Renewable energy through micro-generation - Factsheet

Government defines micro-generation ‘as the production of heat and/or electricity on a small-scale from a low carbon source’. The various technologies have the potential to help industry achieve UK Government targets of tackling climate change, ensuring reliable energy and tackling fuel poverty (Source: Department of Trade and Industry).

Micro-energy systems may be connected to the national power grid in order to sell excess power back to the grid, but generally these systems are referred to as ‘Distributed Energy’ systems as they are not reliant on the national grid.

Types of micro-generation

A) Electricity generation technologies

Solar powered technologies or photovoltaic (PV) systems.
Micro turbines provide electricity, either powered by wind turbines or naturally flowing water (small hydro turbines).

B) Heat generation technologies

Solar thermal hot water provides hot-water supply through heating piped water.
Ground source heat pumps use energy stored in the ground for heating.
Air source heat pumps work in the same way as ground source heat pumps except that the source of the heat is the external ambient air.
Bioenergy is produced from biofuels (see ‘Biofuels’ factsheet) which come from crops such as sugar cane and beet, maize and energy grass or from fuel wood, charcoal, agricultural wastes and by-products, forestry residues, livestock manure and others.

C) Co-generation technologies

Hydrogen energy and fuel cells provide heat and electricity at a commercial level. They are currently being developed and are expected to emerge in the next few years.
Combined Heat and Power (CHP) uses waste heat (produced as a by-product of the electricity generation process) to produce electricity as well as heat.

Benefits of micro-generation

The Energy Saving Trust sees micro-generation as the only realistic option for cutting carbon dioxide emissions from energy generation for the mass market. It is argued that micro-generation brings a unique amount of key benefits:

Clean fuel
Handing power to people
Delivering energy to off the grid locations
Increasing security of supply and impunity from terrorist attack

Greenpeace highlight other reasons to focus on micro-generation:

67% of primary energy input is wasted in the current global centralised model of power generation
$2.7 trillion could be saved globally by 2030 through energy policies incorporating Devolved Energy and energy efficiency measures

UK Government targets

The Government aims to see renewables grow as a proportion of electricity supplies to 10% by 2010, with an intention for this level to double by 2020. Delivery of the government’s 2010 renewable energy targets will rely principally on large scale technologies already being deployed, notably large wind turbines. But delivery of 2020 targets will require a wider range of technologies.

The 2007 Energy White Paper (EWP) encourages investment in mass market micro-generation. Local communities will be encouraged to become producers, as well as consumers of energy which will increase their acceptance of larger scale renewable energy.

‘The Renewable Obligation and the Climate Change Levy exemption is projected to provide around £1billion of annual support for deployment of renewable electricity in 2010, rising to around £2billion of annual support in 2020. A strengthened EU ETS should also support investment in renewables.’ (Source: EWP).

What is the UK government doing to encourage micro-generation?

The UK Government is spending £80 million funding micro-generation grant schemes. This includes the low carbon buildings programme which provides grants towards installing micro-generation technologies.

Government is also encouraging local authority planning departments to adopt micro-generation targets for new buildings. (Source: Defra)

Some facts and figures provide a flavour:

At present the UK has over 1,700 wind turbines which have the capacity to produce 1,900 MW of electricity, enough to supply over 1 million homes. This corresponds to just over 1% of UK electricity supply. (Source: BWEA)
Progress has been made on solar use in the UK. However, the costs involved are unlikely to result in a notable contribution to the 2010 renewable energy target.
At the end of 2005 the total installed PV capacity in Germany was 1,429MWp, but the UK had only installed just 10.9MWp.
Hydro-electric power stations produce around 20 per cent of the world's electricity and they produce a high amount of power cheaply once the initial investment has been made. (Source: IGD)
Wave power generation is not a widely-employed technology with the world's first commercial wave farm being established in 2006, but it has great potential as setup costs are moderate, the energy source is free, and no waste is produced.
The future of geothermal energy (Ground Source Heat Pumps) looks encouraging; it is likely to be hindered by the significant investment required.
The Department of Trade and Industry estimates that by 2050, up to 30-40% of UK’s electricity generation could be produced by small and micro-generation technologies, including 6% from small wind energy generation.

Implementing micro-generation technology in the UK

Issues

Whilst 40% of national electricity demand is met by Decentralised Energy (DE) in the Netherlands, the UK uses very little micro-generation compared to other energy sources and currently only 4% of the UK energy production comes from renewable energy (Source: EWP).

There has been some criticism of a piecemeal approach to the investment in and development of micro-generation technologies in the UK. It is argued that boosting the market for renewable generation and related technologies should also stimulate the necessary innovation.

Food and Drink Industry Commitments

The following gives two examples; it is not intended to be a definitive list as there are many others:

Marks and Spencer is aiming to reduce the amount of energy it uses to make the company 25% more energy efficient. M&S is also committed to powering stores with ‘green’ renewable energy - this will include trialling the use of ‘anaerobic digestion’ with waste coming from M&S food halls, farms and factories.
Tesco has set aside £100 million to spend on sustainable development technologies. Projects to date include a Tesco petrol filling station which has a solar roof made up of 96 photovoltaic panels. This generates around 12,500 units of clean electricity every year, enough to power 4 three-bedroom houses, make 600,000 slices of toast or do 5,500 loads of washing. Through generating its own clean electricity, Tesco’s petrol filling station will prevent 5.5 tonnes of greenhouse gas emissions being released into the atmosphere each year. (source: Solarcentury).

Initiatives in other sectors

Between October and Christmas 2006 the UK home improvement company B&Q started selling micro wind turbines the stores sold 1,500 units, becoming the top-selling item in cash terms as homeowners were apparently persuaded by subsidies, high energy bills and the green cachet to invest in the £1,498 turbines.

In 2007, the company has announced its intentions to move its focus to water efficiency, offering products to recycle ‘grey water’ from washing up to use in the garden. Other retailers including Curry's, part of DSG International, have started selling solar panels, both for heating water and for electricity generation.

Other success stories

The ‘Merton rule’ is the groundbreaking planning policy, pioneered by the London Borough of Merton. Requires developers to ensure at least 10% of all energy production for new development comes from renewable energy equipment on site.

Woking Borough Council has installed almost 10% of the total solar panels (photovoltaic cells) in Britain. It is one of the first councils to sign up to the London Mayor's energy strategy, which calls for a 20% reduction of carbon dioxide emissions by 2010 (based on 1990 levels) and a 60% cut by 2050 (relative to 2000 levels) in London.

Mayor Livingstone is aiming for at least one zero-carbon development in every London borough by 2010, and wants London to try to generate enough electricity and heat to for more than 100,000 homes and 10,000 homes respectively.