Ground-Source Heat Pumps and PA Tier II AECs
Ground-source heat pump retrofits may generate PA Tier II AECs where they conserve electricity. Whether they do depends on the baseline being displaced — see the worked models and the fuel-switching analysis. AECs are issued forward from the date a complete PennAEPS application — including a meter or inverter reading — is filed under 52 Pa. Code § 75.63(i), based on verified MWh of electricity conserved.
Why Geothermal Systems Excel for Tier II RECs
High kWh Reduction Potential
Ground-source heat pumps replace resistance heating, gas heating, and inefficient cooling with a single high-COP system. Where the baseline is electric resistance or older air-source equipment, MWh savings per square foot are among the highest of any Tier II-eligible efficiency measure.
Long Useful Life
Ground-source heat pump systems are long-lived assets and typically generate AECs over the measure's remaining useful life.
Illustrative Revenue Modeling
For a hypothetical 80,000 sq ft commercial building modeled at 400 MWh/yr of verified savings and RY2025 weighted-average pricing, annual AEC revenue would be roughly $10,800/yr. Actual revenue depends on measured savings and market pricing at time of sale.
Stack with Utility Rebates
PA utility rebates (PPL, PECO, FirstEnergy under Act 129) and PA Tier II AECs are separate programs. A geothermal project can pursue both.
Qualifying Geothermal System Types
Closed-Loop Vertical
Bore holes with ground heat exchangers — most common for commercial
Closed-Loop Horizontal
Horizontal ground loops for facilities with available land area
Open-Loop / Standing Column
Groundwater-based systems using wells or standing column wells
Hybrid Geothermal
GSHP combined with cooling towers or boilers for peak loads
Revenue Examples by Facility Size
Facility
40,000 sq ft (illustrative)
Annual Savings
200 MWh/yr
Annual RECs
$5,384/yr
Annual × 15 (Act 129 claimable cap)
$80,760
Facility
80,000 sq ft (illustrative)
Annual Savings
400 MWh/yr
Annual RECs
$10,768/yr
Annual × 15 (Act 129 claimable cap)
$161,520
Facility
120,000 sq ft (illustrative)
Annual Savings
600 MWh/yr
Annual RECs
$16,152/yr
Annual × 15 (Act 129 claimable cap)
$242,280
Illustrative model at RY2024–25 weighted-average pricing of $26.92/AEC (source: PennAEPS). The final column is the annual figure multiplied by 15 — the maximum claimable life under Act 129. Actual claimable life is the TRM measure life for the specific measure, which may be shorter, and actual revenue depends on measured MWh conserved and market pricing at time of sale.
Maximize Your Geothermal REC Revenue with Energy Monitoring
Installing energy monitoring equipment on your geothermal system provides real-time verification of energy savings — the strongest possible evidence for your REC application. Submetering the heat pump compressors, ground loop pumps, and supplemental heating shows exact kWh reductions compared to baseline.
Submetered data supports the measurement and verification package that PennAEPS reviews at certification. Approval outcomes and credit volumes are determined by the program administrator; documented M&V strengthens the record supporting a certification decision.
Calculate Your Geothermal REC Revenue
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Get Custom EstimateRelated guides and case studies
Guides and illustrative examples covering geothermal heat pump AEC qualification and revenue.
- When Does a Geothermal Retrofit Actually Conserve Electricity?PA Tier II AECs are issued per MWh of electricity conserved. A geothermal retrofit that displaces gas heating can raise electricity consumption while lowering total energy use — producing real savings and no credits. May 2, 2026 8 min read
- Pennsylvania's Alternative Energy Credit Market at a CrossroadsA forward-looking analysis of Tier I and Tier II dynamics, the PRESS proposal under House Bill 501, and what the two-phase price dynamic means for compliance buyers and credit generators through 2035. Mar 28, 2026 18 min read
- Geothermal Retrofit AEC Revenue Model: 200,000 Sq Ft Office ComplexA 200,000 sq ft cooling-dominated office complex replacing 25-year-old chillers with a 400-ton GSHP would conserve roughly 840 MWh of electricity annually. Here is what that produces in Tier II AECs, with the arithmetic shown. Mar 27, 2026 8 min read
- How Geothermal Heating and Cooling Systems Qualify for PA Tier II RECsGround-source heat pumps deliver massive energy savings — and those savings translate directly into Tier II Renewable Energy Credits. Learn how geothermal HVAC qualifies and how to maximize your REC revenue. Mar 25, 2026 9 min read
Browse the full library in the PA Tier II AEC insights index.