Bills, Tariffs & Pricing
- Standard Variable Tariff (SVT)
- The default tariff you're automatically placed on if you've never actively chosen or switched to a fixed deal. SVTs move up and down with the Ofgem price cap every three months.
- Price Cap
- The maximum unit rate and standing charge Ofgem allows suppliers to charge on a standard variable tariff. It is not a cap on your total bill — if you use more energy, you pay more, regardless of where the cap sits. Ofgem reviews and resets it every three months.
- Unit Rate
- The price you pay per kilowatt-hour (kWh) of gas or electricity used. This is the "per-unit" figure the price cap actually controls.
- Standing Charge
- A fixed daily fee you pay regardless of how much energy you use, covering the cost of maintaining the network connection to your property. It's charged even on days you use no energy at all.
- kWh (Kilowatt-hour)
- The standard unit of energy used for billing. One kWh is the energy used by a 1,000-watt appliance running for one hour.
- Typical Domestic Consumption Value (TDCV)
- Ofgem's estimate of how much energy an "average" household uses in a year. It's the figure used to translate unit rates into the headline "typical annual bill" you see in the news — your own usage may be higher or lower.
- Direct Debit
- The most common way to pay an energy bill, usually the cheapest, since suppliers charge a premium for standard credit (pay-on-receipt) billing.
- Smart Meter
- A digital meter that sends automatic readings to your supplier, removing the need for manual submissions and enabling more accurate, usage-based billing.
- VAT on Energy
- Domestic gas and electricity are charged at a reduced 5% VAT rate, rather than the standard 20%. From October 2026, VAT on electricity specifically is temporarily cut further, to 0%. Residential solar and battery installations already qualify for 0% VAT.
Efficiency Ratings & Retrofit
- EPC (Energy Performance Certificate)
- A certificate rating a property's energy efficiency from A (most efficient) to G (least efficient), required when a home is built, sold, or rented. It also lists recommended improvements, such as insulation or a more efficient heating system.
- SAP Rating (Standard Assessment Procedure)
- The government's official methodology for calculating the energy rating that appears on an EPC. It's the calculation behind the certificate, not something you'll see quoted directly very often.
- PAS 2035
- A British Standard specification for how retrofit and energy efficiency improvements to existing homes should be assessed, designed, and installed, intended to prevent poorly specified or badly sequenced work (for example, insulating a wall without addressing ventilation first).
- U-value
- A measure of how easily heat passes through a building material — a wall, window, or roof. The lower the U-value, the better the material is at retaining heat.
- Retrofit
- Any work carried out to improve an existing building's energy performance after it was originally built, from loft insulation to a full heating system replacement. See YEERS's retrofit services for what this covers in practice.
Solar & Renewable Generation
- Solar PV (Photovoltaic)
- Panels that convert sunlight directly into electricity. This is distinct from solar thermal panels, which heat water rather than generate electricity. Available for both homes and businesses.
- kWp (Kilowatt-peak)
- The maximum output a solar system can generate under ideal conditions. It describes the system's size and capacity, not how much electricity it will actually produce on any given day, which depends on weather, season, and panel orientation. Use YEERS's solar calculator to see what size system your property might need.
- Inverter
- The component that converts the direct current (DC) electricity generated by solar panels into the alternating current (AC) electricity used by your home and the grid.
- Battery Storage
- A home battery that stores electricity generated by solar panels (or bought cheaply overnight) for use later, rather than exporting or wasting it. More on battery storage installations.
- Smart Export Guarantee (SEG)
- A government-mandated scheme requiring larger energy suppliers to pay households for the renewable electricity they export back to the grid, replacing the older Feed-in Tariff for new installations. Read YEERS's SEG guide.
- Feed-in Tariff (FIT)
- The predecessor scheme to the SEG, which paid households a fixed rate for renewable electricity generated (not just exported). It closed to new applicants in 2019; existing FIT recipients continue to receive payments under their original terms.
- DNO (Distribution Network Operator)
- The regional company responsible for the electricity network in your area. Larger solar and battery installations require DNO approval before they can be connected to the grid — YEERS handles this application as part of every installation.
