Last modified: 5/25/2015 1:58:25 PM
The state of New Hampshire passed legislation encouraging the use of solar electric energy for nonprofit entities, such as towns and schools, with the cooperation of utility companies to allocate grid connections for transmission of projects that are generating electric power. A very noble idea to benefit the public generally, but not individual households. As a longtime resident of New Hampshire I commend our State Representatives for creating this law.
This legislation created much interest and several towns and private schools are applying for state of NH grants that pay about 50 percent of the total cost of these solar projects. These state grants for such projects are intended to reduce the cost of construction and the towns would be charged about 8.9 cents per KW hour rate. The town of Peterborough is building a large solar project to use the reduced rate electricity for their water treatment facility and other municipal buildings. This environmentally clean electricity can also be used for police and fire departments and schools. Besides helping to clean CO2 pollution, these projects can be an economic benefit as well.
Solar photovoltaic energy technology has matured to the point that solar panels are now very cost-effective. Most are guaranteed for 20 or more years. The difference can be that some type of installations are very efficient and others are not. Here is a brief review of the two prominent differences between fixed and tracking solar systems.
A fixed solar panel array is mounted on the ground, which is the case in Peterborough, and/or rooftop. These panels produce only about 50 percent efficiency in KW hour accounting. In New Hampshire during the winter months these installations are inactive, because of snow accumulation. Because they are arranged a few feet apart in long rows, it is impossible to remove the snow by any method. Snow will accumulate on the solar panels and spaces in between rows.
The other solar system is what is known as a tracking panel array that is mounted on a foundation with an electronically controlled function that allows the arrays to follow the sun from sunrise to sunset. They also adjust for seasonal angle variations to optimize light conversion efficiency. In practical terms such tracking arrays produce twice the amount of KW hour capacity as a fixed solar array.
There are also additional differences between these arrays. The tracking arrays are at least 3 foot off the ground and are at very steep angle for winter sun, therefore no snow accumulates on the panels. If snow is not removed, it can accumulate up to 3 feet, without any effect on the array’s daily operation. In the case of fixed arrays, twice as many panels will be needed, along with labor for installation and land to match the efficiency of tracking arrays.
These differences in performance, as well as how the other half of project funding is arranged, can be substantial. In fact, the use of fixed solar arrays may not even result in the projected cost-efficiencies. In the case of Peterborough, the project is almost completed and very possibly will not successfully meet expectations.
I have been a solar PV energy technology advocate for over 40 years, and have engineered and built solar projects in the Middle East and in New Hampshire. I strongly recommend that towns that wish to participate in New Hampshire’s exciting solar energy program consult with qualified electrical engineers to determine how their specific projects should be designed and implemented, before contracting with installation contractors. These projects must comply with state codes and be clearly documented from an engineering point of view and not just rely on contractors’ sales pitches. Towns also must have the project engineering data on file available to the public.
The town of Peterborough is the center of Monadnock valley region and should have the best example of this most useful solar technology. The state of New Hampshire should be praised for passing this legislation that will greatly benefit everyone. Peterborough may have a problem with its current solar installation, but it can add additional tracking units to augment the deficiency of the existing system. This will clearly demonstrate to other towns in the Monadnock area the best way to insure they make appropriate choices to benefit their taxpayers’ interests.
Egon Ali Oglu, PhD, lives in Antrim. He is the CEO of SOLAR*MAGIC Global Corporation.