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Commercial Solar EPC in Connecticut

Ferrius Energy engineers, procures, builds, and maintains commercial solar and battery storage systems for Connecticut businesses, municipalities, and property owners in Eversource and United Illuminating (UI) territory. In 2026, most Connecticut commercial solar economics run through PURA's Non-Residential Renewable Energy Solutions (NRES) program, a 20-year tariff with a buy-all or netting option, stacked with the Section 48E federal credit and, for storage, the Energy Storage Solutions program.

Connecticut is not a "size to the roof and net meter" market anymore. NRES is a capped, competitively priced procurement with two bid windows a year, so the engineering, the bid price, and the interconnection timeline have to be built together. That is the work we do from Saugus, Massachusetts, for owners across the state.

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Last reviewed: September 2026. NRES price caps, budgets, and bid dates reflect the Year 5 (2026) RFP documents published by Eversource and UI; confirm current terms with your utility and PURA before bidding.

NRES replaced LREC/ZREC and virtual net metering

If you have seen older references to LREC/ZREC or virtual net metering (including on parts of our own site), here is where things stand. Connecticut's Low and Zero Emission Renewable Energy Credit program and the state's commercial virtual net metering program have closed to new projects. Their successor is NRES, a six-year program that launched in February 2022 and is administered by Eversource and UI under the oversight of the Public Utilities Regulatory Authority (PURA). Projects that already hold LREC or ZREC contracts keep them; new commercial projects bid into NRES.

NRES gives selected projects a 20-year tariff. At bid time you choose one of two compensation structures, and the choice is binding:

  • Buy-All. The utility purchases all generation at your tariff price. Compensation arrives as an on-bill credit or a quarterly cash payment. The building's own bill is unchanged, which suits owners with a tenant-metered or low-load site.
  • Netting. Generation first serves the building, and net exports are credited in dollars on the bill. This suits sites with daytime load where offsetting retail kWh is worth more than the buy-all price.

State, Agricultural, and Municipal (SAM) customers can share compensation across accounts, which partly fills the role virtual net metering used to play for towns and farms.

Year 5 RFP

NRES categories, caps, and 2026 bid windows

NRES splits projects by AC nameplate. Small projects and School Solar are awarded first-come, first-served within a two-week window (with a lottery if the window is oversubscribed). Medium and Large projects are competitive: you bid a price in $/MWh under the published cap, and the lowest bids win until the budget is spent.

NRES Year 5 (2026) categories and buy-all price caps
CategorySize (AC)Selection2026 cap, buy-allCarport cap
Small Zero Emission200 kW or lessFirst-come, first-served$250.42/MWhn/a
Medium Zero EmissionOver 200 kW to under 1,000 kWCompetitive bid$236.74/MWh$338.20/MWh
Large Zero Emission1,000 kW to 5,000 kWCompetitive bid$182.94/MWh$261.34/MWh
School SolarUp to 5,000 kWAdministratively set tariff$236.74/MWh$307.76/MWh

Annual budgets are set per utility. For 2026, Eversource's caps are about $6.73 million (Large), $5.12 million (Medium), and $6.49 million (Small), plus 20 MW for School Solar. UI's are about $2.25 million (Large), $2.25 million (Medium), and $1.90 million (Small), plus 5 MW for School Solar. Eversource describes its Year 5 allocation as roughly 31 MW Large, 25 MW Medium, and 21 MW Small.

The two 2026 windows opened February 2 and August 3. For the August round, Small applications closed August 17, Medium and Large bids were due September 14, and winners are expected around November 2. The program is scheduled to run six years from 2022, so the 2027 solicitation is currently expected to be the last under NRES as authorized; watch PURA dockets for any successor.

Carports earn a premium

The carport caps sit roughly $80 to $100/MWh above rooftop and ground caps. For a Medium or Large project, a canopy over parking can beat a cheaper ground mount on IRR once the higher cap is applied.

Bid price is an engineering output

A competitive NRES bid is only as good as the cost estimate behind it. We price structure, electrical, interconnection upgrades, and O&M into the bid so the award is buildable at the number you submitted.

Buy-all vs netting is a model, not a guess

We run both structures against twelve months of interval data and your rate class. Netting wins where daytime load is steady; buy-all often wins where load is small or erratic.

Battery storage: the Energy Storage Solutions program

Connecticut's Energy Storage Solutions (ESS) program is co-administered by the Connecticut Green Bank, Eversource, and UI. It launched in January 2022 as a nine-year program with a goal of 580 MW of storage by 2030. For commercial enrollees from April 1, 2026, the program moved to a fully active-dispatch, performance-based framework:

  • Upfront enrollment incentive. $10/kWh for commercial and industrial participants.
  • Performance incentive, small and medium commercial. $325/kW per year in years 1 to 5, then $175/kW per year in years 6 to 10.
  • Performance incentive, large commercial. $275/kW per year in years 1 to 5, then $175/kW per year in years 6 to 10.
  • Dispatch obligations. Summer dispatch of 30 to 60 events per season and up to 10 winter events, called by Eversource or UI on high-demand days. Passive dispatch was eliminated.

Commercial applicants pay a $350 application fee. Because payments depend on performance during called events, the battery has to be sized and controlled so that event dispatch does not conflict with the demand-charge shaving that earns the rest of its value. Our commercial battery storage engineering models both revenue streams on the same load profile, and our BESS cost and ROI guide explains the math.

