San Diego Union-Tribune (Sunday)
HOSPITAL POWERED BY OFF-GRID MACHINE IS CUTTING COSTS, EMISSIONS
In eastern La Mesa, just off a busy highway, is a tan rectangular building.
The structure’s easy to miss. It’s shorter than the gleaming towers nearby that make up Sharp Grossmont, essentially East County’s only hospital, and it’s hardly a draw for the people wearing scrubs and stethoscopes streaming by every hour of the day.
But on the building’s ground floor, hidden in an enormous gray box, is a spinning 52-ton turbine, similar to a jet engine, upon which all of the doctors and nurses and patients depend.
The machine is the core of an energy plant powering the entire complex, and an internal review recently concluded that a multimillion-dollar overhaul several years ago is saving the hospital money, reducing emissions and largely keeping the facility off the state’s electrical grid at a time when rising temperatures have risked rolling blackouts.
While the plant still relies on natural gas, its technology offers a cleaner way forward as regulators push to dramatically reduce the use of fossil fuels.
“It’s impractical to power something as large as a hospital with batteries at this point,” said James Bushnell, a professor of economics at UC Davis who researches energy policy. Medical facilities were far from the biggest polluters and “should be given special consideration” amid efforts to drop natural gas, he added.
Hospitals present a challenge to visions of an all-electric-and-no-fossil-fuels future.
If the power goes out in your bedroom, you may just need to reset the clock. If the electricity fails in an operating room, people can die.
“We need a guaranteed source of energy,” said Anthony D’amico, Sharp Grossmont’s chief operating officer. Until “we can store solar and wind, natural gas is the only option.”
The California Air Resources Board recently released a nearly 300-page plan to make the state carbon neutral by 2045, but the proposal only mentions hospitals to say cleaner air should reduce the number of sick people.
A board spokesman confirmed there is not yet a timeline to specifically get hospitals off natural gas, and the report does offer some wiggle room: Even after 2045, some buildings will likely still require “hydrogen, biomethane, and fossil gas,” the document says.
Sharp’s power plant uses a process known as cogeneration, sometimes shortened to cogen, to capture and use heat that might otherwise drift into the atmosphere, a method long pushed by the U.S. Environmental Protection Agency.
The basic technology has existed for decades, and the California Energy Commission lists around a dozen much larger cogen facilities throughout the state. Though other types of cogen have been used in the city of San Diego, Sharp’s appears to be the only one of its kind in East County, officials said.
The plant went live more than six years ago, in April 2016, and replaced an older and less efficient version.
On a recent tour of the facility, anyone walking near the turbine — its full name is a Mercury 50 combustion turbine generator — was advised to wear ear plugs.
The machine is the core of Sharp’s Central Energy Plant. The facility does include other methods of generating power, and the plant overall generally emits about 560 pounds of carbon monoxide each year, according to Bruce Hartman, Sharp Grossmont’s director of marketing.
That’s about a 28 percent reduction from the roughly 780 pounds that annually came out of the old facility,
Hartman wrote in an email.
The turbine makes heat that shoots through a tube into an enormous metal box on the next floor.
Small viewing screens poke from the box’s red walls. Pulling a small lever gives a glimpse at a whirling orange vortex inside that looks like a cartoon version of Hell.
That heat becomes steam which, in addition to heating the hospital, can help sterilize surgical equipment and manage the facility’s humidity.
A range of 20 percent to 60 percent humidity in critical rooms is ideal: Too much moisture can allow bacteria to grow, while overly dry air raises the risk of fire.
Those numbers can be managed from a single desk.
In December, power plant lead and longtime employee David Ornelas stepped in front of an array of computer screens. He pulled up a brightly colored map that showed specific temperatures in individual hospital rooms.
Someone might call and say, “‘Room C-17 is hot,’” Ornelas said. “We have the capability of taking control of that one individual room to make it comfortable for the patient.”
At the moment, the Central Energy Plant generally cranks out about 3.2 megawatts of power an hour, plenty to run the entire complex and have some left over — generally about 400 kilowatts — to sell back to San Diego Gas & Electric Co.
In fiscal year 2021, selling that extra energy earned about $150,000. Minus expenses, that still left about $30,000 in profit.
The energy bill is also lower. Sharp pays SDG&E about $116,000 a month for natural gas, which is tens of thousands of dollars less than it had been spending on outside electricity, officials said.
Overall, they’ve saved more than $4 million since the plant went live, according to a presentation given last summer by hospital leadership to board members of the Grossmont Healthcare District, which owns the facility.
Furthermore, the plant’s current output is nowhere near the turbine’s estimated capacity of around 4.4 megawatts, giving the hospital room to grow.
Sharp remains connected to California’s grid in case the turbine goes down, which happens about twice a year for maintenance.
Staff writer Joshua Emerson Smith contributed to this report. blake.nelson@sduniontribune.com