A Multifamily PV Project at Ecovillage at Ithaca

If you live in one of the 5 million housing units that are in multifamily condominiums or cooperatives, you may have dreamed about installing a PV system, but couldn’t figure out how to make it work. My co-op neighborhood in Ithaca, New York, was recently able to make this dream a reality.

Challenges

There are many benefits to living cooperatively or in a condominium, but the ease of installing a solar-electric system is not one of them. The first problem is that you don’t own the roof and walls—so a PV installation requires permission from your neighbors and the homeowners’ board. In addition, there are wiring, metering, utility connections, and aesthetic considerations that come into play. For example, your electrical service connection may be located some distance away from your unit, you may need access to a neighbor’s roof or attic for attaching modules or routing wiring , or you may find that some of your neighbors don’t share your delight in seeing solar collectors gleaming on the roof.

An alternative is to expand the PV project into a neighborhood effort. In this scenario, the condo association or co-op owns the system, and the system benefits all of the residents. That solves a few problems, but brings up several more.

One of the thorny problems is the way most utilities implement net metering. Usually a utility will allow you to hook up a PV system only to your own utility connection. Under an annualized net-metering agreement, the utility credits your household only for PV production up to your total usage for that year. Usually, any surplus generation is given to the utility for free or at a low wholesale rate. Since the homes in most multifamily neighborhoods are individually metered, this necessitates having many small PV systems (one per unit), rather than one large, more efficient, cost-effective system.

If this can be overcome, the remaining challenges are how to pay for the system; how to meter and divide the output; and getting approval from utilities, planning departments, rebate providers, and other agencies. Oh yeah, and you have to get everyone in your neighborhood to agree to all of this.

Daunting? Yes. Achievable? Definitely! My community, Ecovillage at Ithaca (EVI) in Ithaca, New York, successfully navigated these obstacles and constructed a 50 kW grid-tied PV system that was financed with local capital and is expected to meet more than half of our community’s electricity needs.

Background

EVI is a community of 60 energy-efficient homes in two distinct neighborhoods (soon to be three) clustered in the center of a 176-acre parcel on the outskirts of town. My neighborhood, built in 1997, has 30 compact townhouses and was designed according to cohousing principles: Homes face onto a meandering, car-free central corridor and share access to a large common house that provides space for community gatherings and meals, playrooms, laundry facilities, and offices. The average townhouse is 1,225 square feet, and up to 40% more energy efficient than typical homes in the area due to extensive insulation and sealing, triple-pane windows, a shared hydronic heating system, and passive solar design.