Glossary

A reference glossary for the energy industry vocabulary you encounter when integrating distributed energy resources. Definitions are concise, regionally aware (UK-leaning where conventions diverge), and link through to Amps concepts where the term has a direct equivalent in the API. For Amps-specific canonical vocabulary, see the cheat sheet.

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Power and energy

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Kilowatt (kW)

A unit of power equal to 1,000 watts. Power is the rate of energy flow at an instant in time. A 5 kW solar inverter, a 7 kW EV charger, or a 2.5 kW kettle all describe instantaneous draw or delivery, not total consumption. Power ratings cap how fast a device can move energy. In Amps, the power parameter on a push uses kilowatts.

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Kilowatt-hour (kWh)

A unit of energy equal to one kilowatt of power sustained for one hour. Domestic electricity bills, battery capacity ratings, and EV range all use kWh. A 13.5 kWh battery holds enough energy to power a 1 kW load for 13.5 hours, a 13.5 kW load for one hour, or any equivalent product. Energy is what gets bought, stored, and sold; power is the rate at which it moves.

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Megawatt (MW) and megawatt-hour (MWh)

Larger units used for grid-scale assets. One megawatt equals 1,000 kilowatts; one megawatt-hour equals 1,000 kilowatt-hours. A utility-scale battery might be rated 100 MW / 200 MWh, meaning it can deliver 100 MW for two hours. Aggregators publish portfolio sizes in MW; capacity market obligations and balancing services are quoted in MW.

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Capacity

The maximum power output or energy storage a resource can sustain. For batteries, capacity refers to total energy in kWh or MWh. For generators and inverters, capacity refers to peak power in kW or MW. Nameplate capacity is the manufacturer rating; usable capacity is what the operator can dispatch after accounting for state-of-charge floors, depth-of-discharge limits, and degradation.

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Load

The instantaneous electricity demand of a building, circuit, or system. A house with a kettle on draws around 3 kW of load. Aggregate load across the grid varies by hour, day, and season, peaking on cold winter evenings in the UK. Load is the demand-side counterpart to generation. Smart-home systems shed, shift, or shape load to reduce bills or earn grid services revenue.

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Peak demand

The highest sustained load over a defined period. Network operators design infrastructure for peak demand, which drives a disproportionate share of grid costs. UK national peak demand sits in the 17:00 to 19:00 winter window. Reducing peak demand through batteries, demand response, or time-shifted load is one of the largest commercial drivers for distributed energy resources.

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Baseload

The minimum level of demand on the grid over a sustained period, typically supplied by generators that run continuously at near-constant output. Nuclear, large hydro, and combined-cycle gas turbines are traditional baseload sources. Renewable generation has reframed baseload as a planning concept rather than a fixed asset class; modern grids meet baseload through a portfolio that includes storage and demand flexibility.

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Power factor

The ratio of real power (kW) to apparent power (kVA) on an alternating-current circuit, expressed as a decimal between 0 and 1. A power factor of 1.0 is ideal: all current does useful work. Inductive loads like motors pull the power factor down. Grid operators penalise large consumers with poor power factor because reactive current loads the network without delivering energy.

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Battery storage

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Battery energy storage system (BESS)

A complete battery installation including cells, battery management system, inverter, thermal management, and controls. Domestic BESS units sit in the 5 to 20 kWh range; commercial systems span hundreds of kWh; grid-scale BESS reach hundreds of MWh. BESS revenue stacks combine self-consumption, time-of-use arbitrage, capacity market payments, and frequency-response contracts. In Amps, every battery integration targets the canonical battery surface.

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Battery management system (BMS)

The embedded controller that supervises a battery pack. The BMS monitors cell voltages, currents, and temperatures; balances cells; enforces safety cutoffs; and reports state-of-charge and state-of-health to the inverter or cloud platform. Manufacturers expose a subset of BMS data through their cloud APIs. The BMS is the source of truth for capacity and degradation; cloud values are derived.

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State of charge (SoC)

The current energy in a battery, expressed as a percentage of usable capacity. A SoC of 100% means full; 0% means empty as defined by the BMS, which sets cutoff thresholds below the cell-level zero. SoC is the most commonly read battery telemetry value. In Amps, SoC surfaces as a canonical pull field, and the target parameter on charge and discharge actions sets SoC bounds.

