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    Module SPG8017

    Introduction to Bioenergy and Photovoltaics

    Module Leader: Dr Paul Bilsborrow

    SPG8017 ? Copyright University of Newcastle

Module SPG8017

    Module Outline

    Units Content

    1 Biomass and biofuel resources, policy and potential contribution to EU

    and UK renewable energy targets (PB)

    2 Biomass heat and CHP technologies, economics and environmental

     benefits (PB) stnd3 Biofuels 1 and 2 generation technologies, economics and

     environmental benefits (PB and DR)

    4 Solar resources (NP)

    5 PV cell, module and system design manufacture and performance


    6 PV applications and implementation, economics and environmental

     benefits (NP)

Staff members

    PB Paul Bilsborrow School of Agriculture Food and Rural Development (AFRD) DR Dermot Roddy Sir Joseph Swann Institute

    NP- Nicola Pearsall Northumbria University

    Intended Knowledge Outcomes

    On successful completion of this module students will be able to: ; Appreciate the potential of biomass and photovoltaics to contribute to

    renewable energy production and reductions in CO. 2

    ; Identify the policy drivers at an International, National and Regional level

    relating to renewable energy especially biomass and photovoltaics. ; Evaluate the barriers to uptake of biomass and photovoltaics as a renewable

    energy sources.

    ; Identify the range of biomass resources available for energy production. ; Understand the solar resources available for energy production. ; Evaluate a range of technologies available for energy production from biomass

    and appreciate the potential for future reduction in costs through technological


    ; Evaluate a range of applications of photovoltaics and appreciate the potential

    for future reduction in costs of photovoltaic systems through technological


    ; Analyse the economics of energy production from biomass and photovoltaics

    when compared with fossil fuels and other sources of renewable energy.

    Intended Skills Outcomes

    ; Illustrate an understanding of theoretical concepts and practical

    implementation associated with engineering systems and processes in

    renewable energy systems.

    ; Identification of problems, production and appraisal of solutions for biomass

    and PV engineering systems.

    ; Cognitive skills identify and utilise data associated with generation and

    energy conversion systems

    UNIT 1

    Biomass resources and policy


    1.0 What is biomass

    1.1 Biomass Resources

    1.2 UK biomass resources

    1.3 UK/EU Energy Policy

    1.4 Potential for biomass contributing to UK and regional energy targets

    1.5 The case for biomass

    1.6 Existing and Future Biomass Projects

Unit Learning outcomes:

    ; Identify the policy drivers at an International, National and Regional

    level relating to renewable energy and biomass

    ; Identify the range of biomass resources available for energy production.

    ; Appreciate the contribution that biomass makes to UK energy production

    both currently and in the future

1.0 What is biomass

    Biomass is anything derived from plant or animal matter including agricultural, forestry wastes/residues and energy crops, biodegradable fraction of industrial and municipal waste.

    Wastes animal waste, food waste, horticultural waste, sewage sludge, municipal solid waste (MSW) etc.

    Can be used for fuel directly, by burning or extraction of combustible materials. Biomass can be differentiated in terms of woody and non-woody.

1.1 Biomass Resources

Woody biomass:

    ; Forestry residues e.g. small branches and tree tops that are usually left on the

    ground when trees are felled and can provide an alternative source of income

    from forestry.

    ; Small round wood as a result of its size the wood is unsuitable for traditional

    uses (such as structural timber, furniture or pallet making). Offers great

    potential as a feedstock for heat and power generation. At present used for

    making paper and various kinds of board.

    ; Industrial wood e.g. sawmill residues, furniture manufacturing waste etc

    (much of which at present is sent to landfill). The use of sawmill residues

    would be in direct competition with its already existing use in chipboard


    ; Energy crops which are specifically grown for heat and electricity production

    e.g. short-rotation coppice (SRC) species like willow and poplar together with

    herbaceous species such as miscanthus and switch grass. The Common

    Agricultural Policy (CAP) regime has resulted in over production of

    agricultural food products across Europe and an increasing cost of agricultural

    support. Policy changes (generally taken the form of quotas and set-aside)

    have been introduced to limit food production and reduce the cost of the


    ; Municipal arisings of a woody nature (from local councils) of which generally

    70% will be unsuitable for energy use but can be composted while the other

    30% could be used to produce energy.


Non woody biomass:

    ; Agricultural residues including straw and animal slurries/manures

    ; Food waste

    ; Sewage sludge following digestion, some gas from which is used to maintain

    optimum temperature for digestion while remainder can be used in combined

    heat and power (CHP) systems.

    ; Organic solid waste (MSW) that can be used to produce energy. As European

    and UK legislation aims to encourage less polluting methods of waste disposal

    a viable option is to burn the waste to generate power. There were 24 waste

    to-energy plants in operation in the UK in 2003 burning unprocessed MSW

    and pelleted RDF (refuse derived fuel produced following separation drying

    and densification). Waste to energy usually involves the process of

    incineration and the associated public perceptions of this technology.

