Microgrids can be carbon-free or fully reliable, but generally not both — at least not yet, according to most experts on a Microgrid 2021 panel that looked at balancing microgrid goals.
The debate comes as businesses and institutions are striving to reduce the risk their power could be cut off, according to Matt Roberts, panel moderator and SimpliPhi Power’s director of marketing and communications.
At the same time, many companies and organizations want to use as much renewable energy as possible to help cut greenhouse gas emissions.
Do clean power, reliability mesh?
“Is there a direct conflict between sustainability and resilience?” Roberts asked.
In general, resiliency and sustainability go together, according to Lorraine Akiba, president and CEO of LHA Ventures and a former Hawaii Public Utilities Commission commissioner.
“Microgrids are tools in that toolkit to help us be not only resilient and reliable in the energy sector, but sustainable,” Akiba said during a panel discussion last week called “The Green Energy Balancing Act: How Microgrids Steady the Scale.”
Without resilience in an energy system, it is impossible to be sustainable, according to Hunter Lovins, president and founder of Natural Capital Solutions, a nonprofit group that supports sustainability initiatives.
“The definition of unsustainable is it’s going to stop and nonresilient systems are going to stop,” Lovins said.
Trade-offs in balancing microgrid goals
The main obstacle to merging the goals of zero-carbon generation with a highly reliable microgrid is the cost and availability of long-duration energy storage, according to Jason Marenda, project manager of renewables for POWER Engineers, an engineering and environmental consulting firm.
Currently, it is very difficult to set up a microgrid that can sustain an institution or a community for a week or more purely on available sustainable technologies, said Erik Svanholm, vice president of non-wires alternatives for S&C Electric, which specializes in the switching, protection and control of electric power systems.
When the facility manager of a pharmaceutical manufacturing plant comes to S&C and is looking for 24/7 reliable power, it can’t be told to wait until the grid is fully sustainable, according to Svanholm.
“So the question becomes really a more complex question of trade-offs between, are we willing to accept incrementally more [carbon dioxide] output for that facility over the next nine or 10 years in order to have it fully operational,” Svanholm said. “I don’t think that simply cutting off the use of new fossil fuel generation for those emergency uses is the best way forward.”
Marenda views fossil-fueled generation as a needed component of microgrids seeking to provide power for more than a week.
“Most people’s appetite for intermediate fossil fuel as a solution is going to change when they or someone they love is the one who doesn’t have power for an extended period of time,” he said.
The use of natural gas in the short-term is necessary to provide resiliency to mission-critical facilities like hospitals and biomedical facilities, according to Michael Bakas, executive vice president at Ameresco, an energy services company.
However, the power sector should move as quickly as possible toward using renewable fuels, such as renewable natural gas produced from methane emissions, Bakas said.
Bakas said he is a “big fan” of battery storage, but noted it has its own sustainability issues such as strip mining and the use of toxic chemicals.
Nearing ‘god parity’
Lovins said that investments in new natural gas infrastructure will quickly become “stranded” as the world rapidly shifts to all renewable energy.
She added, “We are very near to what Tony Seba calls ‘god parity’ which is where it is cheaper to have solar on your roof and the roofs in your neighborhood and to have true microgrids everywhere than to push even free power from central stations through a grid. At that point the cost of building and maintaining wires exceeds the cost of just having distributed renewables everywhere. We’re at grid parity pretty much everywhere on planet earth; we’re getting very near to god parity.”
At that point utilities will disappear unless they “deliver abundant, clean power when we want it, how we want it.”
For example, she pointed out that while she’s away from home her solar system is creating excess electrons. She said her utility should be paying her peak price for the energy but it is not. This kind of situation encourages people to “cut the tie” with their utility, she said.
Emerging tools can boost transition
Microgrid 2021 panelists for the “Green Balancing Act: How Microgrids Steady the Scale”
During the transition to 100% decarbonization, electricity needs to be reliable and resilient, according to Akiba.
There must be an orderly transition away from fossil-fueled generation, but regulators and others need to press utilities and financial investors to move as quickly as possible toward emissions-free power, Akiba said.
“Green” hydrogen, made from water and electricity produced by renewable energy and renewable natural gas, can eventually provide fuel for “baseload” power plants, she said.
“We need to be able to have areas and pockets within our grid that stay powered,” Akiba said. “It is part of that strategy of resilience. I think microgrids really play an important part in that as we use more distributed energy resources, and those microgrids can be a combination of renewables, traditional storage and these new technologies.”
For Svanholm, balancing microgrid goals requires a nuanced approach, one that considers the trade-offs between resiliency and carbon-free electricity.
People considering microgrids can consider a facility’s total carbon output or its life-cycle cost compared with upfront costs, according to Svanholm.
“Really look at the bigger picture as a whole to get to better answers than simply zeroing in on single variables and taking dramatic action in the near term [such as banning natural gas], which feels good … but it may not get us to the place where we really want,” he said.
Learn about what the future holds for microgrids during the final week of Microgrid 2021, a free virtual conference hosted by Microgrid Knowledge.
