Transcript Is Your Home Warm Enough Talk for Wellington City Eco

Energy efficiency in the home –
cost versus comfort
Christchurch Energy Awareness Week
Nigel Isaacs, BRANZ Ltd.
[email protected]
Phone (04) 238 1366
Cost vs. comfort




Will insulating my house save electricity?
Will a heat pump save electricity?
Does turning off the lights save energy?
Are halogen lights energy efficient?
 Answers from HEEP
 NZ wide study of energy use in houses
 Looked at fuels and services they provide
 www.branz.co.nz for more information
2
NZ Stationary Fuels & End-uses
LPG
2%
Nat Gas
9%
Electricity
69%
Heating
34%
Range
6%
Refrigeration
10%
Lights
8%
Solid Fuel
20%
Other
appliances
13%
Oil
0.1%
Hot Water
29%
Includes Electricity, Natural Gas, LPG, Coal & Wood (‘solid fuel’)
Source: HEEP Year 10
3
NZ Space heating energy
Net Heating by Fuel  HEEP gave NEW knowledge
 Wood & gas (55%) Electric (45%)
(Appliance efficiency [ ])
 Heat pumps
Solid Fuel
[Efficency=
60%]
45%





Electric
[100%]
32%
BIG change since HEEP finished
Christchurch ‘Clean Heat’ project
New electric load = new generation
Opportunity to heat & cool
Capital and running costs
 New houses warmer
Oil
[83%]
0%
Retic. Gas
[Efficiency
HEEP Year 10 report
LPG
[94%]
8%
Winter:
 Insulation = warmer & less energy
Summer:
 Design, operation, materials,
insulation
4
How do we heat?
 On Average




1 room
Evening heating
5.5 to 8.5 months of the year
1.7 fuel types
5
5
Impact of ‘Clean Heat’ Project?
Open fire or
Wood burner
Convert to
 Convert open fire or woodburner
Change in
Electricity Use  Use 1 yr before to 1 & 2 yr after
After
1 yr
After
2 yr
Heat pump
+2%
+1%
Solid Fuel
-2%
-5%
Pellet Fire
-3%
-4%
Gas
-7%
-10%
 No allowance for changes in





outside or outside temperature
People & their behaviour
House insulation
Other appliances (but very small)
Limited value to study
 Heat pumps = no less electricity
 Changes in way house heated?
 Now able to cool in summer?
 Convert from open fire ~2% less elect
Source: Impact of Environment
Canterbury’s Clean heat project  Previously under-heating?
 Greater comfort
on Christchurch electricity use
ECan/Meridian/Orion Nov. 2009
6
Temperature & Heater Power
Main heater type
Open fire
Portable Electric
Portable LPG
Fixed electric
Gas
Heat pump (elect)
Central gas
Enclosed wood
Avg. Temp
(°C)
16.0
16.9
17.1
17.8
18.0
18.0
18.3
18.9
 Not just fuel type
 Heater type important




Limit to heat output
Bigger = warmer home
Smaller = cooler home
Low efficiency = high pollution
 25% living rooms <16°C
 Unhealthy
 Especially for young & old
 Unflued Portable LPG
Winter = June to August; 5 pm to 11 pm
 Not healthy, add moisture
 Cheap to buy, costly to run
 Easy to control $
See: www.beaconpathway.co.nz
7
Non-heating Electricity
HUGE growth
potential
(~37% household energy, 460 W average)
Note: Excludes Domestic Hot Water & Space heating
Year 10
8
Lighting




~12% of electricity consumption
Important peak load
Many incandescent but changing
Large improvement with CFL and future
lighting technologies
 What drives lighting consumption?
 Floor area and number of occupants
9
Lighting Efficacy
– higher efficacy is better
Source: http://www1.eere.energy.gov/buildings/ssl/efficacy.html
See also: Buildings Energy Data Book - http://buildingsdatabook.eren.doe.gov/
10
Keeping Warm
 Will insulating my house save electricity?
 YES but only if you heat with electricity
 Can I save electricity and still have a healthy home?
 YES –thermal insulation, weatherstripping
 Switch from an fire to a heat pump?
 Open fire poor source of heat – may also use electricity to heat
 Heat pump adds ‘new’ (or no worse) electric load
 Efficient wood burners, LPG are viable alternatives
 Does turning off the lights save energy?
 YES – but only 8% of household energy (12% electricity)
 Are halogen lights energy efficient?
 NO – slightly higher efficiency incandescent bulbs
More information: www.branz.co.nz under ‘HEEP’
© BRANZ 2009
11