Winter is coming and your power bills are about to send shivers down your spine. Why not anticipate by analysing your consumption and adjusting your usage? Read on to find out what your electricity bill is made of and how to reduce it thanks to solar energy, load shifting and battery storage.

Understand your electricity bill


Your Synergy bills vary according to your plan, consumption and billing period.


1. Your Synergy plan


There are two main household Synergy plans:

  • With the Home Plan A1, you pay the same rate every day: $0.26474 per kWh (inc GST). This is called “anytime tariff”.

    Update: electricity prices have increased on 1 July 2017. However, the anytime tariff remains unchanged.

  • The Smart Home Plan SM1 is a time-of-use tariff, where the electricity charge varies depending on the time of the day and week, as per the table below:
    Time of use Hours Tariff (inc GST) New tariff (inc GST)
    Weekday peak 3 pm - 9 pm $0.492855 / kWh $0.503471 / kWh
    Everyday off-peak 9 pm - 7 am $0.135772 / kWh $0.138697 / kWh
    Weekday shoulder 7 am - 3 pm $0.258122 / kWh $0.263681 / kWh
    Weekend shoulder 7 am - 9 pm $0.258122 / kWh $0.263681 / kWh

    This plan rewards you for using electricity during off-peak times by offering a low rate at night.

    Time-of-use tariff with solar

2. Your usage


Meter reading

It is expressed in kilowatt hours (kWh) - or units - and corresponds to the amount of electricity you have used since your previous meter reading.

Your usage equals to the difference between your current reading and the previous one.

For example, if your previous meter reading was 58,000kWh and your current one is 59,100kWh, then your usage is 59,100kWh - 58,000kWh = 1100kWh.


With Synergy Smart Home Plans, you have a special meter that breaks down your usage into different ‘times of use’:

Time of use Previous reading Current reading Usage
Weekday peak 23,417.5kWh 23,679kWh 261.5kWh
Everyday off-peak 15,698.2kWh 15,964kWh 265.8kWh
Weekday shoulder 8699.3kWh 9026kWh 326.7kWh
Weekend shoulder 10,185kWh 10,431kWh 246kWh
Total 58,000kWh 59,100kWh 1100kWh

Your consumption equals to your usage multiplied by the price of a unit.

  • If you are on a Home Plan, your consumption will be: 1100 kWh x $0.26474 = $291.21.
  • If you are on a Smart Home Plan, your bill will display your time-of-use consumption:

    Time of use Usage Unit price Total New unit price New total
    Weekday peak 261.5kWh $0.492855 $128.88 $0.503471 $131.66
    Everyday off-peak 265.8kWh $0.135772 $36.09 $0.138697 $36.87
    Weekday shoulder 326.7kWh $0.258122 $84.33 $0.263681 $86.14
    Weekend shoulder 246kWh $0.258122 $63.50 $0.263681 $64.86
    $312.80 $319.53

  • 3. Your billing period


    On your Synergy bill, there is an item called “supply charge”. It is a fee charged by Western Power to cover the cost of building and maintaining the grid and supplying power to your house.

    This represents a daily cost of $0.485989 (inc GST) per household, which is charged no matter if you have used electricity or not, and is the same regardless of your Synergy plan.

    This way, if you are billed for the period running from the 1st of March to the 30th of April (61 days), your supply charge will be: 61 days x $0.485989 = $29.65.

    Update: the supply charge has increased from $0.485989 to $0.949058 per day on 1 July 2017. Hence, a 61-day power bill would now include a supply charge of 61 days x $0.949058 = $57.89.

     

    Switch to solar and save


    Below is a realistic example of what you could save with solar. Please note that solar power systems produce 2 to 3 times more energy in summer than in winter, so your summer bills are a lot lower in the summer months. However, we have taken that into account in this example, and the consumption data provided below are yearly averages.

    If you install a 5kW solar power system on your roof, which produces 22.5kWh per day, your production for the March-April billing period will be: 61 days x 22.5kWh = 1,372.5kWh.

