This is a brief overview of the options available in WA for electricity supply. If you would like to know more follow this link click here
A1 Tariff           Smart Power               GreenPower            Photovoltaic (PV)
If you have difficulty in reducing your electricity consumption during day light hours Smart Power is not for you. The peak period cost is double the A1 tariff per unit (during daylight hours).
If you can adjust your lifestyle to consuming your electricity in the off peak period, Smart Power is a good option for you at about half the A1 tariff per unit between 9pm and 7am all year round.
A very interesting thing happens when Photovoltaic (PV) gets added to Smart Power. Synergy will pay at the same rate it charges (-GST), which means during Peak period Synergy will pay double the A1 tariff per unit for Smart Power. (When your PV is operating at its best).
A1 tariff and Smart Power are essentially about what sort of meter you have, where as GreenPower is about how much you wish to pay to assist in the development of renewable energy for a sustainable future. GreenPower can be applied to both A1 tariff and Smart Power.
Photovoltaic (PV) deals with both price and a sustainable future. If you look at the front page of your electricity bill you will see Average Daily Consumption in units (Kwh). If you  install 1Kw of PV on your roof it will produce an Average daily output of 6 units per day. 
Presume for this exercise your bill is about 18 units per day and you have installed 3Kw so you produce 18 units per day with your system. This should now prevent you from receiving further electricity bills. This is based on the A1 tariff, and if you are thrifty with your consumption, and have Smart Power, you should  receive payments back from Synergy. PV’s sustainability credentials are obvious; Sunlight turns the wheel not CO2!
OPTION 1                  A1 Residential Tariff             (INFORMATION Aug 08)
The A1 Tariff is the standard residential tariff, available to private dwellings and used solely for residential purposes. It charges you the same flat rate regardless of when and which time of day electricity is used.

 Table 1 - A1 Tariff Charges      (All prices are inclusive of GST)

* Applies to multiple flats and home units supplied through the main Synergy meter

OPTION 2                Smart Power
SmartPower is an optional product that allows you to take advantage of variable electricity rates, depending on the time of use. By using power in the cheaper time periods, you can save on your electricity bill. To take advantage of the SmartPower rates, you will need to have a SmartPower compatible meter.

Option 3                 Green Power  
To switch on to GreenPower – there is no need to change your current electricity supplier unless you choose.
How much you pay will depend on the percentage of GreenPower you nominate to purchase. There are many accredited GreenPower products. Consumers can choose what proportion of their electricity they want to come from GreenPower.
You can buy 100% GreenPower for approximately $5.50 extra per week or pay less for a lower percentage that better suits your household budget. Your electricity company can advise you of the various products available.  
Click here for more about Greenpower