Base Power’s Illinois expansion marks the Austin-based startup’s first move into PJM Interconnection territory, the largest grid operator in the United States by landmass and arguably the one under the most acute strain. The company began selling its home battery systems to Illinois residents this week, offering electricity rates priced 25% below those of incumbent utility ComEd.
Base Power’s Illinois Expansion and the PJM Opportunity
PJM’s footprint runs from Illinois to Northern Virginia, a corridor that has absorbed an extraordinary volume of new data centre demand. The concentration in Northern Virginia alone makes it one of the densest data centre clusters on the planet. Supply has not kept pace: wholesale electricity prices across PJM have nearly doubled over the past year, and AEP, one of the region’s largest utilities, has threatened to exit the market entirely.
The grid operator’s difficulties are partly self-inflicted. PJM paused applications for new generating sources in 2022 and did not reopen the queue until April this year. When PJM’s reformed interconnection process opened Cycle 1 on 29 April 2026, it received 811 new generation project applications representing 220 gigawatts of potential capacity, a figure that illustrates both the scale of pent-up demand and the depth of the backlog PJM is now working through. Before reform, the transition queue held approximately 200,000 MW of projects; by June 2025 that figure had been trimmed to roughly 63,000 MW, with the remainder expected to be processed through 2026.
Base Power’s strategy is to sidestep that queue entirely. ‘We are deploying capacity behind the meter at the residential home, where an interconnection already exists, so we don’t wait in the interconnection queue,’ Zach Dell, the company’s founder and chief executive, told Canary Media.
A Business Model Built Around the Battery
Base Power does not sell its hardware outright. Customers purchase electricity from the company instead, and the batteries, starting at 25 kilowatt-hours, larger than most competing residential units, sit on-site and arbitrage the grid on Base’s behalf. In Texas, where the company launched two years ago, it is already operating more than 500 megawatt-hours of storage, charging when prices are low and dispatching when demand spikes.
The model has attracted serious capital. On 8 October 2025, Base closed a $1 billion Series C, drawing in new investors including Ribbit, CapitalG, Spark, BOND, Lowercarbon, Avenir, Glade Brook, Positive Sum, and 1789, alongside existing backers Andreessen Horowitz, Lightspeed, Valor Equity Partners, Thrive Capital, Altimeter, and others, according to Wilson Sonsini, which advised on the round.
That raise followed a $200 million Series B completed on 8 April 2025, co-led by Addition, Andreessen Horowitz, Lightspeed Venture Partners, and Valor Equity Partners, according to Wilson Sonsini’s advisory disclosure for that earlier round. The snippet had described the $200 million round as led by Andreessen Horowitz, Lightspeed, and Valor; Addition was in fact a co-lead from the outset.
On the operational side, Base Power is building its first energy storage and power electronics manufacturing factory at the site of the former Austin American-Statesman printing press in downtown Austin, a step that signals the company intends to control more of its own supply chain as it scales.
The Base Power Illinois expansion into PJM comes at a moment when the operator’s structural problems have become impossible to ignore. By routing around the interconnection queue through residential, behind-the-meter deployments, Base is not waiting for PJM to fix itself. It is building a distributed grid that functions in parallel, accreting capacity one home battery at a time. Whether 500 megawatt-hours in Texas becomes five gigawatt-hours across PJM territory is the question the next capital cycle will have to answer.
