In conjunction with the start-up of its new membrane filtration facility, the Camden & Rockland Division of Aqua Maine, Inc. (Aqua) has started construction of a combined solar thermal and photovoltaic energy system at the Mirror Lake facility to reduce purchased power consumption of the membrane filtration facility.

The new $7.2 million facility, required under new EPA regulations, is now complete and operational at Mirror Lake in Rockport. The new facility uses more power to push water through the filters, and the microfiltration membranes must be periodically cleaned with heated water. Rick Knowlton, vice president of operations, says, "While the original design of the facility included a large electric heater to warm water for the membrane cleaning process, we knew that this would be a perfect application for a solar thermal system to supplement or reduce the use of the electric heater. Almost 2,500 gallons of warm water will be needed every day, and the solar system being constructed should reduce our purchased electricity by 80,000 kWh every year. It's one of the larger solar systems installed in Maine."

In addition to the solar thermal system, photovoltaic panels are being installed on the roof of the filtration plant to generate electricity on site to supplement the facility's power needs. The solar thermal and photovoltaic system was designed and is being installed by ReVision Energy of Liberty and is expected to be operational by the end of August.

The total capital cost of the solar thermal heating system and the photovoltaic panels is $145,000, which is then reduced by $41,250 through an Efficiency Maine grant. Power cost savings over the next 20 years are projected at $210,000. The financial benefits of the grant and the power savings have been passed on to the Camden & Rockland Division customers as part of the recent Maine PUC decision on rates.