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State of health (SoH)

A measure of battery degradation, expressed as the ratio of current usable capacity to the original nameplate capacity. A new battery has 100% SoH; a battery at 80% SoH has lost a fifth of its energy capacity. Manufacturer warranties typically guarantee a minimum SoH (often 70 to 80%) at a fixed cycle count or year. Not all OEM APIs expose SoH; where present, it is reported as a percentage.

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Depth of discharge (DoD)

The fraction of a battery’s capacity that has been used relative to its full charge. A battery cycled from 100% to 20% has a depth of discharge of 80%. Higher DoD per cycle accelerates wear. Manufacturers often specify cycle life at a reference DoD, such as 6,000 cycles at 80% DoD. DoD is the inverse complement of state of charge for a given cycle.

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C-rate

A measure of charge or discharge speed relative to capacity. A 1C rate means the battery charges or discharges its full capacity in one hour. A 0.5C rate is two hours; a 2C rate is half an hour. Lithium-ion home batteries typically operate at 0.25C to 0.5C; high-power applications such as fast-charging and frequency response push higher. Higher C-rates increase heat and accelerate degradation.

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Cycle life

The number of full charge-discharge cycles a battery can complete before its capacity falls below a defined threshold, typically 70 or 80% of nameplate. Modern lithium iron phosphate cells reach 6,000 to 10,000 cycles at moderate depth of discharge. Cycle life depends on chemistry, depth of discharge, charge rate, and temperature. Datasheet figures assume controlled lab conditions; real-world cycle life varies.

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Round-trip efficiency

The ratio of energy a battery delivers on discharge to the energy it absorbed on charge, expressed as a percentage. Modern lithium-ion home batteries reach 90 to 95% round-trip efficiency. Losses occur in the inverter, the battery management system, and the cells themselves. Round-trip efficiency directly affects the economics of arbitrage strategies that buy energy cheap and sell it expensive.

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Hybrid inverter

An inverter that handles solar input, battery charge and discharge, and grid interaction in a single unit. Hybrid inverters are common in residential storage and simplify installation compared to pairing a separate solar inverter with a battery inverter. Most domestic OEMs integrated into Amps target hybrid inverter platforms, since the inverter is the cloud-connected device that exposes battery state and accepts commands.

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Solar

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Photovoltaic (PV)

Technology that converts sunlight directly into electricity using semiconductor cells. A PV array is the panel system on a roof or in a field. PV output varies with irradiance, temperature, and shading, peaking around solar noon on clear days. A typical UK domestic PV system sits in the 3 to 8 kW range. PV pairs naturally with batteries, which buffer midday surplus into evening discharge.

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Maximum power point tracking (MPPT)

An algorithm in solar inverters that continuously adjusts the operating voltage of a PV array to extract the highest possible power. Solar panels have a non-linear current-voltage curve, and the optimal operating point moves with irradiance and temperature. Multi-string inverters expose multiple MPPTs to handle panels facing different directions or experiencing different shading. MPPT efficiency is a headline spec on inverter datasheets.

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Curtailment

The deliberate reduction of generation output below what a resource could otherwise produce. Solar farms are curtailed when the grid cannot absorb their output, when local export limits are exceeded, or when negative wholesale prices make generation uneconomic. Curtailment is a growing source of value loss for renewables. Storage and flexible demand recover some of this value by absorbing energy that would otherwise be curtailed.

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String inverter

A solar inverter that converts the combined DC output of multiple panels wired in series (a string) into AC power. String inverters are cheaper than microinverters and dominate residential and commercial installs. Their downside is shading sensitivity: a partially shaded panel can drag down the entire string. Multiple-MPPT string inverters mitigate this by tracking each string independently.

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Microinverter

A small inverter mounted at each solar panel, converting that panel’s DC output to AC at the panel itself. Microinverters eliminate string-level shading losses and produce per-panel telemetry, but cost more per kW than string inverters. Manufacturers including Enphase, IQ, and SolarEdge dominate the residential microinverter market. Microinverter platforms expose rich monitoring data through their cloud APIs.

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EV charging

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Level 1 charging

Charging an electric vehicle from a standard household outlet, typically delivering 1.4 to 2.4 kW. Level 1 adds roughly 5 to 8 km of range per hour. It is slow, but requires no special equipment beyond the cable supplied with the vehicle. Level 1 fits low-mileage urban use cases or as a fallback when faster options are unavailable.

