Assessing the Feasibility of CHP for New Hospitals

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Assessing the Feasibility of CHP for New Hospitals

• Jonathan Williams
• Sustainable Development

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Scope of the presentation

• Energy Policy Framework in the future
• CHP
• the potential benefits
• Factors for CHP to be applicable
• Example analysis for new build hospital
• Energy demands
• Plant selection and sizing
• Economic return
• CO2 savings
• Potential for renewable CHP in the future

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Building a low-carbon economy

• Climate Change Committee
• Independent advice to Government
• Responsible for carbon budgets
• Building a low carbon economy
• 1 December 2008
• UK contribution to tackling Climate Change
• CCC Recommendations on 2050 target
• 80 reduction in GHG by 2050
• First 3 legally binding carbon budgets
• Long term decarbonisation of grid

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80 Reduction in Greenhouse Gas Emissions
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Zero Carbon New Buildings

• New Buildings
• Homes from 2016
• Non-domestic Buildings 2019
• Progressive improvements in Building Regulations
• 2010 non-domestic buildings 25 better than 2006
  in aggregate terms
• Allowable solutions

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Zero Carbon New Buildings
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Health Service Targets

• Reduce Primary Energy consumption by 15
• Base year 2000
• Saving Carbon, Improving Health
• Reducing 2007 Carbon Footprint by 10 by 2015
• New hospitals 35-55 GJ/100m3

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What is CHP?

• Combined heat and
• power (CHP) is the
• simultaneous
• generation of usable
• heat and power
• (usually electricity) in
• a single process.

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The Primary Energy Efficiency of CHP
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Benefits of CHP

• Carbon Savings
• Help to meet national targets
• Regulatory compliance
• E.g. Building Regulations
• Energy Cost Savings
• More resources available for front line services

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CHP in the Health Service

• Overall CHP in the UK
• 7 of UK electricity
• 1,439 Schemes
• 5,469MWe
• Further Potential
• Buildings
• Commercial, Public Sector Res.
• 987 Schemes
• 344 MWe
• Health Sector
• 187 Schemes
• 124 MWe
• Potential for another 150MWe?

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Factors for CHP to be applicable

• Significant and extended thermal load profile
• No heat load no case for CHP
• Other Important factors
• Significant and extended electrical load profile
• Or opportunity to export
• Compatibility between temperatures of CHP heat
  and heating system
• Ability of local distribution network to
  accommodate embedded generation
• Ability of CHP technology to save primary energy
• Carbon savings will be influenced by fuel
  consumed and displaced

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Will there be a heat load for CHP to supply?

• Building Regulations continue to be tightened
• Minimum back stop values regularly improved
• U-Values
• Air-tightness
• Therefore, space heating demand will be lower
• Domestic hot water load remains
• Could serve other buildings through community
  heating

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Hospital Heating Consumption
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Hospital Heating Consumption
Significant domestic hot water load will remain
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Example of Feasibility Study for New Hospital

• 85,000m2 Floor Area
• 500 new beds
• Natural gas fired CHP

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Hospital heating consumption
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Hospital electricity consumption
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Hospital cooling consumption
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CHP systems examined

• Range of CHP Engine Sizes
• 500kWe to 2MWe
• Reciprocating gas engines
• Natural Gas fuelled

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Internal Rate of Return (IRR) for different size
CHP


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IRR for different size CHP with CCL exemption


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IRR for different size CHP with CCL exemption


Will there be a Climate Change Levy? Will a new
carbon levy incentivise CHP?
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Fuel price sensitivity analysis


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Sizing CHP to the heat load


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Sizing CHP to the heat load
Base Load


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Sizing CHP to the heat load
Average Load
Base Load


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Electricity supplied by the 1MWe CHP


All electricity used on-site
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Cooling supplied by absorption chillers


Cooling supply for the 1MWe CHP
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Carbon dioxide savings for different CHP sizes


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Carbon Savings for Natural Gas CHP

• Highly dependent on carbon factor for displaced
  electricity
• Grid Average Now
• Grid Average in the Future
• Power station using the same fuel e.g. gas power
  station for gas CHP
• New 2010 Building Regulations Consultation
• Electricity Carbon Factor 0.591kgCO2/kWh
• Climate Change Committee vision to decarbonise
  grid

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Will grid electricity be decarbonised in the
future?

• Major plank of CCC Vision
• Decarbonisation of grid electricity
• Wind and Nuclear
• Other Renewable and Carbon Capture and Storage
  (CCS)
• Circa 300gCO2 / kWh by 2020
• 40 reduction over 2006
• Less than 100gCO2 / kWh by 2030

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Renewable CHP

• As grid decarbonises, e.g. post 2020, will need
  to use renewable fuels in CHP
• Incentives
• Feed-in Tariff (FiT) for up to 5MWe Renewable CHP
• BUT technologies tend to be unproven
• OR not applicable
• Steam turbines used at much larger scale
• 10 times the size of CHP typically used in
  hospitals

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Wood Gas CHP

• Gasification of biomass
• Gas engine
• Innovative but unproven
• How will they perform?

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Biodiesel CHP

• Carbon Intensity of fuel
• Competition for fuel from Renewable Transport
  Fuel Obligation (RTFO)
• Liquid fuels wear out engine quicker

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Organic Rankine Cycle

• Biomass Fuel
• Heat used to drive ORC
• Working fluid has very low boiling point
• Low temperature sources
• Relatively low electrical efficiency
• Examples in Germany

Image ADORATEC
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Summary

• Significant heat load for domestic hot water will
  remain
• Gas CHP can play a part in short/medium term
• Government vision to decarbonise grid electricity
• Longer term, renewable fuels will need to be used
  for CHP