    ; Crop by-products e.g. palm kernels, olive residues etc (used in a number of

    power stations see Unit 2)

1.2 UK biomass resources

    The DTI have estimated the exploitable energy available from biomass sources in the UK to be 316TWh/yr comprising: 31% from energy crops, 35% from residues, 9% from waste vegetable oils and 32% from MSW.

    The Carbon Trust estimates the current biomass availability from forestry crops, waste wood, dry agricultural residue and wood energy crops of 41 TWh/yr which could be increased to 80 TWh/yr. This 80 TWh/yr represents 3% of the UK’s total 2700 energy consumption in 2003


    The Forestry Commission suggest that there is 3.1 M odt/yr of wood derived fuel annually available in UK (forestry materials, sawmill co-products, municipal arisings and energy crops but not straw) equivalent to 440 MWe (assuming efficiency of 20% in an electricity only plant). The same amount of fuel would produce 1400MWth of heat (assuming 85% efficiency).

    Fig 1.1 Wood fuel distribution for England (source: Forestry Commission)

    At present only 40% of the annual increment in England’s woodlands is harvested and utilised within existing markets. There exists considerable potential to increase the supply of biomass from woodland. In their report A Woodfuel Strategy for England by the Forestry Commission (2007) a target was set to bring an additional 2M tonnes of material to market by 2020 which represents 50% of the estimated un-harvested material available in English woodlands.

    In the North-east (Fig 1.1) there are over 100,000 hectares of woodland covering 12% of the land area. Woodland cover is not spread evenly across the region with the bulk of it (78%) being in Northumberland where it is characterised by mainly large coniferous plantations. With the exception of Kielder Forest, the region’s woodland cover is generally fragmented and geographically widely scattered among many thousands of individual woodland blocks. Forestry Commission statistical data suggest that only 38% of the regions available timber resource is harvested annually with the remaining 62% being largely in the private sector consisting of small broadleaved farm woodlands, coniferous shelter belts and some larger coniferous woodland. Over half of the woodland in the NE is owned or leased by the Forestry Commission with an annual production of in excess of 400,000 tonnes per annum. In addition the privately managed woodlands at present contribute about 100,000 tonnes per annum to the regional output but the exploitation of small private woodlands for timber is very much governed by economics with very few markets available. In the North East the Forestry Commission has identified unmanaged woodland that could support the production of an additional 100,000 tonnes of wood per annum (with 50% of this being targeted for energy production). The promotion of this material for energy production would hopefully lead to greater utilisation of this valuable resource. The forestry industry would benefit from increased biomass demand which would make thinning more economically viable. There are large areas of NE forests which at present are not economic to thin which results in lower productivity and quality.

    Forestry and woodland management activities produce a large amount of material suitable for conversion into energy. Although this material can provide a source of nutrients when decomposing on the forest floor the thinning of woodlands is an essential part of sustainable woodland management. Small diameter woodland thinings which generally make up most of the crop are if utilised generally directed to low-value end markets (e.g. woodchip) and only command a price of about ?20/t (yet are ideally suited to wood chip production for fuel, and are easy to stack, handle and dry).

    There exists considerable potential for energy generation from waste streams e.g. animal, food, horticultural, sewage sludge and MSW for which a variety of methodologies and technologies exist. At present only ~25 Mt of residual MSW (remaining material once the recycled and composted elements of MSW have been removed) is used for energy recovery annually, accounting for approximately 0.4% of the UK’s current electricity consumption. In theory by 2020 residual MSW could

    account for up to 17% of total UK electrical consumption assuming that the theoretical absolute maximum electrical yield for the residual MSW is fully utilised (Oakdene Hollins Ltd 2005 ‘Quantification of the Potential Energy from Residuals in

    the UK’, report for ICE and RPA). In 2001 there was 32M tonnes of MSW produced

    in the UK (Table 1.1) with 19M tonnes of this representing the bio-organic component which could theoretically produce 65TWh or 19% of UK electricity consumption in 2004. By 2020 the amount of biodegradable waste sent to landfill sites must be reduced by 35% of 1995 levels (UK Waste Strategy 2005).

    Table 1.1 Estimated potential biomass feedstock available in the UK

    32 MT of MSW per annum (19 M of which is bio-organic matter, rest consisting of plastics, metal, glass etc)

    122 MT of construction and demolition waste which includes some 6M tonnes of waste wood from construction and demolition industries

    2 MT dry weight of sewage sludge

    150 MT of animal manure and slurry

    3.4 MT of chicken litter

    1 MT of food residues

    24 MT of agricultural residues straw, husks etc

    10MT of garden waste

    Of the MSW collected in the UK 9% is burned to generate energy, 17% is recycled and 74% is sent to landfill (New Civil Engineer 2006). Austria, Germany and the Netherlands all recycle >50% of their MSW and in Germany, France, Luxembourg Sweden, Belgium, Denmark and the Netherlands>20% of MSW is used to generate energy (Fig 2). In Denmark >50% of MSW is used for energy generation.


