# Energy & Power Expert

https://hienglishquiz.com/vocabulary/energy-and-power-c2

- CEFR: C2 (Proficient)
- Theme: Professional & Specialized
- Words: 22
- Premium: no
- Locked: no

The physics that wears out a turbine and the market that trades its electricity: cavitation and wake effect on the machinery side, reactive power and droop…

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## Word list

* **cavitation**: The formation and sudden collapse of tiny bubbles in fast-moving water, which pits and wears away nearby metal surfaces over time. — “Pitting on the runner blades was traced back to **cavitation** at low reservoir levels.”
* **runner**: The bladed wheel inside a water turbine that spins as water pushes through it, turning the shaft that drives the generator. — “Debris in the intake had chipped several blades on the turbine's **runner**.”
* **trash rack**: A metal screen placed where water enters a hydropower plant, stopping debris such as branches and litter from reaching the turbine. — “Leaves and branches had jammed the **trash rack** after the storm.”
* **pumped storage**: A type of hydropower plant that uses cheap electricity to lift water into a higher reservoir, then releases it downhill to generate power when demand is high. — “The utility built a **pumped storage** scheme to bank surplus wind power overnight.”
* **reactive power**: The part of an alternating-current system that doesn't do useful work itself but is still needed to keep voltage steady across the network. — “Grid operators asked the plant to supply extra **reactive power** during the voltage dip.”
* **power factor**: A measure between 0 and 1 of how efficiently equipment uses the electrical current it draws, rather than wasting part of it swinging uselessly back and forth. — “Adding capacitors improved the factory's **power factor** and lowered its electricity bill.”
* **synchronous condenser**: A rotating machine, similar to a generator, that turns in step with the system's frequency purely to support voltage, without supplying any real electricity itself. — “Grid operators installed a **synchronous condenser** to shore up voltage after the coal plant closed.”
* **harmonics**: Unwanted extra electrical frequencies layered on top of the normal wave shape, usually produced by electronic equipment, that distort the quality of the supply. — “Variable-speed drives on the pumps were injecting **harmonics** into the plant's electrical system.”
* **droop control**: A generator setting that automatically reduces its output a little whenever system frequency rises, so several generators share a change in demand smoothly instead of competing. — “Engineers tuned the **droop control** setting so both units responded evenly to the frequency dip.”
* **islanding**: A situation in which part of the electricity network keeps running on its own power sources after being cut off from the main grid. — “The plant switched to **islanding** mode within seconds of the grid fault.”
* **ancillary services**: Extra support a power plant provides to help keep the grid stable, such as voltage support or fast reserve, separate from the electricity it sells to customers. — “The wind farm earned extra revenue from **ancillary services** like frequency response.”
* **interconnector**: A high-capacity line that links two separate electricity grids, often across a national border, so power can flow between them when needed. — “Surplus wind power was exported through the new **interconnector** to the neighbouring country.”
* **merit order**: The ranking of power plants from cheapest to most expensive, used to decide which ones are switched on first to meet demand. — “Cheap wind output pushed the coal plant down the **merit order** that afternoon.”
* **baseload**: A power plant, or the steady background demand it meets, that runs at an unchanging output almost all the time rather than adjusting to daily swings in need. — “The plant supplied **baseload** power around the clock, day and night.”
* **peaking plant**: A power plant built to start up quickly and run only for short periods when demand is at its highest, rather than continuously. — “The gas-fired **peaking plant** fired up for just two hours each evening.”
* **ramp rate**: How quickly a power plant can increase or decrease its output, expressed as a percentage change per minute. — “The turbine's fast **ramp rate** let it follow sudden swings in wind output.”
* **availability factor**: The percentage of time a power plant is able to generate, whether or not it is actually called on to run. — “Scheduled maintenance briefly lowered the dam's **availability factor** last spring.”
* **forced outage rate**: The percentage of time a power plant is unexpectedly unable to run because of an unplanned equipment failure, rather than scheduled maintenance. — “A generator bearing failure pushed up the plant's **forced outage rate** for the quarter.”
* **cut-in speed**: The lowest wind velocity at which a turbine's blades begin turning fast enough to generate electricity. — “Below the **cut-in speed**, the rotor stayed still even in a light breeze.”
* **wake effect**: The area of slower, more turbulent air left behind a wind turbine, which reduces the output of any turbine standing in it. — “Engineers spaced the turbines further apart to reduce the **wake effect** downwind.”
* **feathering**: Turning a turbine's blades edge-on to the wind so they catch as little force as possible, usually to slow the rotor in high winds or for maintenance. — “The turbine began **feathering** its blades as gusts passed the safety limit.”
* **tip speed ratio**: How fast a turbine blade's outer edge moves compared with the wind hitting it, used to judge how efficiently the rotor is turning. — “Engineers adjust blade pitch to keep the **tip speed ratio** within its ideal range.”

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