Hampshire County Council

Buildings, Land and Procurement Panel Item 12

11 July 2006

CHP and Biodiesel

Report by the Director of Property, Business and Regulatory Services

How the conclusion in this report fits with the Corporate Strategy

This scheme will impact on the delivery of the following Corporate Aims

Aim 2 - stewardship of the environment - by reviewing opportunities for alternative forms of energy

1

Introduction

1.1

In earlier meetings, Panel members have requested that a report on Combined Heat and Power (CHP) and Biodiesel be brought forward. This report concentrates on the practical issues of developing these workstreams. The Director of Environment is working on a paper on similar issues and the broader policy framework.

1.2

This report highlights the potential advantages and disadvantages of using CHP, Biodiesel and bioheating oil, and proposes opportunities where these could be used at County Council premises. The report proposes that further work be completed to investigate the viability of using these alternative forms of energy.

2

Summary

2.1

Combined heat and power (CHP) is the name given to the process whereby electricity is generated and the heat output from the plant as a result of this generation is put to use rather than being dissipated to atmosphere.

2.2

CHP, also know as cogeneration, can be classed a macro CHP, mini CHP or micro CHP depending on its scale. Macro CHP is substantial in size, normally serving a large geographical area of a town or industrial plant or business park.

2.3

The CHP plant generates electricity which is distributed to the commercial or industrial premises in the area. The waste heat from the generation process is circulated via a network of underground pipes to the premises where it can be used for a heating, the generation of domestic hot water or for process need as required. The West Quay area of Southampton has a macro CHP plant which provides electricity and hot water to a number of major buildings in the area.

2.4

Mini CHP is essentially a smaller scale version of a macro plant and usually serves either a single large building or small group of buildings. Typical examples would include a leisure centre and swimming pool, a group of office buildings (e.g. the Castle Complex in Winchester), or a small housing development. Micro CHP plants are of a very small scale, from a primary school down to a single domestic dwelling.

3

The Technology

3.1

CHP plant essentially comprises an alternator (to generate the electricity) a motor (to turn the alternator) and a number of electronic devices to ensure the power generated is compatible with that from the mains grid. The majority of CHP plant use some form of internal combustion engine as the motive force. These engines normally use natural gas or diesel as their fuel, although there are a number of gas fired turbine machines on the market.

4

Site Criteria

4.1

Not all sites or buildings are suitable for the application of CHP. For each kW of electricity generated approximately 2 kW of heat is released. For a site to be viable it should have a constant year round electrical load as well as a demand for the heat.

4.2

Many sites will meet one or other or both of these criteria at certain times of the year. For example in winter there will be a demand for heating in an office complex as well as a demand for electricity for computers, lighting and equipment. This demand will vary through the day as people use the buildings.

4.3

The same office site in summer will have no heating load, but will still have an electrical demand from the computers and equipment. It may also have air conditioning which will increase the electrical demand in summer.

4.4

In the example of the office complex outlined above, a CHP plant may well be viable in the winter if the heating loads and base electrical loads are compatible. In summer however when there is no heat demand the waste heat from the CHP plant would have to be dissipated to atmosphere and the viability of the plant is compromised.

4.5

For a leisure centre complex with a swimming pool the scenario is different as the base electrical and heating loads are more constant. During the hours of operation, which can extend to 16 hrs a day for some centres, there will be a constant demand for heat from showers, the pool water and the heating (even in summer most changing rooms are heated). The electrical load from lighting, equipment etc will be constant year round as most areas will be artificially lit. CHP in this application could therefore be viable for the whole of the year and therefore will make more economic sense that a plant fully utilised only in the winter.

4.6

There are a number of school campus' in Hampshire where there would appear to opportunities to exploit CHP. One of these is in Yateley where there is a community school, a junior school, an infant school and a library all on the same site. In addition two of the schools have swimming pools.

A feasibility study is currently being completed on the Yateley campus to establish the viability of the application of CHP to this site.

4.7

Often CHP can be utilized where a building houses an activity where there is a constant electrical demand coupled with a demand for the waste heat. In the commercial office environment these opportunities are rare and more often a permanent electrical demand is allied to the need to reject heat from the space, e.g. as in the case of an IT suite.

