The Orlando Utilities Commission (OUC – The Reliable One) is moving forward with two energy storage projects — one involving hydrogen and the other lithium-ion batteries — to help integrate the public power utility’s growing solar fleet.
OUC, which serves about 250,000 customers in the Orlando, Florida, area, is also in final negotiations to add 149 megawatts of solar to its system, likely in the mid-$20 per megawatt-hour range, according to Sam Choi, OUC manager of emerging technologies and renewables.
OUC’s customers use about 8.1 million MWh a year and the utility has a goal of supplying 20 percent of its retail needs by 2020 from sustainable resources such as solar, nuclear and energy efficiency.
Looking further ahead, OUC has positioned the City of Orlando to meet its goals of being 100 percent renewable by 2050, with city buildings getting all their electricity from renewables by 2030. The public power utility operates independently from the city.
With 108.5 MW of solar coming online next summer and the two pending 74.5-MW solar contracts with Invenergy, OUC is looking for ways to manage the fluctuating output of a significant amount of solar on its system, Choi said.
In August, the U.S. Department of Energy announced the winners of a $40 million funding initiative for large-scale hydrogen generation, transport, storage and utilization projects.
A group led by Giner ELX won a $4 million grant. The group includes OUC, GM, OneH2 and the Florida Solar Energy Center at the University of Central Florida. The three-year study, expected to start in 2021, will help OUC integrate solar onto its system.
The project includes hydrogen storage tanks, a 510-kilowatt electrolyzer, three 70-kW fuel cells and a 750-kVA transformer.
It will focus on mitigating the effects of fluctuating solar generation, including increased wear and tear on power plant units, increased costs for operations and maintenance costs as well as carrying reserves, and possible generator shutdowns during periods of peak solar output, according to OUC.
The hydrogen project will help smooth swings in solar output. The electrolyzer for hydrogen production will be ramped up and down to serve as a “shock absorber” for grid fluctuations, according to OUC.
Hydrogen will be stored for use in fuel cell electric vehicles or in stationary fuel cells for later electricity production.
OUC expects hydrogen will play an important role in the future, but the utility is looking at all types of energy storage, Choi said.
The utility, for example, will contract with Invenergy for 10 MWh of lithium-ion battery storage capacity for two pilot projects, Choi said.
OUC plans to install an 8-MWh battery at a substation and a 2-MWh battery at a customer site that will be linked to a 1-MW floating solar array.
The utility intends to explore several uses of the batteries at the substation, including smoothing solar fluctuations and shifting peak load to off-peak hours, according to Choi.
OUC also intends to test the batteries on helping with frequency regulation and deferring transmission and distribution investments, Choi said.
OUC expects to receive the batteries next year, he said.
Meanwhile, the OUC board at an Oct. 8 meeting gave approval for utility staff to finish negotiating the planned 20-year solar power purchase agreements with Chicago-based Invenergy.
Under the proposed PPAs, Invenergy would build and operate two 74.5-MW solar arrays, each covering over 500 acres, near existing OUC transmission lines in Osceola County, according to the utility.
“OUC is powering the rapid growth of our community with clean, renewable energy and innovative storage technologies,” Clint Bullock, OUC general manager and chief executive officer, said.
Coming in at under $30/MWh, fixed-price solar contracts provide a good hedge against fuel cost volatility while allowing the utility to meet its clean energy goals, Choi said.
The Invenergy PPAs will include an option for OUC to buy storage capacity at the two solar arrays, according to Choi.