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Level 2 charging

AC charging at 3.7 to 22 kW from a dedicated wall unit, the most common home and workplace charging method. Level 2 chargers add 15 to 70 km of range per hour, depending on the vehicle and supply. Smart Level 2 chargers integrate with home energy systems and respond to grid signals or time-of-use tariffs. Most residential EV charger integrations target Level 2 hardware.

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DC fast charging (Level 3)

High-power direct-current charging at 50 kW and above, used at public charging hubs and along motorways. Modern DC fast chargers reach 150, 250, or 350 kW, adding hundreds of kilometres of range in under 30 minutes. DC fast charging stresses batteries more than AC charging and is typically limited by the vehicle’s onboard charging curve, not the charger.

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CCS (Combined Charging System)

The dominant DC fast-charging connector standard in Europe and North America. CCS combines a Type 2 AC inlet (Europe) or J1772 inlet (North America) with two additional DC pins, allowing one socket on the vehicle to accept both AC and DC charging. CCS replaced the older CHAdeMO standard for most new vehicles, with Tesla also adopting CCS in Europe.

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Open Charge Point Protocol (OCPP)

An open communication standard between EV chargers and charging-station management systems. OCPP 1.6 and 2.0.1 cover authentication, transaction lifecycle, smart-charging profiles, and firmware updates. Most commercial charge-point operators use OCPP to manage mixed-vendor fleets. In Amps, EV charger integrations translate canonical commands into native protocols, which may include OCPP.

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Smart charging

Adjusting the rate, timing, or interruption of EV charging in response to electricity prices, grid signals, or local generation. Smart charging shifts load away from peak periods, soaks up cheap overnight electricity, and matches charging to onsite solar surplus. UK smart charging regulations require domestic chargers to default to off-peak charging windows. Smart charging is the entry point to vehicle-to-grid services.

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Vehicle-to-grid (V2G)

Bidirectional EV charging where the vehicle discharges energy back to the grid or the home. V2G turns a parked EV into a battery storage asset, with capacity often exceeding stationary home batteries. Hardware support is limited (CHAdeMO has historically led; CCS bidirectional support is rolling out). V2G enables tariff arbitrage, backup power, and grid-service participation.

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HVAC

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Heat pump

A device that moves heat from one place to another using a refrigeration cycle, providing space heating, cooling, or hot water. Air-source heat pumps extract heat from outdoor air; ground-source heat pumps draw from the ground. Heat pumps deliver three to four units of heat per unit of electricity consumed, making them the dominant low-carbon heating technology. They are flexible loads, well-suited to time-of-use and demand-response control.

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Coefficient of performance (COP)

The instantaneous ratio of heat output to electrical input for a heat pump. A COP of 4 means four units of heat for every one unit of electricity. COP varies with outdoor temperature, output temperature, and load. Datasheet COPs are measured at standard conditions and overstate real-world performance. Lower outdoor temperatures depress COP, which is why winter heat-pump efficiency matters most.

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Seasonal coefficient of performance (SCOP)

The COP of a heat pump averaged across a heating season, weighted by typical outdoor conditions. SCOP is a more honest performance metric than peak COP because it captures real operating conditions. UK heat pumps typically reach SCOP figures in the 2.8 to 4.0 range. Higher SCOP means lower electricity bills for the same heat delivered.

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Setpoint

The target temperature a thermostat or HVAC system aims to maintain. Setpoints vary by zone, time of day, and occupancy. Smart HVAC platforms expose setpoints as the primary control surface. In Amps, HVAC actions adjust setpoint as a canonical command, bounded by per-device limits and conflict-resolution rules.

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Deadband

The temperature range around a setpoint within which the HVAC system does not actively heat or cool. A 21°C setpoint with a 1°C deadband heats below 20°C and cools above 22°C. Deadbands prevent short-cycling and reduce wear. Wider deadbands save energy but compromise comfort. Most thermostats expose deadband as a setting, not a runtime command.

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Grid services

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Frequency response

A grid service that adjusts power output in response to deviations from the system frequency (50 Hz in Europe, 60 Hz in North America). When demand exceeds supply, frequency drops; resources providing frequency response inject power within seconds to restore balance. Batteries dominate the modern frequency response market because of their sub-second response times. National Grid ESO procures frequency response in tiered products by speed.

