Mass Save C&I demand response and battery economics

Commercial ConnectedSolutions is a Mass Save offer run by the four electric Sponsors, usually through curtailment service providers such as CPower or Enel that enroll the site, call the events and share the pay (National Grid). It is paid from the energy-efficiency charge that every business pays. The DPU approves the budget in the three-year plan; the 2025–2027 plan was approved at about $4.5 billion (DPU).

The wires utility controls what matters most for a battery at a business: the demand charge it saves against, the interconnection study, net metering for any solar, and the rate class. Clean Peak certificates and SMART solar incentives are state programs, and ISO New England sets the regional capacity price.

Daily Dispatch pays $200 per kW for up to 60 two- to three-hour events, June through September, capped at 150% of site load. Battery systems over 50 kW get a five-year rate lock plus up to two years to build. Targeted Dispatch pays for up to eight three-hour events: $35 per kW at National Grid, $45 plus a $10 weekend bonus at Eversource (Eversource) and a minimum of $22.50 at Unitil (Unitil). Fossil generators have been ineligible since 2023. Cape Light Compact calls its own events for Cape and Vineyard businesses (Cape Light Compact).

Every deep dive on this site has one feature that changes how its economics read. Here, it is the split between who pays for flexibility and who sets the bill. Mass Save pays every Sponsor’s battery the same Daily Dispatch rate, but demand-charge savings come from the wires company’s tariff, and those vary by about three to one across Massachusetts.

On Eversource G-2, demand-charge savings are worth about twice the Daily Dispatch pay. On National Grid G-3 the order flips: Mass Save pays more than the bill saves. That shows up in where batteries get built. A site on Eversource can justify a battery on demand savings alone; on National Grid or Unitil, the case depends on Mass Save pay continuing past the five-year lock.

Behind that pay is the same efficiency-budget logic as the residential program. Daily Dispatch at $200 per kW is above the roughly $146 per kW-year of regional capacity and transmission value used to screen it (AESC testimony), so its case also relies on distribution and other benefits. The Mass Save residential deep dive explains that test.

Most business participants are not batteries. They are offices, schools, factories and cold storage sites that dim lights, raise cooling setpoints or pause processes for a few hours. Targeted Dispatch alone holds about 70 MW. Daily Dispatch batteries are about 15 MW, and the plan aims for about 31.5 MW of business batteries by 2027 (ESS News). The Sponsors say the five-year lock has not driven many battery installs (2025–2027 plan).

Solar barely touches a business demand charge. The monthly peak often lands late in the afternoon or on a cloudy day, so we credit 100 kW of solar with only 10 kW of reliable peak reduction. Exports from many new business systems earn market net metering credits of 60% of the per-kWh charges, and credits never offset demand charges (Mass.gov). That is the setup where a solar-charged battery is no longer charged at near-retail cost.

Run together, the pair is worth about $13k a year more than the two assets alone. That comes from three sources: storing exports that would earn 12¢ to avoid 20¢ purchases (about $2k); letting solar carry the midday while the battery holds the late-afternoon peak, which we put at 15 more kW off the bill (about $6k); and SMART’s storage adder (about $5k). Daily Dispatch events run 2–7 p.m., so a midday solar refill also keeps the battery ready for the next day’s event. Clean Peak certificates are available to storage that discharges in the seasonal peak windows (DOER); the ceiling is a $65 per MWh alternative compliance payment through 2032 (NuWatt).

This is the tipping point for multi-asset sites. A solar-charged battery adds real value once the export credit falls well below the price the battery displaces. Massachusetts homes are close to break-even, while Massachusetts businesses with market net metering are a third of the way toward PG&E’s Solar Billing Plan. Add demand charges and the Clean Peak and SMART adders that only paired systems earn, and solar becomes a real part of the battery case rather than a side benefit.

Every Eversource and National Grid case pays back within the battery’s life. The question is not whether the economics work on paper. It is why so few sites have acted on them.

The site’s line above is only half of the deal. The developer pays the full $240k, carries maintenance, insurance and performance risk, and prices all of it into the contract to earn a return on its capital (Morgan Lewis). Third-party storage contracts usually run 15 years or more (Peak Power), and lenders treat 15- to 20-year terms as financeable (Illinois Power Agency). The chart below values each deal from the developer’s side.

Massachusetts is financeable for a third-party owner on Eversource G-2. The developer keeps the credit and Daily Dispatch pay, and can leave the site about 50% of demand savings. The developer’s main risk is the program, not the battery: Daily Dispatch is locked for five years, but a 15-year agreement has to assume something about the next ten, and that depends on future three-year plans. On our model, if Daily Dispatch pay stopped after the lock, the Eversource G-2 deal would still cover the developer’s cost at 111% over 15 years with 25% of savings to the site, while the same deal on National Grid G-2 would fall to 84%.

Compare: Eversource C&I, which also covers Connecticut, and National Grid C&I, which also covers upstate New York.