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Anaerobic Digestion
The breakdown of waste plant and animal material by micro-organisms in an oxygen free environment (i.e. anaerobic conditions), generally a sealed tank, to produce a biogas which can be used to provide heat and power. The solid material left at the end of the process is a good fertiliser. Although the process produces some GHG emissions, the impacts are much less than from the emissions that would be produced if the same heat and power were produced using fossil fuels. Suitable feedstocks for an anaerobic digestion plant include food waste and slurries.
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Biofuels
Biofuels are fossil fuel replacements made from feedstocks such as crops e.g. oil seeds, wheat and sugar, or from waste products e.g. cooking oil and tallow. At the moment bioethanol and biodiesel are the most readily available. As part of the Renewable Transport Fuel Obligation (RTFO), fuel currently sold at UK petrol pumps contains at least 5% biofuel; fuel containing 5% biofuel is termed B5. Biofuels have similar tailpipe emissions to fossil fuels, but over their complete lifecycle, can produce less GHG emissions; however, this largely depends on the type, origin and potential other uses of the feedstock, as well as any associated land use changes. Used cooking oil will generally produce lower emissions.
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Biogas
Biogas is the mixture of gases produced in an anaerobic digester; generally it comprises approximately 60% methane and 40% carbon dioxide with traces of other gases. It can be used to provide heat, electricity, or both; Biogas can also be 'cleaned up' into pure methane which can be fed into the gas national grid or used as road transport fuel. As it is classed as a renewable energy technology, the electricity generated is eligible for ROCs .
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Biomass
Biomass is organic matter such as timber and crops. The term is generally used for materials grown specifically or recovered from wood wastes, for burning in special biomass boilers to generate heat.
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Carbon Capture and Storage (CCS)
CCS is a way of removing and managing unavoidable carbon emissions from industry and power generation and can reduce power plant emissions by up to 90%. It involves capture of carbon emissions from the industrial and power plants, transportation usually via pipeline, and final deposition in storage facilities such as depleted oil and gas fields or deep saline formations. The Energy Act 2010 contains provision for financial support for commercial scale demonstration projects.
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Carbon Dioxide (CO2)
one of the Kyoto 'Basket of Six' greenhouse gases. It is produced by e.g. the complete combustion of fossil fuels, and has a GWP of 1; however, it is still a significant GHG as, in 2004, it accounted for 76.7% of the anthropogenic GHGs released into the atmosphere (as a proportion of all gases converted to tonnes CO2e based on GWP; Technical Summary to the IPCC Fourth Assessment Report 2007 ).
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Carbon Emissions
The sum of greenhouse gases released through any activity, such as transportation of goods or management of waste, and converted into carbon dioxide equivalents. In the past, these could comprise either just tonnes CO2 or tonnes carbon (12/44 of tonnes CO2) but are now generally assumed to include all the reportable GHGs.
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Carbon Equivalent
A measure of the impact of GHGs other than CO2; produced by multiplying the total quantity of a GHG by its Global Warming Potential and expressed as t CO2e. It allows the impact of GHGs with different GWPs to be normalised, providing one overall value for climate change impact.
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Carbon Management
Carbon Management is the term used to describe the evaluation, monitoring, and implementation of actions to minimise and mitigate carbon emissions. It often involves a baseline carbon footprint, development of an action plan to reduce carbon emissions, with regular reviews and updates.
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Carbon Neutral
To be Carbon Neutral is to have net carbon emissions equal to zero; this is generally achieved through transparent calculation of carbon footprinting, emission reduction and offsetting. The 2010 document BSI PAS 2060 outlines the processes involved in order for a company to claim carbon neutrality.
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Carbon Offsetting
Offsetting allows companies to compensate for unavoidable carbon emissions produced through their operations by financially supporting other projects/programmes that reduce carbon emissions elsewhere. These projects often involve installation of renewable energy systems such as solar water heating or hydro-power or energy efficiency measures overseas.
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Carbon Sequestration
Sequestration is the removal from the atmosphere of carbon emissions either by natural means e.g. absorption into trees and other plant matter or artificial e.g. carbon capture and storage in depleted oil fields.