4.8

Most air conditioning systems use conventional vapour compression refrigeration systems to remove heat from the space. Vapour compression systems use electrical energy to drive the compressor. Absorption refrigeration systems work in a different manner to the vapour compression system in that they use heat as their primary energy to `drive' the refrigeration cycle.

4.9

Taking the example of the IT suite, a CHP plant providing electrical energy could power the IT equipment and the heat generated by the CHP plant could be utilised by an absorption refrigeration plant which would in turn be used to cool the suite. Whist in principal this arrangement would appear to make the best use of the waste heat from the CHP plant it is not so straightforward in practice.

4.10

There are number of CHP plants operating satisfactorily around the country producing power for a variety of applications. Absorption chillers are, however, much less used partly because of the capital cost (typically 15 to 20% more for absorption machines compared to air cooled direct expansion machines) of the equipment, but primarily due to the difficulty in setting up the plant and its subsequent operation.

5

Biodiesel

5.1

Biodiesel is diesel fuel derived from vegetable oil. The oil can include soya oil, palm oil or, as is the case in Europe, oil seed rape. It can also be produced by recycling waste vegetable oil used for cooking. The production of Biodiesel from oil seed rape is still very small scale in the UK although a major plant is under construction on Teesside and another planned on Humberside which between them will be able to supply almost 400m litres per year or approximately 2.75% of the UK diesel consumption.

5.2

In Europe the market is considerably larger with approximately 1.9m tonnes (1,900,000,000 litres) of Biodiesel produced in 2004 (approximately 0.8% of diesel consumption) amounting to 20% of the oil seed rape production in Europe. By 2010 the EU Biofuels Directive (2003) requires that 5.75% of diesel fuel is Biodiesel, rising to 20% by 2020.

5.3

This Directive is the driver behind the development of oil seed rape Biodiesel production in Europe and the UK. In France, Germany and Italy the Biodiesel market is substantially more developed than it is in the UK.

5.4

In theory, Biodiesel could be used as a direct replacement for mineral diesel. In practice, because of its slightly different physical properties which gives it a higher gelling temperature and a propensity to dissolve natural rubber compounds, it is added to mineral diesel to form a 5% mix by volume. All of the major vehicle manufacturers will accept a 5% mix without modifications to the engine and will honour all warranties.

5.5

As well as producing up to 50% less Carbon Monoxide and 60% fewer particulate emissions, Biodiesel is virtually free of sulphur and is almost carbon neutral (a reduction of 78% on a net lifecycle basis as CO₂ is recycled from the atmosphere not released from the carbon sequestered in mineral oil). It is also biodegradable and non - toxic.

5.6

The Biodiesel market in the UK is set to grow considerably over the course of the next few years to meet the EU Directive. It is unlikely that small scale production will be viable in the long run as major players enter the market. Of more interest could be growing oil seed rape for the production of bio heating oil and biomass.

6

Bio heating oil

6.1

Heating oil varies from Biodiesel in a number of ways, primarily; it is more viscous and has a greater calorific value. Biodiesel is not therefore a direct replacement for conventional heating oil. The technology does however exist to produce bio heating oil from raw vegetable oil and although it is marketed by a number of companies in the UK, its production is not as widespread as Biodiesel.

6.2

The production of bio heating oil could be an opportunity for the County Council, in partnership with the farming community in the South East, to develop a sustainable strategic supply chain for bio heating oil. The County Council uses approximately 3.5m litres of heating oil each year. This would require approximately 3500 hectares of land to grow sufficient oil seed rape to give this yield.

6.3

Any partnership or joint venture arrangement would need to be carefully drawn up in order to protect the County's fuel supply and ensure the farmers have a secure market for their crop. Further research needs to be undertaken to determine the economics of production of bio heating oil on this scale and whether it would be possible to establish a viable oil crushing and refining plant locally to serve the south east.

Recommendation(s)

That the Buildings, Land and Procurement Panel advises the Executive Member for Policy and Resources that:

1

The outcome of the feasibility study on the CHP study at Yateley is considered by BLPP at its meeting in October.

2

A feasibility study is undertaken for a CHP installation in the IT suite of the redevelopment of Ashburton Court.

3

Further investigation be carried out into the viability of bio heating oil production, in particular

a. the technical issues involved in bio heating oil production and biomass for fuel

b. the potential for growing sufficient oil seed rape

c. possible partnership and supply chain arrangements