Interconnection, property tax, and siting in Connecticut

Interconnection with Eversource and UI

NRES awards and interconnection run on parallel tracks. A project that wins an award still needs an approved interconnection application, and a Medium or Large system on a constrained circuit can trigger a study and upgrade costs that change the bid economics. We file early, request pre-application data where the circuit is uncertain, and price likely upgrades into the bid rather than discovering them after award. The sequence from application to permission to operate (PTO) is similar to what we describe in our New England interconnection guide, with Connecticut's own forms and timelines.

Property tax treatment

Connecticut General Statutes section 12-81(57) provides the core exemption for commercial and industrial Class I renewable systems. The mandatory exemption under subdivision (57)(D) applies to qualifying systems whose nameplate capacity does not exceed the load at their location (aggregated load is allowed for systems that used virtual net metering). Separately, subdivision (57)(F) lets a municipality abate up to 100% of property tax on facilities under a power purchase agreement, for no longer than the PPA term and 20 years at most. A buy-all NRES project on a small-load site may not meet the "does not exceed the load" test, so confirm treatment with the local assessor before you close on a financial model.

Siting and sectors

Connecticut's density pushes commercial solar onto roofs, carports, and previously disturbed land. Strong fits include manufacturing and aerospace supply-chain plants along the I-84 and I-91 corridors, distribution warehouses, cold storage, hospitals, universities, and municipal and school buildings eligible for School Solar or SAM credit sharing. Larger ground-mounted projects, especially on farmland or forested parcels, can face state-level siting review in addition to local zoning, which adds time; rooftop and carport projects on existing developed sites usually carry less siting risk. We confirm the approval path for each site during feasibility. See our pages on manufacturing solar, warehouse solar, and solar carports.

Federal Layer

Section 48E and depreciation

Connecticut projects stack NRES revenue with the federal Section 48E investment credit: a 6% base, or 30% for projects under 1 MW AC or that meet prevailing wage and apprenticeship requirements. Under the One Big Beautiful Bill Act (enacted July 4, 2025), solar facilities that began construction on or before July 4, 2026 are not subject to the 2027 placed-in-service deadline (subject to continuity rules). Facilities beginning construction after July 4, 2026 must be placed in service by December 31, 2027. That deadline matters here: a project awarded in the November 2026 NRES round needs a realistic build schedule to reach PTO by the end of 2027. Owners also take 5-year MACRS, and 100% bonus depreciation was made permanent in 2025. Details are in our federal ITC guide.

Feasibility

Interval data, rate class, roof or site condition, buy-all vs netting model, and a go or no-go before you spend on design.

Bid and design

Stamped engineering, interconnection filing, and an NRES bid priced from a real construction estimate.

Build and operate

Self-performed construction, commissioning to PTO, and long-term O&M through the 20-year tariff.

Questions

Frequently asked questions

Is LREC/ZREC still available for new commercial solar in Connecticut?

No. The LREC/ZREC program and commercial virtual net metering were replaced by the Non-Residential Renewable Energy Solutions (NRES) program, which launched in 2022. Existing LREC/ZREC contracts continue, but new commercial projects bid into NRES for a 20-year buy-all or netting tariff.

Should I choose buy-all or netting under NRES?

It depends on your load. Netting tends to win when the building uses most of the solar output during the day at a high retail rate. Buy-all tends to win when on-site load is small, irregular, or tenant-metered. The choice is made at bid time and cannot be changed, so we model both against twelve months of interval data before you bid.

When is the next NRES bid window?

NRES runs two rounds a year. In 2026 the windows opened February 2 and August 3, with August Medium and Large bids due September 14 and winners expected around November 2. The program is scheduled for six years from 2022, so confirm 2027 dates with Eversource or UI as they are published.

What does Connecticut pay for commercial battery storage?

Under the Energy Storage Solutions program, commercial enrollees from April 1, 2026 receive a $10/kWh upfront incentive plus annual performance payments of $325/kW (small and medium) or $275/kW (large) in years 1 to 5 and $175/kW in years 6 to 10, tied to active dispatch events called by Eversource or UI.

Is commercial solar exempt from property tax in Connecticut?

Often, yes. CGS 12-81(57) exempts qualifying Class I renewable systems whose capacity does not exceed on-site load, and lets towns abate up to 100% for PPA-financed facilities for up to 20 years. A buy-all project sized above site load may not qualify for the mandatory exemption, so confirm with the local assessor.

Sources

  • Eversource, Connecticut Non-Residential Renewable Energy Solutions. eversource.com
  • United Illuminating, NRES Program Overview Fact Sheet (Year 5). uinet.com
  • United Illuminating, Year 5 Request for Proposals for NRES (updated 1/9/2026). uinet.com
  • PURA, Non-Residential Renewable Energy Solutions Program FAQs. portal.ct.gov
  • PURA, Energy Storage Solutions Program. portal.ct.gov
  • Connecticut Green Bank, Energy Storage Solutions Program Adopts New Performance-Based Framework. ctgreenbank.com
  • Connecticut General Assembly OLR, Property Tax Exemptions for Solar Installations (2023-R-0214). cga.ct.gov
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