BHE's PV Test Facility

In the summer and early fall of 2004, crews from Advanced Energy Systems installed a photovoltaic (PV) test facility on the rooftop of our building.

Conceived, designed, and funded by a consortium of forward-thinking engineers from Balzhiser & Hubbard Engineers, Inc., the facility features eight separate arrays with panels from five different manufacturers. In addition to the variety of panels on the roof, eight inverters from four different manufacturers were installed in the inverter room on the second floor. Why so many choices? To address one goal of the facility: to learn more about PV products through direct comparison of the performance of different products under different conditions.

Inverter output is being monitored using monitoring software from Fat Spaniel Technologies. The output data from each inverter is calibrated using portable metering. Throughout the first year, the performance of different combinations of inverters and arrays was tracked and compared under differing conditions of inverter loading, sunlight, cloud cover and indoor and outdoor temperature. In subsequent years we have measured changes in system efficiency in response to inverter loading, and we have compared system performance using different combinations of arrays and inverters.

The power generated by the PV's is not used directly by the occupants of The Balzhiser Building, although we could certainly do so. The reason we don't use the power is two-fold: first, the system is "grid-tied", which means the generated power flows directly to the electrical utility, because there are times, particularly on weekends and summer evenings, when we could not begin to use all of the power generated by the facility. The second reason is financial. in an effort to promote use of alternative energy sources, EWEB started their PV Eugene program under which EWEB pays customers 25 cents per KWH for power generated by PV systems for the period of the program. Even with the EWEB incentives, the array will not work economically unless we were to take advantage of state and federal tax incentives. The goal of the tax incentive programs is to encourage development of the PV equipment, which will ultimately reduce the cost of purchasing and installing these systems.

How much power are we generating? Click HERE to find out.