Something New is Cooking in the Concentrated Solar Power Industry

The first solar thermal parabolic concentrator in the United States, which may be the first installation on a private residential home, is now operational at a residence on Martha’s Vineyard, MA. This may be the most powerful solar collector, for its size, ever installed on any residence in the world.

For the past 40 years, if you wanted to heat your water with the sun, you had a choice of buying either a flat plate collector, or an evacuated tube collector. A company based in Nova Scotia, Solartron Energy Systems (https://www.solartronenergy.com),  has finally made available, at a reasonable price, by using a more efficient  method of collecting the suns rays, a parabolic concentrator. Almost all of the parts of this concentrator are fabricated in Michigan, but are assembled at the company headquarters in Nova Scotia, , and then shipped world wide.

Paul D. Adler received a grant from the Massachusetts CEC, to install this concentrator, and is very happy with the results. This may be the first time in the United States that any State solar incentive program has ever awarded a grant for a parabolic concentrator. Paul, a building designer for 30 years on Martha’s Vineyard, who attended Worcester Polytechnic Institute, said,

 I have been studying solar thermal and solar electric for years, and I was ripe for a system that could produce the higher temperatures I was seeking, for both space heating, and a system that could produce electricity at the same time. As soon as  I reviewed a news article of this parabolic concentrator, I knew that was it.

A parabolic concentrator is sort of a reverse magnifier. The concentrator made by Solartron Energy Systems is called the SolarBeam, and it collects the sun’s rays from a 15 foot diameter dish, which focuses these rays to a small 10” x 10” collector that is filled with water running through copper coils. The collector, also called an “absorber”, can reach temperatures of 1200 F degrees on a sunny day. This thermal gain is then transported to the home or commercial building via underground insulated pipes just like any other solar thermal collector will do. The heated water is then used for space heating or domestic hot water, or heating one’s swimming pool. Heated water can also be used for air conditioning through a conversion process called absorption chilling.

The SolarBeam is usually mounted on the ground, though commercial roof mounts are available, in a location where there are few trees to block direct exposure to the sun throughout the day. Because the SolarBeam is a two axis tracker, meaning it can move in two directions, it perfectly and automatically tracks the sun from sunrise to sunset, through a sophisticated celestial GPS navigation system, similar to those in used in expensive telescopes.

“Many confirmed test prove that tracking”, claims Mr. Adler, “increases the efficiency and solar gain, over a standard fixed panel system, by at least 25-35%. A standard flat or evacuated tube system can not adequately utilize early morning sun or late afternoon sun, due to the diffuse solar ray’s angle”.

Other advantages of concentrator are the higher temperatures that can be achieved. Mr. Adler points out “I could produce water temperatures in excess of 400 F degrees Fahrenheit, but for safety reasons, the system is set to a maximum of 200 F degrees. Achieving 200F degree water in the winter months is effortless. Other flat plate systems also have a high heat loss in the winter times, due to their excessive use of glass and/or copper tubing radiating heat to the cold outside temperatures, which is only a very minor issue with a concentrator. Also, unlike a standard flat plate system, a concentrator will never overheat, as it will simply turn away from pointing at the sun in a few seconds, if any over heating ever occurs. This overheating is called stagnation, a design criteria that plagues designers of all flat plate type thermal systems.“

Is this concentrator for everyone? No, says Mr. Adler. “A concentrator, due to its higher initial cost, will mainly be used for larger residential homes, or commercial buildings, wanting both space and/or pool heating. If you live in an average size home, and you just want to heat your domestic water,  your best bet is a standard flat plate or evacuated tube system. However, if you have a large heating demand, the higher efficiencies of a concentrator will no doubt be the preferred system, as long as you have a wide exposure to the southern sky”. The SolarBeam can produce up to 13kw (42,000 BTUs) of thermal heat per hour, making it the most powerful solar collector for its size in the world”

The average installed cost of a concentrator is from $35,000 and up. However, with the current State and Federal rebates, this price can be reduced by up to 40%. Mr. Adler’s current oil fired hot water heating and domestic hot water bill, for his home and pool, was averaging about $9,000 a year. After the rebates, his system should pay for itself in only 3-4 years. “The first day the SolarBeam was working, I shut off all oil use, what a great feeling”.

In the next several months Solartron will be sending Mr. Adler the first commercially available high temperature photovoltaic solar cells, that will be inserted into the current absorber. These triple junction PV solar cells, currently produced by Boeing for space vehicles and used in high heat situations, will be able to produce up to 4.5 kW of electricity from just one SolarBeam, and the SolarBeam will still make 8kw of thermal water at the same time. This will be the first commercially available solar collector in the world that can produce both electricity and thermal energy at the same time. Triple junction high temperature photovoltaic cells achieve efficiencies up to 44%, as compared to current PV photo cells, with efficiencies of around 11-14%.

Mr. Adler was so excited by this product that he formed a company called Southern New England Solar (www.solarbeam.us), and received a three state exclusive distributorship for the SolarBeam. Currently, several large homes and commercial business have expressed great interest in this product. The SolarBeam is the first parabolic concentrator to be registered and certified by the independent testing labs of the SRCC, a requirement in receiving State or Federal funding.

Mr. Adler claims “The SolarBeam, unlike wind turbines, makes no noise, is low to the ground, not exceeding 14 feet high, and your neighbors will never know you even have one. Though I also love wind power, if I installed a noisy 100 foot tall wind tower in my neighborhood, it would create a lot of problems, and rightfully so”.

The concentrator system was installed by Paul D. Adler and the system components were designed Peter Skinner, a solar engineering design expert from Albany, NY (https://www.e2gsolar.com) , who has written several solar thermal books and travels the USA teaching solar thermal workshops. Peter also has assisted in formulating the NEBCF certification testing qualifications for solar installers nationwide.

Tags: concentrated solar hotwater, diameter dish, energy systems, foot diameter, nova scotia, parabolic concentrator, residential solar, solar collector, solar power home, solartron, space heating, suns rays

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