NBS | National Building Specification | Building services: Sustainable services and microgeneration

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Sustainable services and microgeneration

by Brian Ware
NBS Technical Author

Microgeneration refers to small scale systems that generate electricity and/ or heat for domestic dwellings. It is seen as a step towards decentralizing power generation, reducing fuel poverty and increasing the percentage of power generated from renewable or low carbon sources.

The types of microgeneration are:

Air source heat pumps: These absorb heat from outdoor air to heat buildings and warm domestic water. Three to four units of heat can be produced for every one unit of electricity needed to drive the pump
Bio-energy: This is generated from biomass (organic material) that absorbs CO₂ during its growth. This absorbed CO₂ offsets that released in burning. Hence, unlike fossil fuels, biomass is considered carbon neutral. Wood chips, pellets or logs tend to be the most usual form for most small scale schemes
Ground source heat pumps: These work by transferring heat from the ground and can be used to warm homes and buildings, and pre-heat domestic hot water. Like air source pumps, they can provide three to four units of heat for every one unit of electricity used by the pump
Solar photo-voltaic (PV): This generates electricity using energy from the sun
Solar thermal hot water: This uses solar energy directly, the sun's heat warming a series of solar panels which then heat up domestic water
Small scale hydro-electric: This turns the energy of moving water into electricity, using a turbine which is turned by the flow of water
Wind turbines: The wind turns a generator unit, which produces electricity
Combined heat and power (CHP): This produces heat and electricity at the same time
Fuel cells: These are electrochemical energy conversion devices. A fuel cell converts the chemicals hydrogen and oxygen into water and in the process produces electricity.

To be classed as microgeneration, the energy production levels should not exceed:

50 kilowatts in relation to the generation of electricity
45 kilowatts thermal in relation to the production of heat.

Microgeneration Certification Scheme (MCS)

In 2006 the Department for Business, Enterprise and Regulatory Reform (BERR) set up the Microgeneration Certification Scheme (MCS), designed to independently certify renewable energy technologies, microgeneration products and installers in accordance with documented standards.

The BERR MCS Scheme replaced the Clear Skies and PV programmes. Microgeneration products must be transferred and certified under the MCS Scheme by the end of December 2009 in order to be eligible when applying for grants, such as the 'Low Carbon Building Programme (LCBP) grant'.

The BBA offers the MCS Certification service to both product manufacturers and installers of solar heating collectors (thermal solar systems), solar PV (photovoltaics), micro and small wind turbines, heat pumps and biomass technologies. In addition, the BBA is offering the full Agrément Certificate process for all of these products. This includes important information not covered by the BERR scheme, such as regulatory compliance, durability, output performance, weatherproofing, structural stability and practicability of installation.

Product certification requires verification that the product complies with the technical requirements set out in the MCS Scheme documents, including compliance with relevant Standards and an assessment of the manufacturing process. Installer's certification requires an office audit to assess the competence of staff and to confirm that the necessary documentation and training is in place, and a witnessed installation of the microgeneration technology.

Low Carbon Buildings Programme (LCBP)

Following the Budget announcement on 22 April 2009 an additional £45 million has been allocated to the LCBP.

Phase one
This programme provides grants for the installation of microgeneration technologies in a range of building types - including housing and community facilities in public, private and non-profit sectors. Householders can apply for grants of up to £2,500 per property towards the cost of installing a certified product by a certified installer.

LCBP Phase One will receive an additional £10 million of funding to extend the current programme from July 2010 to April 2011. The new funding will continue to support household applications and technologies offered under the current scheme.

Phase two
This programme provides grants for the installation of microgeneration technologies in public sector and charitable buildings - including schools, hospitals and housing (for associations and local authorities) LCBP Phase Two has received an additional £35 million of funding. This sees the current programme deadline for grants to be made and installations to be completed extend from 1 July 2009 until April 2011.

Microgeneration technologies have the potential to make a significant contribution to our energy policy goals of tackling climate change, ensuring reliable energy supplies and tackling fuel poverty.