Dr. Jonathan Kimball, an Assistant Professor in the Electrical Engineering Dept. at S&T, is working on methods to improve the amount of energy gained through the use of solar electricity harnessing systems.

If a homeowner or business is going to apply a photovoltaic solar power system to their home or facility, they would expect to get the most for their money. With the standard practice of installing solar panels in series, there is a big loss that can occur when one or more of the panels aren’t performing optimally.

Dr. Kimball is creating a component to add to the system that will take the energy captured and immediately convert it from Direct Current (DC) to Alternating Current (AC) at the solar panel. With the power conversion already done, a parallel circuit, in the stead of a series circuit, can be created between the solar panels and the grid.

In a parallel circuit, the performance of individual panels will not limit the total amount of energy produced. Photovoltaic solar panels create Direct Current (DC) electrical flow (as a result of the photovoltaic effect) so long as there is an intense enough light source available. But appliances and the standard electrical ‘grid’ run off of an Alternating Current (AC) flow.

When all of the panels are creating different amounts of electricity, and the panels are interconnected by a series circuit, the DC electricity from one panel passes to the next panel, and so on, until the cumulative DC energy reaches a DC-AC converter.

After the electricity has gone through all of the panels and has made its way to the DC-AC converter, the electrical energy may have been diminished by some noticeable percentage, depending on the conditions affecting each panel.

By converting the DC electricity flow into AC electricity at the panels themselves, the amount of electricity produced will not depend on the operation of individual panels. The result is a parallel circuit where each panel’s created energy is relayed to the system at 100 percent of the power captured.

Dr. Kimball indicated that, when purchasing a solar electricity system for your home, about 60 percent of the cost goes directly into the panel itself. The remaining 40 percent of costs go towards installation of the panels, the structural support components themselves, and the AC-DC power converters. That 40 percent is what Kimball hopes his technology will impact.

Dr. Kimball identified two sides to owning a solar power system: the costs and the revenues. The costs include purchasing the panels and the system you intend to use. Revenues include the excess energy created by your system, which can be sold back to electricity companies. Kimball’s research into cost effective micro-inverters will make the installation of solar panel arrays cheaper, as well as increase an owner’s return on their investment.

By converting the direct current into alternating current at the panel, via Dr. Kimball’s micro-inverter, the electricity need not pass through the other panels before entering the grid. Instead, the AC electricity can run along a parallel circuit and make it to the grid without being diminished by unproductive solar panels.

The technology being created by Dr. Kimball and his team will continue to have an application in the field, regardless of innovations in the production of solar panels themselves.

New materials for the photovoltaic panels, new components and procedures for the handling of produced electricity, and an increased number of tax incentives for utilizing ‘clean energy,’ all mean that the purchase of an efficient solar power electrical system should become more economical than at present between the next five and 10 years.

By purchasing a solar electricity system, “you’re buying all of your electricity now and using it for 20-30 years. … If you think about the way electricity costs are probably going to go up, [purchasing a system] becomes a better argument. There are a lot of things that will ultimately push energy costs up. So if you have a solar electricity system now, you’re insulated from those cost increases, because you’ve already bought your electricity.”

Don’t jump on the boat right away, though. One’s geographic location and climate should play a big role in one’s choice as to whether or not to buy a solar powered electricity system with current technologies. In Missouri, there are sun filled, long summer days, but on average during winter, the sun can only be seen shining its face a couple of times a week. Depending on where one goes from here, a solar powered electrical system could be an uneconomical choice.

In Rolla, the average residential electricity meter run by Rolla Municipal Utilities uses about 33 kilo-watt (kW) hours every day. If one were to purchase a 3 kW solar panel array, to the tune of about $20,000, and that array saw 8 hours of “peak sunlight.” a potential of 18kW hours could be generated, possibly offsetting your monthly electricity bill by a substantial amount over 30 years.