Energy Dictionary
Definitions and explainers for core energy industry terms, units and concepts.
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What Is a Battery Energy Storage System (BESS)?
Last updated: November 9, 2026 A battery energy storage system (BESS) is a grid-connected installation of rechargeable batteries, usually lithium-ion, that stores electricity when it...
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What Is Henry Hub and Why Does It Set U.S. Gas Prices?
Last updated: November 9, 2026 Henry Hub is a natural gas pipeline interconnection point in Erath, Louisiana, that serves as the official delivery point for...
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What Is a Power Purchase Agreement (PPA)?
Last updated: November 2, 2026 A power purchase agreement (PPA) is a long-term contract between an electricity buyer and a generator that locks in a...
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What Are Upstream, Midstream and Downstream in Oil and Gas?
Last updated: November 2, 2026 Upstream, midstream and downstream are the three broad segments of the oil and gas industry. Upstream covers exploration and production...
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What Is LCOE (Levelized Cost of Electricity)?
Last updated: October 26, 2026 The levelized cost of electricity (LCOE) is the average cost, in dollars per megawatt-hour ($/MWh), of building and running a...
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What Is a Small Modular Reactor (SMR)?
Last updated: October 26, 2026 A small modular reactor (SMR) is an advanced nuclear reactor design that produces up to 300 megawatts of electricity (MWe)...
