Let the numbers do the talking

Been a few weeks into our big solar project and beginning to get it all sorted . The story can be told by the contact energy smart meter graphs that give me an hourly breakdown of electricity consumption . I do not have an import export meter and when it is fitted I will be able to get paid for the power we return to the grid. For the moment I have been happy to get the data from the old new smart meter.

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This is a typical day pre solar panels — about 45 kWh of electricity used.

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This was after we had the solar panels installed . It means that during a normal sunny type day the power use is very small. Unfortunately power consumption peaks in the early evening and early morning so power is still being purchased from the grid. This however reduces consumption from the 40 + days to about 13 KWH on this graph.

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This is what it looks like now — we only will be paying for about 2 kWh per day . I estimate that we will be exporting about 10 – 25 KWH back to the grid and even with the miserly rate offered by contact energy we will more than offset the meager bill for purchased electricity.
Our battery storage system runs the upstairs part of the house — fridge freezer , Hot water and coffee machine😉 , Entertainment system and power points.
So what — you ask — is the little peak about midday?
Like this
The batteries run the house from 6 pm in the evening till midday the following day ( 16 hours) The inverter then stops drawing down on the battery and switches to mains supply which is connected to the solar too. It begins a charge cycle which pushes 50 amps back into the storage. A little spike occurs if the day is still a bit cloudy at this switchover time.

3 comments

  1. Thanks Bruce, you have done a great service to those interested by sharing your graphs and giving the explanations to the variances and facts. question: Do you see any potential or future benefit to actually separate yourself from the grid – sooner or later ? Is there any additional components that you could add to cover the spike when the inverter cuts in for its charge cycle? Like an auxillary battery or generator. Ros

  2. Thanks Ros
    we will stay grid connected as this offers flexibility to ramp up consumption should we have a full house of visitors or a succession of really bad weather when we do not have enough solar to recharge. naturally it remains possible to go off grid however we might want to have 2 inverters instead of one and more battery storage. Everything is possible – but cost benefit may make it unattractive. the project has been lots of fun.. i think having a 5th wheel has made a life of electrical self sufficiency a really cool thing. The power Co’s will keep on ramping charges up so weaning oneself off crazy consumption and doing something like i have done appeals to me. like being on the road again.
    Are you guys still in the big kimberly?

    • Yeah…Good points. winter months and wet summers could be a barrier to going completely off the grid. We have come down the west coast now and currently in Perth. I am overdue to get the next update in photos posted. Have had the refit of the solar so looking forward to leaving town soon and getting off the main drags. Looking forward to Margaret River, Esperance then cross the Nullorbor. Weather more changeable now. Missing the sunny warmth of the Kimberley. Want to go again next year.

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