Chameleon on branch

The Many Flavors of Community-Scale Solar

Community-scale solar has the potential to become the next market segment to present a real gigawatt-scale growth opportunity, as outlined in RMI’s recent insight brief. So far, the growth of solar photovoltaics (PV) in the U.S. has been concentrated in two markets. One is residential rooftop solar, which is like a colony of ants with a few different roles executed by many different ants, and utility-scale solar, which is like whales, each unique, but large. Community-scale solar is like a chameleon: it adapts to its environment.

Community-scale Solar Takes Many Forms in Many Contexts for Many Reasons

RMI defines community-scale solar as mid-size (i.e., 0.5–5 MW), distribution grid-connected PV, with a variety of potential customers. Community-scale solar includes community, or shared, solar as well as mid-size arrays owned by utilities or owned by third-party providers that sell power to utilities. RMI sees a roughly 15 GW opportunity through 2020 for shared solar and for solar owned or purchased by co-ops, municipalities, or investor-owned utilities through power purchase agreements (PPAs).

A wide range of buyers pursue community-scale solar. Motivations vary: some buyers may pursue lower-cost electricity, others may want to reduce carbon emissions, while others may want to foster a stronger community by owning local electricity-generation assets. A parish in western Massachusetts may procure a shared solar system for a church parking lot to give low-income parishioners ownership of an asset that will produce free, clean electricity. A rural electric cooperative in Arizona may sign a 2 MW PPA to reduce the average cost of electricity generation for its members. An electricity retailer in Texas may see community-scale solar as a chance to bind customers to their company and reduce customer churn. Community-scale solar enables buyers to create solutions customized to their needs.

Community-scale solar’s adaptability gives buyers who are not served by current rooftop or utility-scale solar offerings access to clean electricity. For most residents of Rochester, NY, rooftop solar is not economic. Community-scale solar provides a solution. Our team at RMI works with a local community-based organization that is planning several community-scale solar systems that fit into the local scenery while producing solar electricity at or below residential retail rates.​ The ability to customize community-scale solar makes it the chameleon in the solar kingdom.

Counter-intuitively, a high degree of standardization and modularization of solar PV hardware enables customized community-scale solar offerings. We consider community-scale solar as a single segment because the hardware components and development activities are similar across a wide range of customer offerings.

Community-Supported Development Can Reduce Development Costs

The distinctive nature of community-scale solar resists standardization and may require community solar developers to spend more time creating customized solutions. This can raise installed costs if for-profit developers execute an entire project.

However, these cost increases can be avoided. RMI works with buyers using a strategy we call community-supported development. Community-supported development means that buyers, not developers, execute early-stage development activities such as finding sites, obtaining permits, filing for interconnection, and acquiring subscribers. Buyers and sellers can work independently and collectively to reduce installation costs by as much as 40 percent, as detailed in RMI’s insight brief.

Private Enterprise Specializes in Specific Activities in Community-Scale Solar

Rooftop solar providers have largely converged on offering a small number of products. SolarCity, America’s largest solar installer, offers three residential options: buy the installation outright, lease it, or buy only the power through a PPA. But if community-scale solar developers were to collectively offer such a small number of products, they’d miss out on much of the opportunity.

Instead of focusing on specific products or systems, private enterprise is focusing on specific services and offerings. Acadia Micro offers a service for customer engagement and billing. Cleargrid Energy identifies sites suitable for 0.5–5 MW arrays based on GIS data. Even turnkey-developer Clean Energy Collective now licenses a software product to utilities who want to engage in community-scale solar.

The Best is Yet to Come, and We Will Help Find It

In our ongoing writing about community-scale solar, we will cover in detail the dynamics, objectives, and opportunities of different community-scale solar models for buyers including:

  • Rural electric cooperatives
  • Groups of residential customers
  • Community Choice Aggregators (CCAs)

For each model we will answer the following questions: Who and what drives the model? What are the financial and non-financial benefits, and for whom? How can this market segment be scaled-up to one gigawatt? What are the main barriers for rapid market growth?

Our Shine team at Rocky Mountain Institute works actively with different buyers of community-scale solar. Around the nation, we see communities pursuing community-scale solar, translating hope for a better community into on-the-ground change. Defining a practical cause that can unite community, lower carbon emissions, and reduce electricity bills. Ultimately, it is this spirit of Applied Hope that makes community-scale solar so interesting to pursue.

If community-scale solar is a chameleon, we want to discover its colors. If you are pursuing community-scale solar in your utility or community, we’d like to know what your intentions are, and how you’re designing a system to meet these objectives. Please reach out if you want to share your experiences and insights, by sending an email to

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