1. How to Reduce Home Energy Bills? Some practical actions
Alan Pears AM
Senior Industry Fellow RMIT University
Bayside Climate Change Action Group
30 May 2018
Air conditioners in Krosnoyarsk, Siberia
Hottest month average top 25C, min 14C

2. What do we use energy for?

3. Residential: Technology transformation (Based on Pears presentation to Sydney A2SE Workshop, April 2014) NOTE: For 2-3 people, total annual cost around $3,000 of which annual electricity fixed charges up to $450, gas $350. Greenhouse gases around 12 tonnes carbon dioxide for 10,000 kilowatt-hours (Victoria)
Many households are also installing on-site and local renewable energy generation and smart management systems – and storage
Building
+ equipment

4. Energy rating website: www.energyrating.gov.au
Choose appliance features to see a list of options on market in order of efficiency
Appliance efficiency programs are saving an Australian household up to $400 each year on energy bills. Product lists are at and an ‘app’ is now available. Labelled products include:
* Air conditioners
* TVs, computer monitors * fridges and freezers, * dishwashers, * clothes washers, * clothes dryers * voluntary labels on pool filter pumps
Voluntary gas appliances

5. Heat flows – uninsulated house on timber floor
INSULATION cuts heat flow by 60 to 90% through roof, walls, floor.
SUMMER
WINTER

6. Residential building energy performance –driven by mandatory standards and simple rating scheme As building envelope performance improves, energy requirement for heating declines dramatically – but cooling has increased! NOTE: these are thermal energy flows, ignoring equipment efficiencies. Energy levels vary for different climate zones
Legal minimum in many countries
2011 building code
2005 building code
This slide highlights the significant improvements in residential building thermal efficiency we are achieving – if we enforce present building code requirements. But it also shows we can make significant further improvements if we catch up with world leaders. I’ve just come back from China where I looked at a new housing development with all windows double glazed and other features that put them ahead of us on performance.
Typical 1990s home
Many pre- 1990s homes

7. Blower door tests can also identify air leaks

8. Watts per square metre of glazing
Unshaded 1.5 square metre window = single bar radiator
* Assumes drapes have effective air seal – see next slide
Watts per square metre of glazing

9. Filler strip fitted to curtain brackets to fill gap

10. Air Leakage (source: Sustainability Victoria)
Do you leave some windows open? On windy days they can lose OR gain a lot of heat!
Vented light fittings
If central heating, 1 airchange/hour loses approx 2 kW, costs approx $ per year – well-sealed home has 0.5 airchanges/hour.
Many homes have 2 or more airchanges/hour

11. Heating Options Ducted Heating and Cooling
If internal doors are closed, air from outlets can’t get back to return air duct, so it leaks from the house
A reverse cycle air-conditioner is an economical heater too! Similar or cheaper than gas space heater and much cheaper than ducted heating

12. Other heating and cooling tips
Personal comfort
Electric throw rugs – 1-5 cents/hour
Low power radiant panel for under desk or warm feet
Appropriate clothing
For summer, personal fans
Protect thermostat from draughts
For ducted or hydronic heating – keep heat away from windows, uninsulated walls to cut energy costs by 5-15% due to higher temperature and air movement
Air deflectors
Insulating panels behind hydronic heating panels

13. How long are your showers?
An extra minute per day per person of showering costs $15-20/year extra.
For 3 people, each showering 3 minutes longer each day, extra annual cost $
A water-efficient shower saves ~40% on showering hot water cost
Hot Water
If using 3+-star water- efficient showerhead, exhaust fan should NOT be above shower cubicle, and should be switched separately from room light
Most mixer taps waste hot water – unless you move the lever to ‘hard right’
Cold air from room is drawn over wet body, evaporating water and cooling your lower body!
Rinsing dishes under running hot water 10 minutes/day adds $90-$130 annually

14. Home Energy Scorecard https://www. victorianenergysaver. vic. gov

15.
You can explore energy and lifestyle options and their impacts

16. https://liveability.com.au/
Also

17. Energy use 2-door fridge/freezers models (Class 5) available at March 2018 (from – each extra star saves 23% on lower star rating energy use
Typical 2-door early 1990s fridge: 1100 kWh - $325/year
Many older fridges are faulty, using up to 3 times rated energy!
Energy label re-scaled in 2000 and 2009 – 5 stars in 1990s now = 1.5 stars
Typical Victorian fridge in existing homes:
2000: 715 kWh
2005: 655
2010: 585
2015: 535
5-star saves 54% compared with 2 star – over 15 years saves ~ $1200
Best 460L fridge 260 kWh – at 30c/kWh that’s $78/year
Star rating based on energy use per litre of storage

18. Buy efficient appliances – eg TVs: wide range of energy use for each size Data from ‘available’ products as at 23 March 2018 Note some TVs (especially internet connected) may have standby power 5 to 30 watts for part of time: check they have automatic ‘sleep’ mode
Each extra star saves 20%
Dimming screen brightness can save energy
For ‘background noise’ use a radio or small, high efficiency TV
Add-on sound systems can use a lot of energy
New rating scale April 2013: 9 star now 6 star
10 hours/day
Old 100 cm flat screen 10h/day
Star rating based on energy consumption per square centimetre of screen area

19. Evolution of computer energy use….
Desktop – watts
Laptop 5-45 watts
Tablet ~4 watts
Computer monitors now carry energy labels
Dimming screens saves energy
Enable energy saving options

20. THE END – Q&A