Please note: this glossary is in no way comprehensive, but we hope it covers the basics. If you feel like we’ve missed out on a particularly important term or there’s a term you would like us to explain, get in touch.
Alternating Current (AC)
Alternating current means the direction of flow of electricity is constantly being reversed back and forth. The electricity in our mains grid is AC, mainly because AC is easier to transfer over longer distances and can provide more power. However, most electrical circuits require DC (direct current), so AC power must be converted prior to being suitable for certain devices (hence the use of adapters in power supplies to e.g. laptops). Also see ‘Direct Current’ and ‘Power’.
Amperes, or amps, are the unit of measurement for electrical current – the amount of electric charge passing a point in an electric circuit per unit time. 16A and 32A are two of the current ratings used in standardized industrial plugs. The type of supply needed will depend on the amount of kit plugged in and how much current each piece of equipment will draw. Also see ‘Power’.
Biodiesel is a fuel that can be used in conventional diesel engines as a replacement for mineral diesel (fossil-fuel derived). It is made from plant or animal oils or fats that have been chemically processed into alkyl esters. Their environmental sustainability depends hugely on what types of plant/animal material the fuel is derived from (and where). Waste vegetable oil (WVO) biodiesel is a good environmental choice, but virgin biodiesel (produced from crops) can have many damaging impacts such as deforestation, food crop displacement and travel miles. [See also Biofuels]
Fuels derived from organic matter, mainly crops and waste. There are many different types of biofuels (e.g. biodiesel, biogas, bioethanol, wood), many of which are controversial from an environmental and social perspective as they can contribute to land use change (converting forests and other habitats into agricultural land) which in turns contributes to climate change and can drive up food prices (either because they are derived from edible crops, or because they displace the growing of edible crops). However, others are considered more sustainable alternatives to fossil-fuel-derived power and fuels.
A naturally occurring gas, and also a by-product of burning fossil fuels and biomass, land-use change, and other industrial processes. It is the principal anthropogenic (man-made) greenhouse gas driving climate change. CO2 is the reference gas against which other greenhouse gases are measured and therefore has a ‘Global Warming Potential’ of 1.
Carbon Dioxide Equivalent (CO2e)
There are 6 greenhouse gases recognised in international treaties and documents (such as the Kyoto Protocol and the Intergovernmental Panel on Climate Change). Each of these has a different Global Warming Potential. The combination of the six is expressed as carbon dioxide equivalent - the amount of CO2 that would cause the same amount of warming. CO2e is frequently used to evaluate the impacts of releasing (or avoiding the release of) different greenhouse gases.
A measure of the impact human activities have on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide (or CO2e).
Used to denote when there is no net release of CO2. For example, growing biomass takes CO2 out of the atmosphere, while burning it releases the gas again. The process is carbon neutral if the amount taken out and the amount released are identical.
A change of climate attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability over comparable time periods. Climate change is attributed predominantly to the release of greenhouse gases (mainly CO2) into the atmosphere.
Direct Current (DC)
Direct current is the unidirectional flow of electric charge i.e. current flows only in one direction. It is produced by sources including batteries, solar cells, fuel cells, and some types of generator. Most electronic circuits require a steady DC. Also see ‘Power’.
Emissions that are produced by organisation-owned equipment or emissions from organization-owned premises/spaces, such as carbon dioxide from electricity generators, gas boilers and vehicles, or methane from landfill sites.
EE MUSIC IG Tools
The EE MUSIC IG Tools are free online carbon calculators, adapted from the Julie’s Bicycle Creative IG Tools, designed specifically for the creative industries. They help event organisers, venue owners/operators and other arts organisations to measure and manage their carbon emissions.
Embodied Energy Embodied Energy is the sum of all the energy required to produce goods or services, considered as if that energy was incorporated or 'embodied' in the product itself – from the mining of raw materials through to the manufacture and distribution process all the way to the end user. The concept can be useful in determining the effectiveness of energy-producing or energy-saving devices (does the device produce or save more energy than it took to make it over its lifespan?), and, because energy-inputs usually entail greenhouse gas emissions, in deciding whether a product contributes to or mitigates global warming.
The release of a substance (usually a gas when talked about in the context of climate change) into the atmosphere.
Requirements that set specific limits to the amount of pollutants that can be released into the environment. Many emission standards focus on regulating pollutants released by cars but they can also regulate emissions from industry, power plants, and equipment such as diesel generators.
Efficient energy use, sometimes simply called energy efficiency, is the goal of efforts to reduce the amount of energy required to do something or provide a service. This can be used both in the context of efficiency in usage (i.e. energy conservation) and efficiency in terms of carbon (lowering emissions from energy use, moving to renewable energy sources); with the ultimate aim of de-coupling growth from resource use according to the principles of Avoid, Reduce, Replace.
Energy Efficient Equipment
Energy efficient equipment uses less energy to operate than ‘standard’ equipment. In the entertainment sector, many energy efficiency gains can be made via the types of technology and equipment employed - for example by using more LED lighting or energy efficient refrigeration.
The effects human activity has on the environment. Examples of negative impacts on the environment include pollution, biodiversity loss, and climate change.
Environmental sustainability refers to the ability of natural ecosystems to remain diverse and productive, thus being able to support life over a period of time. All human activity is based on these ecological goods and services. Some human activities, such as the excessive production of greenhouse gas emissions (including carbon dioxide), have led to a decline in natural ecosystems and to changes in the balance of natural cycles, thus undermining and degrading the capacity of ecosystems to continue supporting life. Living sustainably will ensure the long-term viability and productivity of these ecosystems, providing humans and other species with a habitat in which we can thrive for generations.
