This was my thought however at present I am logging both MainsC and Solar until I get get some real stats and check it with an official reading.
We haven’t had a meter read yet, let alone a bill so I need to wait until then to see whats actually there. There is a safe of paperwork I am starting to go through - they were connected early on to the initial solar scheme but I cant see exactly how it is running now and I suspect we would be getting a very poor rate on solar export.
Of positive note is that the roof is large and unshaded 10-12 hours/day and I could play a large (10kw?) solar grid on the roof and replace the 10 year old panels with something close to current sweet spot.
If I did that then Teslra power wall might be an option as well as I could use that to smooth out the power to at least the house…
You can always read your own meter. I keep a log and record the meter reading along with the total kWh as per IoTaWatt at the same time. After a few days, the increase in meter readings can be compared to the increase in IoTaWatt kWh. You can view the kWh to date for your combined three-phase output by plotting it with the local graph app under the “energy” tab. There will be a min and max in the detail line below. Max is the kWh to date.
Great idea - I had been logging solar. I might start taking daily photos of the meter as that will give me stats for both Mains and Solar. Hopefully they will start to tally up with emoncms after a few days - otherwise I can troubleshoot as needed.
I was going to go back and post no the emoncms forum…
I am using the official shared app - is there are way to get a database/stats reset?
I don’t really want to have to delete and create all the feeds again and now am sure I have it correct with CT location and derived phase so would rather ditch the original numbers. I know it will even out in time.
With wiring a picture is better than words. This is a typical single phase gross metering arrangement which is what I think you have on Phase C (see two wires leaving service fuse like your arrangement). The other phases just have their own final subcircuit load. The other difference for your three phase is that the three load phases go through a three phase meter that adds up kWh on each phase and gives a total energy for the three phases.
Do your sums on the battery its unlikely to save you money over the life of the battery until battery prices fall.
Adding more solar if you can, moving to net metering, replacing inefficient appliances, shifting load to when solar is producing, reducing usage and depending on your load, adding offpeak and switching to time of use metering and shopping around for the best retail deal will be much much more beneficial in saving cost.
However some people just want a battery which is OK I guess if its an informed decision.
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For comparison here is a net metered arrangement. Note that the solar is on the load side of the meter so the meter will see import and export depending on the amount of load and generation.
In this case the meter will have two registers (will be an electronic meter) for import and export because there is a difference between the input and export rates being charged and paid.
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What you have just posted is exactly how I understand my current situation to be.
I am noting manual readings and will also go test everything to ensure my Phase/etc are all good.
Once I get an actual contact/bill (we only moved 2 weeks back) I will follow up
This is where we need to get to. Trying to get a handle on load but I have roof space and sun for a 10kVA
either way to go up I need new panels and a new inverter
@Giraffe I am getting some quotes but won’t be doing anything until I have more data - eg what is really using power and what time of day…
I appreciate your help and input as I am trying to figure out if a battery is worth it.
Likely course of action so far is to:
- Sort out the box (validate wiring/neutrals and label/confirm phases etc).
- replace the AirCon with a modern unit as based on verbal research it will massively improve power usage requirements
- Replace the solar with either a 10K or 2 x 7k systems (depends on cost / business case)
- Replace the metering with modern meter and using net vs gross.
- possibly add a battery if it makes practical and economic sense.
Slowly we move forward.
In purchasing new AC, new solar or battery its a matter of comparing both the benefit achieved and the cost. I see a lot in the media and from salesmen about savings but never anything about costs.
Yes a new AC will be more efficient but if over the expected life of the AC the costs (new capital plus operating) are higher than your current AC then you are worse off.
Same thing with solar and batteries. Calculate cost over full life verse benefit over full life and see if you are ahead.
Your monitoring with Iotawatt is a very key input that most people do not have. Use it to get a good understanding of what power you are using now and when it is used and then you can do a sensible analysis.
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