General Renewable Energy Glossary
A thermal water-storage tank which is integrated into the heating system. It collects and stores heat energy from the system to allow its flexible use at all times and to smooth out daily demand profiles.
- Base load
The minimum heat or electricity demand from a system which is maintained throughout a defined period.
- Code for sustainable homes
The Code is the national standard for the sustainable design and construction of new homes. The Code aims to reduce our carbon emissions and create homes that are more sustainable.
- Combi boilers
Boilers that provide DHW and space heating.
- Combi stores
Combination of DHW and space heating storage.
- Combined Heat and Power (CHP)
The sequential production of electricity and heat from the same fuel source.
- Combined storage
A single vessel that includes heat sources other than solar thermal/heat pump/biomass.
- Commissioning engineer
Responsible person for declaring a fitted system is fit for purpose and safe.
Movement of heat in solid.
Movement of heat in a fluid.
Domestic hot water consumed in the dwelling.
- Display Energy Certificate (DEC)
Certificate showing the actual energy performance of a public building against its predicated use.
- ELV (extra low voltage)
Electricity that is sub 50 V AC or ripple-free 120 V DC.
- Environmental Impact Assessment (EIA)
A study of the environmental effects of a proposed project.
Energy Performance Certificate (EPC) - a certificate which gives a building an asset rating based on its energy efficiency (from A to G). An A rating shows it's very efficient, meaning lower fuel bills, while G is inefficient, meaning higher fuel bills. The certificate also shows the building's environmental impact by indicating its carbon dioxide emissions.
- Greywater Harvesting
Greywater is wastewater generated from domestic activities such as laundry, dishwashing, and bathing, which can be recycled on-site for uses such as landscape irrigation and constructed wetlands.
- Green deal
The Energy Act 2011 includes provisions for the new 'Green Deal', which intends to reduce carbon emissions cost effectively by revolutionising the energy efficiency of British properties. The new innovative Green Deal financial mechanism eliminates the need to pay upfront for energy efficiency measures and instead provides reassurances that the cost of the measures should be covered by savings on the electricity bill.
- Greenhouse Gas (GHG)
The main greenhouse gas of concern due to global warming is carbon dioxide. Others include methane, ozone, chlorofluorocarbons, and nitrous oxide.
Assembles and fits components into a system. Equivalent to a manufacturer where the assembly is customised.
The annualized effective compounded return rate which can be earned on the invested capital, i.e., the yield on the investment. The calculated IRR can be compared to any alternate costs of capital, or the internal investment hurdle rate to determine whether an investment will provide an acceptable return. The IRR is, effectively, the discount rate that makes the net present value of the investment's income stream come to zero.
Electromagnetic energy incident per unit area.
Kilowatts of thermal energy.
Amount of energy or power required from a system.
Produces components and assembly kits.
- Microgeneration Certification Scheme (MCS)
An industry-funded assurance scheme to ensure the quality of renewable technology installations, companies and products. MCS-certified products and installation company needed to qualify for FiTs in sub-50kW category.
- Million tonnes of oil equivalent (Mtoe)
A unit of energy: the amount of energy released by burning one million tonnes of crude oil (approximately 42M GJ).
- Rainwater Harvesting
Rainwater harvesting is the accumulation and storage of rainwater for reuse before it reaches the aquifer. It has been used to provide drinking water, water for livestock, water for irrigation, as well as other typical uses.
- Renewable Energy Directive/Fuel Quality Directive
A set of stretching renewables targets for 2020 across the EU. Includes targets for uptake of renewable fuels and sustainability criteria. The UK has submitted a National Action Plan to the European Commission, detailing how it will meet its obligations.
- Renewable Heat Incentive (RHI)
Incentive for the generation of renewable heat - similar to Feed-in Tariffs. RHI opened to applications for commercial installations on 28 November 2011. Managed by DECC, but administered by Ofgem.
- Renewable Heat Premium Payment (RHPP)
The Renewable Heat Premium Payment is a one-off grant designed to help towards meeting the costs of installing renewable technologies in your home, until the Renewable Heat Incentive (RHI) is introduced for domestic customers.
- Renewables Obligation
The main support scheme for renewable electricity projects in the UK. It places an obligation on UK electricity suppliers to source an increasing proportion of their electricity from renewable sources. Suppliers meet their obligations by presenting sufficient Renewables Obligation Certificates. Where suppliers do not have sufficient ROCs, they must pay an equivalent amount into a fund, the proceeds of which are paid back on a pro-rated basis to those suppliers that have presented ROCs.
- Renewables Obligation Certificate (ROC)
A green certificate issued to an accredited generator for eligible renewable electricity and supplied to customers within the UK. One ROC is issued for each megawatt hour (MWh) of eligible renewable output generated, although some technologies get more, some less.
It is a UK Government scheme designed to help you afford renewable technologies for your home, such as:
- solar thermal panels
- heat pumps ( air to water, ground source or water source but excluding air to air and exhaust air heat pumps), and
- biomass boilers.
- Seasonal efficiency
The ratio of delivered useful energy relative to the input potential fuel energy determined over a full heating season (or year), taking into account the efficiency of the heating equipment and system.
- Underfloor heating
Underfloor heating and cooling is a form of central heating and cooling which achieves indoor climate control for thermal comfort using conduction, radiation and convection.