Hull Street Energy expands Milepost Power portfolio with acquisition of Illinois gas assets from J-Power USA

Why Did Hull Street Energy Acquire J-Power’s Illinois Power Plants?

Hull Street Energy, LLC, a U.S.-based private equity firm focused on electricity infrastructure investments, has announced the acquisition of key gas-fired generation assets near Joliet, Illinois, from Elwood Energy LLC, a subsidiary of J-Power USA. This move, disclosed on June 5, 2025, significantly expands the operational capacity of Hull Street’s affiliate, Milepost Power, bringing its total portfolio to approximately 3,500 megawatts of flexible, dispatchable generation capacity across North America.

While neither Hull Street Energy nor J-Power USA is publicly traded, the deal indirectly influences North American power reliability markets, particularly those exposed to grid transition risks and extreme demand volatility. The acquisition reflects a broader strategic shift in the U.S. power sector, where dual-fuel and gas-fired assets are increasingly viewed as essential tools for grid stability amid decarbonization pressures.

The Joliet-area assets—capable of operating on both natural gas and backup fuels—are ideally positioned within the Midcontinent Independent System Operator (MISO) region, which faces capacity constraints due to accelerated coal retirements and delayed renewable interconnection. As climate resilience, energy affordability, and system reliability become more entangled in public policy and investor expectations, firms like Hull Street Energy are stepping in to fill reliability gaps with proven thermal assets optimized for transitional energy markets.

What Is the Strategic Value of the Joliet Acquisition?

The acquired facilities are part of a legacy generation hub near Joliet, strategically situated to serve both industrial and residential demand centers in the Midwest. Historically, Elwood Energy’s assets have been used as peaking units—coming online during high-demand periods to stabilize voltage and frequency. This makes them highly valuable as the grid integrates increasing levels of intermittent renewables like solar and wind.

Hull Street Energy’s acquisition comes at a time when PJM and MISO market operators are issuing regular alerts about capacity shortfalls and calling for investments in fast-ramping assets. According to sector analysts, gas-fired generation remains a vital buffer in such scenarios. By acquiring dispatchable generation in an area of constrained supply, Hull Street is both de-risking its portfolio and capitalizing on emerging price volatility in capacity and ancillary services markets.

Milepost Power, the operating affiliate into which these assets will be folded, is engineered to manage such challenges. With its emphasis on flexibility, operational readiness, and analytically driven risk protocols, Milepost has emerged as one of the more resilient non-utility platforms managing gas and dual-fuel infrastructure in transition-prone regions.

How Does This Deal Align with Hull Street Energy’s Long-Term Playbook?

Founded with a clear focus on North American electricity infrastructure, Hull Street Energy specializes in acquiring undervalued or strategically critical assets and reengineering them for long-term utility through operational optimization, regulatory alignment, and environmental upgrades.

The firm’s portfolio includes a mix of conventional fossil, renewable, and energy storage assets. It differentiates itself through deep operational know-how—its leadership team includes former utility executives and grid operators—and a consistent focus on the energy transition’s reliability frontier.

This acquisition builds upon prior Hull Street transactions across the Northeast, Midwest, and Texas markets, where the firm has selectively acquired generation assets that provide essential grid services. Investors familiar with the firm’s strategy note that while Hull Street does not chase speculative green assets, it invests where reliability intersects with decarbonization, often ahead of regulatory or pricing curve shifts.

What Role Does Milepost Power Play in This Transaction?

Milepost Power, an affiliate of Hull Street Energy, will take ownership and operational control of the newly acquired assets. Milepost was created to unify Hull Street’s growing fleet under a standardized platform that emphasizes real-time risk management, environmental compliance, and high availability.

Its power plants—spread across the PJM, MISO, and ERCOT markets—are tasked with providing both energy and critical reliability services such as frequency regulation, spinning reserve, and black start capability. In a grid increasingly characterized by renewable intermittency, battery storage limits, and demand-side variability, Milepost’s value proposition lies in its ability to deliver dispatchable megawatts when and where needed.

Analysts view Milepost as a growing “mid-stack” player—offering grid services traditionally supplied by vertically integrated utilities or large IPPs (independent power producers), but with the nimbleness of a private equity-backed platform. With the Joliet plants now part of this fleet, Milepost’s relevance in the reliability-constrained Midwest region is likely to grow.

