The terms used when a power plant or a turbine changes hands, in plain words, starting with the one Genloop is built around.
What owners, buyers, lenders and their advisers mean by the words they use about a sale.
In power generation, investment recovery is returning idle generating equipment to service. It runs in two directions: the owner recovers the capital held in a surplus, mothballed or retired plant or turbine by selling it, and a new project recovers the years a new machine would take by buying that unit restored.
How Genloop does it
A buyer that purchases for its own account and takes title to the equipment. The seller has one counterparty and a firm price, and nothing depends on a further buyer being found. Genloop buys as principal.
Sell equipment
Generating equipment its owner no longer needs: a unit replaced by a newer one, a spare that was never installed, or a plant whose site is closing.
Equipment left without a use by events outside the machine itself, such as a project that stalled after the equipment was built or delivered, or a plant whose fuel supply, contract or permit has ended.
Taken out of service and preserved so it can run again. How well a unit was preserved, and for how long, decides how much work it needs before it returns to service.
A plant its owner has permanently withdrawn from service. The equipment inside it can still have decades of working life on another site.
The sale and removal of equipment an owner no longer needs. For a power plant it covers valuation, the sale itself, dismantling, export compliance and transport.
Moving a generating unit or a whole plant to a new site: dismantling, transport, restoration and re-erection. A combined cycle block can be bought whole and relocated whole.
Generating capacity delivered sooner than an order for a new machine allows, using equipment that already exists.
Fast-track power
Generation installed on or beside a site to carry its load until a grid connection or a permanent plant arrives. Common for data centers whose load comes before their connection.
Units for bridge power
Generation on the customer’s side of the utility meter, serving the site’s own load directly.
An overhaul that returns an engine to the start of its maintenance cycle, so the hours to its next major inspection are counted from zero.
The main kinds of generating equipment, and the words that tell one from another.
An engine that compresses air, burns fuel in it and expands the hot gas through a turbine to drive a generator. Sold by frame, such as the GE 7EA or the Siemens V94.2.
Compare the frames
A gas turbine designed for power generation from the start, also called heavy-duty. Large, long-lived and maintained in place. The GE Frame 5, 6B, 7EA, 7FA, 9E and 9FA are heavy frames.
A gas turbine built around an aircraft engine core. Lighter than a heavy frame, quick to start and quick to exchange. The GE LM2500 and LM6000 are aeroderivatives.
A generation of heavy-frame gas turbines that includes the GE 7EA, the GE 9E and the Siemens V94.2. Lower firing temperature than F-class, simpler, and tolerant of a wide range of fuels.
The generation of heavy frames that entered service around 1990, such as the GE 7FA, the GE 9FA and the Siemens 501F. Higher firing temperature, more output and better efficiency than E-class.
A gas turbine driving a generator with its exhaust heat released to the air. Quick to build and quick to start, and less efficient than combined cycle.
A gas turbine whose exhaust heat raises steam, and the steam drives a second turbine. More power from the same fuel.
Heat recovery steam generator: the boiler behind a gas turbine that turns its exhaust heat into steam for a steam turbine or a process.
A turbine driven by steam. A condensing unit exhausts to a condenser and is built for power. A back-pressure unit exhausts at a pressure a process can use.
Steam turbines in the register
A power plant made of several large piston engines, each with its own generator, on gas, heavy fuel oil or diesel. Modular, so it can be moved engine by engine.
Engine plants in the register
A complete generating set on road trailers: turbine, generator, controls and auxiliaries. The GE TM2500 is a widely deployed example.
Mobile units in the register
The machine a turbine or an engine drives to make electricity. Rated in MVA, and built for one grid frequency.
Generator step-up transformer. It raises the generator’s voltage to the voltage of the transmission line.
Generators and transformers in the register
Everything in a power plant besides the main machines: fuel, cooling and water systems, electrical equipment, controls, piping and structures.
The measures a buyer reads before an inspection, and the inspections themselves.
The output a machine was built to deliver at stated conditions, as stamped on its nameplate.
The reference conditions for gas turbine ratings: 15°C, 60% relative humidity and sea-level pressure. Output falls as the air gets hotter or thinner.
The fuel energy a machine uses to make one kilowatt-hour, in Btu or kJ per kWh. Lower is better.
The hours a gas turbine has run with fuel burning. With starts, the basic measure of how much life a unit has used.
The number of times a gas turbine has been started. Each start stresses the hot parts, so a peaking unit ages by its starts and a base-load unit by its hours.
Fired hours and starts adjusted for how the unit was run: fuel, load and trips all count for more than steady running on gas. Makers set inspection intervals in factored terms. Siemens machines use equivalent operating hours for the same purpose.
The shortest of a heavy frame’s scheduled inspections, covering the combustion liners, fuel nozzles and transition pieces.
A scheduled inspection of the parts the hot gas touches, from the combustors through the turbine nozzles and buckets. On a GE 7EA the interval is 24,000 factored hours or 1,200 factored starts.
What sets a 7EA’s value
The full inspection of a gas turbine from inlet to exhaust, with the casings opened and the rotor examined. On a GE 7EA, every 48,000 factored hours or 2,400 factored starts.
An internal inspection made with a camera through ports in the casing, without opening the machine. Usually the first look at a unit’s condition.
The expensive life-limited parts of a gas turbine, mainly in the hot gas path: combustion hardware, nozzles, buckets and shrouds. Bought and sold on their own, with records.
Parts in the register
A combustion system that keeps nitrogen oxide emissions low by premixing fuel and air, without injecting water or steam. DLN on GE heavy frames, DLE on aeroderivatives. Often what decides whether a unit can be permitted.
Four terms that decide which countries a unit can be sold into.
The rate at which alternating current reverses: 50 Hz or 60 Hz, depending on the country. Generating equipment is built for one or the other.
50 Hz and 60 Hz by country
The speed a generator must turn to match its grid. A two-pole generator turns at 3,000 rpm on a 50 Hz grid and 3,600 rpm on a 60 Hz grid.
A turbine coupled straight to its generator, so it turns at synchronous speed. A direct-drive machine is fixed to its frequency.
A turbine that drives its generator through a gearbox, so the turbine’s own speed does not depend on the grid. The GE Frame 5 and Frame 6B are geared and serve either frequency.