New and Used Steam Turbine Generators for Sale

A simple-cycle gas turbine converts 30% to 42% of its fuel energy into electricity. The remainder leaves as exhaust at 500°C to 650°C.

A combined cycle plant captures that exhaust in a heat recovery steam generator (HRSG), raises steam, and expands it through a steam turbine driving a second generator. The result is roughly 50% more electricity from exactly the same fuel, lifting plant efficiency from around 38% simple cycle to 60% or more in combined cycle on modern H-class machines.

The reference case. Siemens delivered Egypt’s Megaproject as three 4.8 GW plants at Beni Suef, Burullus and New Capital, totalling 14.4 GW. Each plant comprises four 1,200 MW combined cycle blocks in 2-on-1 configuration: two SGT5-8000H gas turbines, each with its own generator and HRSG, feeding a single SST5-5000 steam turbine with its own generator. Beni Suef operates above 61% efficiency. All twelve blocks were built and grid-connected in 27.5 months, against a normal build time of roughly 30 months for a single block.

Configurations you will be quoted:

2-on-1 (multi-shaft) — Two gas turbines, two HRSGs, one steam turbine, three generators. The most common utility arrangement. One gas turbine can be taken offline while the block continues to run.

1-on-1 (single-shaft) — One gas turbine, one HRSG, one steam turbine, sharing a single generator on a common shaft. Lower cost and smaller footprint, but the whole block stops when any element does.

3-on-1 — Three gas turbines feeding one steam turbine. Better capital efficiency at scale, more complex steam balance.

The economic case is straightforward. Adding a steam bottoming cycle to an existing simple-cycle plant adds roughly 50% more output with no additional fuel cost whatsoever. Where gas is expensive or supply is constrained, the payback is short.

Not every steam turbine sits behind a gas turbine.

Back-pressure turbines in process industry. Sugar mills, pulp and paper mills, refineries, chemical plants and distilleries all raise steam for process use. Routing that steam through a back-pressure turbine on its way to the process generates electricity as a by-product, with effectively zero incremental fuel cost. The turbine exhausts at the pressure the process requires rather than to a condenser.

Waste heat recovery. Cement kilns, steel furnaces, glass plants and incinerators produce high-grade waste heat continuously. A waste heat recovery boiler plus steam turbine converts a thermal liability into generation and reduces the site’s grid draw.

Biomass and waste-to-energy. Bagasse, wood chip, rice husk and municipal solid waste all fire boilers that drive steam turbines. In sugar-producing regions this is often the most economically attractive renewable generation available, because the fuel is already on site as a processing residue.

Concentrated solar power. Solar receivers raise steam that drives conventional turbines. The 19.9 MW Gemasolar tower plant in Spain is the best-known example of a molten-salt CSP plant using a standard industrial steam turbine.

Condensing turbines exhaust into a vacuum condenser below atmospheric pressure, extracting the maximum possible energy from the steam. Highest electrical output, but all the heat is rejected to cooling water or air. The standard choice for combined cycle and for any plant whose sole product is electricity.

Back-pressure turbines exhaust at a useful pressure — typically 3 to 20 bar — for process heating downstream. Lower electrical output per kilogram of steam, but total energy utilisation far higher because the heat is used rather than rejected. The standard choice for industrial cogeneration.

Extraction-condensing turbines combine the two, bleeding steam at one or more intermediate pressures for process use while condensing the remainder. The most flexible arrangement where process steam demand varies through the day or the season.

Mechanical drive turbines produce no electricity at all. They drive boiler feedwater pumps, compressors and blowers directly, and are built to API standards. Common in refineries and petrochemical plants where steam is abundant and electrical reliability is not guaranteed.

Across Africa, the Middle East, South Asia and the Caribbean, three steam applications recur.

Uprating existing simple-cycle plants. Many frontier-market gas plants were built simple cycle for speed. Adding a bottoming cycle raises output roughly 50% on unchanged fuel supply — often the cheapest megawatt available to a utility already short of gas.

Sugar and agro-processing cogeneration. Bagasse-fired cogeneration in sugar-producing regions turns a milling residue into grid export during crushing season.

Mining and heavy industry waste heat. Smelters, cement plants and refineries operating on constrained grids can offset a substantial fraction of their own draw through waste heat recovery.

USP&E has delivered projects across Ghana, Nigeria, the Democratic Republic of Congo, Zambia, Mozambique, Kenya, Iraq, Uzbekistan and the Caribbean, supplying equipment and delivering EPC and O&M with its own teams.

EPC scope: feasibility and heat balance modelling, steam cycle design, HRSG specification and procurement, turbine and generator installation and alignment, condenser and cooling system, water treatment and demineralisation, steam and condensate piping, MV switchgear and grid interconnection, control system integration, commissioning and performance testing.

O&M scope: operator staffing and training, chemistry control and water treatment management, scheduled inspection and overhaul, blade and rotor inspection, governor and control system maintenance, condition monitoring, spares holding and availability guarantees.

Typical delivery for a combined cycle conversion of an existing simple-cycle plant is 12 to 18 months. A new-build combined cycle block runs 18 to 30 months depending on size and site.

Water treatment is the single largest O&M risk on any steam plant. Poor boiler feedwater chemistry causes scaling, corrosion and blade deposits that destroy efficiency and ultimately the machine. USP&E’s O&M scope includes chemistry control as standard.