a roof is because of limited space – especially in the urban environment.
on the other hand, roofs represent significant unused space, and are usually not shaded by trees, nearby buildings, etc – they are the highest point of a building with great sun exposure, which makes them perfect to install solar panels on.
In this article we will discuss solar roofing systems, which integrate roofing materials with solar PV panels or solar thermal systems. Although most roof-mounted solar systems are installed on top of an existing roof – be it an asphalt shingles roof or any type of flat roof – these solar systems are not integrated into the roofing material, and therefore are not solar roofs.
What is solar roofing? Roof-integrated solar systems explained.
Solar roofing is a final product which integrates a Solar Panel with the roofing material suitable for either a sloped or a flat roof. The solar panels used in solar roofing are usually thin-film photovoltaic laminates. Most popular Solar PV laminates commercially used today, are the Unisolar thin-film PV panels.
Unisolar thin-film PV laminates were originally designed to fit into and be integrated with standing seam metal roof panels. Unisolar panels are 15.5 inches wide and fit perfectly into a 16″ standing seam panels, and are attached or laminated with special butyl adhesive that is on the back of each Uni-solar PV panel.
As time progressed and solar integrators were having flat roof leak repair issues with solar systems they installed on flat commercial roofs. After they installed solar mounting racks and attached them to the roof deck, the fasteners would start leaking after a while. Roofing manufacturers adressed this issue with different versions of flat roofing materials that integrated Unisolar PV panels – one such system is IB Solar Roof. There are many types of both solar metal roofs and solar flat roofs, using solar PV panels from various manufacturers (though as I said, most do use Unisolar PV laminates).
In this article we will discuss different types of solar roofing systems such as Solar Metal Roofing, Solar Flat Roofs, and Solar Shingles that get integrated with regular asphalt shingles roofs.
Solar Metal Roofing
The most common type of solar metal roofing is the standing seam metal roof with integrated Unisolar PV laminates. Unisolar PV laminates were initially designed to fit in the pan of standing seam panels, with the connection terminals concealed by the ridge cap. Because the connectors or terminals of these PV panels are not UV stable, they need to be hidden from the sun, while the rest of the panel is of course exposed to the sun to generate solar electricity.
Read the rest of this entry »
Update – Dec. 12, 2010 – recently we’ve uploaded a gallery of many metal and flat roofs that we’ve installed in Massachusetts, Connecticut and Rhode Island – see the roofing jobs gallery. All roofs mentioned below are listed on the roof gallery page, with references to job profiles, and before / after pictures.
Roofing in Massachusetts
Massachusetts is our home state, and we install majority of our roofs here (with Connecticut being in second place). In Massachusetts, the roofing market is very different, depending on location, and although there are a lot more sloped roofs, not only in Mass., but in the rest of the country, we still install more Flat roofs than Metal roofs. As for the geographic location of your home in Massachusetts, up north, toward the New Hampshire border, roofs are more prone to Ice Dam roof leaks and damages than houses located in the southern MA.
Although Massachusetts is not a very big state, your location can have a dramatic effect on the amount of snow fall in the winter, and thus your chances of having Ice dams and related roof leaks. For example, on the same day, an average roof in Sharon or Norwood will have 1-2 inches of ice along the eaves, whereas an average roof in Lowell will have 5+ inches of ice build-up. If you go further north or south away from Boston the amount of annual snow accumulation and ice dams will increase or decrease respectively. Read the rest of this entry »
As I’m writing this, the 2009 Solar Decathlon in Washington, DC is nearing its completion. Twenty teams from around the globe are competing to build the best Solar Home, judged in ten different categories, including: architecture, engineering, net metering, living comfort as well as others. This year, Massachusetts – home to some of the greatest colleges and universities in the world – is represented by Team Boston - the joined efforts of Tufts, Boston Architecture College and a team of volunteers, all with the common goal to create green and sustainable home designs that could be readily available and affordable for actual home buyers and home builders. You can read my 2009 Solar Decathlon Review with pictures and videos I took there during Columbus Day weekend.
Cool Flat Roofs and IB Roof Systems are proud sponsors of Team Boston’s solar home. We provided the project with IB flat roofing materials (provided by IB Roof Systems) and a professional installation, as well as last minute roof design changes, and modifications to roof penetration placement and drainage setup. Read the rest of this entry »
The word on the “roofing contractor street” is such that a large PVC roofing manufacturer has problems with their Roof-integrated Solar PV systems. Apparently, the way they designed and installed these solar roofs, the electrical wiring which connects Solar PV panels to the inverter and essentially the Electric Grid, is overheating and poses serious risks of fire. Since this information is still in rumor stage, and I doubt there will be an official announcement or acknowledgment of these, I for many reasons cannot name the manufacturer, the specifics of the problems or the source. However, there is evidence that it is real. If you are a large roofing contractor in Boston, MA area or in the rest of New England, you are getting the roofing bid lists such as the Blue Book. We do not as large commercial and government roofing jobs are a little out of our league, and we get plenty of work without paying huge sums of money for these bid lists (it costs anywhere from $3000/year to get periodic updates). However, in the last 3 weeks I’ve been contacted twice by two different gentlemen from Suffolk Construction. Basically Suffolk is arguably the largest GC in Boston area with $1.57 Billion in sales in 2008, have over 800 employees and are rated #313 of America’s Largest Private Companies by Forbes.
