In case you haven’t heard, there is a big hullabaloo in Washington over the bankruptcy of Solyndra, a solar energy manufacturer that was developing a new product. The U.S. taxpayer is on the hook for a half-billion in loans, and the company executives are being hauled in before congress for hearings. As a result, congress is talking about cutting green energy research loan guarantees. Let’s get something straight. The technology that Solyndra was developing was no miracle product. They were taking existing thin-film solar electric technology and stuffing it into a glass cylinders assembled into large panels. Ok, that is an over-simplification, but generally thereRead More →

To design photovoltaic systems we need to meet 130 mph design wind speeds in most locations around Southwest Florida, and higher wind speeds on Sanibel, Captiva, and some parts of Naples. That means there are tremendous pressures acting on solar panels, particularly from wind uplift. The pressures in corner wind zones are even higher, especially on gable roofs. The above pictures shows a solar array on a home in Port Charlotte, FL. the area where the gable eaves meet the ridges are corner zones known as Zone 3. The wind uplift pressure in this area are often more than double that of the pressures inRead More →

How low can it go? That is the question that solar contractors and customers have been asking for the last year. In the last 6 months alone, the cost of solar photovoltaic modules has come down 20%! Every time I get a new price sheet from a manufacturer, I am amazed to see a new low. That is not to say that the total cost of a solar photovoltaic system as a whole is nosediving. The modules are now a small percentage of the total cost of system ownership. Just two years ago, the solar modules could be upwards of 60% of the total price.Read More →

I deal with over a dozen jurisdictions in which my employer does business. Each one has it’s own idiosyncrasies, costs, procedures, and problems. One county, which shall remain nameless, is now requiring a higher level of engineering than any other jurisdiction in which we operate. I can’t say that I am surprised, and it is absolutely the prerogative of the building official in that building department. However, I don’t have to like it! The effect is not earth shattering – it amounts to approximately 1% increase in price for a solar electric system on a typical home. However, it highlights something that the solar contractingRead More →

Can solar pool heating panels be put on a two-story home? Of course! However, there are some considerations that we need to look at. The first consideration is whether the existing pump is sufficiently powerful to lift water all the way up to the roof and keep an adequate flow rate to circulate and filter your pool. In most cases the answer is yes, but sometimes if you have a very small pool, a 3/4 horsepower pump may not provide sufficient flow. In this case, you best bet is to replace the pump with a variable speed pump that can operate at slow speed mostRead More →

One of my favorite things to do is take a 2 dimensional roof plan for a home in the construction phase and pop it up into a 3D computer model to show solar energy products on the roof. It’s relatively easy to make 3D models using aerial and satellite imagery, but when I have access to architectural drawings, the accuracy of the roof size is nearly perfect. I can determine exactly how many solar panels will fit on a roof and the optimal placement. The drawings can then be sent to the homeowner or builder as part of a sales presentation. We can also provideRead More →

Lots of roofs in Cape Coral, Fort Myers, and Naples have off-ridge vents. If you have this type of vent and want a solar attic fan, you are in luck! With this type of vent, the fan can be mounted inside the attic. Originally designed for the gable end of buildings, you don’t see the fan at all from the outside. The only roof mounted component is a small solar electric (photovoltaic) panel. This 12V panel provides power to the fan whenever sunlight is available (i.e. when your attic is getting hot). The solar panel can be mounted in a low profile to keep itRead More →

What happens when you want solar energy, but also want a lush landscape with lots of tall trees and shading to keep your home cool? This kind of installation requires careful planning and a tradeoff between system performance and keeping the ambiance the customer desires. In the case of this solar photovoltaic system, the customer has some pretty tall trees along the west side of the home. We calculated that late afternoon sun would shade a number of modules. This is where Enphase microinverters become very important. We did not want to lose the production capacity of the remaining unshaded modules. With microinverters, each solarRead More →