    If your household uses 10kWh of that production daily and sends the remaining 12.5kWh back to the grid, your usage will be 61 days x 10kWh = 610kWh and your export, 61 days x 12.5kWh = 762.5kWh.

    Out of your usual bimonthly usage of 1100kWh, if 610kWh are generated by your system, you only have to import 1100kWh - 610kWh = 490kWh from the grid.

    A solar power bill will show you not only the amount of energy that you’ve imported from the grid, but also the amount that you’ve exported back to the grid.


    If you have a Home Plan, your new bill will show the following information:


    • Anytime consumption

      If you are on the A1 tariff, your consumption will be: 490kWh x $0.26474 = $129.72.
      Compared to the same usage without solar power, that is $291.21 - $129.72 = $161.49 of savings.

    • Renewable Energy Buyback Scheme

      The power you produce during the day is either used by your household or sent back to the grid (export). Synergy buys back your exported power at the REBS rate of 7.135c per kilowatt. Thus, if you export 762.5kWh, Synergy will owe you 762.5kWh x $0.07135 = $54.40. So, on top of saving money when you use solar energy, you earn money when you feed that sun power back to the grid.


    If you have a Smart Home Plan, your bill will show the detail of your usage and export per time of use.

    • Time-of-use consumption
      Time of use Usage Unit price Total New unit price New total
      Weekday peak 200kWh $0.492855 $98.57 $0.503471 $100.69
      Everyday off-peak 206kWh $0.135772 $27.97 $0.138697 $28.57
      Weekday shoulder 0kWh $0.258122 $0.00 $0.263681 $0.00
      Weekend shoulder 84kWh $0.258122 $21.68 $0.263681 $22.15
      $148.22 $151.41
    • Renewable Energy Buyback Scheme
      Time of use Export Unit price Total
      Weekday peak 0kWh $0.07135 $0.00
      Everyday off-peak 27.2kWh $0.07135 $1.94
      Weekday shoulder 518.3kWh $0.07135 $36.98
      Weekend shoulder 217kWh $0.07135 $15.48
      $54.40

      In this example, switching to solar has saved you $312.80 - $148.22 = $164.58, and exporting your excess solar production to the grid has earned you $54.40 on just one bill. All in all, that is $1313.88 saved in a year.

      Update: on the new tariff, it comes down to $1335.12 of annual savings.

      Your bill tells you when you export the most energy, but doesn’t give you the total amount of power your solar PV system has produced or the part you have used.

      However, depending on your inverter brand, you may be able to monitor your consumption. For example, if you have a Fronius inverter with a Fronius Smart Meter, you can keep track of your production and usage, and adapt your habits.

     

    Lower your bills even further by load shifting

    Going solar is the first step to saving money and energy. Just by switching to solar and without doing any load shifting, you can expect to save about 25% on your power bills. However, depending on your usage, you may save a lot more.

    As you know, solar panels are only efficient during the day so, if you wait to come home from work at night to start turning on your electric appliances, you’re not taking full advantage of your solar PV system. But if you move your consumption to the middle of the day, when the sun is out, you can really bring your power bill down.

    Solargain has listed some examples of effective load shifting for you. Following these simple tips may save you 50% to 75% of your usual spend for the most committed.

    Not only are you not paying for the power generated by your system, but you even get paid for any surplus that you export to the grid.

     

    Store the excess energy you’ve produced in a battery

    All the energy that your solar power system produces during the day and that you are not using is sent back to the grid. Synergy buys that electricity from you at 7c a kilowatt and then sells it back to you at 26c a unit. Don’t you wish you could store this energy and use it when you need it?

    If you are already making the most of your generated electricity and are still producing extra power, then you should think about storing that energy.

    If you export too much to the grid during the day and you can’t increase your self-consumption, contact us online or call 1300 73 93 55 to discuss a battery option for your home.