Energy and Water Efficiency Case Studies

Medium Sized Home

LWood_System

Figure 1 –Seasonal electricity demand for the existing house, with suggested improvements and compare to a newly built, energy efficient home.

Figure 2 – Break-down of electrical energy including standby energy.

Figure 3 – Potential improvement by replacing major appliances and reducing standby power.

Your Appliance Energy Use Better Appliance Energy Use Reduction in Daily Demand
Fridge/Freezer 450L 2.67 kW h/d 1.3 kW h/d 1.37 kW h/d
Dishwasher 2.224 kW/use 0.62 kW/use 0.69 kW/use
Clothes Dryer 0.985 kW/use 0.56 kW/use 0.18 kW/use
Standby 0.64 kW h/d Use of power boards or replacement
with less than 1W standby power
appliances
0.4 kW h/d

Figure 4 – Comparison of Electricity Use before and after energy efficient target changes

End Use Breakdown Previoius Energy Use (kW h/d) Percent (%) Energy Effecient Target (kW h/d)
Lighting 0.71 2.5 0.71
Refigeration 4.72 16.6 1.30
Water Heating 6.56 23.0 1.30
Space Heating 0.03 0.1 0.03
Space Cooling 0.31 1.1 0.31
Water Pumping 11.07 38.9 5.54
Kitechen 2.35 8.3 2.08
Entertainment /
Communication
1.38 4.9 0.98
Cleaning 1.06 3.7 0.82
Tools 0.00 0.0 0.00
Other 0.26 0.9 0.26
TOTAL 28.47 100.0 13.34

List of changes and suggested priority order

  • Investigate more efficient water pumping technology and management strategies – expensive but worthwile.
  • Install Solar Water Heater
  • Buy and install power boards to reduce standby – easy and cheap to do.
  • Insulate the roof – realtively expensive – improved comfort year round, particularly during extreme weather events.
  • Replace fridge/freezers – reduce to one fridge/freezer and upgrade to a more efficient model when replacement is due.
  • Replace dishwasher and clothes dryer when required.

 

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