Biomass Jargon Buster

Glossary of Terms/Jargon Buster including commonly used acronyms in the renewable industry

Accreditation - The process by which an installation becomes certified to receive the RHI

Accumulator Tank - Also known as a buffer tank, this is a large tank of water used as an energy store and would normally sit between the heat source (boiler) and the heat demand (radiators etc). Not normally required in a single domestic installation, unless log gasification or wood chip is being used as fuel, or primitive or old fashioned wood pellet boilers are being installed.

Air Source - A shortening of air source heat pump, where energy is extracted from refrigerant which is pumped around pipes that are exposed to outside air - the opposite to an air conditioning system in that heat is produced.

Anaerobic digestion - A biological process where bacteria break down organic matter under oxygen-free conditions to produce a biogas containing methane.

Back-end protection - A boiler protection system consisting of a series of temperature control valves fitted between the flow and return of a boiler unit, to ensure that the water being returned to the boiler from the heating system emitter (radiators etc) is not so cold that it would damage the boiler upon entry, by causing "thermal shock".

Biomass - Biological material derived from living or recently living organisms. From a heating perspective this is generally wood, wood pellets, wood chip or energy crops.

Biomass heating - A heating system that uses biomass fuel. In the domestic market this is generally wood pellets but can also be wood logs or wood chip.

BTU - British Thermal Units. A traditional unit of energy based upon the ability to heat 1 pound of water to 1o F. Many older UK boilers were sized in BTUs (3414 BTUs = 1kW).

Buffer Tank - See accumulator tank.

Capacity - The maximum power output.

Carbon Trust - A government funded organisation to promote carbon reduction in business and the public sector.

CERT - The carbon emissions reduction target programme of the UK government (formerly called EEC - the energy efficiency commitment).

Clean Energy Cashback - The term for the government schemes to encourage renewable generation of heat and electricity - the RHI and the FIT (feed in tariff).

Climate Change Levy - A tax on energy delivered to non-domestic users in the UK, Introduced in 2001.

CHP - Combined Heat and power - A plant designed to produce both heat and electricity from a single source.

Combustion efficiency - The calculations, in percentage terms, of how well equipment is burning a specific fuel.

Commissioning - The completion of procedures and tests in order to determine whether an installation is suitable, capable and safe for operation.

DEA - A domestic energy assessor, who is certified to undertake and EPC (energy performance certificate) on your property

DECC - The Department of Energy and Climate Change of the UK government.

DUKES - The digest of UK energy statistics.

Energy crops - Crops grown specifically for their fuel value.

Energy efficiency - Programmes that reduce energy consumption whilst maintaining a given level of output.

Energy mix - The distribution or proportion of different energy resources within the total energy supply.

Energy resources - Everything which could be used as a source of energy.

Energy savings trust - Government organisation to promote energy efficiency.

Energy security - The extent to which a nation's energy supplies are robust against potential disruption, including factors such as depletion of natural resources.

EPC - Energy Performance Certificate - This must be produced by a qualified DEA (district energy assessor) or GDA (green deal assessor). This is the document which shows the energy in kWhours "deemed" to be required annually by your property in order to provide heat and hot water. This is a key document when it comes to calculating what the RHI would be worth to you.

Evacuated Tube - In a solar thermal collector, an absorber tube contained in a glass cylinder, through which collector liquid flows.

FIT - Feed in Tariff - An incentive scheme designed to promote the generation of renewable electricity production via long term index linked payments. Launched in April 2010, payment rates vary depending on type and size of technology employed and, are subject to periodic review.

Flue - Where an existing chimney cannot be used, a flue must be used for biomass - see also twin walled flue.

Fossil fuels - Irreplaceable forms of fuel used for most heating applications in the UK, currently these include natural gas, coal and oil.

Gasification systems - these systems use high temperatures and an oxygen starved environment to convert biomass into "syntheses gas" - a mixture of hydrogen and carbon monoxide. The syntheses gas or "syngas" can then be chemically converted into other fuel or products.

GDA - (i) Green Deal Assessment - An assessment of your property that evaluates the energy efficiency of the fabric of your property and the way you use it. It will include an EPC. You have to have one of these carried out in order to get the RHI (ii) - a Green Deal Assessor - a person qualified to carry out a Green Deal Assessment.

Gemserve - The UK government quango that operates and administrates the MCS scheme.

Geothermal - Originating from or produced by the internal heat of the earth.

Greenhouse gas - The main greenhouse gas of concern, due to global warming, is carbon dioxide. Others include methane, ozone, chlorofluorocarbons (cfcs) and nitrous oxide.

