The photovoltaic system in the following article was designed and installed by Thirsty Lake Solar.
Lincoln Electric Demonstrates Solar Energy System at Co-op Office
New net metering policy allows members to interconnect renewable energy systems with utility grid.
Rural Montana, October 2003
It's kind of ironic, says Lincoln Electric's Tim Engleson. The day the Co-op commissioned their new grid-tied solar power system to harvest mother nature's free energy, mother nature was consuming some natural resources of her own. A large wildfire just over the Canadian line was making a run and thick, dark smoke poured into the Tobacco Valley. The dense haze affected folks with breathing problems and limited the electrical output of the new renewable energy system installed at the Co-op's office. The system could only generate about three-quarters of its rated output", said Engleson. "There is no doubt the smoke has reduced power output from the system, but that's not what's important right now, educating our members about technology is."
The Cooperatives's new solar demonstration project follows a recent action by the board of trustees who approved a new policy that allows members to interconnect their small, renewable energy systems to the utility grid. The Cooperative's solar demonstration project has three goals:
Educate members about the advantages and disadvantages of small renewable energy systems. Familiarize the Cooperative with safety and reliability issues of interconnected renewable energy systems and how they impact the existing distribution system. Demonstrate how renewable energy systems can be tied to the electric grid by taking advantage of the Co-op's new net metering policy.
Increasing interest in renewable energy from Co-op members, and a progressive board of trustees drove the Co-op to further explore its role in renewable energy, said Engleson.
Events such as 9/11 and the recent Northeast blackout that darkened the homes of over 50 million Americans underscores the vulnerability of the nation's electrical grid. Folks want to know more about what role renewables can play in providing them power, independent of the grid, or grid-tied," Engleson said. "And our board of trustees thought it was high time to further explore this clean, reliable energy source.
The Cooperative's one KW solar system uses six- 185 watt solar panels to generate DC electricity directly from the sun. This electricity is fed into an inverter, which changes the voltage to AC. It is then fed into LEC's main distribution panel. "After panel, wiring and inverter losses, the system should be feeding about 800-900 watts of AC power onto the grid during prime solar hours," said Engleson. "We estimate the system will deliver 1,000-1,200 kWh's annually to the grid."
To allow members to interconnect to LEC's system, the cooperative first needed to approve a net metering policy that specifies how a member can legally and safely connect a renewable energy system to the co-op's poles and wires. Net metering allows homeowners to receive the full value for the electricity that their renewable energy system produces. The term, net metering, refers to the method of accounting for the electricity production of a photovoltaic or wind energy system. Net metering allows homeowners with such systems to use any excess electricity they produce to offset their electric bell. As the homeowner's system produces electricity, the kilowatts are first used for any electric appliances in the home. If more electricity is produced from the system than is needed by the homeowner, the extra kilowatts are fed into the utility grid.
At the end of the billing month, if the member has generated more electricity than they used, LEC "banks" the excess kilowatt-hours, allowing the member to offset future usage. If the members use more electricity than they generate, they pay the difference. The billing period for net metering is monthly with an annual true up.
Members are encouraged to stop at the office, take a look at this system and get their questions answered. The solar panels are roof-mounted with the remaining equipment located adjacent to the front door. "it's a great location for the system,' Engleson said. "Folks have to walk right by it to get through our front door."