Sharp rise in demand: data centres bring power plant in Chicago’s ‘Czech’ district back into play

Demand for electricity in the United States is rising at a pace the energy infrastructure has not been accustomed to for many years. The main driver is data centres powering artificial intelligence systems, whose computing capacity requires a continuous and stable supply of energy. This pressure is now bringing even very old fossil-fuel plants back into operation. One of them is a coal-fired power plant in Chicago dating from 1968. It is located in the working-class district of Pilsen, historically associated with Czech immigration.

An ageing power plant in the heart of a ‘Czech’ district

The industrial site on Cermak Street, on the edge of Dvorak Park, has been important to Chicago’s energy system for more than a century. A coal-fired power plant was built there in 1903, becoming an integral part of the working-class Pilsen district, named after the west Bohemian city. At the time, the surrounding area was home to a sizeable community of immigrants from Bohemia and Moravia, whose legacy remains not only in street names but also in cultural institutions and public spaces.

Coal-fired generation at the site operated for more than a hundred years. The main coal-fired unit, dating from 1968, was retired in 2012 following sustained opposition from local residents. However, eight smaller light fuel oil-fired units remained at the site, intended to cover demand peaks. They stood idle for most of the year and were due to be permanently shut down next year. Then the digital revolution entered the picture: the boom in artificial intelligence and the rapid construction of data centres.

Data centres bring ageing plants back into play

The sudden return of these plants is not merely a local anomaly but part of a broader systemic shift. PJM Interconnection, the largest US transmission system, which covers 13 states and serves the area with the world’s highest concentration of data centres, faces unprecedented load growth. Electricity consumption has begun to exceed available generating capacity, raising concerns about capacity shortages during periods of peak demand.

The market has responded with a strong price signal. Payments that PJM makes to generators for providing available capacity rose by more than 800 percent year on year this summer. This has fundamentally changed the economics of operating older plants. Power stations that had been earmarked for closure have become profitable again. According to a Reuters analysis, around 60 percent of coal, gas and other fossil-fuel power plants in the PJM network this year postponed or cancelled their planned closures. Most of them are plants designed to cover peak demand, known as peakers.

Grid operators openly warn that demand growth is outpacing the construction of new generation and transmission infrastructure. PJM says the system currently cannot afford to lose any existing generating capacity until new sources capable of delivering rapidly available power are connected. Data centres require not only large volumes of electricity, but above all real-time supply stability.

From an operational perspective, older backup units serve as a last line of defence. They can start up quickly and stabilise the grid during outages, extreme temperatures or sudden consumption peaks. Energy industry experts say this flexibility is crucial today, particularly given the parallel electrification of industry and transport.

The paradox of today’s energy sector

At the same time, the conflict between technical necessity and the long-term goals of the energy transition is deepening. Government analyses show that backup fossil-fuel sources produce significantly higher sulphur dioxide emissions per unit of electricity generated than standard power plants. The systemic solution is expected to involve strengthening transmission grids, improving regional balancing of capacity and expanding battery storage. However, their deployment is time-consuming.

The boom in artificial intelligence thus presents the energy sector with a practical paradox. A technology associated with the future of the economy is now increasing grids’ reliance on facilities built more than half a century ago. The case of the Chicago power plant in Pilsen shows that the transition to a new energy architecture will be gradual, and that supply stability in the coming years will also rely on infrastructure whose return was not anticipated until recently.