Heating & Heat Pumps
- Air Source Heat Pump (ASHP)
- A heating system that extracts heat from the outside air (even in cold weather) and uses it to heat a home and hot water, replacing a traditional gas or oil boiler. Explore YEERS's heat pump installations.
- Ground Source Heat Pump (GSHP)
- Similar in principle to an ASHP, but extracting heat from the ground via buried pipework, typically requiring more outdoor space but delivering more consistent efficiency year-round.
- SCOP (Seasonal Coefficient of Performance)
- A measure of a heat pump's average efficiency across a full year, accounting for seasonal temperature changes. A SCOP of 3, for example, means the system delivers roughly three units of heat for every one unit of electricity it consumes.
- Boiler Upgrade Scheme (BUS)
- A UK government grant, administered by Ofgem, currently offering £7,500 towards an air source or ground source heat pump installation in England and Wales, running until 2028. The grant is deducted directly from the installation quote by the certified installer rather than claimed by the homeowner. Check your eligibility.
- Heat Loss
- The rate at which a building loses heat, driven by factors like insulation, window quality, and draughts. Heat pump installations should always be sized around a proper heat loss calculation for the specific property, rather than a generic assumption.
Accreditations & Trust Marks
- MCS (Microgeneration Certification Scheme)
- The UK's quality standard for small-scale renewable technology, covering both the equipment and the installer. MCS certification is generally required to access government grants like the Boiler Upgrade Scheme. See all of YEERS's accreditations.
- TrustMark
- A government-endorsed quality scheme for tradespeople, covering standards of work, contracts, and consumer protection across a wide range of home improvement trades, including renewables.
- NAPIT
- A certification body for electrical and building services competence, commonly held by electricians and renewable energy installers.
- RECC (Renewable Energy Consumer Code)
- A consumer protection code that renewable energy installers can sign up to, covering fair sales practices and complaints handling.
- NICEIC / Gas Safe
- Certification bodies covering electrical work and gas work respectively; relevant if a renewable installation involves rewiring or interacts with an existing gas system.
General Terms
- Net Zero
- A state in which any greenhouse gas emissions produced are balanced by an equivalent amount removed from the atmosphere. The UK has a legal target of reaching net zero by 2050.
- Carbon Footprint
- The total amount of greenhouse gases generated by a person, household, or organisation's activities, usually expressed in tonnes of CO₂ equivalent (CO₂e) per year.
- Permitted Development
- Building work that doesn't require a full planning application because it falls within pre-approved limits. Most residential solar installations qualify, though listed buildings and some large commercial arrays don't. More planning questions answered in our FAQ.
Bookmark this page — energy terminology changes as fast as the schemes and prices themselves, and it's easier to check back here than to decode a quote or a news article from scratch each time.
Frequently asked questions
What is a kWp?
Kilowatt-peak — the maximum output a solar system can generate under ideal conditions. It describes the system's size and capacity, not how much electricity it actually produces day-to-day, which depends on weather, season and panel orientation.
What does SCOP mean for a heat pump?
Seasonal Coefficient of Performance — a measure of a heat pump's average efficiency across a full year. A SCOP of 3 means the system delivers roughly three units of heat for every one unit of electricity it consumes.
What is the Smart Export Guarantee (SEG) scheme?
A government-mandated scheme requiring larger energy suppliers to pay households for the renewable electricity they export back to the grid, replacing the older Feed-in Tariff for new installations.
What does MCS certified mean?
MCS (Microgeneration Certification Scheme) is the UK's quality standard for small-scale renewable technology, covering both the equipment and the installer. It's generally required to access grants like the Boiler Upgrade Scheme.
What is a standing charge?
A fixed daily fee you pay regardless of how much energy you use, covering the cost of maintaining the network connection to your property — charged even on days you use no energy at all.
What is TDCV?
Typical Domestic Consumption Value — Ofgem's estimate of how much energy an "average" household uses in a year, used to translate unit rates into the "typical annual bill" figure you see quoted in the news.