Who makes HRSGs for AI data centers

A gas turbine on its own throws away most of its fuel energy as hot exhaust. A heat- recovery steam generator is the boiler that catches it: exhaust passes over tube bundles, raises steam, and that steam drives a steam turbine to make additional electricity from fuel already burned. Turbine plus HRSG plus steam turbine is what combined cycle means, and the efficiency gain over the turbine alone is substantial. The reason it matters to this catalog is that behind-the-meter generation at an AI campus is a long-lived asset burning purchased fuel continuously. A simple-cycle turbine is cheaper and faster to install and is the right answer for peaking; a campus intending to self-generate a base load has an operating-cost argument for combined cycle that compounds over the plant's life. The trade is capital, footprint, water, and — the one that bites on an AI schedule — construction time, since the HRSG and steam turbine add a substantial block of work after the turbine itself is running. That sequencing is what to look for. Some campuses install simple cycle to get power quickly and add the recovery train afterwards, which is a design decision that has to be made before the first foundation. Also worth checking is water: the steam cycle needs makeup and cooling, in the same places where the data center itself is already negotiating for water. The suppliers here are the specialist HRSG fabricators rather than the turbine makers.