The following is a contributed article from Lincoln Bleveans, former assistant general manager of power supply at Burbank Water and Power.
Middle-aged conventional power plants are still the backbone of the US power system. Magnolia Power Project (MPP) — a hulking natural gas-fired combined cycle power plant in downtown Burbank, California — is no different.
Sure, it had been a big deal in its youth, winning Platt's 2005 International Power Plant of the Year for environmental innovations like its Zero Liquid Discharge system and its use of plentiful recycled — rather than scarce potable — water to slake its one-million-gallons-per-day thirst. But that was 16 years ago ("power plant years" being a bit like "dog years" relative to the human calendar).
Until very recently, those middle-aged power plants — steady, efficient, large-scale conventional power production — were the stars of the power system. MPP was designed for exactly that: making as much power as possible as efficiently as possible, 24/7. Like a long-haul truck, continuous operation and fuel efficiency were its calling cards (with much smaller "peaking" plants, derived from airplane engines, taking up the slack when demand spiked). MPP thrived in that world.
Then the world began to change, slowly at first and then faster and faster. In MPP's case, only a year after commissioning California's path-breaking 2006 Global Warming Solutions Act gave a policy kick-start to the Age of Renewables. Soon economics took over: solar and wind power became cheaper and cheaper, and more and more plentiful. A virtuous cycle is transforming the power system.
Today it's the intermittency of renewables — especially solar — that dominates power system operations, from the diurnal cycle of solar switching on and off with the sun to its intraday volatility as clouds pass over solar farms. (Wind power is slightly easier to forecast and manage). And California's latest target, 100% greenhouse gas-free power by 2045, means that today's renewable integration challenges are just a taste of what's to come. That's a massive challenge for the always-on electric service reliability that our societies and economies rely on: physics does not negotiate with policy, yet we must reach our goals to best mitigate global climate change.
Back in Burbank, that left MPP with a massive mid-life crisis. As a member of the Los Angeles Department of Water & Power balancing authority (and not the California Independent System Operator — or "CAISO" — system) BWP must integrate the increasing amounts of renewable in its portfolio in real time using the resources that it has. MPP most of all: Designed for baseload operation, it MPP now must operate like a sports car, rapidly accelerating and decelerating, and not like the always-on, steady-as-she-goes long-haul truck it was designed to be. It's one thing to trade-in a vehicle as needs change (or a mid-life crisis hits — ask me how I know!). How about a profoundly complex, highly engineered $320 million power plant? Especially one that our customers will be paying for until 2037?
It had never been done before. A mid-life crisis indeed.
But Burbank (and its MPP partners) saw a mid-life opportunity. MPP's turbine manufacturer General Electric suggested a unique retrofit innovation, to upgrade to their latest combustion system (the system that delivers natural gas into the turbine) and then to push even further by adapting technology currently used in its most modern turbine designs and retrofitting it for our 16 year old plant. The technology — known as Axial Fuel Staging would open up the operability window of the turbine and could give MPP near-sports car flexibility, allowing it to run at a much lower output levels during the solar hours (lowering natural gas usage and costs) as well as accelerate and decelerate more quickly in response to solar's volatility.
GE's first application of this technology was in 2011 (on a 7E turbine), and it is now applied on new HA turbines from the factory. While the use of Axial Fuel Staging at MPP was the first application on a F-Class turbine, I suspect, they knew that MPP's innovation had the potential to become a sought after feature for their F Class fleet (over 600 turbines in North America) in the Age of Renewables. We carefully studied the alternatives — like shutting MPP down early, replacing it with energy storage, or simply operating it as-is until 2037 — but none made as much economic and operational sense as GE's proposal. After negotiating the risks to prudent levels, GE and MPP took the plunge in 2019.
It hasn't been easy. A first installation in early 2020 revealed some engineering challenges with retrofitting the technology and maintaining long term reliability and thus only a portion of the benefits we contracted for are currently operational, but the testing showed what was possible.
The GE team took back what they had learned during the initial testing and started refining the retrofit to address the challenges. The calendar has been on our side: GE was ready with the enhancements just as we started a long-scheduled major maintenance outage in early January 2021. It created a perfect opportunity to complete MPP's transformation.
The strategic timing is right for BWP too: we'll jump vault from one-third to more than two-thirds renewables in 2025-6, on our way to 100% GHG-free. That's a huge and sudden jump which creates an unprecedented renewable integration challenge and one that, in turn, will challenge BWP's ability to maintain reliable and affordable electric service to Burbank. MPP's world-beating transformation from baseload generator to renewable integration machine is key to that challenge.
Like other middle-aged power plants, though, MPP's challenges are not over. Fighting climate change decrees that MPP's primary fuel, GHG-producing natural gas, will eventually come out of the mix. We don't yet know how that next mid-life crisis will become mid-life opportunity. But MPP's transformation today points the way for other mid-life power plants that will still serve the power grid — and the grid's renewable transformation — for years to come. Even as the world continues to change around them.