As Michigan transitions to more renewable energy, affordability and reliability – even during peak demand – are key. Engineers and developers are always looking for new ways to store excess energy and harness it when it’s needed to help support wind and solar generation – while keeping the lights on and energy bills affordable. Way ahead of its time, the Ludington Pumped Storage hydroelectric power plant, co-owned by DTE Energy and Consumers Energy and located on a 1,000-acre site on Lake Michigan in Mason County, helps both companies do just that.

The plant, one of the largest of its kind in the world, acts like a giant battery. It consists of a man-made reservoir located above six 300-ton turbines. The reversible turbines work as pumps when energy is plentiful and low-cost, such as when the sun is shining and the wind is blowing, and as power generators when demand is higher and renewable sources less abundant. The plant pumps water from Lake Michigan uphill to the 27 billion-gallon reservoir at low-demand times and releases the stored water downhill through the turbines to generate electricity when energy demand is higher. Ludington Pumped Storage supports the expansion of our renewable energy sources while ensuring Michigan residents and businesses can depend on a reliable energy grid that produces clean, affordable energy.

The plant, which first became operational in 1973, is licensed by the Federal Energy Regulatory Commission (FERC). On June 6, the Commission gave DTE and Consumers Energy the green light to run the Ludington Pumped Storage plant an additional 50 years. The two companies came together on June 20 along with the local union and retirees to celebrate the facility’s relicensing.

“For nearly 50 years, Ludington has provided a sustainable, clean, reliable energy source that quickly responds to the daily, weekly and seasonal highs and lows of Michigan’s energy demand,” said DTE’s Ryan Randazzo, manager, Asset Optimization. “The plant plays an increasingly important role as a storage facility for renewable energy produced during off-peak periods, thereby making renewable energy more affordable and reliable.”

An $800 million upgrade project to replace each of the six turbines is on schedule to be completed in 2020. Ludington will then support enough power for 1.65 million residential customers – an increase of 250,000 customers over the current output.