Maryland Geothermal Credits: ~$3,567/Year from Your Heat Pump

Researched and reviewed by the GeothermalFinder Editorial Team

Maryland runs the most mature geothermal credit market in the country. As of mid-2026, credits sell for ~$87 each, and a typical residential system generates about 41 credits per year — roughly $3,567 per year in gross credit value. That's annual income from a system you're already running, on top of whatever you're saving on heating and cooling.

This page covers how the program works, what the numbers look like, and how to get started. For background on geothermal credits across all states, see our main geothermal credits guide.

How much Maryland geothermal credits are worth

The math is straightforward. A typical residential geothermal system in Maryland generates about 41 credits per year. At the current market rate of ~$87 per credit, that works out to roughly $3,567 per year in gross credit value.

The word "gross" matters. Most homeowners sell credits through a broker, and broker fees reduce the net amount you receive. The actual amount you keep depends on your broker's commission structure — some charge a flat per-credit fee, others take a percentage. Even after fees, this is meaningful annual income from a system you're already running.

How many credits your system generates depends on its output. Larger systems produce more credits. The 41-credit figure is a typical residential number, but your system could generate more or fewer depending on its capacity and how much heating and cooling it delivers.

The ACP step-down: what it means for credit prices

Maryland's alternative compliance payment (ACP) is the amount a utility pays when it falls short of its clean-energy targets. Because utilities can always choose to pay the ACP instead of buying credits, the ACP generally caps what credits can sell for.

That cap is stepping down:

What this means practically: credits trading at ~$87 today have room under the $90 ceiling. As the ACP drops to $80 in 2027 and $65 from 2028 onward, credit prices may drift downward to stay under the new caps. At $65, a 41-credit system would generate roughly $2,665 in gross credit value per year — less than today, but still substantial.

The step-down makes the timing relevant. Registering now — while the ACP is still at $90 and credits are near $87 — captures the current rate before the ceiling drops. Source: Maryland PSC renewable energy schedule.

How long do Maryland credits last?

Maryland's regulations do not set a fixed expiration on geothermal system certification. Under COMAR 20.61.02.04, a certified system stays certified unless it is decertified — meaning the certification is open-ended for as long as the system remains operational and eligible.

There is a separate rule on credit banking: under PUA § 7-709, a renewable energy credit exists for five years from the date created. That means credits need to be sold within five years of generation, but new credits keep being generated every year your system runs.

How to register and start earning

Maryland credits are recorded in PJM GATS (the PJM Generation Attribute Tracking System) — the same online registry that tracks solar credits for states throughout the PJM region. Here's the path from installation to income:

1. Gather your system documentation.You'll need proof of installation, your system's specifications (make, model, capacity), and utility interconnection details. If your installer gave you a commissioning report or a Manual J load calculation, keep those handy.
2. Choose a broker or aggregator.Most homeowners don't register or sell credits directly. Brokers handle the paperwork, pool credits from many homeowners, and manage the sale. Active brokers in Maryland include Carbon Solutions Group, ClearPath Renewables, and Flett Exchange. We don't endorse any of them — compare fees, payment terms, and contract length before signing.
3. Register with PJM GATS.Your broker typically handles registration as part of their service. The process includes a certification review by the Maryland PSC. Expect registration to take several weeks to a few months.
4. Credit generation begins.Once registered, credits are generated based on your system’s calculated energy savings — not a dedicated meter. Maryland uses a savings-based methodology (the ClimateMaster Savings Calculator) to determine how many credits your system earns each year. No monitoring equipment is required.
5. Credits sell, you get paid.Your broker sells the credits to utilities that need them for RPS compliance. You receive payment minus the broker's commission. Keep records — credit income is generally taxable.

Choosing a broker

Several brokers and aggregators serve Maryland geothermal homeowners. They vary in fees, contract terms, and how they handle payment. Questions worth asking before you sign:

• What's the fee structure? Some charge a flat per-credit fee, others take a percentage of the sale price. The difference matters — a flat fee is easier to predict, while a percentage means your costs rise with credit prices.
• How long is the contract? Some brokers require multi-year commitments. Shorter contracts give you more flexibility but may come with higher per-credit fees.
• Is registration included? Most brokers handle PJM GATS registration as part of their service, but confirm before assuming.
• When and how do you get paid? Payment timing varies — some pay quarterly, some annually. Ask about the schedule and method upfront.

How Maryland compares with other states

Maryland has the highest credit values and the most established market among geothermal credit states. Here's how it stacks up:

Maryland's ACP is stepping down, which may reduce credit values over time. But even at the 2028+ ACP of $65, a typical Maryland system would earn roughly $2,665 per year in gross credit value — still higher than Pennsylvania or the Illinois estimates.

Frequently asked questions

Ready to start?

If you already own a geothermal system in Maryland, your earning path starts with choosing a broker and registering through PJM GATS. If you're still deciding on geothermal, use our planning tools below — and factor in that credit income changes the payback math.

Sources and methodology

This guide uses official Maryland state regulations, regulatory filings, and program documents. All credit values, program parameters, and dates were verified against primary sources as of September 2026. Published amounts are reported as market figures — not guarantees. Program details are monitored for changes; homeowners should confirm current terms with the Maryland PSC or their broker before acting.