Half-hourly Data


Definition: Electricity consumption data recorded every half hour and collected by the metering system.


Head and Shoulders Top


Definition: A pattern characterised by a series of three peaks, the first and third being lower than the middle. Volume, heavy on the first peak, declines on the next two. Completion is marked by the breaking of the “neckline” (an extension of the line connecting the troughs between the three peaks) accompanied by heavy volume. An inverse head and shoulders is the same pattern upside down volume increase through the pattern.




Definition: A trade to reduce the impact of price variations.


Henry Hub


Definition: The Henry Hub is a distribution hub on the natural gas pipeline system in Erath, Louisiana. Due to its importance, it lends its name to the pricing point for natural gas futures contracts traded on the New York Mercantile Exchange (NYMEX) and the OTC swaps traded on Intercontinental Exchange (ICE).


High Voltage (HV)


Definition: Connection to an electricity distribution network at a voltage of 11,000 (11kV) or above.


High-voltage Direct Current Cross-channel (HVDC CC)


Definition: Two different high-voltage direct current connections that operate or have operated under the English Channel between the continental European and the British electricity grids.


High-voltage Direct Current Moyle


Definition: A high-voltage direct current link between Auchencrosh, South Ayrshire in Scotland and Ballycronan More, County Antrim in Northern Ireland.


Hydraulic Fracturing


Definition: The fracturing in a rock layer by a pressurised fluid, commonly known as fracking. A technique used to release petroleum, natural gas (including shale gas, tight gas, and coal seam gas), or other substances for extraction.




Definition: Electrical energy produced by flowing water. A hydroelectric power plant uses the movement of water to spin a turbine generator that produces electricity.