Geothermal · Analysis
I.What a networked geothermal loop actually is
Networked geothermal (also called a thermal energy network) is a set of pipes buried in the ground carrying water, sometimes mixed with antifreeze, connected to heat pumps inside buildings. The earth a few feet down in this region stays roughly 50 to 55 degrees year round, so the loop pulls warmth up in winter and sends heat back down in summer. There is no flame and no meter burning therms; the work is electric heat pumps plus a lot of buried pipe.
Crews who dig up Spring Garden Street to fix a gas main already know how to trench, fuse pipe, restore pavement, and keep a system pressurized. A geothermal loop is different plumbing but similar labor. That overlap is the quiet reason a gas utility studies it at all: the pipes change, the crews and the trucks largely do not.
II.What the study recommended, and what it did not
The diversification study laid out several paths PGW could take, geothermal among them, alongside options like renewable natural gas and hydrogen blending. It did not tell the company to abandon gas tomorrow. Read honestly, it flagged networked geothermal as promising enough to pilot and study further, while noting the high costs, the open regulatory questions, and the slow pace at which any of this would scale.
What PGW has committed to is much narrower than the idea sometimes sounds. As of the last public filings, the company has explored small pilots and kept studying the concept, not launched a citywide program to swap mains for loops. If a number or a schedule sounds too precise in coverage you read elsewhere, check it against the study itself and PGW's filings, because the gap between "studied" and "building" is the whole story here.
III.Who decides, and who would do the work
PGW answers to more than one body. The Philadelphia Gas Commission reviews its budgets and operations, City Council holds the purse strings and the politics, and the Pennsylvania Public Utility Commission has jurisdiction over its rates. A real shift toward geothermal would have to survive all three, plus the city's own climate goals out of the Office of Sustainability, and none of those move quickly.
People who would actually build it are the current workforce, many of them union gas workers. That is the part that makes clean heat a labor story on your block: whether a networked loop under a Kensington or Point Breeze street gets installed by PGW crews or by someone else shapes whether those jobs survive the transition. The study took that seriously, and anyone watching the clean-heat debate should too.
IV.Worth watching this month
1. Watch the Philadelphia Gas Commission's meeting calendar, where PGW's capital and operating budgets surface and where any geothermal pilot funding would show up, though most items on it are routine.
2. Check PGW's own filings and board materials for any update to the diversification study, which the company revisits periodically rather than on a fixed schedule.
3. Keep an eye on the Pennsylvania Public Utility Commission docket for PGW rate matters, since how the company is allowed to recover costs shapes what it can afford to pilot.
4. Follow the City of Philadelphia Office of Sustainability for building-decarbonization plans that could lean on networked geothermal, with timelines that tend to slip.
5. Watch for any state-level thermal energy network legislation, which a few other states have passed and which Pennsylvania has only discussed at last public report.
Frequently asked questions
- Is PGW switching from gas to geothermal?
- No. It commissioned a study that listed networked geothermal as one possible future line of work, and it has explored only small pilots at last public report. There is no citywide plan to replace gas mains with ground loops.
- Would geothermal lower my heating bill?
- It depends. Ground-source heat pumps are efficient to run, but the upfront cost of drilling and equipment is high, and who pays for the shared loop is unsettled. Nobody can honestly promise a bill figure yet.
- Why would a gas utility study geothermal at all?
- Because the trenching and pipe work overlap with what PGW crews already do. The company sees a networked loop as a possible way to keep its workforce employed if the city burns less gas over time.
- Does this mean my gas service is ending soon?
- No. PGW continues to run the gas system, and any geothermal work discussed so far is limited and early. Nothing in the public record points to a near-term shutoff of gas service.
Sources on the bench
Philadelphia Gas Works (utility) The utility's own site, where its business diversification study and company filings are posted; read what the consultants actually recommended. · www.pgworks.com
Philadelphia Gas Commission (city government) The city body that reviews PGW's budgets and operations; meeting agendas and records show where any pilot funding would appear. · www.phila.gov/departments/philadelphia-gas-commission
Pennsylvania Public Utility Commission (state government) The state regulator with jurisdiction over PGW's rates; search its dockets for how the company recovers costs. · www.puc.pa.gov
U.S. Department of Energy, Geothermal Heat Pumps (federal government) A plain federal explainer of how ground-source heat pumps work and what drives their cost. · www.energy.gov/energysaver/geothermal-heat-pumps
City of Philadelphia Office of Sustainability (city government) The city office setting climate and building-energy goals that any geothermal push would have to fit. · www.phila.gov/departments/office-of-sustainability