How Does This Fit into Broader U.S. Energy Market Trends?

Hull Street’s latest acquisition comes against the backdrop of an evolving U.S. power market. According to data from the U.S. Energy Information Administration (EIA), more than 13 GW of coal generation is expected to retire in 2025, while only 8.5 GW of firm capacity—mostly gas—is forecasted to come online in the same period. Renewable additions continue to grow, but delays in permitting, transmission interconnection, and equipment imports are slowing deployment.

Moreover, several states in the Midwest—including Illinois, Indiana, and Michigan—have seen significant growth in electricity demand from industrial sectors, including steel production, data centers, and advanced manufacturing. Simultaneously, summer peak forecasts are being revised upward due to rising temperatures and electrification of cooling.

In this environment, the value of fast-ramping, dual-fuel generation is increasing. Institutional investors and infrastructure funds are paying closer attention to capacity pricing, reserve margins, and non-energy revenues. Hull Street’s acquisition is thus reflective of how reliability economics are reshaping deal-making in power markets.

What Are the Legal and Financial Details of the Transaction?

While the transaction value has not been disclosed, the deal involved several prominent advisors. Hull Street Energy was advised by Troutman Pepper for legal matters, while financial advisory support came from CIBC Capital Markets and Merit Capital Advisors. J-Power USA, the seller, was represented by Baker McKenzie.

J-Power USA Generation, L.P.—a subsidiary of Electric Power Development Co., Ltd. of Japan—has been active in the U.S. independent power production space since the early 2000s. The company has developed and operated gas and coal assets across the U.S., though in recent years, it has signaled a desire to shift toward renewables and battery storage.

Industry observers believe this divestment may be part of a strategic rebalancing, with J-Power USA potentially freeing up capital for cleaner technologies. The company retains a presence in multiple U.S. states and is expected to continue investing in development-stage projects aligned with Japan’s global climate goals.

What’s the Investor and Sector Sentiment Around This Deal?

Although not a listed firm, Hull Street Energy’s market actions indirectly influence sentiment across the broader infrastructure investment community. Analysts and institutional players have responded positively to the transaction, viewing it as further validation of the “firming asset” thesis. This idea centers on the notion that legacy thermal generation—particularly when strategically located and properly managed—remains essential even in a net-zero-aligned market.

Fund flows into infrastructure vehicles with similar holdings (e.g., Brookfield Renewable Partners, Clearway Energy, and LS Power affiliates) have remained steady in Q2 2025. Many of these funds are reporting stable or improved internal rates of return (IRRs) thanks to higher capacity market prices and lower-than-expected curtailments.

Private equity newsletters and infrastructure ratings services have praised Hull Street’s disciplined, regionally targeted strategy. Several have noted that the firm is positioning itself well for eventual monetization, either via asset recycling or sale to yieldcos or public infrastructure aggregators.

What’s Next for Hull Street Energy and Milepost Power?

Going forward, Hull Street Energy is expected to continue evaluating acquisitions in under-capacity nodes across the Midwest, Texas, and the Southeast. The firm may also explore hybridization opportunities—such as adding battery storage to existing thermal sites—as market structures begin to reward flexible, zero-carbon-ready configurations.

There is also growing speculation that Hull Street could enter into offtake arrangements with utilities, data centers, or community choice aggregators (CCAs) seeking firm, clean-adjacent power. Such deals could offer premium pricing and longer revenue visibility, further boosting the value of assets like those recently acquired in Illinois.

Moreover, policy signals from the U.S. Department of Energy and Federal Energy Regulatory Commission (FERC) increasingly emphasize the need for “resource adequacy reform,” potentially introducing new market products that reward reliability and resilience—areas where Milepost Power is well-positioned to compete.

In summary, Hull Street Energy’s acquisition of gas-fired generation assets from J-Power USA adds another high-value node to its Milepost Power network. At a time when U.S. grid operators are under pressure to balance renewable ambitions with firming needs, the deal offers both operational relevance and long-term strategic potential. For infrastructure investors and market observers, it reaffirms that in the transitional energy economy, reliability is the new premium.