Natural resources (e.g. coal, oil, natural gas) containing hydrocarbons. These are formed in the Earth over millions of years and release carbon dioxide when burnt.
The power delivered by a generator at any given time, determined by the power demands of the circuit/equipment hooked up to the generator. Peak load is the maximum power requirement of a system. Base load is the more or less constant power requirement of a system underlying any peaks.
Green Energy Tariffs
The exact specification of a ‘green tariff’ varies from company to company. Some specialize in providing up to 100% of energy directly from renewable sources. Other suppliers of green energy tariffs make a contribution to environmental schemes such as renewable energy projects. Green tariffs are sometimes more expensive than standard tariffs, however they have better environmental credentials and by switching you are contributing to increasing the market demand for greener energy.
Trapping and build- up of heat in the atmosphere near the Earth’s surface. Some of the heat flowing back towards space from the Earth’s surface is absorbed by water vapour, carbon dioxide, ozone, and several other gases in the atmosphere and then reradiated back toward the Earth’s surface. If the atmospheric concentrations of these greenhouse gases rise, the average temperature of the lower atmosphere will gradually increase.
The current Intergovernmental Panel on Climate Change (IPCC) inventory includes six major greenhouse gases. These are Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), Sulphur hexafluoride (SF6).
Hybrid Generator Systems
‘Hybrid’ refers to generators that use a combination of technologies, for example the use of diesel generators with storage batteries and solar panels or wind turbines, and are able to intelligently switch between them.
Emissions that are a consequence of the activities of an organisation but occur from sources owned or controlled by another organisation or individual. They include outsourced services as well as the emissions associated with downstream and/or upstream manufacture, transport and disposal of products used by the organisation, referred to as product life-cycle emissions.
An electrical power converter used to switch direct current (DC) to alternating current (AC). They are commonly used to change the power from DC sources such as solar panels and batteries to AC.
Kilowatt Hour (kWh)
Energy as the product of power and time i.e. energy = the amount of power expended x the amount of time. This is the common unit used to bill electricity to consumers. For example, a 60-watt lightbulb that burns for one hour uses 0.06 kWh.
A light-emitting diode (LED) is a semiconductor light source – they are used as indicator lamps in many devices and are increasingly used for other lighting. LEDs present many advantages over incandescent lighting, in particular in terms of energy efficiency. LED technology is developing rapidly and is becoming a much more realistic option for outdoor and daytime use.
Life Cycle Analysis (LCA)
Also referred to as a life cycle assessment, or cradle to grave analysis. Investigation and valuation of the environmental impacts of a given product or service across its entire lifespan – from cradle (extraction of raw materials) to grave (disposal and decomposition).
A carbon offset is a mechanism that allows a company, organisation or individual to reduce their greenhouse gas emissions in one area of activity (e.g. building energy use or air travel) by investing in projects that seek to reduce the greenhouse gas emissions in another (i.e. energy efficiency, new clean technology, forestation). The idea of carbon offsetting is to neutralise net emissions. Carbon offsetting should be seen as a last resort, when all possible action to reduce emissions have been taken.
Carbon offset projects should be accredited by an officially recognised standard, so you can be sure that the projects your money goes to genuinely reduce emissions. For more information, see http://www.juliesbicycle.com/resources/offsets-factsheet and http://www.e-missionneutral.com/en/content/6-projects/45-criteria
Power is the rate at which energy is transferred, used or transformed – in this context, mainly the rate at which a piece of equipment transforms the energy it receives into its particular output. For example, the rate at which a generator transforms fuel into electricity, or the rate at which a light bulb transforms electricity into heat and light. Power is measured in watts (W).
One measure of power in a circuit (the rate at which electric energy is transferred by the circuit) is voltage multiplied by current, or volt-ampere. Power = volts x amps, or W = VA. This type of measurement is only accurate for direct current (DC) electricity. In most alternating current (AC) circuits, the VA figure will be larger than the actual delivered power in watts because of reactance – opposition to the passage of AC exhibited by some electronic components. For example, a supply rated at 800 VA will usually deliver 1/2 to 2/3 of this in terms of wattage. When it comes to ratings for devices, the VA rating is limited by the maximum permissible current, and the watt rating by the power-handling capacity of the device. Generators are normally sized in kVA – kilo-volt-ampere, or thousands of VA.
Renewable energy sources
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished in a relatively short period of time).
Photovoltaic cells mounted on panels convert sunlight into electricity which is then generally stored in batteries. Electricity generation is higher when it’s sunny, but is also possible with overcast conditions. An inverter is used to step up the voltage for use with standard equipment. When equipment is used, energy is drawn from the storage, which is simultaneously recharged by the solar panels during daylight.
Development that meets the cultural, social, political and economic needs of the present generation without compromising the ability of future generations to meet their own needs.
VA or kVA
Volt-ampere or kilo-volt-ampere, generally used to size generators. Also see ‘Power’.
The electrical potential difference, or electric tension, between two points. measured in volts (V). Also see ‘Power’.
Watt (W or kW)
The universally used unit for power, measured as joules per second (J/s) – i.e. the rate of energy transformation. The more wattage, the more power, or the more energy is used per unit of time. kW are kilo-watts – or thousands of watts. Also see ‘Power’.
Temporary wind power works in a similar way to solar. Kinetic energy (from the wind rotating turbines) is converted into electrical energy, generally stored in batteries. There are currently few temporary wind systems on the market for events, despite widespread small-scale use in other sectors.