You know someone is confident in their success when they’re not afraid to talk about what they could have done better.
Such is the case with Pittsburgh International Airport, which last year became the first airport to get all of its power from a microgrid.
Tom Woodrow, the airport’s senior vice president for engineering and intelligent infrastructure, spoke recently at a webinar hosted by Southern California Gas. I was there, too, talking about microgrid policy and was especially taken by Woodrow's presentation because he did something few people do. He talked about an oversight made in contracts. That kind of information offers a golden lesson for the microgrid industry, which is on a steep learning curve as it rapidly grows and innovates.
First, what the airport did right
Woodrow began exploring the idea of creating the microgrid in 2017 at the direction of the airport’s CEO Christina Cassotis.
“We wanted to put together an innovative project that met some primary goals,” he said.
Those goals were:
- Improve resilience and reliability.
- Lower the cost of electricity to the airport authority and its tenants.
- Support the airport’s sustainability goals.
- Support the local natural gas industry.
In late 2017, Georgia’s Hartsfield-Jackson Atlanta International Airport experienced an 11-hour power outage that sent a “ripple across the aviation industry” and underscored to Pittsburgh that it was on the right track.
“It was an example of how bad things can get if you have a complete power outage in an airport,” Woodrow said. “So the timing, although horrible for them, was good for us because it gave us more of an example of what we didn't want to happen.”
The Pittsburgh airport chose its microgrid contractor through a solicitation process that netted a robust response, with 82 companies requesting application packages. Sixteen responded, and eight were invited to then submit technical proposals. After narrowing it down to two applicants, the airport chose Peoples Gas in late 2018, and 11 months of contract negotiations followed.
Construction began in June 2020 during the COVID-19 pandemic when much of the US was still shut down. Still the team was able to keep the project on schedule. The 20-MW microgrid was completed in June 2021 and now acts as the primary power supply for the entire airport, including the airfield, terminals, hotel and fuel station.
The airport’s on-site power comes from five natural gas generators and 9,360 solar panels installed across eight acres. The microgrid was built to meet the airport’s 14-MW peak and provide a surplus. Because it’s connected to the grid, it can export surplus energy to the grid. The grid also acts as emergency backup if there is an on-site power outage – which did occur for the first time during a severe ice storm in February.
“The good news is the system worked exactly the way it was designed,” Woodrow said. “Since we had the interconnect in place, in a billionth of a second the electricity came on and stayed on.”
The airport had similar outages when a car struck electrical equipment outside of the airport and again during severe heat this summer.
A big part of the airport microgrid’s story revolves around the cost savings it has achieved in part because of its low-cost, long-term natural gas contract with Peoples Gas. Earlier this year, the airport announced it had achieved an estimated $1 million in savings for its first year in operation. Woodrow said that the figure is conservative.
“I know exactly what we're paying per kilowatt hour now, and I know that, regionally, electricity prices have gone up anywhere between 25% and 40% within the last year. I can do simple math and tell you that we have saved at least a million dollars, and I would bet you it's even closer to $1.5 to $2 million.”
What could Pittsburgh airport have done better?
When asked if there is anything the airport would change if it could start over again, Woodrow said he would have more carefully negotiated contracts for emergency power – the periods when the airport takes power from the utility.
“None of us knew exactly how that was going to work or what that was going to cost when we did need backup or emergency power,” he said.
The summer outage that the airport experienced was short, but it happened during a period when the grid was charging peak electric pricing between noon and 10 p.m., June to September.
“If in those months, and in those hours of the day, you bring in emergency power, it's very expensive. Very expensive,” Woodrow said. “One thing that I could do over would be that I would have found a way to negotiate the backup or emergency power agreements into the overall agreement so that isn't a stand-alone thing that we have to deal with on our own. It would've been nice to have had that baked into the overall contract and pricing of the project.”
Do you have a lesson learned that you’d like to share with the microgrid community? What would you do differently in building or operating your microgrid if you could do it over? Send us an email with a brief description, and we’ll be in touch to learn more. Email [email protected]