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Dynamic Containment

The fastest of National Grid ESO’s frequency response services, requiring full response within one second of a frequency deviation outside the 49.8 to 50.2 Hz band. Dynamic Containment is procured in 1 MW units through day-ahead auctions. It is the highest-value frequency product for grid-scale batteries in the UK and a primary revenue stream for storage operators.

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Dynamic Regulation and Dynamic Moderation

National Grid ESO’s slower frequency-response services, targeting smaller deviations within the 49.8 to 50.2 Hz band. Dynamic Regulation responds proportionally to frequency deviations; Dynamic Moderation is symmetric around 50 Hz. Both stack with Dynamic Containment in a battery’s revenue model. Auctions clear day-ahead alongside Dynamic Containment.

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Fast frequency response (FFR)

A general term for frequency-response products that respond within seconds, contrasted with traditional response from spinning thermal generators that took tens of seconds. UK Fast Frequency Response was retired and absorbed into Dynamic Containment, Dynamic Regulation, and Dynamic Moderation. The term remains in use across Australia (FCAS), Ireland, and the rest of Europe.

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Ancillary services

The collective name for grid services beyond bulk energy supply, including frequency response, reactive power support, black start, and reserve. Ancillary services keep the grid stable and recoverable. System operators procure them through markets or bilateral contracts. Distributed energy resources increasingly displace traditional generators in ancillary-service markets, with batteries leading.

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Voltage support

A grid service that injects or absorbs reactive power to maintain voltage within limits. Long transmission lines and distribution circuits experience voltage rise and drop; voltage support corrects these. Solar inverters with reactive-power capability provide voltage support without consuming real energy. Distribution network operators increasingly procure voltage support locally rather than relying on transmission-level resources.

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Markets and mechanisms

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Capacity market

A long-term auction that procures firm capacity to meet future peak demand. The UK Capacity Market clears T-1 and T-4 auctions for one-year and four-year-ahead delivery. Successful participants receive a capacity payment in exchange for being available during system-stress events. Batteries, demand response, and traditional generators all compete. Capacity payments are a foundational revenue stream for storage developers.

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Balancing mechanism (BM)

The UK’s near-real-time market through which National Grid ESO calls on generators and large consumers to adjust output to balance supply and demand. Participants submit bids and offers each settlement period; the ESO accepts those it needs. Battery participation in the BM has grown rapidly. The BM is operated alongside Dynamic Containment, capacity-market dispatch, and bilateral arrangements.

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Demand-side response (DSR)

A category of programmes that pay end-consumers (usually commercial and industrial) to reduce or shift load in response to grid signals. UK DSR includes the Demand Flexibility Service, Capacity Market participation, and bespoke aggregator products. DSR is a key tool for managing peak demand without building new generation. In Amps, DSR programmes can be wired through a push action to participating devices.

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Demand response (DR)

The North American equivalent of DSR, with similar programme structures. DR markets in PJM, ERCOT, CAISO, and NYISO pay aggregated load to curtail or dispatch in response to grid signals. The terms DR and DSR are often used interchangeably; UK contexts favour DSR, US contexts favour DR. The technical mechanics of dispatching customer load are identical across both regions.

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Day-ahead market

The wholesale electricity market clearing each day for delivery the next day, in hourly or half-hourly blocks. UK day-ahead is operated by Nord Pool and EPEX SPOT. Prices reflect expected supply and demand, with renewable forecasts and weather as primary drivers. Day-ahead prices set the baseline for many smart tariffs, including the Octopus Agile time-of-use tariff.

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Settlement period

The smallest unit of time over which UK electricity is settled, currently 30 minutes. Each day has 48 settlement periods. The market-wide half-hourly settlement (MHHS) reform aligns retail and wholesale settlement at 30 minutes. Half-hourly granularity enables fine-grained time-of-use tariffs and demand-response products.

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Imbalance pricing

The price applied to suppliers and generators whose actual deliveries differ from their day-ahead positions. Imbalance prices are calculated each settlement period based on the cost of the actions National Grid ESO took to balance the system. Volatile imbalance prices reward accurate forecasting and flexible dispatch, creating arbitrage opportunities for storage and smart loads.

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Tariffs

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Time-of-use tariff (TOU)

An electricity tariff that varies by time of day, typically with cheaper overnight rates and higher daytime rates. Economy 7, Octopus Go, and Octopus Cosy are common UK examples. Time-of-use tariffs reward shifting flexible loads (EV charging, heat pumps, batteries) into cheap periods. In Amps, scheduling a battery push to charge during cheap hours is the canonical time-of-use pattern.

