Electricity Prices

In Western Australia, electricity customers fall into two general categories.

1. Non-contestable customers

Non-contestable customers are customers within the South West Interconnected System (SWIS) who use less than or equivalent to 50 megawatt hours of electricity a year (MWh/a).

These customers are supplied by Synergy and pay capped tariff rates determined by the State Government under electricity by laws.

Residential households (including permanent caravan park residents) and small businesses usually fall within this category.

2. Contestable customers

Contestable customer types include:

• small to medium businesses
• large businesses
• regional and non-integrated grids.

Within SWIS

All customers within SWIS who consume more than 50 MWh/a (an average of 137 units a day) have a choice of electricity retailers and may negotiate the rates they pay with their chosen retailer.
Consumers who use more than 50 MWha/a and less than 160 MWh/a may choose between:

• paying the relevant capped tariff rates offered by Synergy that are prescribed under electricity by laws, or
• be supplied by Synergy or another retailer and negotiate the rates they pay.

Outside SWIS

There is no electricity consumption threshold for contestability that applies to customers outside the area served by the SWIS. This means that all customers outside of the SWIS are contestable and can choose their retailer. However, please be aware that there may not be any alternative retailers to Horizon Power servicing a particular region to allow for customer choice.

More information

Please visit the website of the Economic Regulation Authority for detailed information about choosing a retailer and entering into a contract with a retailer. 

Electricity prices determined by the State Government  

(Updated: 1 July 2011)

• Residential
• Community and charitable bodies
• Small to medium business
• Government
• Large business
• Regional non-integrated grids
• Street lighting  

---

Residential

Residential electricity tariff (non-contestable)

Tariff	Charges	Previous	From 1 July
A1	Supply charge - cents per day	38.23	40.14
	Supply charge for additional homes - cents per day	29.68	31.17
	Electricity charge - cents per unit*	20.83	21.87

* one unit equals one kilowatt hour (kWh)                                             Top of page

Residential hot water heating tariff (non-contestable)

Tariff	Charges	Previous	From July 1
B1	Supply charge - cents per day	19.81	20.80
	Supply charge for additional homes - cents per day	19.81	20.80
	Electricity charge - cents per unit*	10.94	11.49

* one unit equals one kilowatt hour (kWh)                                              Top of page

Combined Residential / Business tariff (non-contestable)

Tariff	Charges	Previous	From 1 July
K1	Supply charge - cents per day	38.23	40.14
	Electricity charge - cents per unit* for:
	First 20 units per day	20.83	21.87
	Between 21-1650 units per day	26.11	27.41
	More than 1650 units per day	23.57	24.75

* one unit equals one kilowatt hour (kWh)                                             Top of page

Community and charitable bodies

Community and charitable organisation tariff (non-contestable)

Tariff	Charges	Previous	From 1 July
C1	Supply charge - cents per day	34.91	36.66
	Electricity charge - cents per unit for:
	First 20 units per day	19.03	19.98
	Between 21-1650 units* per day	23.84	25.03
	More than 1650 units* per day	21.51	22.59

* one unit equals one kilowatt hour (kWh)                                              Top of page

Charitable organisation – Residential accommodation tariff
(non-contestable)

Tariff	Charges	Previous	From 1 July
D1	Supply charge - cents per day	34.91	36.66
	Supply charge for additional homes - cents per day	27.11	28.46
	Electricity charge - cents per unit*	19.03	19.98

* one unit equals one kilowatt hour (kWh)                                             Top of page

Small to medium business

Small / medium business time-of-use tariff (contestable)

Tariff	Charges	Previous	From 1 July
R3	Supply charge - dollar per day	$1.78	2.14
	Electricity charge - cents per unit* for:
	Peak charge rate	31.30	37.48
	Off-peak charge rate	9.64	11.54

* one unit equals one kilowatt hour (kWh)                                               Top of page

Small / medium business tariff (contestable)

Tariff	Charges	Previous	From 1 July
L3	Supply charge - cents per day	38.01	49.32
	Electricity charge - cents per unit* for:
	First 1650 units* per day	24.97	32.40
	More than 1650 units* per day	22.54	29.25

* one unit equals one kilowatt hour (kWh)                                              Top of page

Small business tariff (non-contestable)

Tariff	Charges	Previous	From 1 July
L1	Supply charge - cents per day	36.28	38.09
	Electricity charge - cents per unit* for:
	First 1650 units* per day	23.84	25.03
	More than 1650 units* per day	21.51	22.59

* one unit equals one kilowatt hour (kWh)                                            Top of page

Small business time-of-use tariff (contestable)

Tariff	Charges	Previous	From 1 July
R1	Supply charge - dollar per day	$1.49	1.56
	Electricity charge - cents per unit* for:
	Peak charge rate	26.11	27.41
	Off-peak charge rate	8.05	8.45

* one unit equals one kilowatt hour (kWh)                                              Top of page

Government

Commonwealth Government or Foreign Government instrumentalities

Tariff	Charges	Previous	From 1 July
P2	Supply charge - cents per day	44.80	58.13
	Electricity charge - cents per unit for:
	Electricity charge - cents per unit*	29.71	38.56

* one unit equals one kilowatt hour (kWh)                                               Top of page

Large business

Large business tariff (contestable)

Tariff	Charges	Previous	From 1 July
M1	Supply charge - cents per day	38.00	45.46
	Electricity charge - cents per unit* for:
	First 1650 units* per day	24.12	28.86
	More than 1650 units* per day	21.67	25.92

* one unit equals one kilowatt hour (kWh)                                             Top of page

Large business low-voltage tariff (contestable)

Tariff	Charges	Previous	From 1 July
S1	Supply charge - dollar per day	$356.10	400.71
	Electricity charge - cents per unit for:
	Peak charge rate	12.94	14.56
	Off-peak charge rate	8.18	9.21
	Demand charge - per day multiplied by (i) the on-peak half-hourly maximum demand; or (ii) 30% of the off-peak half hourly maximum demand; whichever is the greater	90.45	101.78

* one unit equals one kilowatt hour (kWh)                                             Top of page

Large business high-voltage tariff (contestable)

Tariff	Charges	Previous	From 1 July
T1	Supply charge - dollar per day	499.39	568.70
	Electricity charge - cents per unit for:
	Peak charge rate	12.86	14.65
	Off-peak charge rate	8.55	9.74
	Demand charge - per day multiplied by- (i) the on peak half-hourly maximum demand; or (ii) 30% on the off-peak half hourly maximum and; whichever is the greater	87.98	100.19

* one unit equals one kilowatt hour (kWh)                                              Top of page

Regional non-integrated grids

Regional non-integrated systems-cost of supply tariff-
Indexed on the Singapore Oil Price (contestable)

Tariff	Charges	Previous	From 1 July
N2	Supply charge - cents per day	31.31	31.31
	Electricity charge - cents per unit for:
	Indexed on Singapore Oil Price

* one unit equals one kilowatt hour (kWh)                                              Top of page

Street lighting

Traffic lighting tariff

Tariff	Charges	Previous	From 1 July
W1	Per day per kW of installed wattage	$     4.02	4.39

Street lighting tariff

Tariff	Charges	Previous	From 1 July
Z1	See chart in Tariff Z tab for detailed information

                                                                                                         Top of page