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Carbon Sink
A carbon sink is anything that absorbs more carbon than it releases. The following can all act as sinks depending on prevailing conditions: forests (through tree photosynthesis), soils (stored in plant litter), peat bogs (trapped carbon from ancient vegetation), and oceans (absorbed into micro-organisms that die and sink to the ocean bed). These sinks can also become carbon sources depending on the prevailing conditions.
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Carbon Source
A carbon source is anything that releases more carbon than it absorbs. For example, mature trees release carbon through decomposition, and through respiration; soils also release CO2 through decomposition of organic material; peat bogs will release stored carbon as methane when disturbed, and oceans will release CO2 gas when the water temperature increases.
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Climate Change
The term climate change is generally used to describe changes seen over the last few decades in recognised regular global weather and climate patterns; general consensus amongst scientific experts is that this is a result of the increasing quantities of anthropogenic (man-made) greenhouse gas emissions released from human activities.
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Climate Change Agreements (CCAs)
As some industries are much more energy dependent than others, CCAs have been set up to allow the heaviest users to claim an 80% discount on the Climate Change Levy obligation if they meet stringent targets for energy efficiency and emissions reductions. These Agreements may be between individual companies and DECC or between specific sectors and DECC (umbrella agreements).
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Climate Change Levy (CCL)
Introduced in April 2001, the CCL is a tax on the consumption of certain types of energy (e.g. electricity from non-renewable sources, natural gas, petroleum, coal and others) levied on the industrial, commercial, public and service sectors. It is designed to promote energy efficiency and stimulate investment in renewable energy sources through their exemption from the Levy, helping the UK meet its GHG emission reduction targets.
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Combined Heat and Power (CHP)
CHP is an integrated system producing both electricity and heat i.e. the heat produced as part of the electricity generation process is also collected rather than lost. This greatly increases the efficiency of the system; CHP can reach efficiencies of up to 80% compared with 48-52% for traditional gas turbine technology and 38% for traditional coal-fired power stations .
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Department of Energy and Climate Change (DECC )
DECC was created in October 2008 to provide a single UK Government department that covers energy policy and climate change; a major area of focus for DECC is to help the UK move to a low carbon economy.
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Emission Factor (EF)
An emission factor is a metric that provides an average GHG emission associated with an individual activity, usually expressed in kg or tonnes CO2e per unit e.g. kg CO2e/kWh for electricity use from national grid ; t CO2e saved/tonne waste for paper waste recycled.
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Energy from Waste (EfW)
see Thermal Treatment of Waste.
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Enhanced Capital Allowance Scheme
The Enahnced Capital Allowance Scheme was introduced in 2001 to facilitate the uptake by businesses of low carbon energy saving technologies. It provides tax relief known as Enhanced Capital Allowances (ECAs) on energy-saving equipment, water-efficient equipment and low carbon emission vehicles, and is available to all businesses regardless of size, sector or location. All technologies eligible for the relief are detailed in the Energy Technology List .
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Feed-in Tariffs (FITs)
FITs are a payment made on electricity generated by renewable resources to the generator from the utilities. Eligible generators can be organisations, businesses, communities or individuals and the technologies covered include AD, wind, solar PV, hydro, and micro-CHP. Units must have been installed within the UK on or after 15th July 2009 and both the technology and the installer must be registered with the Microgeneration Certification Scheme.
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F-Gas Regulations
The F-Gas Regulations were introduced in July 2007 to monitor the use, and control the release, of F-gases. They place a requirement on owners of industrial/commercial refrigeration units which contain more than 3kg of these gases to have the units regularly inspected by certified professionals; the larger the unit, the more frequently they need to be inspected. The Regulations also prescribe the phase out of virgin HFCs (by January 2010) and recycled HFCs (by January 2015). These regulations are enforced by either the Scottish Environment Protection Agency or Local Authority Officers (depending on premises type) and failure to demonstrate compliance with the Regulations may result in fines and possibly prosecution.
