Base Power’s Illinois expansion puts the startup squarely inside the most strained grid in the United States. The Austin-based energy storage company began selling its home battery systems to Illinois residents this week, marking its first move into the territory operated by PJM Interconnection, the largest U.S. grid operator by territory.
The timing is not accidental. Wholesale electricity prices across PJM have nearly doubled over the past year, driven by a surge in data centre demand and a shortage of new generation capacity. Northern Virginia, one of the densest data centre regions on the planet, sits squarely within PJM’s footprint. The power crunch has grown severe enough that AEP, one of the region’s largest utilities, has threatened to leave the market.
Base Power Illinois Expansion: The PJM Angle
Base Power’s pitch to Illinois customers is straightforward: its electricity rates are 25% below those of incumbent utility ComEd. The startup does not sell its batteries outright. Instead, customers buy electricity from Base, which supplies systems starting at 25 kilowatt-hours, larger than most competitors’ units.
The business model does something else, too. By installing batteries at individual homes, Base sidesteps PJM’s notoriously slow interconnection 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, Base Power’s founder and CEO, said.
That queue has been a sore point. PJM paused applications for new generating sources in 2022 and only reopened the process recently, replacing its old first-come, first-served model with a first-ready, first-served approach intended to prioritise projects that are more advanced and better positioned to move forward. The response from developers was immediate: 811 new generation projects totalling 220 gigawatts applied through Cycle No. 1, with a deadline of 27 April 2026. Of that total, 106 GW consists of gas-fired generation. The queue is long, the wait is real, and Base is not in it.
A Grid in Crisis, and a Company Positioned for It
Base launched in Texas two years ago, building what it calls a virtual power plant from residential batteries. It charges those batteries when electricity is cheap and dispatches stored power when the grid needs relief. The company now operates more than 500 megawatt-hours of battery storage in Texas. It has also expanded its Texas footprint through a partnership with GVEC, bringing whole-home backup power to households across that co-operative’s entire service territory, according to a Base Power Series C announcement.
On the manufacturing side, Base is building its first energy storage and power electronics factory at the site of the former Austin American-Statesman printing press in downtown Austin, a move that signals the company intends to control more of its own supply chain as it scales.
The capital to fund all of this arrived quickly. In October, Base announced a $1 billion Series C led by Addition. That followed a $200 million Series B co-led by Addition, Andreessen Horowitz, Lightspeed, and Valor Equity Partners, with participation from Thrive Capital, Altimeter, Terrain, Trust, and other existing investors, according to Sourcery VC. Two substantial rounds in close succession, each larger than the last.
The Illinois entry is Base Power’s Illinois expansion into genuinely difficult territory, in every sense. PJM has been slow to embrace distributed energy storage, and the grid operator is under scrutiny for how it has handled the surge in electricity demand over the past four years. Base’s answer is to route around the problem: connect at the home, aggregate the storage, and let the grid operator catch up later.
Whether PJM’s reformed interconnection process will eventually unlock enough new generation to ease the pressure is an open question. With 220 GW of applications and a queue that only just reopened, the crunch is unlikely to resolve quickly. For Base, that is less a risk than a runway.
