Presentation on theme: "Woodfuel opportunities in Oxfordshire 5 August 2012 Matthew Woodcock Forestry Commission – South East England."— Presentation transcript:
Woodfuel opportunities in Oxfordshire 5 August 2012 Matthew Woodcock Forestry Commission – South East England
Woodfuel opportunities in Oxfordshire 2 South east England Woodland - Background Undermanaged mixed (conifer/broadleaf) woodland planted in the 1950s Typical broadleaved woodland of south east England – overstood coppice last cut > 40 years ago Also ancient woodland with high ecological value – declining through under-management
Woodfuel opportunities in Oxfordshire 3 Our energy culture Didcot Power Station Were used to the convenience of energy from large scale power stations Yet the overall efficiency in converting solid fuels into usable power is low (around 30-35%) – all the steam going up the cooling towers is wasted energy! On the continent powerstations are often smaller and the heat is circulated around the community via district heating mains (just as we have gas mains)
Woodfuel opportunities in Oxfordshire 4 The case for woodland management Pearl–bordered fritillary populations 1970-1982 Population 1992-1995 Decline due to lack of active management maintaining the diversity of woodland habitat this, and many other native woodland species, require
Woodfuel opportunities in Oxfordshire 5 Woodland cover
Woodfuel opportunities in Oxfordshire 6 A vision for Oxfordshires woods? Active management of coppice with standards woodland Impacts of management
Woodfuel opportunities in Oxfordshire 7 Maintaining our history
Woodfuel opportunities in Oxfordshire 8 Potential for sustainable production? Traditional broadleaved trees like beech and oak can grow at 4m 3 per ha per year Conifers like Scots pine can grow at > 8m 3 per ha per year Traditional coppice species like sweet chestnut and ash can grow at > 6m 3 per ha per year
Woodfuel opportunities in Oxfordshire 9 Potential production from Oxfordshire Non FC Woods ha Est YC m 3 /ha/ yr m 3 per yrFrom 75% of woods Proportion of sawlogs Proportion of woodfuel Prop. Of Slabwood Energy of Wf MWh/yr Conifer89987,2005,400 3,2002,2001,6003,900 Broadleaved10,643442,60031,900 3,20028,7001,60071,800 Mixed (* 3 )2,683616,20012,100 7,2004,9003,60010,600 Coppice (* 8 )0600 0000 Coppice with standards (* 8 )0600 0000 Windblow (* 4 )0400 0000 Felled (* 4 )854300200 0 0400 Open space3,286 00 0000 TOTAL 17,606 66,30049,50013,60035,9006,800 86,700 FC Woods haEst YC m 3 per yr Assume all is managed Sawlogs Woodfuel Slabwood MWh/yr Conifer262102,600 1,5001,1007001,800 Broadleaved1244500 50450201,100 Mixed24361,500 9006004001,300 Coppice060 0000 Coppice with standards060 0000 Windblow040 000 Felled040 0000 Open space0 0 0000 TOTAL (* 2 )629 4,6002,4502,1501,120 4,200
Woodfuel opportunities in Oxfordshire 10 Assumptions * 1 includes all woods of < 2 ha * 2 Area of FC woodland will have been reduced by sales during this period so area of non FC woods could be slightly greater. * 3 Assume 60% broadleaves by area and 40% conifer by area – on basis that most mixed crops will be > 40 years old and well into their thinning regime to establish a final crop of broadleaves * 4 Assume windblown and felled areas will be restocked with broadleaves *5 Estimate that 25% of all woods will not be actively harvested due to owners preference or site difficulties *6 Estimate that 60% of conifer and mixed crops, and 10% of broadleaf growing resource could be used as sawlogs *7 Estimate that there is a 50% conversion rate of saw logs into sawn timber, hence 50% of the sawlog volume will be slabwood or sawdust and hence potential woodfuel *8 Traditionally many of the broadleaved woods in SEE would have been managed as coppice, or as coppice with standards, whereby the stems were felled every 7 (hazel) to 15 (sweet chestnut) years and then allowed to regrow from the cut stump. Having the well established root stock effectively supporting regrowth the growth rates of coppiced woods are significantly higher in their early years than would be possible from newly planted trees. Our ancestors found that this was the most effective way to produce the fuel and building material they needed. I have used an estimated growth rate of 6 m3 per ha per year to balance between hazel where the volumetric growth rates appear to be lower (no-one to my knowledge has done any research on this as hazel has traditionally been used for the hurdle and thatching market) and where we break the estimate down to counties I have dropped the estimated growth rate for Hampshire coppice to 2 m3 per ha per year as a good proportion of Hampshire coppice is hazel). At the other end of the spectrum sweet chestnut on a 15 year rotation will deliver 8 m3 per ha per year BUT if the rotation is extended to 20-25 years this increases to up to 12 m3 per ha per year. However, we should also remember that sweet chestnut coppice can be converted into a whole range of products - spile fencing, cleft fencing, even faggots for flood defence but having a use for the lower quality elements and offcuts is essential to make the whole business work. This principle of increased average growth rates by extending coppice rotations to 20-25 years is likely to hold true for all major broadleaved coppice species such as ash and hornbeam. Overall traditional coppice management appears to offer considerable opportunites for woodfuel production - just as our ancestors found! *9 Assumes wood is seasoned to 30% moisture content (as a proportion of overall weight), broadleaves deliver 2,500kWhrs per m 3, conifers 1,800kWh per m 3 and mixed crops 2,200kWh's per m 3. Again figures are conservative as oak and beech will manage 2,800 and 2,700kWh per m 3 respectively but poplar and willow will deliver about 1,800kWh's per m 3
Woodfuel opportunities in Oxfordshire 11 Heating oil at 60 pence per litre Provides 10kWhrs per litre Cost = 6 pence per kWhr Seasoned beech (30% MC) Provides 2,800 kWhrs per m 3 Matched against oil = > £160 per m 3 OR the cost of heating oil to deliver the same heat as the 35,900m 3 of wood which could be sustainably produced from 75% of Oxfordshires existing woods is about £5million per year! OR enough to heat about 6,000 homes Potential opportunity?
Woodfuel opportunities in Oxfordshire 12 Existing markets: timber and wood VerdoSloughBedmax
Woodfuel opportunities in Oxfordshire 13 Medium scale CHP BAA – Heathrow T2
Woodfuel opportunities in Oxfordshire 14 Small scale CCHP Waitrose
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