Waiting for load growth: Maine’s Boothbay project shows how non-wires alternatives head off expensive grid upgrades

In 2008, Central Maine Power (CMP) submitted a rate case to the state’s Public Utilities Commission (PUC) looking for approval of a $1.5 billion capital spending program. To meet expected load growth in the state, the utility’s plan called for more than 300 miles of new transmission lines, construction of six new high-voltage substations and upgrades of existing infrastructure across the grid.

That plan got pushback from a local clean technology development organization called GridSolar, which argued CMP’s predictions were based on an out-of-date analysis. Rather, the group proposed a much less expensive, non-wires alternative (NWA) comprised of a major buildout of solar photovoltaic (PV) generation with back-up diesel and natural gas generators, plus other distributed energy resources (DERs).

Thus began the Boothbay pilot, one of 10 NWA projects profiled in a new report, Non-Wires Alternatives: Case Studies from Leading U.S. Projects. Jointly produced by the Smart Electric Power Alliance (SEPA), E4TheFuture and PLMA (Peak Load Management Alliance), the report documents the growing interest in the use of distributed energy resources (DERs) — such as solar and storage — in place of expensive grid upgrades.

From 2015 to earlier this year, the project — combining solar, storage, demand response and energy efficiency measures — successfully cut demand in a small coastal region around Boothbay Harbor in central Maine. Its termination was due, not to any failure of the project, but rather because the predicted load growth failed to materialize.

“Boothbay was unique in that the project was led by a third party, with collaboration between GridSolar and Central Maine Power,” said Brenda Chew, a SEPA research analyst and lead author of the report. “It was immensely successful in helping avoid a very costly transmission upgrade that ultimately was not needed.”

“As our first NWA pilot, [Boothbay] was a great learning experience for us, GridSolar, the regulator – all the stakeholders,” said Michael DeAngelo, program manager for Non-Wires Alternatives for Avangrid, CMP’s parent company. “We learned a lot of things, especially about demand response, that we take into consideration on other projects,” including several NWA projects in New York State.

Rich Silkman, president of GridSolar, also points out that the batteries, while not currently in use, could find their way back onto the grid someday, while the project’s solar and efficiency measures continue to benefit the area.

While still in its early stages, the trend toward non-wires alternatives is gaining momentum and represents a major shift in 100-year-old utility business and operational models. Certainly, utilities and regulators are becoming more open to considering NWAs to defer large investments in traditional grid upgrades. Typically these projects include various combinations of DERs, ranging from rooftop solar and storage to energy efficiency and demand response programs.

According to the new report, more than 100 NWA projects are now in various stages of planning and development across the U.S. Navigant Research estimates that global spending on NWAs will grow from $63 million in 2017 to $580 million in 2026.

“Non-wires alternatives are an important way to leverage DERs to provide benefits back to the grid,” Chew said. “A big plus is the flexibility of deploying a portfolio of DERs that can provide the ability to scale up and down depending on grid needs, for example whether or not load forecasts are realized in a particular service territory.”

A Peak Load Solution

That’s exactly what happened in Maine. Following CMP’s $1.5-billion plan for extensive grid upgrades, GridSolar, which was started specifically to respond to the rate case, offered its alternative vision.

The organization challenged the utility’s forecast of potential load growth, which was based on trend lines that were established before the 2008 Recession, when electric demand across the nation plummeted. Rather, GridSolar argued that NWA solutions could sufficiently address maximum or peak load shortfalls — especially in certain areas. It proposed a major buildout of solar photovoltaic (PV) generation along with back-up diesel and natural gas generators.

The group’s rationale was that peak load on the CMP system occurred in summer months, due to air conditioning demand and a significant influx of tourists along the coast. Solar PV is well-suited for use in the summer, and the back-up generators could be used if needed in rainy weather and evening hours.

Further, the GridSolar proposal would cost less than a full adoption of the CMP plan, plus the price of solar PV was expected to drop over the life of the program. Consequently, policymakers, regulators and consumer advocates supported the GridSolar approach and encouraged CMP to incorporate an NWA element in its plan.

“We were fully on board with that idea,” said Eric Bryant, senior counsel at the Maine Office of the Public Advocate. “It makes a lot of sense for utilities, the commission and third parties to find ways to spend less on transmission while not sacrificing reliability.”

After months of negotiation and discussion, the Maine Public Utilities Commission agreed to a settlement. Most of the CMP transmission investments would be approved, but the utility agreed to work with GridSolar on pilot NWA projects.

Boothbay was chosen for the first pilot because CMP’s proposal included $18 million in new transmission for the region, where additional power seemed to be needed for a small number of peak-load hours each year, all in the summer months, and not exceeding about 2 megawatts (MW).

GridSolar’s plan for a pilot, on the other hand, would cost about $1.85 million for a portfolio of DERs, designed to both lower demand on the distribution system and provide flexibility and fast response to changing, seasonal load curves.

Rolled out between 2013 and 2015, the project portfolio included:

• Energy Efficiency: Energy efficient commercial lighting was installed to lower demand.
• Demand Response: GridSolar worked with commercial building owners to replace aging air conditioning systems with Ice Bear systems, which could be turned on and off to respond to peak demand, shifting start and stop times as needed.
• Solar PV:  Residential solar PV systems were installed on some homes to lower the amount of energy required to be imported into the region.
• Storage: 500 kilowatt (kW), 3 megawatt-hour (MWh) battery of energy storage system, the first storage project installed in Maine. GridSolar managed it as a DR resource to respond to local load conditions on the grid.
• Back-up Generation: A 500 kW diesel generator provided flexibility to meet grid conditions when other systems, including solar, were insufficient.

Unique to this  project, GridSolar was given the power to control some of the NWA resources, such as the commercial air conditioners and storage batteries, taking on the role of smart grid coordinator for the Boothbay pilot. The organization created and ran a network operation center, with CMP providing real-time load data on each distribution circuit in the region.

For example, the GridSolar operations center directly controlled the Ice Bear commercial air conditioning systems; on high-load days, it could delay their start and let them run later in the evening to better follow the local demand curve.

For CMP, “one big lesson learned was the need to automate dispatch resources,” DeAngelo said. “When load got to a certain level in Boothbay, an alarm would ring and an operator would have to go online and manually enter a dispatch command to GridSolar. That took away from the operator’s other responsibilities. So we now can automate that dispatch command, and that’s a lesson learned that we’ve taken“ to Avangrid’s New York NWA projects.

As noted, the pilot was, to an extent, a victim of its own success, terminated when the predicted load growth didn’t occur. Despite that outcome, the project proved that NWA programs can indeed handle peak-load requirements, mitigating the need for costly traditional investments. Maine ratepayers saved more than $12 million in present value terms compared to the transmission alternative.

“This was a really good pilot that showed a lot of promise,” Bryant said. “The mix of resources that GridSolar deployed worked well.”

The completed Boothbay pilot stands as early validation that NWAs can be integrated into a utility’s grid and reduce load demand. In the coming years, with an increasing number of policy directives to increase use of renewables and the rapid adoption of electric vehicles, electric loads will likely grow. Utilities, regulators and policymakers will be open to alternatives to traditional transmission and distribution upgrades to address these challenges.

Beyond their financial benefits, NWAs will also continue to drive innovation as other projects build on the experiences and lessons learned of early pilots such as Boothbay. New incentives, regulations and utility business models — not to mention customer demand — will make NWAs, if not the new normal, an accepted option for energy system transformation across the country.