Understanding Your Bill

Your Synergy Bill (see images below) shows the number of electricity units you have sold to Synergy (kWh exported back to the grid) and the number of units that you have consumed (kWh imported from the grid).

The sold units are offset against the number of units you have consumed (refer to # 17 and 18 in the Synergy example bill below). It also shows your average daily usage (units) and cost consumed – refer to # 8 in image below.

IMPORTANT NOTE: Your Synergy bill does NOT include the units your home has consumed from your solar power system during the billing period.  Your bill only shows the amount of surplus energy sent to the grid.

20170328_Blogpost_1 20170328_Blogpost_2

(Source: Synergy, pls refer to:  https://www.synergy.net.au/Your-home/Help-and-advice/Bills/Understanding-my-solar-bill)


Watts in a Unit?

These electricity calculations will give you something to think about!

1Unit = 1000Whr = 1kWhr

1kWhr = 1000 Watts of power being consumed for 1 hour

1MW = 1,000,000 Watts or 1000 kW

1 kW hr = 3.6 MJ (if energy expended at a constant rate of 1000W for 1hour)

1J=1Ws or 1W for 1 second

Synergy WA Home Plan A1 Residential Tariff Electricity Charge (as of 1 January 2017) = $0.26474  (https://www.synergy.net.au/Your-home/Energy-plans/Home-Plan-A1)

Note: on the bottom right hand side of your electricity bill you will find your ‘Average Daily Consumption’ in Units.

How much electricity do my appliances use?

If you want to find out how much an appliance uses then read below.

Using the information above lets works out what a Plasma TV would cost to run for one year.

Firstly find out the Watts for your appliance – see the energy rating or serial number sticker as it should state the WATTS of the device which demonstrates watts per hour.

EXAMPLE: If a Plasma TV uses 350Watts per hour and is on for 6 hours per day, then the total energy consumed per day will be 350W x 6hours = 2100Whrs =2.1kWhrs = 2.1units p/day.

To find the daily cost of running this appliance at 6 hrs/day multiply the daily units consumed by the cost per unit= 2.1units x $0.2647 cents = $0.55 cents per day

For one billing cycle of 61 days, multiply the daily cost by 61days:
$0.55 x 61 days (billing cycle)= $33.55 for running the Plasma TV for 6hrs p/day for approx 2 months, or approx $201.30 p/y for just 1 appliance!

YOUR Environmental footprint from electricity use per year

If you want to find out the environmental impact of your electricity bills per annum, using Green House Gas (GHG) as a metric, you will need to determine how much you consume, averaged per day.

Perth’s average household uses 20 units of electricity per day = 7300 kWh/year (20 x 365 = 7300kWh)

The NGERS GHG impact from Electricity Emissions Factor = 0.83 kg Co2–e/kWh (as at 2012/2013)

Therefore using calculations above as an example, the yearly emissions from electricity use for the average Perth Home = 7300 x .83 = 6,059 kg Co2-e/ YEAR = 6.1 Tonnes p/yr

For your imagination picture this… 1 x standard large Garbage Bag = 1kg CO2-e (CSIRO, 2009).

2 thoughts on “How to Read Your Electricity Bill & Calculate Your Annual Environmental footprint

    1. greengurus_admin Post author

      Hi, apologies in delay responding to your question. On your solar PV inverter you can see how much energy your system produced. If you also install an energy monitoring system, you can see how much energy you consum. If you deduct the consumption from the production, you know what your direct consumption is. You can also consider installing some extra clamps in the meter box with your energy monitoring system so you can see what direct consumption is through that interface. Trust that helps. The Green Gurus team.


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