MassACA Cap Allocations: Applying, Reservation Fee, and Reporting

A MassACA cap allocation is the reservation a Massachusetts renewable energy project needs under its utility’s net metering cap before it can receive net metering credits, and it is obtained by filing an Application for Cap Allocation (ACA) with the Massachusetts System of Assurance of Net Metering Eligibility at massaca.org. The platform is run by the Cadmus Group under the Department of Public Utilities (DPU) and processes requests first-come, first-served against the capacity remaining in each utility’s territory.¹

Below is what qualifies, what you need in hand, what it costs, and what happens after you file.

Do You Actually Need a Cap Allocation?

Not every net-metered facility goes through MassACA. Several categories are cap-exempt and skip the process entirely:

Class I renewable facilities with a nameplate capacity of 25 kW-AC or less. The threshold was raised from 10 kW in November 2024.²
Class I facilities larger than 25 kW, and Class II and Class III facilities, that generate renewable energy, serve on-site load, carry an interconnection service agreement dated January 1, 2021 or later, and are not owned by a municipality or governmental entity.³
Facilities that were net metering before January 24, 2013, and have not undergone design changes.¹
Facilities that exclusively offset load at their own site and do not export to the grid.¹

Everyone else needs an allocation. A non-exempt facility that skips the MassACA process will not qualify for net metering services.⁴

The facility must also use an eligible technology — solar PV or thermal electric, wind, small hydro (2 MW or less), anaerobic digestion, agricultural net metering, fuel cells using renewable fuels, landfill gas, ocean thermal/wave/tidal, geothermal, or low-emission advanced biomass — and must interconnect to Eversource, National Grid, or Unitil.⁵

Check Cap Availability Before You File

Each utility has a separate private cap (7% of its historical peak load) and public cap for municipal and governmental projects (8%).³ As of December 2024, the general program caps stood at:

Eversource: 408.24 MW private, 466.56 MW public.
National Grid (Massachusetts Electric): 359.191 MW private, 410.504 MW public.
National Grid (Nantucket): 4.069 MW private, 4.650 MW public.
Unitil: 7.167 MW private, 8.191 MW public.

A separate Small Hydroelectric Net Metering Program carries a 60 MW statewide cap, split 32.4 MW Eversource, 27 MW National Grid, and 0.6 MW Unitil.³ MassACA publishes weekly utilization reports showing what has been allocated and what remains. If the applicable cap is full when you apply, you go on a waiting list rather than receiving an allocation.

What You Need Before You Apply

Have these four items in hand before starting the ACA:¹

An executed Interconnection Service Agreement (ISA), signed by you and the electric company. The capacity, technology, and site address on the ACA must match the ISA.
Proof of site control for the facility location.
All non-ministerial governmental permits and approvals needed to construct the facility. Building permits are excluded from this requirement.
The $150 non-refundable application fee.

Public entities applying under the public cap must first obtain a DPU Public Entity ID through a separate application on Mass.gov.⁶ Governmental facilities on government-owned land have a narrow break: they can submit an ACA without all permits, provided the permits are obtained within nine months of receiving the allocation.⁷

Who Files the Application

Only the Host Customer, meaning the person or entity named on the electric bill, can initiate the application. Developers, engineers, and other third parties can be added in supporting roles, but a developer cannot serve as the Host Customer Administrator. Applications that try to put a developer in that role will be rejected by the administrator.⁴

Review Timeline and the Reservation Fee

Once you submit, the MassACA administrator reviews the application for completeness. Review typically runs 10 to 15 business days, with the clock paused whenever a request for clarification is outstanding.⁶⁷ You receive an automated notice telling you whether the project has been offered a cap allocation or placed on a waiting list.

If an allocation is offered, you have 15 business days to pay a non-refundable reservation fee of $3.15 per kW-AC of nameplate capacity. Miss that window and the allocation is forfeited.⁸

How Long You Have to Build

Paying the reservation fee starts the clock on the reservation period, during which the facility must reach authorization to interconnect. The length depends on technology and whether the project is a special public project:⁸

Solar and other standard facilities: 274 calendar days (about 9 months).
Wind, anaerobic digestion, and small hydro: 548 calendar days (about 18 months).
Special public solar facilities: 548 calendar days.
Special public wind or anaerobic digestion: 822 calendar days (about 27 months).

Extensions

If the project cannot reach authorization to interconnect in time, request an extension at least 30 calendar days before the reservation period expires. A standard extension adds six months and requires a refundable deposit of $3.15 per kW-AC, refunded once the facility successfully interconnects. A separate extension is available at no charge if a required governmental permit is under legal challenge.⁸

Quarterly Reporting While Your Allocation Is Active

Everyone holding a cap allocation or a waiting-list position must file at least one status report per calendar quarter until authorization to interconnect is granted. Reports have to disclose any changes to facility design, equipment, ownership, or capacity. A missed quarterly report can cost you the allocation.⁸

A Note on the Single Parcel Rule

Massachusetts defines a net metering facility as equipment on a single parcel, behind a single meter, at a single interconnection point. In November 2024, the DPU established five statutory exceptions, implementing changes from the 2022 clean energy legislation:²

Government-owned parcels, up to 10 MW total.
Low- or moderate-income housing, up to 10 MW total.
Separate and distinct rooftops, up to 2 MW total.
Separate customers under the same rooftop, up to 10 MW total.
Additional facilities installed at least one year apart, up to 2 MW total.

Eligibility for these exceptions is self-certified through a process managed by the Cadmus Group. The rooftop cap-exempt exception was discontinued as of March 2025.³

Help and Disputes

The MassACA helpline is (877) 357-9030, open business days 9 a.m. to 5 p.m., and the administrative email is help@massaca.org. Broader net metering policy questions go to the DPU distributed generation team at dpu.netmetering@mass.gov.⁹ If you disagree with an administrator ruling, a formal dispute resolution process is available; guidance documents and a DPU complaint form are posted on the MassACA website.¹⁰

1
Mass.gov. Apply for a Cap Allocation With MassACA
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Mass.gov. DPU Expands Net Metering Program
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Mass.gov. Net Metering Guide
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MassACA. Frequently Asked Questions: System of Assurance
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MassACA. Glossary of Terms
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MassACA. General Net Metering Program
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MassACA. DPU 23-20-B Attachment C
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MassACA. Reservation Period Guidance
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Mass.gov. Net Metering Laws and Regulations
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MassACA. MassACA Help and Guidance