Green Energy Glossary
Plain English explanations of key terms for solar panels, heat pumps, EV chargers, grants, and more.
ASHP (Air Source Heat Pump)
A heating system that extracts heat from the outside air to warm your home and hot water. Works efficiently even in temperatures as low as -15C. Eligible for the BUS grant of up to 7,500.
BUS Grant (Boiler Upgrade Scheme)
A UK government grant providing up to 7,500 towards the cost of installing an air source heat pump or 7,500 for a ground source heat pump. Available for homes in England and Wales with an EPC rating.
COP (Coefficient of Performance)
A measure of heat pump efficiency. A COP of 3.0 means for every 1 kWh of electricity used, the heat pump produces 3 kWh of heat. Higher is better - typical values range from 2.5 to 4.5.
CPA (Cost Per Acquisition)
The price an installer pays per lead received through the platform. Varies by product type and lead quality tier.
DNO (Distribution Network Operator)
The company responsible for the electricity distribution network in your area. You may need DNO approval for larger solar installations or battery systems that export to the grid.
ECO4 (Energy Company Obligation)
A government scheme requiring large energy suppliers to fund energy efficiency improvements in low-income and vulnerable households. Can cover insulation, heating upgrades, and solar panels.
EPC (Energy Performance Certificate)
A rating from A (most efficient) to G (least efficient) that shows how energy efficient a property is. Required for the BUS grant and useful for identifying upgrade opportunities.
EV Charger (Electric Vehicle Charger)
A dedicated charging point for electric vehicles installed at home. Typically 7kW for single-phase homes, providing a full charge overnight. Much cheaper than public charging.
Feed-in Tariff (FiT)
A now-closed government scheme that paid homeowners for generating renewable electricity. Replaced by the Smart Export Guarantee (SEG) for new installations.
GSHP (Ground Source Heat Pump)
A heating system that extracts heat from the ground via buried pipes (ground loops). More efficient than air source but requires more space and higher installation costs.
Inverter
A device that converts DC electricity from solar panels into AC electricity used by your home appliances and the grid. Modern inverters also optimise panel output and provide monitoring.
kWh (Kilowatt Hour)
A unit of energy equal to using 1,000 watts for one hour. Used to measure electricity consumption and generation. Average UK home uses about 3,500 kWh per year.
kWp (Kilowatt Peak)
The peak power output of a solar panel system under standard test conditions. A typical UK home installs 3-4 kWp. Each kWp generates roughly 850-1,050 kWh per year depending on location.
MCS (Microgeneration Certification Scheme)
The quality assurance scheme for small-scale renewable energy installations in the UK. MCS certification is required for installers to be eligible for government grants and feed-in schemes.
Net Zero
Achieving a balance between the greenhouse gases emitted and those removed from the atmosphere. The UK has a legal target to reach net zero by 2050.
PVGIS (Photovoltaic Geographical Information System)
An EU tool providing solar irradiance data for any location. Used to estimate how much electricity solar panels will generate based on your postcode, roof angle, and orientation.
SCOP (Seasonal Coefficient of Performance)
The average COP of a heat pump across the entire heating season. More realistic than COP alone as it accounts for varying outdoor temperatures throughout the year.
SEG (Smart Export Guarantee)
A scheme requiring large energy suppliers to pay you for excess renewable electricity you export to the grid. Rates vary between 3-15p per kWh depending on the supplier and tariff.
Self-Consumption
The percentage of solar energy you use directly in your home rather than exporting. Higher self-consumption means greater savings. Adding a battery can increase this from around 50% to 70-80%.
Smart Meter
A digital energy meter that sends automatic readings to your supplier. Required for time-of-use tariffs and useful for monitoring solar generation and export.
Solar Panel (Photovoltaic/PV Panel)
A panel that converts sunlight into electricity. Modern panels typically produce 380-440W each. A typical UK home needs 8-12 panels for a 3-4 kWp system.
Time-of-Use Tariff
An electricity tariff with different rates at different times of day. Off-peak rates (typically overnight) can be as low as 7-10p/kWh - ideal for charging EVs or batteries.
Zero-Rate VAT
Since April 2022, energy-saving materials including solar panels, heat pumps, and insulation installed in residential properties benefit from 0% VAT, reducing costs by 20%.
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