Using a Demonstration of Energy and Efficiency Developments program grant from the American Public Power Association, the Northern California Power Agency has completed a study marking the initial development of a clean hydrogen production and storage facility.
In December 2020, the Association awarded NCPA a $48,500 DEED grant to study the feasibility of developing a renewable hydrogen production facility. Specifically, NCPA used the grant to understand the cost drivers and processes needed for the development phase of hydrogen production facility.
In addition to the $48,500 grant, APPA also provided NCPA with a $100,000 grant in early 2023, which produced a development plan outlining aspects of the pre-Front End Engineering and Design for developing the Lodi Hydrogen Center.”
NCPA is looking to develop the Lodi Hydrogen Center at the site of the joint powers agency’s existing 300-megawatt, combined-cycle, natural gas-fired Lodi Energy Center, which also is the site of the City of Lodi White Slough Water Pollution Control Facility, and Pacific Gas and Electric’s proposed Hydrogen-to-Infinity complex. The project is also included in the State of California’s statewide hydrogen hub funding application to the US Department of Energy under the Infrastructure Investment and Jobs Act.
The initial design of the Lodi Hydrogen Center calls for an electrolyzer facility capable of producing 24 tons of hydrogen per day, equivalent to about 56.7 MW, using a proton exchange membrane electrolyzer.
Hydrogen produced at the facility would primarily be used to supply the natural gas-fired Lodi Energy Center with fuel that would be up to 45 percent hydrogen. According to NCPA’s technology partner, Siemens Energy, the plant is on track to operate on 100 hydrogen as early as 2028.
The hydrogen produced on-site is also slated to be utilized for medium to heavy-duty trucking along adjacent highway corridors, and to reduce emissions from shipping and overall operations at the Port of Oakland. The project also includes a significant Pacific Gas and Electric-led research and development program to help facilitate the future transmission of hydrogen through the state’s existing natural gas pipeline infrastructure.
When the original turbine at Lodi failed early in 2020, NCPA opted to replace it with a newer model capable of burning a fuel mix with up to 45 percent hydrogen. The new turbine at the Lodi Energy Center began operation in 2012.
“We expect to eventually move to 100 percent clean energy,” Scott Tomashefsky, regulatory affairs manager at NCPA, said. “Our objective is to make sure this plant can play a role going forward.”
The combined-cycle plant has fast start capability, and Tomashefsky expects that, with a growing renewable resource mix and policies in California that are moving toward the use of natural gas plants, the Lodi Energy Center will be more and more important with hydrogen as a fuel source. “State policy is moving away from the use of natural gas for power generation,” he said, “and this work provides us with a pathway to have the plant continue to serve our customers for years to come.”
NCPA has evaluated other storage technologies but found they have limitations. Lithium-ion battery storage is expensive for long term storage. Pumped hydro storage is capital intensive, heavily regulated, and not suitable for all geographical areas. Flywheel storage is difficult to scale up to utility size and has significant capital costs. Flow batteries, thermal salt storage, compressed air energy storage, and various other technologies have all been evaluated by NCPA, but thus far “have not been deemed beneficial to our agency objectives,” the report said.
Hydrogen emerged as a technology that can offer baseload and carbon-free generation, depending on the feedstock used for hydrogen production. So NCPA said it chose hydrogen storage to reduce emissions and extend the life of this invaluable fast-ramping plant that still plays a key role in assuring the reliability of the state’s electrical grid.
NCPA contracted with California engineering, architecture and construction services firm GHD, which authored the preliminary engineering, pre-Front End Engineering Design study for the Lodi Hydrogen Center project.
The scope of the report included preliminary site layout; modelling of power consumption, water consumption analysis, process volumes and flowrates; balance of plant engineering; a review of permits and authorizations that could be needed; and the preparation of a risk register to identify key project design, permitting, implementation, construction, and operational risks.
The scope of the project itself included the electrolyzer, a hydrogen compression system, a hydrogen storage system capable of storing about two days of production, hydrogen loading and staging facilities, and balance of plant infrastructure.
The two most critical technical obstacles to successful completion of the project would be securing a sufficient supply of water for the electrolyzer from the City of Lodi via recycled water produced from the White Slough Water Pollution Control Facility and the procurement of long-term, low-carbon dioxide power that would be wheeled to the facility, the report said. The City of Lodi is a founding member of NCPA.
Accounting for emission credits when hydrogen is introduced into a gas pipeline or is blended for use in a turbine can be tricky, Tomashefsky said. “We know hydrogen combustion produces zero emissions,” but accounting for the credits from an electrolyzer can be difficult, he said. “People have a wide range of perspectives.”
Tomashefsky compared the green hydrogen market to the solar power market 20 years ago. “It is still in the early stages of development.”
GHD estimated a total installed cost for the Lodi hydrogen project at $208.29 million with an annual operating cost of $28.66 million.
NCPA said it expects that the hydrogen study will help other utilities that operate natural gas plants in California and across the public power community understand the scope and costs needed to undertake similar analyses.
“Discoveries and knowledge gained during this study, and subsequent ones performed by the industry, will define the roadmap needed to keep California’s gas turbines relevant as the grid transitions to carbon-free resources,” the report said.
NCPA said it plans to present the report to its governing commission and to monitor the state of the industry with regard to technology, legislation, and capital costs so it can be ready to capitalize the project if warranted by circumstances.
NCPA represents its 16 public power utility members that collectively provide electricity to more than 700,000 Californians. NCPA owns and operates a nearly 800-MW power portfolio, including hydroelectric, geothermal, and natural gas-fired generation facilities.
APPA on August 2 will hold a webinar related to NCPA’s hydrogen project. The webinar is free for DEED members.
The report is available to DEED members here.