One advantage of cohousing is that it is much easier as a community to install projects that save energy and increase community independence by combining resources. Generally, community members are already oriented toward cooperative action. Cohousing communities also have decision-making structures and practices in place and experience in using them, so the decisions around community projects can move forward more rapidly and smoothly than in a situation that involves a city council or neighborhood association.
The creation of a microgrid is one such project. A microgrid is a portion of the larger electrical grid that has its own power-generating capacity. This generation could be from wind turbines, solar PV panels, gas generators, or any other method of generating power a community can live with. Living Energy Farm, a forming community 50 miles west of Richmond in Louisa County, has even experimented with household-level biogas generation.
The microgrid connects to the main electrical grid through a switch. In ordinary circumstances microgrid generation feeds into the grid, and microgrid owners (such as cohousers) can sell that generation to a larger utility like Dominion that runs the main grid. When the main grid goes down, as during an ice storm, hurricane, or thunderstorm, the switch can be cut off, and the microgrid can continue to function for its owners to distribute power within the community. The US Department of Energy has more information on microgrids and the Berkeley Lab Grid Integration Group gives examples of microgrids from around the world. The Sendai microgrid, while larger than what we would need in Richmond Cohousing, is especially notable for functioning in the aftermath of the earthquake and tsunami that produced the 2011 Fukushima nuclear disaster. The Mesa del Sol microgrid powers a mixed-use commercial-residential community in Albuquerque, New Mexico that is similar in size to Richmond Cohousing’s plans.
Richmond Cohousing plans a community of twenty to thirty households, with dwelling sizes ranging from 800-1600 square-feet, and a large common house. While our development has not yet been fully planned out, it is likely that we will have roof space for 150-200 kW of solar PV panels if all households participate. This likely would result in an average of 600-800 kW per day of electricity generated, translating to 218-292 SRECs (Solar Renewable Energy Certificates) generated, which are worth $55-60 each to Pennsylvania utilities. That could bring $12,000 to $17,500 in revenue to the development, distributing $400 to $875 in benefits to each household each year.
We could form a co-op with the help of a group
called VA SUN, a project of the Center for Community Energy out of Mt. Pleasant, Maryland which has already helped co-ops in Harrisonburg and Rockbridge County join for bulk purchases and volume discounts on installation. VA SUN estimates savings of 20-33% off the typical single-home price ($9000 to $40000 per home depending on the size and circumstances of the system) and each household, or the LLC as a whole, could take an additional 30% federal tax credit on top of that, making the installation cost per household as little as 46% of retail value.
A microgrid is the kind of unique, groundbreaking project perfectly suited to cohousing communities like Richmond Cohousing. Our values include environmental stewardship, and a microgrid could be a great way to meet this value for a minimal additional cost. One more thing to think about as we move towards site and dwelling design!
While we continue to work towards a design for Richmond Cohousing, John uses his computation skills daily as a math teacher. You’ll see him commuting to work via bike throughout the year. According to him – the colder, the better for a bike ride!
One thought on “Looking Ahead: Microgrid Possibilities in a Connected Community”
Great info John. I appreciate the detail and links. Yes, we must fold a solar array concept into our cohousing orientation and architecture. Best, Richard