Low Energy Building Design Group B

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Low Energy Building DesignGroup B
Embedded Generation
Romain Jauffres, Karen Kennedy, Pedro Ros Zuazua,
Ulrich Sanson
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Presentation

• Introduction Project and Building
• Base Case Results
• Demand
• Supply
• Initial Matching Procedure
• Initial Conclusions
• Demand Minimisation
• Power and Energy Storage
• Final Conclusions
• Questions

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
3
Introduction The Aim

• To establish if demand side management can
  facilitate the embedding of renewable
  technologies in buildings,

• Our project
• We have focused on a residential building type
  similar to perhaps a hostel or student
  accommodation,
• The building scenario is unconstrained as
  regards renewable potential,
• We will utilise the simulation programme ESP-r
  to establish our demand profiles and then
  quantify how design changes affect those
  profiles.

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Introduction Building

• The building accommodates 16 people in Winter
  and 52 in the summer, it consists of 16 bedrooms
  with en-suite and has a communal Lounge, Library
  and Kitchen,
• As it is a residential building it will be
  predominantly occupied between 5pm and 9am, with
  some residents returning during the day.

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results

• The base case results are simulated using
  standard building constructions and utilising
  Scottish climate data

• Initial Demand Profiles
• Heating loads
• Hot water
• Lighting
• Small power

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial demand

• Heating Loads Winter

Average Load 3.61 kW/h
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial demand

• Heating Loads Summer

Average Load 0.83kW
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial demand
Hot Water Loads
Average Load Summer 0.105kW Winter 0.03 kW
Volume of Hot Water Required (m3)
Summer 31.72
Winter 9.76
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial Demand
Lighting Loads
Winter Average Load 0.73 kW
Summer Average Load 0.68 kW
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial Demand
Small Power Loads
Winter Average Demand 0.65 kW
Summer Average Demand 1.28 kW
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial supply
Solar thermal
Heat (kW) Average Supply (kW/hr) Duration of Day
June 34.26 13.08 0500-2100
Oct/Feb 12.71 2.87 0800-1800
December 3.86 0.61 0900-1700
Based on a Collector Area of 200m2
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial supply
Photovoltaics
Peak Power (kW) Average Power (kW/hr) Duration of Day
June 16.64 6.35 0500-2100
Oct/Feb 6.17 1.40 0800-1800
December 1.87 0.30 0900-1700
Based on a Collector Area of 200m2
Using Data from the CIBSE Guide
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial supply
Wind daily analysis Ducted wind turbines 40 0.5m
diameter turbines 20 1m diameter turbines
Summer
Winter
Avg supply
0.5m diameter 0.10
1m diameter 0.20
Avg supply
0.5m diameter 0.21
1m diameter 0.41
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial supply
Wind daily analysis Stand alone wind turbines
Winter
Summer
Avg supply
2m diameter 0.04
4m diameter 0.22
6m diameter 0.32
Avg supply
2m diameter 0.07
4m diameter 0.29
6m diameter 0.66
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial supply
Wind monthly analysis For a 6m diameter turbine
operating at 20m height For a 4m diameter turbine
operating at 13m height For a 2m diameter turbine
operating at 10m height
Avg supply
2m diameter 0.15
4m diameter 3.42
6m diameter 16.26
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Base Case Results Initial supply
Ground source heating

• A 12 kW ground Source Heat Pump (GSHP) is
  embedded in our building. (Coefficient of
  Performance COP 3)
• Advantages of this technology for our building
• Reliable (temperature of the ground is constant)
• Constant supply profiles for space heating
• Suitable for heating and for cooling

Main disadvantage of this technology for our
building Heat pump needs to be powered with
electrical energy and therefore this increases
the electrical power load during utilisation.
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Initial Matching
Summer
  Average Demand (kW)   Average Supply (kW)
Hot water 0.105 Solar thermal 13.08
Heating 0.83 Ground source heating as required
Lighting 0.68 Photovoltaic 6.35
Small Power 1.28 Wind ducted 0.2
    stand alone 0.32
Winter
  Average Demand (kW)   Average Supply (kW)
Hot water 0.03 Solar thermal 0.61
Heating 3.61 Ground source heating as required
Lighting 0.73 Photovoltaic 0.3
Small Power 0.65 Wind ducted 0.41
    stand alone 0.66
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Initial Matching
Mismatched graph
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Initial Matching
Mismatched graph
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Initial Matching
Mismatched graph
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Initial conclusions

• From our initial profiles, supply and demands,
  there is no one suitable technology for our
  scenario, i.e. some technologies are out of phase
  completely and others are not reliable power
  sources,
• We feel that the best way to move forward is
• to reduce the building demands by altering the
  construction and introducing more control, for
  example,
• to identify demands which can be potentially
  moved to more appropriate times to match supply,
• to establish efficient methods of storing heat
  and power.

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Matching Procedure

• Our matching Criteria
• When does the load occur?
• Does the load have to occur at this time or at
  all?
• Will shifting/removing the load reduce the
  peaks?
• When can we shift the load to? Will this create
  another Peak?
• Does this make the demand profiles match the
  supply profile better?

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Demand minimisation

• Which demand can be reduced?
• Heating loads by altering the design of the model
• Lighting by adding a control system taking into
  account the natural daylight and room occupancy

• Moving demands?
• Because the building is residential, the
  potential for displacing loads is quite limited,
• Some possibilities are
• Limiting times when laundry can be done,
• Staggering cooking times.

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Demand minimisation
Design changes Heating
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Demand minimisation
Construction design changes Heating
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Demand minimisation
Control design changes for Heating
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Demand minimisation
Control design changes for Heating
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Demand minimisation
Lighting To make maximum use of daylight, light
is now controlled No change for winter
significant reduction for summer
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Supply
Matching Supply Sources to Demand Profiles
Required (kWh) Ground Source Heating (kWh)
Weekdays 87.00 97.5
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
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Power and Energy Storage
We embedded a lead acid battery of 50kWh
capacity to store energy at least for 1 day

    Summer Winter
Total Power Demands   30.85 kW 15.5 kW
Total lighting demands   16.4 kW 17.5 kW
TOTAL   47.25 kW 33 kW
  Volumetric Specific Heat Capacity (kJ/Km3) Energy Stored in 1m3, ?T 60 C (kWh)
Rock 2140 35667
Water 4180 69667
Water tank with external heat exchanger
efficiency is up to 80
In order to use the Ground Source Heat Pump at
the most suitable time during the day (9am to
5pm) we decided to store thermal energy in a
sensible heat storage a water tank. Due to a
high specific heat (4180 J/kg.K, Rock is 794
J/kg.K), water is easy to use for heat exchanges
and is able to store heat for some hours with a
good heat-storage-to-volume ratio (10 kWh/m3,
Rock is 4kWh/m3).
Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson
31
Final Conclusions

• The use of energy from renewable sources for our
  model is limited
• Combination of ground source heating and solar
  thermal is the most appropriate combinations,
• Wind may meet our power demands, however it is
  not a reliable supply,
• The use of embedded generation in our case would
  make sense only if this use is combined with
  effective and efficient storage means.
• By using demand side management throughout our
  project we feel that we have been able to
  minimise demands where possible, however due to
  the nature of our building it has not been
  possible to establish a definitive match with any
  of the supply profiles.

Group B Romain Jauffres, Karen Kennedy, Pedro
Ros Zuazua, Ulrich Sanson