Solar panel interactions explained

Elisse Lorenc

Electricity can be generated through a variety of resources and John Maurer, president of Ames Engineering, Inc., is researching the use of solar panels in particular.

More specifically, Maurer works with solar thermal, which can be used to heat buildings, and solar electric, which is used to generate electricity for lights and other appliances.

“Light is composed of particles called photons, so when light rays come and strike a semi-conductive material [the solar panel], it excites those photons and converts them into electrons,” said Vikram Dalal, professor of electrical and computer engineering. “The electrons float to the outside wires as one way to produce electricity from the sun.”

Maurer’s history with solar energy began with his summer home in Canada, where he supplemented solar electric panels as a cleaner and more silent form of electricity.

“I was looking for a solution because prior to that when you wanted power your only choice was really to run a generator and it’s noisy … it makes it unpleasant,” Maurer said.

Maurer started with a battery-based electric system, using the generator to power up the battery as an alternate source of electricity.

“I evolved from using that generator charger battery system into supplementing it then with solar panels to the point where now I’ve got about 500 watts of solar panels up there,” Maurer said.

His next project will be implementing solar electric panels to his home in Ames this summer.

Currently, Maurer has been monitoring the solar thermal panels attached to storage buildings for Ames Engineering Inc., providing a constant source of insulation.

Each panel costs $11,000 and are constructed with strong glass, designed to hold up against one-and-a-quarter-inch hail.

Sunlight passes through the panel, inside that panel are absorber plates, and attached to the absorber plates are vertical pipes that go from top to bottom. There is a mantle fold at the bottom where the fluid arrives, distributing it equally to each vertical pipe, Maurer said.

“As the fluid moves upward through [the absorber plates], it is heated by the sun that has gone through the glass and is striking these absorber plates, heating the pipe where the fluid is rising in. Across the top from the inside, there’s another pipe where all the fluids go into and where the heated water is piped back into the building,” Maurer said.

Inside the storage building is plastic piping buried in the concrete where heated water is pumped beneath the floors for insulation.

Maurer has a webcam implemented to constantly monitor how much heat is being generated via the solar panels.

There he can monitor the temperature of the water being stored and the number of times the pump has cycled since Maurer turned on the pump.

“It’s a real simple system; it’s going to give me a good idea of what the performance in Iowa of those panels are because there’s no other real heat being generated in this building,” Maurer said.

Maurer said that by this fall, he’ll try to absorb as much solar energy into the floors as possible in hopes to gain a warmer consistency in room temperature for the following winter.

But Maurer has other objectives in mind, such as the construction of a sustainable apartment complex in Ames, incorporating both solar thermal and electric panels.

“It’s expensive to [implement solar panels] when you think about investing money in it, whether or not there’s any payback,” he said.

Brian Trower, assistant director of electric services for the Ames Power Plant, is concerned about the cost of implementing these panels.

“Solar is still a much more expensive choice for electric generation. It still does not compete well with nuclear- or coal-fired, gas-fired or oil-fired generation,” Trower said. “We just do not have the sun angle and the sun intensity here to make [solar energy] competitive yet and it’s considerably expensive.”

The Ames Power Plant runs on coal- and refuse-derived fuel, a fuel supplement derived from collected trash.

“The curb-side trash in all of Story County by contract comes to our recycling facility here in Ames and then they process it into refuse-derived fuel and then that’s injected into the boiler and that’s a supplement of fuel,” Trower said.

The Ames Power Plant generates electricity for close to 9 cents per kilowatt hour for an Ames resident.

On the other hand, if the same amount of electricity was generated from solar energy, it could cost an Ames resident up to 16 cents per kilowatt hour.

However, Dalal argued that solar energy’s potential is only in its infancy as opposed to coal and nuclear energy which has been around much longer.

“The technology is evolving,” Dalal said. “We can design solar panels and provide both electricity and heat at the same time. [Iowans] need a lot more energy for heat than they require for electricity because [Iowans] have these very harsh winters. One can design solar panels so that in the winter, it produces more heat and less electricity and in the summer, more electricity and less heat.”

Maurer said he will continue to work with solar energy, since it has great potential but is not cost-competitive.