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Power Supplier


Southern Illinois Power Cooperative (SIPC), located at the Lake of Egypt, just south of Marion, Illinois, is your cooperative’s wholesale power supplier.  Formed in 1948, SIPC began producing electricity in 1963 for three distribution cooperatives which included Southern Illinois Electric Cooperative, Egyptian Electric Cooperative of Steeleville, Illinois and SouthEastern Illinois Electric Cooperative of Eldorado, Illinois.  At the time, SIPC’s plant capacity was 99 megawatts (MW) which was produced by three 33 MW turbines each powered by a cyclone boiler.  SIPC constructed the Lake of Egypt so it could be used as a source of cooling water.  The lake also offers public recreation and residential development areas.

In the 1970’s, the demand for electricity surged and threatened to exceed SIPC’s plant capacity.  A decision was made to construct a fourth generating unit.  Unit 4 came online in 1978 and provided 173 MW of generating capacity.

In the 1990’s, changes in the utility industry made it increasingly difficult for a small power producer such as SIPC to thrive.  SIPC also faced making a decision on how to replace capacity on a plant that was nearing the end of it’s useful life.  Over the next few years, SIPC doubled its membership to include Monroe County Electric Cooperative in Waterloo, Illinois, Clinton County Electric Cooperative in Breese, Illinois and Tri-County Electric Cooperative in Mt. Vernon, Illinois.  Later, Clay Electric Cooperative in Flora, IL became a member of SIPC.  With these additions, the number of end users receiving power from SIPC grew to nearly 80,000.

The growth in membership enabled SIPC to completely refurbish the old units.  The three aged cyclone boilers were replaced with one circulating fluidized bed boiler.  The new boiler is environmentally friendly and burns mostly carbon.  While the new boiler was under construction, SIPC also added additional pollution control equipment to Unit 4.  Taken together, these improvements allow SIPC to meet environmental standards and insure that the plant will continue to operate well into the future.  Both the new unit and Unit 4 burn local coal and carbon.

In the past, SIPC relied on neighboring utilities when demand for electricity was more than they could produce.  In today’s market, electricity is traded like any other commodity.  To reduce reliance on the market, SIPC built two natural gas-fired combustion turbines.  These units can be started when market prices are high or when incoming transmission lines are too congested to import power.

To deal with the increasingly complex electricity market, SIPC and three other similar power cooperatives formed ACES Power Marketing in 1999.  ACES, which is headquartered in Indianapolis, Indiana, has grown to 16 members and provides numerous services related to buying and selling power.

The electricity market continues to evolve.  Most utilities have been ordered to join a group to improve reliability of the transmission system.  SIPC belongs to the Midwest Independent System Operator (MISO).  MISO monitors power flowing throughout much of the Midwest.