A

• AC - Alternating Current

  The type of electricity supplied by the National Grid.

• Air Source Heat Pump

  A unit that moves heat energy from one place to another. Air Source Heat Pumps harvest low grade heat from the ambient environment and convert it into useful high grade heat for use in the home.

• Anemometer

  Wind measurement tool.

B

• Biomass

  Any biological material burnt to generate energy. Biomass for domestic use is usually derived from wood. Wood fuels are carbon neutral because trees release the same amount of carbon whether they rot naturally or whether they are burnt.

C

• Carbon Dioxide (CO2)

  A natural gas, essential for life. But as a greenhouse gas, CO2 is now a major contributor to global warming because we are releasing it into the atmosphere in increasing quantities as we burn fossil fuels.

• Carbon Neutral

  The practice of balancing carbon dioxide (CO2) released from burning fossil fuels with an activity that reduces carbon emissions. This could be using renewable energy to create a similar amount of useful energy, or planting trees that absorb CO2.

• Cavity Wall

  Wall constructed of two layers of masonry separated by a cavity.

• CoP - Coefficient of Performance

  Heat pump performance measure. Tells you how many units the heat pump alone generates per unit of electricity it uses. For a measure of the efficiency of the system as a whole, see System Efficiency Ratio.

D

• DC - Direct Current

  The type of electricity produced by solar panels and wind turbines.

E

• Energy Company Obligation (ECO)

  Through ECO, the government aims to help low-income households or those in low-income areas. There will be a 75:25 split between the carbon and affordable warmth obligations.

• Energy Performance Certificate (EPC)

  EPCs show the energy efficiency rating for homes and other buildings on a scale of A to G

• External Wall Insulation

  Insulation fixed to the exterior of an existing or new dwelling. The high performance insulation slab is then rendered to give a protective and decorative coating to the existing facade.

F

• Feed-in Tariff

  Government incentive scheme that pays you to generate your own electricity.

• Fossil Fuels

  Fuel formed from once living organisms that have decomposed over millions of years. The main fossil fuels are oil, natural gas, and coal. Fossil fuels are high in carbon, which is released as they are burnt.

G

• Global Warming

  The effect of the increase in greenhouse gases. Small percentage rises have a big impact. We have seen a rise of 1% in the last 100 years. Just a 2% rise means increasingly unpredictable weather conditions,? storms, floods and droughts; increasingly acidic seas,? coral and krill die, food chains are destroyed; and the end of arctic ice in the summer. Some predictions say we could see a 6% rise by the end of this century if we don't drastically cut back on greenhouse gases emissions.

• Green Deal

  Innovative financing mechanism that enables householders and businesses to install energy efficiency measures at no up-front cost. Expected energy savings, over the lifetime of the measures, are then used to pay back the loan through electricity bills.

• Greenhouse Gases

  Gases that form part of the earth's atmosphere and help trap and retain the sun's heat. The main greenhouse gases are water vapour, carbon dioxide, methane, and ozone. The greenhouse effect makes Earth habitable. But these gases are now building up, raising the earth's temperature. The burning of fossil fuels is one of the biggest contributory factors to this build up.

H

• Hard to Treat

  Hard to treat properties are typically where standard cavity wall insulation is not a viable option.

• Heat Exchanger

  Device that transfers heat from one element to another. Used, for example, to transfer heat from the fluid in heat pump system pipes into the water in a tank.

I

• Internal Wall Insulation

  A form of solid wall insulation, usually applied when it is not possible to alter the external aesthetics of a property.

• Inverter

  Part of a solar PV or wind turbine system that converts direct current (DC) electricity to alternating current (AC), so it can power domestic appliances or be exported to the grid.

K

• kWh - kilowatt hour

  Measures energy produced. Electricity bills are charged in kWh, and it is the unit used for the energy produced by wind turbines and solar panels.

• kWh/year - kilowatt hour per year

  The amount of energy generated or required over a year.

• kWp - kilowatt peak

  Measures how much power a solar PV system produces from the sun under test conditions. The higher the kWp, the smaller the area of panels needed.

L

• Low Carbon Energy

  Energy produced by technologies which minimise the amount of carbon (or greenhouse gas) released into the atmosphere.

M

• Micro-generation

  Small scale generation of heat or power by renewable or low carbon means.

• Micro-generation Certification Scheme (MCS)

  Independent scheme for the certification of micro-generation installers and products. Only MCS accredited products installed by MCS accredited firms can qualify for government incentives. Ellipse products and installation teams are all MCS accredited.

P

• Pellets

  Small pellets made from wood waste and used in biomass stoves and boilers.

• Photovoltaic (PV) cells

  The technology used in solar panels to generate electricity from the sun.

R

• RECC

  A consumer code of conduct produced by the Renewable Energy Consumer Code and approved by the Office of Fair Trading. Ellipse Energy are RECC members and subscribe fully to the code.

• RdSAP - reduced data Standard Assessment Procedure

  A simplified process used to assess a building's energy and environmental performance cost-effectively. Surveyors use it to get the ratings for Energy Performance Certificates. Green Deal assessments will be based on an improved version of RdSAP.

• Renewable Energy

  Energy generated from resources that aren't going to run out. These resources include sun, wind, water, geothermal heat, biogas, biomass, and tidal power.

• Renewable Heat Incentive

  UK government scheme paying you to install renewable technologies to generate heat. The RHI is due to be launched for householders in summer 2013.

• Renewables Obligation

  UK government scheme that requires electricity suppliers to source an increasing percentage of their supply from renewable sources.

• Retro-fit

  Where systems are installed in an existing building, rather than built in from the start.

S

• SAP - Standard Assessment Procedure

  Methodology used to assess a building's energy and environmental performance.

• SAR - System Efficiency Ratio

  Heat pump system efficiency measure. Tells you how many units of electricity are need to run the whole heating system, including the heat pump, hot water and any supplementary heating such as an immersion. For a measure of the heat pump alone, see CoP.

• Solar Collectors

  The devices used in solar thermal panels that collect the sun's energy for heating a building.

• Solar Hot Water

  The technology used to generate hot water provided by solar hot water panels.

• Solar Irradiation

  The energy from the sun that can be converted into heat.

• Solar PV - solar photovoltaic

  The technology used in solar panels to generate electricity from the sun.

• Solid Wall

  Construction method usually found on properties built prior to the 1920's.

U

• U-Value

  Measure of how well a part of the building e.g. roof, window, door, wall) keeps the heat in. The higher the U-value, the greater the heat loss.

W

• Wind Turbines

  Wind turbines harness the power of the wind and use it to generate electricity.

Z

• Zero-Carbon

  Where activities don't produce any carbon emissions at all. Solar power and wind power generate zero carbon energy, once the carbon costs of manufacture have been paid back.