4. Technology parameters#

To model residential demand at the technology level, we include the following parameters for residential demand technologies:

Efficiency
Capital and maintenance costs
Asset lifetimes
Availability factors

These are detailed below and are carried forward from TIMES-NZ 2.0 assumptions.

4.1. Efficiency#

Efficiency is a measure of how much input energy is required for a unit of energy service demand output. For each end use, the implied units of energy service demand may be different, so efficiencies are often not comparable between use types.

Note that these efficiency assumptions apply to slightly different technology definitions than those used in the census heating disaggregation method. While efforts have been made to align the two sets, the figures in Table 48 are the actual assumptions applied to TIMES-NZ residential technologies.

Table 48 Residential technology efficiency by end use#
End Use	Technology	Fuel	Efficiency
Clothes Dryer	Clothes Dryer	Electricity	25%
Clothes Washers	Clothes Washers	Electricity	25%
Cooking	Cooking Appliances	Electricity	75%
	Cooking Appliances	LPG	40%
	Cooking Appliances	Natural Gas	40%
Dishwashers	Dishwashers	Electricity	25%
IT and Entertainment	Electronics	Electricity	90%
Lighting	Fluorescent	Electricity	68%
	Incandescent/Halogen	Electricity	15%
	LED	Electricity	95%
Miscellaneous	Electronics	Electricity	100%
Motive power	Internal Combustion Engine	Diesel	25%
Motive power	Internal Combustion Engine	Petrol	25%
Refrigeration	Refrigeration Systems	Electricity	180%
Space cooling	Heat Pump (for Cooling)	Electricity	345%
Space heating	Burner (Direct Heat)	LPG	80%
	Burner (Direct Heat)	Natural Gas	80%
	Burner (Direct Heat)	Wood	70%
	Coal Heaters	Coal	55%
	Ground source heat pump	Geothermal	40%
	Heat Pump (for Heating)	Electricity	375%
	Resistance Heater	Electricity	100%
Water heating	Burner, with Wetback	Wood	60%
	Gas Water Heater	LPG	80%
	Gas Water Heater	Natural Gas	80%
	Hot Water Cylinder	Electricity	100%
	Solar thermal hot water cylinder	Solar	60%

4.2. Lifetime assumptions#

Technologies that reach their technical lifetime are replaced in the model. We assume that currently existing stock has a uniformly distributed range of ages. These lifetimes are detailed below and have been carried forward from TIMES 2.0.

Table 49 Residential technology lifetime assumptions#
End Use	Technology	Fuel	Lifetime (years)
Clothes Dryer	Clothes Dryer	Electricity	15
Clothes Washers	Clothes Washers	Electricity	15
Cooking	Cooking Appliances	Electricity	13
	Cooking Appliances	LPG	13
	Cooking Appliances	Natural Gas	13
Dishwashers	Dishwashers	Electricity	15
IT and Entertainment	Electronics	Electricity	5
Lighting	Fluorescent	Electricity	5
	Incandescent/Halogen	Electricity	7
	LED	Electricity	1
Miscellaneous	Electronics	Electricity	14
Motive power	Internal Combustion Engine	Diesel	15
Motive power	Internal Combustion Engine	Petrol	15
Refrigeration	Refrigeration Systems	Electricity	18
Space cooling	Heat Pump (for Cooling)	Electricity	12
Space heating	Burner (Direct Heat)	LPG	20
	Burner (Direct Heat)	Natural Gas	20
	Burner (Direct Heat)	Wood	50
	Coal Heaters	Coal	50
	Ground source heat pump	Geothermal	20
	Heat Pump (for Heating)	Electricity	12
	Resistance Heater	Electricity	5
Water heating	Burner, with Wetback	Wood	50
	Gas Water Heater	LPG	20
	Gas Water Heater	Natural Gas	20
	Hot Water Cylinder	Electricity	20
	Solar thermal hot water cylinder	Solar	20

4.3. Availability factors#

Availability factors detail our assumptions on how often a particular technology might run to meet the energy service demand. These assumptions are detailed in Table 50. While the percentage share is the direct model input for TIMES, we include the implied average running hours per week for each technology. This impacts the relationship between capacity and output, as it might be more cost-effective to upgrade technology that is used more often.

Table 50 Availability factor assumptions#
End Use	Assumed weekly hours	Availability factor
Electronics	28	16.70%
Cooking	7	4.20%
Lighting	28	16.70%
Dishwashers	7	4.20%
Clothes Drying	1	0.60%
Clothes Washing	7	4.20%
Space Heating	13.8	8.20%
Water Heating	21	12.50%
Motive Power, Mobile	0.5	0.30%
Refrigeration	70	41.70%
Space Cooling	1.8	1.10%

4.4. Capital and operating costs#

Capital costs are from TIMES 2.0 and have been adjusted for inflation to 2023 dollars. Costs are listed specifically for technology at detached dwellings. If the cost is different for a joined dwelling, these are listed in parentheses. Some technologies do not include a capital cost. These are technologies that we assume can no longer be built, so capital costs are not relevant. Maintenance costs are included for natural gas technologies, as per TIMES 2.0.

Table 51 Capital and operating costs for residential service technologies (NZD 2023)#
End Use	Technology	Fuel	Capital cost NZD/kW		OPEX NZD/kW/year
			Detached	Joined
Clothes Dryer	Clothes Dryer	Electricity	2,045	2,045
Clothes Washers	Clothes Washers	Electricity	4,907	4,907
Cooking	Cooking Appliances	Electricity	553	553
	Cooking Appliances	LPG	430	430	184
	Cooking Appliances	Natural Gas	430	430	184
Dishwashers	Dishwashers	Electricity	3,243	3,243
IT and Entertainment	Electronics	Electricity	900	900
Lighting	Fluorescent	Electricity	1,444	1,444
	Incandescent/Halogen	Electricity	955	955
	LED	Electricity	1,410	1,410
Motive power	Internal Combustion Engine	Diesel	1,801	1,801
Motive power	Internal Combustion Engine	Petrol	1,801	1,801
Refrigeration	Refrigeration Systems	Electricity	4,028	4,028
Space cooling	Heat Pump (for Cooling)	Electricity	1105	841
Space heating	Burner (Direct Heat)	LPG	1548	991	184
	Burner (Direct Heat)	Natural Gas	1548	991	184
	Burner (Direct Heat)	Wood	458	NA[1]
	Coal Heaters	Coal
	Ground source heat pump	Geothermal
	Heat Pump (for Heating)	Electricity	685	863
	Resistance Heater	Electricity	29	29
Water heating	Burner, with Wetback	Wood
	Gas Water Heater	LPG	307	307	184
	Gas Water Heater	Natural Gas	307	307	184
	Hot Water Cylinder	Electricity	931	931
	Solar hot water cylinder	Solar	2,121	2,121