Ground source - A shortening of ground source heat pump, where geothermal energy is extracted from refrigerant which is pumped around pipes dug into the ground.

Igniters - These are the electric heat source which actually set the wood pellets in your boiler's burner bowl alight when the boiler first fires up. These are like an oversized car cigarette lighter. For most boilers they are deemed a consumable and will need changing periodically.

Kilowatt (kW) - A unit of power equal to a thousand units. Energy installations are often rated by their maximum power output in kW.

kW hours (kWh) - A measure of total energy produced, one kWh being also known as a unit of electricity. A boiler of 25kW rating, running at full power for one hour will produce 25kWh of heat.

Log gasification - A process with a specifically designed boiler unit, where wood logs are burned at extremely high temperatures and the gas produced by this process is harnessed to generate heat. Log gasification boilers are normally not suitable for domestic use, except in rural settings and for "hardy hands on people", as they require manual loading and cleaning pretty much on a daily basis during cold weather and peak periods.

LPG - Liquid petroleum gas, used as a fuel for domestic heating.

Microgeneration - The generation of heat or power on a small scale, typically for domestic use and by methods that do not contribute to the depletion of natural resources, such as biomass and solar.

MCS - An industry-funded assurance scheme to ensure the quality of renewable technology installations, companies and products. The use of MCS products and installers is mandatory in order to qualify for the domestic RHI and for commercial installations of 45kW or less.

Miscanthus - An energy crop, also known as elephant grass. It is one of the front runners in the search for a commercially viable biomass crop in the UK

Ofgem - The UK government quango that operates and administers the RHI schemes.

Off Peak - Periods of relatively low system demands.

Payback - The length of time it takes for the savings received to cover the cost of implementing the technology

Peak - Periods of relatively high system demands.

Pellet store - A structure capable of holding significant amounts of wood pellets, in an environment to protect them from damp, to maintain their quality prior to being used as a boiler fuel

PV - Photovoltaic cells. These are an electronic device capable of turning sunlight into electricity.

rdSAP - A reduced (rd) version of SAP which is the methodology behind the ECP.

REA - The Renewable Energy Association.

RECC - The Renewable Energy Consumer Code to which all MCS companies must subscribe.

Renewable Energy - Energy derived from renewable sources such as biomass, solar and ground source and air source heat pumps.

Renewable Energy Directive - A set of stringent renewable targets for 2020 across the EU. This 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.

RHI - The renewable heat incentive. The UK government's incentive for the generation of renewable heat. The RHI (Phase 1 commercial) opened to applications in November 2011 and the RHI (Phase 2 domestic) opened in April 2014. The scheme is managed by DECC but administered by Ofgem.v

RHPP - Renewable Heat Premium Payment - a government incentive scheme that came to an end in Spring 14 as the domestic RHI replaced it.

SAP - Standard Assessment Procedure - a systemised method used to assess a dwelling's energy performance.

Solar Thermal - This is a technology for harnessing solar power via thermal collector panels and in a domestic setting is generally used to help heat domestic hot water or pre-load a thermal store.

Syngas - A syntheses gas produced through the gasification of biomass in a gasification boiler.

Thermal Store - This is a tank of water used within the renewables industry, as a way of storing collected energy until it is ready for use. Different from a buffer tank in that a domestic thermal store is not normally required for the technology to work but, is installed by choice, as a way of combining different heat sources into one heating system or of capturing otherwise wasted heat. For example, a thermal store supplies heat for both domestic heating and domestic hot water and could have inputs from multiple sources i.e solar thermal panels, a wood stove with a back boiler and a biomass boiler.

Twinwall flue - This is a steel flue which is insulated by having an inner lining inside an outer wall (hence twinwall). Where an existing chimney cannot be used, a twinwall flue must be used for biomass installations - in fact, Building Regulations dictate and demand that the highest quality of laser welded twinwall flue must be used.

Woodchip - A form of biomass fuel made by chipping wood into small enough pieces to be used in a wood chip boiler. The fuel must also be dried to achieve pre-determined levels of moisture content prior to use. Wood chip boilers are not normally suited to a purely domestic application, as the fuel is difficult to handle and needs large storage areas and careful control of moisture levels.

Wood Pellets - The most common form of domestic biomass fuel, wood pellets are made by compressing sawdust into small pellets that look a lot like horse nuts, they are pure and no chemicals or glue are used in their production because the naturally occurring lignite from the wood is enough to bind them together.


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