Dillington House 04 March 2008 Johnny Lewis
In a Nutshell? Johnny Lewis What can actually be achieved? • • • • •
Energy efficiency Low and zero carbon technology Persistence values Management and maintenance – ESCos? Viability/Feasibility?
Achieving Carbon Reductions Onsite
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Robert’s Pukka Buildings Bob wants to build to Code level 6…
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Energy Credits of the Code Dwelling Emission Rate
Performance Requirements
Credits
Mandatory Levels
% improvement DER over TER > 10%
1
> 14%
2
> 18%
3
> 22%
4
> 25%
5
> 31%
6
> 37%
7
> 44%
8
> 52%
9
> 60%
10
> 69%
11
> 79%
12
> 89%
13
> 100%
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Level 5
Zero Carbon
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Level 6
Achieving Carbon Reductions Onsite
Level 1
Level 2
Level 3
Level 4
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Energy credits of the Code
CO2 Baseline (kgCO2/yr) Appliances
kgCO2/yr
4000.00 3500.00
Pumps and fans
3000.00 2500.00
Lighting
2000.00
Hot water
1500.00 1000.00 500.00
Space Heating Secondary
0.00
Space Heating Primary Code Level 1-5
Code Level 6
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Energy credits of the Code
Carbon emissions breakdown for Code Level 1-5
Carbon emissions breakdown for Code Level 6
3% 15%
Space Heating Primary
26%
Space Heating Secondary
36%
41%
Hot water Lighting 6%
Pumps and fans 32%
Appliances
2%
9%
Achieving Carbon Reductions Onsite
10%
20%
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Energy Hierarchy Energy Efficiency • No minimum requirements for Code Level 1-5 apart from Part L limiting values • ‘Heat Loss Parameter’ < 0.8 W/m2K for Code 6 (2016 regs) Renewable Energy • onsite or building integrated renewable/ low carbon installations • offsite where connected by private wire • For mixed use schemes, electrical output to be allocated based on their relative energy consumption • Green tariffs not compliant Efficient Supply • communal heating / CHP most cost effective for Code Level 4 and above
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Energy Efficiency? 12-15% carbon savings from energy efficiency measures • Fabric insulation –U-values of 0.25W/m2K for walls, 0.15 for floors and 0.13 for roofs • Glazing Performance – U-values of 1.5 W/m2K, • Air permeability – 5 m3/m2/hr at 50Pa
15-20% carbon savings from energy efficiency measures • Fabric insulation –U-values of 0.13W/m2K for walls, 0.15 for floors and 0.11 for roofs • Glazing Performance – U-values of 1.2 W/m2K, • Air permeability – 1.5 m3/m2/hr at 50Pa • Ventilation – Mechanical ventilation with heat recovery (assumed 90% efficiency, SFP >1W/l/s) • Boiler Efficiency – 91%, SEDBUK ‘A’ rated condensing gas boiler 20-25% carbon savings from energy efficiency measures • Code 6 HLP of 0.8 • Reduced heat load = reduced feasibility for CHP etc.
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Energy Efficiency – Viability? • A Real Case Study
250 residential dwellings + 80,000sqm commercial CSH 6 for Resi in brief Developers invited to bid for land
• Code 6 Fabric Specification
Wall, floors and roofs – 0.1 Glazing 0.8 Air tightness of 1.5, MVHR 90% efficient
• Cost Uplift
£8,725/dwelling -£3m off the land value
• Is this feasible????
Ask the landowners…
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Robert’s Pukka Buildings Bob wants to build carbon neutral housing… • Bob’s QS says he can afford 12-15% savings
Walls = 0.2, Floors = 0.2, Roof = 0.15 Glazing = 1.6 Air tightness = 5
• Bob is currently scoring CSH 1 • What else can Bob do?
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Electricity • • • •
Wind Technology Solar PV Gas CHP Renewable CHP
Solid biofuel Liquid biodiesel Gaseous biofuel
• Hydro • Tidal + Wave
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Micro wind Benefits
Swift
• Sustainable signpost
Pitfalls • • • • • • • •
High capex High visual impact Low energy density Poor data for analysis Utilise conservative load factors Lifecycle carbon? O+M? Unlikely to achieve 10% in most cases
Proven
Ropatec
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Macro Wind Benefits • Capex • Ongoing business case?
Pitfalls • Proximity to dwellings • Appropriate siting • ROCs
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Solar Photovoltaics (PV) Benefits • Clean + silent • Aesthetically acceptable? • Modular • Long life – 25y+ • Low maintenance Pitfalls • High Capex • Inverter life – 5-10y • Low energy density • Many varying types • Poor design integration • Availability
Achieving Carbon Reductions Onsite
Solar Century
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Solar PV Other issues • RAB report – clear winner • Density issues avoided • ROC retirement? • ESCo delivery of PV??