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Fluorinated Greenhouse Gases (F-Gases)
The F-Gases are a family of chemicals which contain fluorine such as the Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulphur hexafluoride (SF6). These are generally very powerful greenhouse gases, with a GWP ranging from 140 (HFC-152a) to 23,900 (SF6). HFCs in particular are significant for the food and drink sector as they were common refrigerants used in refrigeration and air conditioning. Units may contain a mix of 2 or more F-gases, and often the gas trade name (given on the metal plate on the refrigeration unit) is an 'R-number' i.e. it begins with an 'R' followed by a number such as R404A.
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Global Warming
Global warming is another name for climate change but slightly less accurate as, although the overall average temperature of the planet surface will increase, there will be regional variation with some areas potentially seeing a drop in average temperature within their region. It also ignores the change in other equally significant climate aspects such as rainfall patterns and wind speeds.
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Global Warming Potential (GWP)
The GWP is a measure of the potency of a gas with regard to its impact on the greenhouse effect. CO2 is considered to be the baseline with a GWP of 1, with all other GHGs being considered in multiples of CO2 GWP e.g. CH4 has 21 times the greenhouse effect of CO2 so has a GWP of 21, according to the IPCC Second Assessment Report ( SAR 1995). The GWP values are constantly under revision but, under current reporting mechanisms, the SAR values are still used and referenced in the Technical Summary to the IPCC Fourth Assessment Report (AR4) 2007.
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Green Electricity Tariff/Green Supply Tariff
Green Tariffs reflect additional investment by utility companies into renewable energy technologies, contributing to a reduction in the carbon emissions associated with the entire National Grid. These emission savings can be allocated to the consumer purchasing a Green Tariff to reduce their own energy footprint. Details of verified Green Supply Tariff can be found on the Green Energy Supply website http://www.greenenergyscheme.org/index.php
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Greenhouse Effect
The naturally occurring phenomenon whereby certain gases in the atmosphere act like a layer of insulation around the planet, retaining the sun's energy by trapping heat energy reflected from the Earth's surface, is known as the 'greenhouse effect'. Gases with this property are known as greenhouse gases (GHGs).
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Greenhouse Gases (GHGs)
Often abbreviated to GHGs, the term greenhouse gases covers a number of gases that, when they occur in the atmosphere, increase the insulation effect resulting in an overall relative warming of the atmosphere and planet. The commonest is carbon dioxide but there are 6 main gases monitored and reported on by Governments known as the 'Kyoto Basket of Six'.
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Ground and Air Source Heat Pumps
The average temperature a few metres below the ground is 10-150C; ground source heat pumps exploit this, using either a ground collector (slinky) or ground probe (bore hole) to draw the heat to the surface/building interior. Air source heat pumps work on a similar but less consistent basis (because ambient air temperature varies), drawing the heat from the surrounding air. In effect, they work like refrigerators in reverse.
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Intergovernmental Panel on Climate Change (IPCC)
The IPCC is a voluntary body comprising thousands of scientists from all over the world; they review and assess the most recent scientific, technical and socio-economic information produced worldwide to provide an objective and complete assessment of climate change. Established in 1989 by the United Nations Environment Programme (UNEP) and World Meteorological Organisation (WMO), the organisation describes itself as "policy-relevant and yet policy-neutral, never policy-prescriptive.”
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Kyoto Basket of Six
The six main greenhouse gases identified in the Kyoto Protocol are known as the Kyoto 'Basket of Six' and are monitored and reported on by Governments internationally. The gases are, in order of increasing potency, CO2 (carbon dioxide); CH4 (methane); N2O (nitrous oxide); the HFCs (Hydrofluorocarbons); the PFCs (Perfluorocarbons), and SF6 (sulphur hexafluoride).
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Methane (CH4)
CH4 is one of the Kyoto 'Basket of Six' greenhouse gases. It is produced by the breakdown of organic matter in the absence of air e.g. in landfill sites, and in the digestive tracts of cattle and sheep, and has a GWP of 21 (Technical Summary to the IPCC Fourth Assessment Report 2007).
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Nitrous Oxide (N2O)
N2O is one of the Kyoto 'Basket of Six' greenhouse gases. It arises from transportation, wastewater treatment and nitrogenous fertilisers in agriculture, and has a GWP of 310 (Technical Summary to the IPCC Fourth Assessment Report 2007 ).