The picture bellow, shows a Solar roof produced by IB roof systems. This roof does NOT have overheating problems, and is intended to demonstrate what Solar Roofing is.
In any case, the two gentlemen from Suffolk, asked me to bid a new job in the pipeline of roof bidding lists: A 4,000 squares (400,000 sq. ft.) on the IRS building in Andover, MA, and also they wanted 500 KW solar PV system that would be roof integrated – essentially they were interested in our IB Solar Wise PV system which in some ways is similar to the one above, but without the wiring overheating of course Read the rest of this entry »
Electricity of the 21st century.
Do you know how your electricity is generated? For a long time I kind of knew, but was too lazy to actually ask my father, who is a physicist, what exactly is going on in the power plant. Now it boggles me to live with the fact that in our modern time when an all-inclusive communication and Internet device (iPhone, BlackBerry, etc.) is smaller than a deck of cards, we still use 19th century technology and basic principles to generate our electricity. Once you actually give this idea a thought, it becomes a shocking notion that our best minds have not been able to create a better way to create electrical power than to burn coal and natural gas – two most commonly used sources of energy to create electricity.
Just in case you were wandering, coal or gas is BURNED to heat up water which then becomes hot steam and drives the turbines. This is a basic principle and the actual process is more complicated, but even the “sophisticated” nuclear power plants work in similar manner.
Note: I did know that electricity can be generated in the old fashioned way, but I actually thought that there was some kind of a mechanism to directly convert energy stored in gas / coal / oil directly “into” electricity, instead of emulating the old steam-engine – oops… It is a shame that our 21st century society is still burning fossil fuels to make the turbine spin.
Aside from the fact that we get our electricity the same way as before WW I, natural gas, oil and especially coal are extremely dirty fuels, emitting dangerous pollutants, which affect our environment in such a drastic way that just a couple of generations from today, our children may not be able to enjoy the outdoors the same way we can today. I won’t even start talking about climate change and global warming. On top of everything mentioned above, humanity is quickly approaching a world-wide energy crisis. Our oil reserves are getting depleted, and if you believe in “Peak Oil” theory, we are about to approach the peak of the curve, which means that oil will continue to become more scarce and prices will keep on rising.
Although coal is very abundant, it is also becoming more expensive to mine, and delivery once again involves burning petroleum based fuels, creating more and more pollution. It is obvious to most intelligent people (except those heavily invested in oil, coal, cars, etc.) that we need a clean, renewable source of energy. Despite what may seem like rhetoric about renewables, I do honestly believe that this is the way we will power our world. However, the renewable energy must be affordable and/or competitive with current sources of energy.
So what is the answer – what is a modern and clean way to generate electricity? Well, there are a few, and the most popular ones are Wind and Solar. My personal favorite is Solar and here is why.
Wind Turbines require lots of open space and lots of (you guessed it) wind to work effectively. Although wind is a great source of renewable energy, and unlike solar can work at night, it is not “customizable” or adaptable for the urban environment. There is just not enough space or wind in the city.
Solar on the other hand works just as well in city as in the country side. All you need is southern exposure with no or minimal shading. Solar can be installed on a roof of a sky-scraper, on the ground or even on a roof of a car. Solar is also a scalable system, and you can add or remove PV panels and/or inverters at any time. The bottom line is that solar photo-voltaic power generation is much more practical, and can be implemented where that power is needed. Besides that, both ways of getting “free” electric power from renewable sources are great. Given the notion that solar is more practical and flexible, lets get to the solar PV systems design and implementation.
Getting solar for your home or business.
Despite all the positive aspects of solar, it is expensive – VERY expensive. Additionally, not every site is suitable for a solar system installation. Therefore, if and when you decide to get into solar, the system must be designed and installed to operate at maximum efficiency, to offset its high costs and speed up the pay-off time.
Step 1: Gathering information about a perspective site for the solar project, and how much solar electricity you will need.
As mentioned before, the first step in determining if a solar system should be installed, a basic site survey must be perfored. Sinse most solar PV systems are installed on roof tops, the basic requirements for a site survey ar as follows:
- The roof plane where the solar system would be installed must have a southern exposure with some variations to the east and west. You can figure this out with a simple compas.
- There should be no shading from trees and surrounding buildings and structures to achieve the highest sun light exposure. This gets tricky, as the sun has a different angle to the earth during winter and summer months. Thus, even in the winter, when the sun is at its lowest point, solar panels should have unobstructed exposure to it. The best way to determine where your shading is throughout the year is to use a special tool called “pathfinder”