Synchronous condensers are playing a vital role in stabilizing the transmission grid as energy sources shift from large generating plants to more distributed sources. They are one of several solutions utilities are incorporating to adapt to the challenges of intermittent power supplies from renewable energy sources.
What Are Synchronous Condensers?
Synchronous condensers are dynamic controllers of reactive power—alternating current (AC) whose current wave leads or lags the voltage wave and whose presence determines local grid voltage. Adding current to the condenser’s spinning coils produces reactive power—measured in volt-amperes reactive, or VARs—and boosts grid voltage. When the current is reduced, the machine absorbs VARs, depressing voltage and absorbing power spikes, according to IEEE Spectrum.
Boosting grid voltage is especially important during a switch from one generating source to another, when power levels may drop for a few seconds. The condensers help maintain a constant flow of electricity during these shifts.
Synchronous condensers also help improve the efficiency of long power lines. By absorbing reactive power, the condensers can improve the power factor and allow more real power to be transmitted through a fixed size line.
The need for maximizing transmission capacity and increasing electrical power consumption is driving growth in the synchronous condenser market. A recent report predicted that the market will reach $572.9 million by 2021, representing 2.1% in growth from 2016.
Condensers in Substations, Shuttered Plants
While some utilities are installing new synchronous condensers, others are repurposing existing generators at old power plants that have closed. The California Independent System Operator ordered a condenser conversion following the shuttering in 2012 of the San Onofre nuclear power plant. Without the 2,200 MW plant, located between Los Angeles and San Diego, voltage control weakened all across Southern California, raising the risk for blackouts, according to IEEE Spectrum.
A Southern California utility is currently adding synchronous condensers at three sites, including a substation in Oceanside. Beta Engineering is providing the engineering, procurement and construction services for this project, which is slated to be completed by the end of the year.
Each condenser weighs 400,000 pounds, or 200 tons, and is about 20 feet tall and 40 feet long. The condensers are being manufactured in Germany, and will be delivered to Oceanside in April on a 326-foot-long, multi-axle trailer.