Glossary

To help you understand the Energy and Environmental Sector, we’ve put together a list of some commonly used terms and their definitions.

Anaerobic digestion:  A biological process that produces a gas principally composed of methane (CH4) and carbon dioxide (CO2) (known as biogas). These gases are produced from organic wastes such as livestock manure, food processing waste, etc.  Anaerobic processes could either occur naturally or in a controlled environment.  In the controlled environment, the gas is collected and used as a fuel.

Biomass and biomass fuels: Organic non-fossil material of biological origin. For example, trees, plants, excreta etc.

Biomass Energy: Energy produced by combusting biomass materials such as wood. The carbon dioxide emitted from burning biomass is only the carbon recently taken in by the organism (e.g. tree) from the atmosphere.  Therefore this does not increase total atmospheric carbon dioxide.

Carbon Dioxide (CO2): The greenhouse gas whose concentration is being most affected directly by human activities. CO2 also serves as the reference to compare all other greenhouse gases (CO2e). The major source of CO2 emissions is fossil fuel combustion for heating, transport and electricity generation plus forest clearing, cement production etc. Atmospheric concentrations are now about 30% above pre-industrial levels.

Carbon Reduction Commitment Energy Efficiency Scheme: From April 2010, organisations using more than 6,000MWh of electricity per annum (around £500,000) are required to measure and report on their carbon emissions. From 2012, companies will be required to buy carbon allowances from the government to cover the previous year’s emissions. The current price for one ton of carbon in £12.

Carbon Sequestration: The uptake and storage of carbon. Trees and plants, for example, absorb carbon dioxide, release the oxygen and store the carbon.

Carbon Trading: A market-driven mechanism whereby participating countries are allocated a permitted amount of carbon emissions or credits (based on 1990 levels).   Instead of reducing their emissions, they can buy unused credits from countries that have reduced their emissions.

CFL (Compact fluorescent lamp); Commonly known as an energy-saving lamp.  90% of the electrical energy used is converted to light via a small folded fluorescent tube.  Typically they generate 5 times more light than an incandescent (filament) lamp for the same electricity consumption.  Many lamps have enclose the tube in a diffused glass bulb in order to give the appearance of a standard incandescent bulb.

Climate: The average weather (usually taken over a 30-year time period) for a particular region and time period. Climate is not the same as weather, but rather, it is the average pattern of weather for a particular region. Weather describes the short-term state of the atmosphere. Climate elements include precipitation, temperature, humidity, sunshine, wind velocity, phenomena such as fog, frost, and hail storms, and other measures of the weather.

Climate Change: (Also referred to as ‘global climate change’ or ‘global warming’). The term ‘climate change’ is sometimes used to refer to all forms of climatic inconsistency, but because the Earth’s climate is never static, the term is more properly used to imply a significant change from one climatic condition to another. In some cases, climate change’ has been used synonymously with the term, ‘global warming’; scientists however, tend to use the term in the wider sense to also include natural changes in climate. See also Enhanced Greenhouse Effect.

Climate Change Act 2008: Set a legally binding target of at least an 80% cut in greenhouse gas emissions by 2050 in the UK. It also created the Committee on Climate Change to advise the government and set processes for the introduction of the CRC Energy Efficiency Scheme.

Cogeneration: The simultaneous production of electrical power and thermal energy from a process, thus reducing any heat or energy lost from the process. Also known as combined heat and power (CHP).

Emissions: The release of a substance (usually a gas when referring to the subject of climate change) into the atmosphere.

Energy-efficiency: The ratio of energy input to energy output – often expressed as a percentage i.e. a boiler than is 50% efficient (ratio 2:1) is less efficient than a boiler that is 75% efficient (ratio 3:4).

European Union Emissions Trading Scheme: Launched in 2005 to tackle climate change, it requires large emitters of CO2 in the EU to monitor and report their CO2 emissions.

Fossil fuels: Hydrocarbon fuels formed many millions of years ago from decayed plants and animals i.e. oil, coal and natural gas.  Can also include other fuels such as petrol or LPG derived from fossil fuels.

Green Electricity Purchasing your electricity through a green supplier, who buys enough energy from renewable sources to offset any electricity consumed in your home/business.

Greenhouse Gas (GHG): Any gas that absorbs infra-red radiation in the atmosphere. Greenhouse gases include water vapour, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halogenated fluorocarbons (HCFCs), ozone (O3), perfluorinated carbons (PFCs), and hydrofluorocarbons (HFCs).

Greenhouse Gas (GHG) Reporting: Under the Climate Change Act a requirement was made for the government to make greenhouse gas reporting mandatory, or explain why it has not done so, by 6th April 2012.

Ground Source Heat Pumps Heat is extracted through pipes laid horizontally or vertically in the ground, which can be used to heat buildings. Generally, for every 3kW of heat provided, the pump will consume 1kW of electricity.

Kilowatt hour (KWh) A unit or measure of electricity supply or consumption of 1,000 Watts over the period of one hour; can be used to measure the heat energy of fuels such as coal, mains gas, heating oil, petrol etc.

Kyoto Protocol: An international agreement, reached in 1997 in Kyoto, Japan, which extends the commitments of the UNFCCC. In particular, it sets targets for future emissions in developed countries.

Light emitting diode (LED): A small electronic device that lights up when electricity is passed through it. LEDs are highly energy-efficient and have very long lives.

Nuclear fuel: Energy derived from atomic nuclear processes during the fission or fusion.

Payback: The amount of time required (usually in years) for positive cash flows to equal the total investment costs. This is often used to describe how long it will take for energy savings resulting from using more energy-efficient equipment.

Renewable energy: Energy from sources that cannot be used up: sunshine, water flow, wind and vegetation.

Solar Photovoltaic Sunlight can be used to generate electricity and many everyday bits of equipment can now be powered by solar energy. Solar photovoltaic cells generate a small electrical voltage when exposed to light. Producing energy this way means there are no CO2 emissions, no moving parts and the electricity generation is silent.

Solar Water Heating Solar water heating systems work by absorbing heat on a flat plate, usually mounted on the roof of a building. Fluid (usually anti-freeze) passing through the panel is heated  then fed into a hot water tank. Solar water heating can provide all of a domestic homes hot water in the summer months, and up to 50% in the winter months.

Sustainable Development: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.