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Dynamic pricing

A tariff where the price changes frequently, often every half-hour, tracking wholesale market movements. Dynamic pricing exposes consumers directly to market volatility, including occasional negative prices. It rewards real-time flexibility but requires automation to capture value. UK dynamic tariffs include Octopus Agile and Octopus Tracker. Dynamic pricing is the natural counterpart to smart-home automation.

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Agile tariff

The Octopus Agile tariff, a half-hourly dynamic price that updates the next day’s rates each afternoon. Prices follow wholesale day-ahead clearing, capped at a regulated ceiling. Agile occasionally produces negative prices when the grid has surplus renewable energy, paying customers to consume. Agile is the most popular UK dynamic tariff and a common target for battery and EV-charging optimisation.

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Economy 7

A long-standing UK time-of-use tariff offering seven hours of cheap overnight electricity, typically running from around 00:30 to 07:30. Originally designed for storage heaters, Economy 7 has found a second life with EV chargers and home batteries. Tariff windows vary by region and supplier. Economy 7 remains widely available even where newer dynamic options exist.

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Feed-in tariff (FIT)

A historical UK subsidy that paid generators (mostly small-scale solar) a fixed rate for every kWh exported to the grid. The FIT scheme closed to new applicants in 2019 but ongoing contracts persist for up to 25 years. The Smart Export Guarantee replaced it for new installations. FIT contracts vary in rate and term, and their cash flows are factored into many existing solar economics.

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Smart Export Guarantee (SEG)

The UK successor to the feed-in tariff, requiring large suppliers to offer payment for exported electricity from small-scale renewables. Unlike the FIT, SEG rates are set by individual suppliers and vary widely. Some SEG offers track wholesale prices; others are fixed flat rates. SEG underpins the export economics of new solar and battery installations in the UK.

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Players and entities

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Aggregator

A company that bundles distributed energy resources (batteries, EVs, heat pumps, controllable loads) across many sites and dispatches them as a single virtual asset into wholesale and ancillary-service markets. Aggregators handle market participation, dispatch optimisation, and revenue distribution. Octopus Energy, Axle Energy, Tesla, and Fuse Energy operate UK aggregator platforms. Amps integrations often coexist with aggregator dispatch on the same device.

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Virtual power plant (VPP)

A networked collection of distributed energy resources operated as a single dispatchable asset. VPPs aggregate behind-the-meter batteries, EVs, and flexible loads to provide capacity, frequency response, or arbitrage services. The boundary between aggregator and VPP is fuzzy: VPP emphasises the technical dispatch layer, aggregator emphasises the commercial layer. Amps is not a VPP but provides the API layer that VPPs build on.

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Distribution network operator (DSO/DNO)

The companies that own and operate the local electricity distribution networks, the wires from substations to homes and businesses. The UK has 14 DNO licence areas operated by six companies. DNOs are evolving into Distribution System Operators (DSOs), actively managing local flexibility rather than just maintaining wires. DSOs run local flexibility markets that distributed energy resources can participate in.

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Transmission system operator (TSO)

The operator of the high-voltage transmission grid, responsible for system-wide balancing and bulk-energy transmission. National Grid ESO is the UK TSO. TSOs procure grid services (frequency response, capacity, reserve), operate the balancing mechanism, and ensure system security. The TSO/DSO interface is an active area of regulatory development as more flexibility moves to the distribution network.

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Prosumer

A consumer who also produces electricity, typically through rooftop solar combined with a home battery or EV. Prosumers buy from the grid when their generation is insufficient and export when they have surplus. The prosumer business model depends on tariffs that fairly value imports and exports. Most domestic energy-flexibility products target prosumer households.

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Retailer

The company that sells electricity to end consumers, holding the supply licence and operating the customer billing relationship. Retailers procure energy from wholesale markets, offer tariffs, and pass through network and policy costs. UK retailers include Octopus Energy, EDF, OVO, British Gas, and Ovo. The retailer is the typical contracting party for time-of-use and dynamic tariffs that smart-home automation targets.

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Protocols and standards

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OpenADR

The Open Automated Demand Response standard, a protocol for sending demand-response signals between utilities, aggregators, and end devices. OpenADR 2.0 dominates US demand-response programmes; OpenADR 3.0 introduces a REST-based architecture. OpenADR is widely adopted in commercial and industrial demand response and is gaining traction in residential aggregator platforms. It is the lingua franca of programme-driven flexibility.

