Overview
The Gordon Research Conferences (GRC) has a 22 kilowatt (kw) DC solar electric (or photovoltaic)
system that can currently produce about 30% (on average) of the electricity GRC consumes on an annual
basis. On average, the GRC solar electric system generates about 60 kw of electricity on a daily basis -
which is enough electricity to power about 6 typical residential homes!
The GRC solar electric system is comprised of two separate classes of solar electric equipment.
One is a 17 kw, Pure Grid-Tied System and the other is a 5 kw, Bi-Modal Grid-Tied System
(see the diagrams section for more details). The installation of both systems was made possible
by generous grants from the Rhode Island Renewable Energy Fund / Rhode Island State Energy Office.
GRC currently sells 75% of the "energy attributes" generated by the GRC solar electric system to
People's Power & Light, Inc (a Rhode Island non-profit). These attributes are aggregated with other solar
energy attributes to create "certificates" that can be traded through the New England Power Pool.
To find out more about this program, visit the People's Power & Light
website.
How the GRC Solar Electric System Works:
Sunlight hits the solar electric panels on the roof of the building and the sun's energy is converted to
flowing electrons (DC electricity, like in a car battery). For the Bi-Modal System, that DC
electricity travels through wires into the electric room in the building and enters a device called a
charge controller. The charge controller feeds this DC electricity into four batteries, which are
stored in a box in the electric room. These storage batteries allow us to store this DC electricity
for use should we need the electricity during a power outage or when the sun is not shining. Wires
connect these batteries to a device called an inverter, which converts the DC electricity to
AC electricity (which is wall socket electricity). The DC electricity made by the solar panels in the
Pure, Grid-Tied System is connected directly to the inverters (no battery storage). The inverters
then send this AC electricity into the GRC building's electrical distribution system.
Meters in the electric room inside the building record the amount of energy (measured in kilowatts) that
the GRC solar electric system produces. The amount of electricity that GRC makes and distributes to the
electrical grid from this renewable source is then deducted from the total amount of electricity that GRC
consumes, so GRC purchases only the difference between what it uses and what it makes (this is called
net metering). If GRC ever makes more than it needs, the excess electricity would go out into the
grid to be used by others, and GRC would actually get a credit from Narragansett Electric.
The GRC solar electric system was funded by generous grants from
The Rhode Island State Energy Office and
The Rhode Island Renewable Energy Fund.
For information on renewable energy programs in Rhode Island, contact the State Energy
Office at (401) 222-3370.