I have been procrastinating with writing this update. Partly because thorough research was needed and as a busy new mum, time is not always my ally. Also partly due to my concern that this post will deter people to investigate the investment of solar PV for themselves.
You can read part 1 of this post by clicking here.
Above is a graph of our electricity usage since we commenced with our current supplier. The graph shows four billing periods. For simplicity, I will refer to the bill ending 10 of October 2013 column as ‘period 1’. Bill ending 15 Jan 2014 column as ‘period 2’. Bill ending 14 Apr 2014 column as ‘period 3’ and bill ending 15 May 2014 column as ‘period 4’.
Period 1 – is total grid dependency NO SOLAR PV
Period 2 – is total grid dependency NO SOLAR PV
Period 3 – is partial grid dependency SOLAR PV INSTALLED FOR PART DURATION OF THE PERIOD
Period 4 – is partial grid dependency SOLAR PV INSTALLED FOR THE WHOLE DURATION OF THE PERIOD
In order to compare the periods, firstly I calculated what the daily kWh usage was for each period (divided the total period kWh usage by how many days made up the period).
Period 1 was 9.65 kWh
Period 2 was 11.06 kWh
Period 3 was 12.53 kWh
Period 4 was 9.13 kWh.
Interesting that period 3 had the largest daily kWh usage with the Solar PV installed for part of the billing period. This of course was the cause of my concern and motivation for writing part 1 of this post.
The second part of my research involved contacting different electricity suppliers to understand their charges, so to compare against our current supplier.
What Electricity Suppliers are currently charging and offering (for NSW residential homes with a non peak meter):
AGL (our current plan – Freedom 3% + 60)
They charge (GST incl) 0.28589 cents for every kWh we use from the grid 24 hours a day (first 1725kWh in each quarterly billing cycle). Also their service fee is 0.81521 cents daily.
They offer 0.08 cents for every kWh we feed into the grid. Also this plan gives us a 3% discount (with no contract). There is a 10% discount option if we go on a two year contract.
Renewable Source? This plan means the electricity we draw from the grid is not from renewable sources. Currently AGL don’t offer green / renewable sourced energy as an option.
They charge (GST incl) 0.2651 cents for every kWh we use from the grid 24 hours a day (first 1700kWh in each quarterly billing cycle). Also their service fee is 0.76870 cents daily.
They offer 0.05 cents for every kWh we feed into the grid. They also offer a 10% discount on the entire bill if we pay on time. This is a 2 year contract plan.
Renewable Source? Red Energy is owned by the Snowy Mountain Hydro-Electric Scheme, so all electricity we use is matched by renewable sources – we take out dirty fossil fuel sourced energy and Red replaces it with renewable energy.
They charge (GST incl) 0.24960 cents for every kWh we use from the grid 24 hours a day (1750 kWh in each quarterly billing cycle). Also their service fee is 0.76870 cents daily.
They offer nothing for the kWh we feed into the grid. They also offer no discounts.
Renewable Source? Momentum Energy is owned by Hydro Tasmania, so all electricity we use is matched by renewable sources – we take out dirty fossil fuel sourced energy and Momentum replaces it with renewable energy.
So which plan would be cheaper for us?
From the graph above, I will use the period 4 electricity usage to calculate. Period 4 shows we used 283kWh in total from the grid. The blue line next to the period 4 column is the electricity we generated from our solar PV that we fed into the grid (it doesn’t show on this screen captured image of the graph but I can tell you that the total amount generated for this billing period was 190kWh). There are 31 days in this billing period.
service charge 31 days x $0.81521 = $25.27
usage charge 283kWh x $0.28589 = $80.91
feed in tariff 190kWh x $0.08 = ($15.20)
Sub Total = $90.98
TOTAL less 3% discount = $88.25
service charge 31 days x $0.76870 = $23.83
usage charge 283kWh x $0.2651 = $75.02
feed in tariff 190kWh x $0.05 = ($9.50)
Sub Total = $89.35
TOTAL less 10% discount = $80.42
service charge 31 days x $0.76870 = $23.83
usage charge 283kWh x $0.24960 = $70.64
feed in tariff 190kWh x $0 = $0
Total = $94.47
* I currently believe, having solar PV connected to the grid is not going to be a big financial benefit for every residential home in NSW. If you use very little energy during the day in your household, solar PV being connected to the grid isn’t going to be a huge benefit (will take a very long time to recoup your financial investment of installing solar PV).
If however like us, you are able to use a lot of your energy usage during sunlight hours, you will benefit much more (put the washing and dish washing machines etc on during the day, while being frugal with your energy usage at night).
* My next step will be to investigate the option of removing our solar PV from the grid – using batteries to save our generated electricity to use at any time without any charge. I will add a post update with my findings.
* If removing our solar PV from the grid is not possible or economical, we will probably sign a contract with Red Energy as our electricity provider . Not only as they are the cheapest (using my figures and calculations) but they can also replace the electricity we take from the grid with renewable energy.