    MSW Management in Europe (2003)










    Fig 2. MSW management and use in Europe 2003 (source: Eurostats Energy, Transport and Environment Indicators)

    By 2020 the government want to increase the amount of municipal waste burned from 9% to 27%. Incineration reduces the volume of waste solids by up to 90% with 40% of this able to be recycled and used in road building or breeze-block production.

    There are currently 12 energy from waste sites in operation in England and Wales although 22 local authorities have plans to build incinerators as the battle to find alternatives to increasingly expensive landfill increases. There have been large reductions in emissions from incinerators in the UK since the 1990’s and in particular that of dioxins. Energy from Waste is partly carbon neutral but is responsible for 1.6% of UK CO emissions. 2

    Sheffield City Council have operated a scheme for 30 years but the old plant is now being replaced with a new one handling 220,000 t of MSW pa, providing 21MW of electricity to the national grid and 60MW of heat to a district heating scheme. Planning permission was also granted in July 2006 for UK largest incinerator at Belvedere in South London.

1.3 UK/EU Energy Policy

a) Carbon dioxide

    At the 1992 Earth Summit the United Kingdom became one of more than 150 nation signatories to the Framework Convention on Climate Change. The UK made a commitment in 1997 according to the Kyoto Protocol to reducing CO emissions by 2

    12.5% below 1990 levels by 2012 with a national goal (EWP) to reductions of 60% by 2050. The 2050 target will be dependent on a significant expansion in renewable energy generation. Government is likely to make the 2012 target, largely as a result of the switch to gas from coal electricity generation (although in recent times with increasing gas prices there has been a switch back to coal with evidence of increasing CO concentrations). 2

    The Energy White Paper (2003) suggests that these cuts can be achieved through a combination of renewable energy and increased energy efficiency. It is predicted that UK carbon dioxide emissions will amount to some 135 MtC in 2020 such that cuts of 15-25MtC are required to meet targets by 2020 and to be on course for reductions of 60% by 2050 (EWP, 2003).

b) Renewable electricity

    The UK Government’s renewables policy is to stimulate the development of

    renewable energy sources, wherever they have prospects of being economically attractive and environmentally acceptable in order to contribute to diverse, secure and sustainable energy supplies and reduction in the emission of pollutants including greenhouse gases, carbon dioxide and methane.

    The Energy White Paper (2003) sets a target for 10% of electricity production from renewables by 2010 (DTI suggests that 7-8% is more likely) with an aspiration to 20 % by 2020. To meet this and future targets a broad range of renewable energy resources is required and to avoid a monostructural use of renewable energies that bring about the danger of supply problems due to generation fluctuations e.g. wind energy.

    In the UK the contribution of renewables to electricity generation is low of the order of about 3% when compared with other EU countries (Table 1.2) with large increases required if the target of 10% of electricity generation from renewables by 2010.

    Table 1.2 Renewables share in power consumption in European countries in 2002 (Ringel 2005 Renewable Energy, p1-17).

Austria 66%

    Denmark 19%

    Finland 23%

    Germany 8.1%

    Portugal 21%

    Sweden 47%

    UK 3%

c) Transport fuels

    There are both EU and UK targets for biofuels (see Unit 3) which can be derived from stpurposely grown agricultural crops via 1 generation technologies or from resources ndcovered in this unit via 2 generation technologies.

1.4 Potential for biomass contributing to UK/regional energy targets

    Can biomass make a significant contribution to carbon dioxide and renewable energy targets?

    Yes - based on the evidence from other European countries such as Austria and Sweden (Table 1.2) and according to the Renewables Innovation Review (2004) (Fig 1.3).

    Biomass is the largest renewable energy contributor to total UK electricity supply and in early 2008 this amounted to 1.55% (BERR 2008). In 2006 biomass represented 82% of renewable energy used in the UK (wind 8.2%, large hydro 8%, small hydro 0.9% and geothermal 0.9%) and of this:

    33.1% from landfill gas

    18.7% from co-firing

    4.5% from sewage gas

    4.6% from domestic wood

    1.8% from industrial wood

    11.6% from waste combustion

    7.7% from other fuels

    There is considerably greater potential for energy generation from landfill. In Europe alone landfill has the potential to generate as much as 94 billion cubic metres of methane each year. Yet according to the European Commission’s energy directorate only about 1% of this is being trapped. The remainder is burnt off to prevent a build up of dangerous quantities of flammable gas. As well as wasting energy burning off methane pumps pollutants into the atmosphere caused by impurities in the methane

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