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Renewable Energy
Renewable energy (heat and electricity) is produced using sources that can constantly be renewed/are not finite e.g. solar (thermal and photovoltaic), hydro, wave, tidal, wind, and geothermal sources. These generally have significantly lower carbon emissions associated per kWh generated compared with traditional fossil fuel generation, even including the construction phase for each technology. Scotland has plentiful renewable resources, the equivalent of 10 times its current electricity demand.
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Renewable Heat Incentive (RHI)
The RHI is a Government scheme to provide financial support for the generation of heat from renewable sources such as solid biomass, solar thermal, geothermal, and ground and water source heat pumps. Different technologies will receive a different tariff rate (p/kWh). Businesses, the public sector, not-for-profit organisations and communities in England, Scotland & Wales are all eligible to receive the RHI. To be eligible, plant must have been completed and commissioned on or after the 15th July 2009, and both the plant and its installers must be registered under the Microgeneration Certification Scheme.
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Renewables Obligation Certificate (ROC)
A ROC is a certificate issued to accredited producers of electricity from eligible renewable sources, both generated and supplied to customers within the UK. The number of ROCs produced per MWh of renewable energy depends on the energy source from which the electricity is generated. Microgenerators using wind, solar, anaerobic digestion or hydro power are NOT eligible for ROCs.
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Renewables Obligation Order (RO)
The RO (or Renewables Obligation (Scotland) Order in Scotland) is designed to provide incentives for including electricity generated from renewable resources into the National Grid. In effect, since April 2002, it places an obligation on licensed electricity suppliers in the UK to source an increasing proportion of electricity from renewable sources. Since April 2009 this has been based on the number of ROCs per MWh rather than as a percentage of the supplier's sales; in 2009/10 the figure was 0.097 ROCs per MWh for Scotland and increasing to 0.111 in 2010/2011. If suppliers fail to purchase enough over a year, they must pay an equivalent amount into a 'buy-out' fund which is then redistributed amongst those who have bought a sufficient number of ROC s over that period.
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Solar Photovoltaics (solar PV)
Solar PV technology uses silicon-based panels to convert sunlight into DC electricity. Panels are categorised as being monocrystalline, polycrystalline or thin-film/amorphous technology, depending on the alignment of the crystals. Both monocrystalline and polycrystalline units are readily available, cost effective and can be fitted retrospectively. Amorphous is more flexible but more expensive and less efficient. Efficiencies of 15-18% are available (though potentially up to 38% in laboratory conditions). Payback period in Scotland can be as low as 8 years.
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Solar Thermal/Water Heating
Solar thermal technology uses radiation from the sun to heat water in panels situated on the roofs of buildings; the heat trapped can be used to provide warm water or to supplement a central heating system. Current systems can be either flat-plate collectors or evacuated tube collectors and can provide 40-70% of domestic hot water needs.
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Sustainability (local definition)
Sustainability implies working as far as practicable in harmony with the economy, society and environment, to ensure longevity whilst avoiding having a negative impact on any of the triple bottom line.
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Sustainable Development/Sustainability (global definition)
Originally defined by Brundtland in 'Our Common Future' in 1987 as "Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs"; in short, it can be likened to having a bank account where to live sustainably means living off the interest and never drawing on the capital so that you don't reduce its ability to provide in the future.
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Thermal Treatment of Waste
Thermal treatment of waste is defined by SEPA as "the recovery of energy value from waste by burning the waste directly or burning a fuel produced from the waste”; also known as 'Energy from Waste' (EfW).
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Triple Bottom Line
Working to the triple bottom line means giving equal consideration to the economy, society and environment in business decision making.
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UK Low Carbon Transition Plan 2009
This is a UK Government White Paper setting out a 'roadmap' for the UK to decarbonise its economy building on existing and new policies, across a number of Departments, relating to issues such as a competitive energy market, security of energy supply, technological development and assisting individuals in making low carbon choices.
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United Nations Framework Convention on Climate Change (UNFCCC)
The UNFCCC was established in March 1994 to provide an overall framework for governments to work together to tackle climate change. With nearly universal membership, it allows governments to share research on emissions, national policies and best practice, and to co-operate in preparations for adaptation to the impacts of climate change.