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IEEE 2030.5 (CSIP)

An IEEE standard for communicating with distributed energy resources, used heavily in California (under the CSIP profile) for utility-mandated DER integration. IEEE 2030.5 covers metering, monitoring, and dispatch, and is the protocol behind California’s Rule 21 interconnection requirements. Outside California, adoption is patchy. Where adopted, IEEE 2030.5 is the link between utility platforms and customer-owned devices.

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Modbus

A serial and TCP/IP protocol widely used in industrial automation and distributed energy. Most inverters, batteries, and heat pumps expose Modbus interfaces locally, often as the primary read/write surface for site controllers. Modbus is simple, vendor-neutral, and stable but lacks security at the protocol level. Modbus integrations are common in commercial and aggregator platforms; cloud APIs typically front the Modbus interface upstream.

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EEBus

A European standard for energy-management communication between devices, building automation, and the grid. EEBus targets domestic appliances, EVs, heat pumps, and batteries, with a particular focus on Germany. EEBus competes with Matter for energy and IEEE 2030.5 in different regions. Adoption is meaningful in Germany; outside Germany it is still emerging.

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Matter for energy

The energy-management extensions to the Matter standard, the cross-vendor smart-home protocol backed by Apple, Google, Amazon, and the Connectivity Standards Alliance. Matter for energy targets domestic appliances, EVs, batteries, and grid-signal handling. It is a long-horizon play; commercial deployments remain limited. Matter’s appeal is the universal device discovery and onboarding it inherits from the parent Matter standard.

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Regulators and operators

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Ofgem

The UK Office of Gas and Electricity Markets, the regulator for Great Britain’s electricity and gas markets. Ofgem grants supply licences, sets price caps, approves network charges, and authorises new market structures (capacity market, MHHS, smart-meter rollout). Ofgem decisions shape the regulatory environment in which distributed energy products operate. Aggregator licensing, supplier obligations, and metering rules all flow from Ofgem policy.

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National Grid ESO

The Electricity System Operator for Great Britain, responsible for balancing supply and demand on the transmission network in real time. National Grid ESO operates the balancing mechanism, procures frequency response and other ancillary services, and runs the capacity market auctions on Ofgem’s behalf. Most UK grid-services revenue for distributed energy resources flows through National Grid ESO contracts.

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Elexon

The administrator of the Balancing and Settlement Code (BSC), the rule book governing how UK electricity is metered, balanced, and settled. Elexon publishes settlement data, calculates imbalance prices, and operates settlement systems. Elexon does not buy or sell electricity. Suppliers, generators, and aggregators interact with Elexon for registration, data exchange, and settlement.

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FERC (US)

The Federal Energy Regulatory Commission, the US federal regulator for interstate electricity transmission and wholesale markets. FERC oversees the seven US regional transmission organisations (PJM, MISO, ERCOT, CAISO, SPP, NYISO, ISO-NE), setting the framework for capacity markets, ancillary services, and wholesale demand response. FERC Order 2222 opened wholesale markets to aggregated distributed energy resources, a landmark for US flexibility participation.

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Smart meters and metering

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SMETS2

The second-generation UK smart meter specification, the only smart meter type now installed in Great Britain. SMETS2 meters communicate through the Data Communications Company (DCC) network, enabling supplier switching without losing smart functionality. SMETS2 underpins half-hourly settlement, time-of-use tariffs, and consumer access to consumption data. Earlier SMETS1 meters are being upgraded to operate on the SMETS2 network.

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Market-wide half-hourly settlement (MHHS)

The UK reform programme transitioning all electricity meters to half-hourly settlement, replacing the legacy non-half-hourly profiling. MHHS aligns retail and wholesale settlement at 30-minute granularity, enabling tariffs, demand-response products, and grid services that depend on accurate half-hourly consumption data. The full MHHS rollout is phased through several go-live milestones managed by Elexon.

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Half-hourly settlement (HHS)

The settlement of electricity consumption on a 30-minute basis using actual meter readings rather than estimated profiles. HHS is the precondition for fine-grained time-of-use tariffs and accurate demand-response measurement. Large customers have settled half-hourly for years; MHHS extends HHS to domestic customers. HHS data is the foundation for evidence-based flexibility products.