The most expensive air conditioning in the world runs for a few hours on the hottest afternoons of the year. For a supermarket, a data center, or a big-box retailer, those hours can define an entire year's electricity bill, thanks to punishing demand charges that scale with peak power draw. It’s a problem that has launched a thousand software dashboards and demand-response schemes, but NETenergy, a Chicago startup founded in 2013, is taking a more physical approach. They are building a thermal battery, a box of phase-change material that stores cold like a battery stores electrons, designed to slot into the existing rooftop units of commercial buildings [TechEmerge, April 2026].
The premise is elegantly simple. Instead of asking the compressor to work hardest when the grid is most stressed and electricity is most expensive, you run it a little harder overnight or in the morning to "charge" a reservoir of frozen material. Then, during the afternoon peak, you let that reservoir melt, absorbing heat from the building's air or glycol loop. The compressor idles, the peak demand charge falls, and the owner gets a quieter, more predictable bill. NETenergy claims its hybrid system can cut that peak demand by 40% and improve overall efficiency by more than 10%, with a payback period of about three years [F6S, April 2018]. After testing more than 25 prototypes, the company is now working to commercialize the technology [NETenergy, retrieved 2026].
A License from the National Labs
The core intellectual property behind NETenergy’s thermal battery didn’t originate in a garage. It came from the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) and researchers at the University of Illinois at Chicago. In 2021, NETenergy secured an exclusive field-limited license to develop and commercialize the hybrid HVAC-thermal energy storage system [Phase Change Matters newsletter, April 2021][REJournals, retrieved 2026]. This is a significant credential in the climate hardware world, where lab-to-market valley-of-death stories are common. The license provides a patented technical foundation and, just as importantly, a story of validated science that resonates with building engineers and cautious facility managers.
The Founder's Second Battery Act
Driving this effort is Dr. Said Al-Hallaj, a research professor of chemical engineering at UIC and a repeat entrepreneur in energy storage. His first company was AllCell Technologies, a lithium-ion battery firm he co-founded and led as CEO, which grew to an estimated 44 employees [Reuters, May 2009][Manta.com, retrieved 2026]. That experience,navigating the complexities of battery chemistry, manufacturing, and commercialization,is directly applicable to the thermal storage challenge. Mike Pintar, listed as a co-founder and COO, brings a background in business development and utilities [F6S, April 2018]. The team’s composition suggests a deliberate balance: deep technical credibility from the academic and lab world, paired with commercial operational experience.
The Funding Path: Grants Before Venture
NETenergy’s capitalization table reads less like a traditional venture story and more like a patchwork of strategic grants and foundation support. This is common for deep-tech hardware plays with long development cycles. The company has secured backing from the U.S. Department of Energy, Wells Fargo, Evergreen Climate Innovations, and the Exelon and Pritzker foundations, among others [NETenergy, retrieved 2026]. Its most recent publicly noted infusion was a $2 million grant in September 2024 [FundedIQ, September 2024]. Total funding reported by aggregators sits between roughly $750,000 and $2.1 million [Energy Startups, retrieved 2026][Dealroom.co, retrieved 2026].
| Funding Source Type | Notable Backers | Recent Round |
|---|---|---|
| Grants & Foundations | U.S. DOE, Wells Fargo, Evergreen Climate Innovations, Exelon Foundation, Pritzker Foundation | $2M Grant (Sep 2024) [FundedIQ, September 2024] |
| Accelerator/Program | University of Chicago's New Venture Challenge | Participation in 2015 [F6S, April 2018] |
| Corporate/Industry | International Copper Association | Not specified [NETenergy, retrieved 2026] |
This grant-heavy path has likely allowed NETenergy to de-risk the core technology without giving away significant equity early on. The next logical step, should the technology prove manufacturable and the unit economics hold in the field, would be a larger venture round to fund production scaling and a sales team.
Where the Bet Gets Real
The ambition is clear, but the path from licensed prototype to ubiquitous rooftop box is paved with hard questions of cost, reliability, and sales motion. The company reports four "invested partners," but the identities and scale of these partnerships are not public [NETenergy, retrieved 2026]. For a hardware product that requires integration into complex, mission-critical building systems, the sales cycle will be long and involve convincing risk-averse building owners and engineers.
- Integration complexity. The product’s wedge is its design for integration with existing HVAC infrastructure [TechEmerge, April 2026]. This is also its hurdle. Every building’s system is a unique snowflake, and retrofit installations are never trivial.
- Proving unit economics. The promised three-year payback is compelling, but it depends on local electricity rates, demand charge structures, and installation costs. Real-world performance must match the prototype claims.
- Manufacturing scale. Moving from 25 prototypes to volume production is its own engineering and capital challenge. The phase-change materials and heat exchangers must be produced consistently and cost-effectively.
NETenergy’s answer to these risks appears to be a focus on deep technical validation and strategic partnerships, hoping that the lab pedigree and clear economic logic will overcome commercial inertia.
The Cold Math of Cooling
Let’s run the numbers for a mid-sized commercial building, the kind with a $10,000 monthly electricity bill where 40% might be demand charges. If a NETenergy system can shave 40% off the peak cooling load, it might cut that demand portion by a third. That could mean saving over $1,000 a month, or $12,000 a year. At that rate, a system costing $36,000 would hit the three-year payback target. The actual math will swing wildly with utility tariffs, but the principle is what matters: thermal storage turns a volatile, weather-dependent cost into a fixed, depreciable asset. It’s a hedge, built into the mechanical room.
For NETenergy to become a standard spec for new construction or retrofits, it must beat the incumbent solution, which isn't another startup. It's the status quo: oversized chillers, demand-response penalties, and simply writing the check for the peak bill. Their competition is inertia, and their product is a calculated argument for why spending capital today saves more operational expense tomorrow. In the race to decarbonize and stabilize the grid, that’s an argument worth making.
Sources
- [NETenergy, retrieved 2026] Company Website | https://www.netenergytes.com/
- [TechEmerge, April 2026] NETenergy Innovator Profile | https://www.techemerge.org/innovators/netenergy/
- [F6S, April 2018] NETenergy Company Profile | https://www.f6s.com/company/netenergy
- [Phase Change Matters newsletter, April 2021] NETenergy Licenses NREL PCM Technology | https://phasechangematters.org/2021/04/netenergy-licenses-nrel-pcm-technology/
- [REJournals, retrieved 2026] NETenergy License Article | https://www.rejournals.com/
- [Reuters, May 2009] New emissions rules seen driving "green" success | https://www.reuters.com/article/us-column-cohen-greenauto/new-emissions-rules-seen-driving-green-success-idUSTRE54Q31L20090527
- [Manta.com, retrieved 2026] AllCell Technologies Profile | https://www.manta.com/
- [FundedIQ, September 2024] NETenergy Funding Update | https://fundediq.co/netenergy-netenergytes-com-funding/
- [Energy Startups, retrieved 2026] NETenergy Funding Profile | https://www.energystartups.org/startup/netenergytes/
- [Dealroom.co, retrieved 2026] NETenergy Company Information | https://app.dealroom.co/companies/netenergy