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Gas CHP Benefits • Attractive investment model • Proven technology Pitfalls • Over-estimated CO2 savings • Limited carbon savings potential • Not renewable! • Requires community/district heating network Viability • ESCo?
Sales revenue, fuel costs, technology risk, salaries etc…
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Renewable CHP Benefits • Attractive investment model • Renewable Pitfalls • Offsite, really • Over-estimated CO2 savings • Requires community/district heating network • Fuel supply + catchment area • Technology risk for biomass particularly • Differing carbon factor for different fuels • Sustainability of fuels
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Biomass CHP Benefits • High carbon savings • Good use of waste heat • Fit into district systems Pitfalls • • • • • •
Technical risk Shortage of working examples Immature industry at small scale Wood supply at right price & quality Financial and management risk Market focus not buildings
Achieving Carbon Reductions Onsite
ESD – Talbotts unit
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Biomass CHP Technical Potential • 100kWe can deliver zero carbon for 265 residential units • Range of units 100 – 250 – 350kW, 2MW, 3.5MW • Combustion of wood • Gasification of wood
Wartsilla
Cost • ~£3000/kWe • extras for urban location
ESD - Biomass Engineering unit
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Emerging Technologies – Anaerobic Digestion
Bio energy village Juehnde, Germany
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Emerging Technologies – Anaerobic Digestion
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Heat • Solar thermal • Biomass heat • Heat pumps
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Solar Thermal Benefits • • • •
Mature technology Low maintenance Running cost savings Clean, silent, fits buildings
Pitfalls • Carbon savings limited to ~ 10% • Best for low rise residential • Incompatible with CHP
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Solar Thermal Technical Potential • • • •
Serves 50-60% DHW load 2-3m2 per house 10% carbon savings Evacuated tubes or flat plate
Cost • £2700/system • Approx £700/m2
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Biomass Boilers Benefits • Low capital cost for boiler • High carbon saving density • Mature technology Pitfalls • Extras – wood store, communal heating system • Immature fuel supply chains • Uncertain fuel costs • Air quality + delivery • Low revenue margins
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Biomass Boilers Technical Potential • • • • •
500kWth boiler for 170 apartments 2000+ running hours per year Aim for base load Basement store cheapest delivery Blowing system for pellets
Cost • • • •
Wood Energy
£100k for 500kWth boiler 10-15 year lifetime £85/ODT wood chips >£100/ODT pellets
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Biomass boiler images (200 – 300kW)
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Wood pellet delivery lorry
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Pellet delivery by blower
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Biomass supply
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Biomass supply
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Biomass supply
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ESCo Delivery of Biomass Viability? Business model for running system Sale of heat only? Fuel price risks? Fuel availability and provenance? FSC/Organic fuel? Land availability and food prices – Pigs?
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Ground and Air Source Heat Pumps Benefits • • • •
Low maintenance cost Replaces conventional heating system No deliveries or fuel storage Can be used for cooling
Pitfalls • Needs low temperature system • Integration with distribution tricky • Limited carbon savings – lots of boreholes • Needs space for boreholes or external condenser Achieving Carbon Reductions Onsite
Earth Energy
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Ground Source Heat Pumps Technical Potential • • • • •
5kWth system for a house 70m borehole Boreholes 5m apart Trench slinky alternative Install in a day
Cost • • • •
Approx £7000/system Prices rising Running costs similar to gas boiler Little payback if any
Achieving Carbon Reductions Onsite
Earth Energy
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Robert’s Pukka Buildings Bob wants to build carbon neutral housing… • Bob’s QS says he can afford 12-15% savings • Bob’s friendly planning officer says ‘Not on your nelly’ to:
large wind on aesthetics to anaerobic digestion on odour PV on aesthetics to liquid biofuels on sustainability to solid biofuels on air quality and transport concerns
• Bob’s QS says ok to solar thermal, and a little PV – Bob reaches CSH 3
The QS then value-engineers out the energy efficiency standards post-planning
• Bob achieves in practice CSH 2 – poor Bob!
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Planning, Persistence Values and O+M What is the best guarantee of long-term carbon savings? • Consider Planning Framework
Consider where the real teeth lie in planning requirements Ensuring accurate estimations of carbon savings in the first place Ensuring accurate estimation of technology performance
• Persistence value of carbon savings?
Commercialisation status of technology? Susceptibility to market forces?
• Operations and Maintenance
Consider eventualities beyond each application such as fuel availability, price, price of alternative fuel sources in future Price of maintenance contracts Replacement parts – e.g. inverters
• Off-site – the way forward, but only if carefully controlled Achieving Carbon Reductions Onsite
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Dillington House 04 March 2008 Johnny Lewis