The Withington Estate - Regensw
The Withington Estate – biomass district heating system Alastair Stevens MSc GradEI Severn Wye Energy Agency
Withington Estate – before biomass • Cotswolds grassland estate – 300ha – 100ha of own managed woodland
• Manor house, pool, plus 8 tenant cottages – Heated by 7 separate oil-fired boilers
• High running and maintenance costs • Landlord attended site visit to Austria to learn about biomass systems
Withington Estate – the process • Coming together of ideas – Make use of own resources: woodland thinning – Simplify maintenance and management – Reduce exposure to oil price volatility – Reduce environmental footprint
• Extensive research on technical options, local supply chain, economics and funding
Withington Estate – the system • • • •
220 kW Fröling wood chip boiler (Austria) Integrated 16t fuel bunker, in existing building 5,000 litre buffer tank, 435 MWh annual demand Small district heating network (329m pipe length) – Direct flow system, no hydraulic interface units – Flow rate adjusted by control valves (problematic) – Tenants have heat meters and are billed on usage
• Oil backup boiler connected to heat main – immersion DHW backup in cottages
Withington Estate – the partners • Withington Estate – landowner, landlord, specifier, customer to equipment and fuel suppliers, seller of metered heat to on-site tenants, machinery ring participant (formerly), woodland manager, wood fuel processor • Roundwood supplier – providing locally-sourced logs to agreed spec, for on-site chipping by the estate, to supplement own arisings.
Withington Estate – the partners • Local chip supplier – single load purchased annually, to maintain backup supply relationship and for sampling purposes (to benchmark the estate’s self-supplied chip) • Tenants – customers of metered biomass heat, incorporated into tenancy agreement. Prices oil-indexed (to 95% of heating oil price) and adjusted on quarter days • UK distributor – sole importer and distributor of Fröling boilers, providing a turnkey installation and support (assisted by manufacturer)
Withington Estate – photos Log stacking to enable seasoning (up to 18 months) before transport & chipping into main fuel storage barn
Withington Estate – photos Wood chip storage barn, holding up to 150 tonnes of chip (approx 1 year of consumption)
Withington Estate – photos Wood chip bunker with agitator (left)
Withington Estate – photos Main boiler area showing heat circuit expansion vessel and ash cart
Withington Estate – photos
Heat meter (above) Flue and thermal store (right)
Withington Estate – economics • Payback time estimated at 6 years – Installation was grant supported – Not eligible for RHI (installed 2007)
• System installed now would attract RHI payment of around £17,000/year for 435MWh of metered output – Similar payback time achievable now
Any Questions? Alastair Stevens – Project Manager Severn Wye Energy Agency Gloucestershire [email protected]
Withington Estate – before biomass • Cotswolds grassland estate – 300ha – 100ha of own managed woodland
• Manor house, pool, plus 8 tenant cottages – Heated by 7 separate oil-fired boilers
• High running and maintenance costs • Landlord attended site visit to Austria to learn about biomass systems
Withington Estate – the process • Coming together of ideas – Make use of own resources: woodland thinning – Simplify maintenance and management – Reduce exposure to oil price volatility – Reduce environmental footprint
• Extensive research on technical options, local supply chain, economics and funding
Withington Estate – the system • • • •
220 kW Fröling wood chip boiler (Austria) Integrated 16t fuel bunker, in existing building 5,000 litre buffer tank, 435 MWh annual demand Small district heating network (329m pipe length) – Direct flow system, no hydraulic interface units – Flow rate adjusted by control valves (problematic) – Tenants have heat meters and are billed on usage
• Oil backup boiler connected to heat main – immersion DHW backup in cottages
Withington Estate – the partners • Withington Estate – landowner, landlord, specifier, customer to equipment and fuel suppliers, seller of metered heat to on-site tenants, machinery ring participant (formerly), woodland manager, wood fuel processor • Roundwood supplier – providing locally-sourced logs to agreed spec, for on-site chipping by the estate, to supplement own arisings.
Withington Estate – the partners • Local chip supplier – single load purchased annually, to maintain backup supply relationship and for sampling purposes (to benchmark the estate’s self-supplied chip) • Tenants – customers of metered biomass heat, incorporated into tenancy agreement. Prices oil-indexed (to 95% of heating oil price) and adjusted on quarter days • UK distributor – sole importer and distributor of Fröling boilers, providing a turnkey installation and support (assisted by manufacturer)
Withington Estate – photos Log stacking to enable seasoning (up to 18 months) before transport & chipping into main fuel storage barn
Withington Estate – photos Wood chip storage barn, holding up to 150 tonnes of chip (approx 1 year of consumption)
Withington Estate – photos Wood chip bunker with agitator (left)
Withington Estate – photos Main boiler area showing heat circuit expansion vessel and ash cart
Withington Estate – photos
Heat meter (above) Flue and thermal store (right)
Withington Estate – economics • Payback time estimated at 6 years – Installation was grant supported – Not eligible for RHI (installed 2007)
• System installed now would attract RHI payment of around £17,000/year for 435MWh of metered output – Similar payback time achievable now
Any Questions? Alastair Stevens – Project Manager Severn Wye Energy Agency Gloucestershire [email protected]
