PA Tier II AEC Monetization for CHP Systems

Pennsylvania's Alternative Energy Portfolio Standard is the largest and most liquid CHP-eligible compliance REC market in the country. A natural-gas CHP system in Pennsylvania is explicitly Tier II eligible — and at RY2025 weighted-average pricing of $26.92 per MWh against an ACP ceiling of $45, the gap between today's market price and the regulatory penalty cap is wide enough to sustain another decade of price appreciation.

Updated June 4, 2026 · PA S-RECs Knowledge Hub · ~7 min read

Why PA Tier II is the strongest CHP REC market

The AEPS Act of 2004, as amended, requires electric distribution companies and electric generation suppliers serving Pennsylvania load to acquire alternative energy credits covering a defined percentage of their retail electricity sales each Energy Year. The Tier II obligation reached 10% in 2021 and remains at that level indefinitely. Pennsylvania retail electricity sales totalled 136,554,641 MWh in RY2025, so the 10% Tier II obligation came to 13,655,464 AECs — about 13.7 million, trending toward 14 million as load grows roughly 1.7% a year (derived from Table 2 of the 2024 and 2025 AEPS Annual Reports: 134,242,935 MWh in RY2024 to 136,554,641 MWh in RY2025). The PUC-reported Tier II compliance cost for RY2025 was $367,594,667 on 13,654,235 credits retired.

That demand is being met by a supply pool that has not kept pace. Waste coal — historically the largest Tier II supply source — is retiring. Demand-side management projects enrolled in the early 2010s under contracts written against the measure's TRM life, which Act 129 caps at 15 claimable years are reaching expiration. New CHP and distributed generation projects are the primary supply growth opportunity, and registration rates have lagged the available eligible asset base. The result is a structurally tightening market.

What CHP qualifies for Tier II

Pennsylvania's AEPS statute defines Tier II resources broadly, and CHP enters through two distinct pathways defined by system size:

• Distributed generation under 5 MW — CHP falls within the 52 Pa. Code § 75.1 distributed generation definition. AECs are issued per § 75.63 on metered electricity generated.
• Demand-side management at or above 5 MW — systems above the § 75.1 threshold are evaluated under the demand-side management pathway. § 75.63 provides for credit issuance on MWh of electricity conserved; the specific measurement basis is established during certification.

A CHP system at a hospital, university, food processing facility, district energy plant, or wastewater treatment operation may qualify under one of these pathways depending on nameplate capacity. There is no fuel restriction — natural-gas-fired CHP is fully eligible, as are biomass, biogas, and waste-fuel CHP systems.

Act 114 of 2020 added an in-state requirement: Tier II eligibility now requires the facility to be physically located in Pennsylvania, with limited grandfathering for facilities certified before the cutoff date. This restriction tightened supply further and supports the upward price trajectory.

The registration and monetization process

• Pre-application review — confirm the facility meets the applicable Tier II pathway (distributed generation under 5 MW, or demand-side management at or above 5 MW), gather nameplate capacity data, interconnection documentation, and metering specifications.
• PA PUC application — submit an application to the PUC's alternative energy credit administrator through the PennAEPS portal. The administrator reviews technical qualifications, fuel sources, and metering setup. Under 52 Pa. Code § 75.64, the administrator provides written notice of the qualification decision within 30 days of receiving a complete application; total elapsed time depends on how quickly complete documentation is assembled.
• PJM-GATS registration — open a generator account at PJM Environmental Information Services. Once the PUC approves the facility, AECs are minted directly into the GATS account based on metered production data submitted monthly.
• Sales — AECs can be sold spot through OTC brokers, contracted forward with obligated load-serving entities, or transacted on exchange-listed futures (Nodal Exchange, ICE). Most CHP hosts use an aggregator to handle all three channels.
• Operational cadence: production data is submitted to GATS monthly, and most spot transactions settle within 30 days of certificate transfer.
• Documentation typically required for registration

To register a CHP project and generate Tier II AECs in Pennsylvania, asset owners and developers should be prepared to provide:

• Interconnection agreement with the electric distribution company
• Commissioning documentation and system specifications
• Meter specifications, location, and calibration records
• Generation history where the system has been operating
• Fuel supply documentation
• Air quality permit or exemption determination
• Documentation of environmental attribute ownership

For detail on why attribute ownership documentation matters most — and how PPA, ESA, and ESCO contracts affect it — see CHP and PA Tier II AECs.

A complete documentation package is the difference between a 30-day registration approval and a 90-day back-and-forth with the PennAEPS administrator. PA S-RECs handles documentation packaging and submission as part of the standard aggregation engagement.

Pricing context and outlook

PA Tier II weighted average pricing has climbed steadily for nearly a decade. The trajectory:

• RY2020: ~$11/MWh
• RY2022: ~$18/MWh
• RY2024: ~$26.47/MWh
• RY2025: $26.92/MWh (weighted average)
• RY2025 weighted average: $26.92/AEC

The fundamental supply-demand imbalance — increasing compliance obligation, retiring legacy supply, slow new project enrollment — supports a price floor well above historical lows. Today's market reflects the $26.92/AEC RY2025 weighted-average benchmark, which is the figure cited in long-term contracts and compliance settlement. The $45 ACP ceiling provides hard upside protection: at no point would a load-serving entity rationally pay above $45 for a credit, so that cap defines the maximum achievable price in any future market state. The gap from the $26.92 benchmark to the $45.00 cap is the runway available to continued price appreciation as supply stays tight.

The bottom line for a PA-based CHP host

A 1 MW CHP system operating at 80% capacity factor in Pennsylvania generates roughly 7,000 MWh of electrical output annually. At the RY2025 weighted-average benchmark of $26.92/AEC, that is approximately $188,440 per year in incremental revenue (7,000 × $26.92). Over a 15-year contract horizon — the Act 129 cap on claimable life — that is roughly $2.83 million in cumulative credit revenue at a flat price.

The decision facing most PA CHP hosts isn't whether to register — the math is overwhelming — it's how to register without diverting operating staff to a regulatory process they don't run today. That's the role of an aggregator.

Compare to other markets

• Connecticut Class III for CHP →
• Massachusetts APS for CHP →
• CHP and PA Tier II AECs →