An important task for the elected Public Regulation Commission — before the governor-appointed version of that body takes over — is to smooth the way and incentivize development of microgrids for new, single-family home subdivisions.
Microgrid is one of those terms that means different things. Santa Fe Community College has one, but that’s not what we’re talking about. The first and only subdivision-scale microgrid in New Mexico went online in 2019 for housing at Kirtland Air Force Base in Albuquerque.
It was installed by Emera Technologies, a subsidiary of Emera, a Nova Scotia-based electric utility company that happens to own New Mexico Gas Co. More on that later.
The revolutionary product of Emera Technologies is a cube called Block Energy. It’s the size of central air-conditioning units set outside typical suburban homes. It’s partially buried to cool batteries filling most of the box.
Also inside is an inverter, converting direct current power from rooftop solar panels to alternating current needed to power our homes. So far, nothing revolutionary. But then they add artificial intelligence communication capability that connects every box in the subdivision via fiber-optic cables.
Machine learning is the secret to the smartest of smart grids. Every Block Energy box is communicating with every other box in the neighborhood, as are rooftop solar arrays. That means when one rooftop array is creating more energy to power lights, gadgets and top off batteries, excess power goes to a neighbor’s depleted battery box and vice versa.
Distributed energy, the industry term for thousands of individual rooftop solar systems tied into the wider electrical grid, is well-established and part of PNM’s plans to achieve carbon-neutral energy delivery by 2040.
Also part of the plan is energy storage. But that’s where it gets dicey.
It’s one thing to have utility-scale fields of solar panels or windmills as far as the eye can see. It’s another thing to contemplate utility-scale storage batteries. They don’t exist. There’s a lot of research and pilot programs trying to solve the conundrum, but they’re still a long way off.
Distributed storage coupled with distributed energy at each new home is an immediate and proven solution. There’s no power loss from long-distance transmission and because microgrids are connected to the larger grid — but can isolate themselves if the larger grid goes down — they guarantee reliability that Texans would have loved last winter and Californians would love today.
Emera Technologies is so certain of the wisdom of distributed storage powered by distributed energy — all connected to the larger grid — that it is willing to design and install everything at no cost to developers. That includes rooftop solar panels, Block Energy boxes, fiber-optic cables and a backup, natural gas-fired electric generator in the subdivision to guarantee the microgrid’s reliability.
Their business model with PNM will be: If we build it, they’ll buy it. For subdivision developers, it means free 100 percent renewable energy homes. For homeowners, it means the system on their roof and the battery box outside are owned by PNM. In exchange, the homeowner gets 100 percent reliability and rates that should stay fixed for decades.
Santa Fe should be the center of new subdivisions with microgrids daisy-chained together. Tierra Contenta, with 1,200 homes coming online scattered over multiple small subdivisions, is the perfect place to start. All-electric homes are the future. Microgrids will help get us there. And unlike many other communities, New Mexico Gas Co. may even help facilitate the transition.
Kim Shanahan has been a
Santa Fe green builder since 1986 and a sustainability consultant since 2019. Contact him at shanafe@aol.com.
