Energy technology

RDK (Karlsruhe) power station

The RDK (Karlsruhe) power station, formally the Rheinhafen-Dampfkraftwerk, is a power plant complex on the Rhine harbor in Karlsruhe, Germany, operated by EnBW with 1,811 MW capacity.

RE100

RE100 (Renewable Energy 100) is a global corporate initiative led by the Climate Group with CDP, launched in 2014, asking companies to commit to 100 percent renewable electricity.

Reactive power

Reactive power is the portion of AC electricity that sustains the electric and magnetic fields of equipment like motors and transformers, and it directly influences grid voltage.

Sep 29, 2026

Reactive power optimization

Reactive power optimization, also known as optimal reactive power dispatch or Volt/VAR optimization, adjusts generator voltages, transformer taps, and VAR sources to cut grid power losses.

Reactor containment building

A reactor containment building is the air-tight, usually steel-reinforced concrete structure housing a nuclear reactor, acting as the primary barrier against radioactive release in an accident.

Reactor coolant pump

A reactor coolant pump is the large centrifugal pump that circulates primary coolant through a nuclear reactor core, with shaft seals that limit radioactive water leakage.

Reactor pressure vessel

The reactor pressure vessel is the thick steel container holding a power reactor's fuel and coolant under high pressure, one of the barriers keeping radioactive material from the environment.

A reactor protection system (RPS) is the instrumentation and control system of a nuclear reactor that automatically initiates a rapid shutdown, or scram, when monitored parameters indicate unsafe operating conditions.

Reactor-grade plutonium

Reactor-grade plutonium is plutonium recovered from nuclear fuel irradiated in a power reactor under normal conditions, containing about 24% Pu-240 versus 6% in weapons-grade material.

Real-time control of tearing modes

Real-time control of tearing modes is the set of tokamak techniques that detect and suppress tearing modes, magnetic instabilities, chiefly with steerable electron cyclotron current drive.

Realta Fusion

Realta Fusion is an American fusion startup spun out of the University of Wisconsin–Madison that develops compact magnetic mirror devices, aiming first at industrial process heat.

REBCO high-temperature superconducting magnet

A REBCO high-temperature superconducting magnet is an electromagnet wound from rare-earth barium copper oxide tape, which superconducts near 92 K and can operate above 20 tesla.

REC Group

REC Group is a solar panel manufacturer founded in 1996 in Oslo, Norway, with operational headquarters in Singapore, and wholly owned by Reliance Industries since 2021.

Recharge (trade association)

Recharge, formally RECHARGE aisbl, is a Brussels-based trade association founded in 1998 representing the European advanced rechargeable and lithium battery industry, from raw-material suppliers to manufacturers and recyclers.

Rechargeable battery

A rechargeable battery, also known as a secondary cell, is a battery designed to be electrically recharged. Lithium-ion versions power electric vehicles and grid storage.

Rechargeable zinc–manganese dioxide battery

A rechargeable zinc–manganese dioxide battery pairs metallic zinc with a manganese dioxide cathode in aqueous electrolyte; Kang and co-workers proposed the modern rechargeable design in 2011.

Recloser

A recloser is an automatic switching device on electric power lines that interrupts fault current and recloses to test whether the fault has cleared, locking open if it persists.

Recombination layers in tandem solar cells

A recombination layer, also called the interconnecting layer (ICL), is the thin internal layer that connects the stacked sub-cells of a tandem solar cell in series so their voltages add.

Recon Technology

Recon Technology, Ltd is a China-based oilfield services company traded on NASDAQ under the ticker RCON, providing automation equipment, software, and services mainly to CNPC and Sinopec.

Reconductoring

Reconductoring is the replacement of the wires on an existing overhead transmission or distribution line with new conductors, reusing existing towers and rights of way to increase capacity.

Reconnaissance Energy Africa

Reconnaissance Energy Africa (ReconAfrica) is a Canadian junior oil and gas company exploring in the Kavango Sedimentary Basin of northeastern Namibia and northwestern Botswana, upstream of the Okavango Delta, and listed on the TSX Venture Exchange.

Recovery factor

The recovery factor is the percentage of hydrocarbons originally in a reservoir that can be produced with current technology, ranging from 1% for tight reservoirs to 80%.

Rectifier transformer

A rectifier transformer is a specialized power transformer that supplies AC from the grid to a rectifier converting it to DC, serving electrolysis, plating, and DC drives.

Recycled aluminium

Recycled aluminum, also called secondary aluminum, is aluminum recovered from scrap and remelted, using about 5% of the energy of producing it from bauxite ore.

Red Adair

Red Adair, born Paul Neal Adair, was a Texan oil well firefighter who pioneered techniques and equipment for controlling oil and gas well fires, notably in Kuwait in 1991.

Red Eléctrica de España

Red Eléctrica de España (REE) is the sole transmission system operator of Spain, running the national high-voltage grid since 1985 as the first company in the world dedicated exclusively to electricity transmission.

Redaptive

Redaptive is an American energy technology company, founded in 2015 and based in Denver, Colorado, that funds, installs, and owns efficiency equipment such as LED lighting, HVAC, and solar.

Redbud power plant

The Redbud power plant, formally the Redbud Generating Facility, is a 1,230 MW combined-cycle natural gas plant near Luther, Oklahoma, operating since 2004 and run by OG&E.

Reder Advisors

Reder Advisors is a Chicago utilities consultancy founded in 2018 by Wanda K. Reder, an electric power engineer elected to the National Academy of Engineering in 2016.