Portable Power Plant to Charge up during The day then run Frig/Freezerduring PeakCost

[PeterInSa]

We are on 3 electricity Tariffs ( Solar Sponge) during the day 10am to 3pm 24c/Kw, 3pm to 1am? 57c/Kw ditto 6am to 10 am, and 1am to 6am 29c/ Kw. ( Times and cost approx.)

What I would like to have is a timer box that charges a portable power plant during the low cost period 10am to 3pm, while at the same time running the Frig and Freezer from the grid, and at 3pm switches over to the power plant to run the Frig and Freezer until the end of the peak period 1am. Then switch back to the grid until 6 am the next day. After 6am on the power Plant to 10 am.

[fandtm666]

that is just a big ups setup , you could just use a basic timer
plugged into your GPo then that unit pluged into it.

[Tiny]

Peter, you should check the maximum current draw of the 2 fridges before going ahead with this.
The biggest of those power stations you linked are rated at 1500W maximum power output.
That's only 6.25A/h at 240V.
Some fridges will need 1000W to start the pump, so if both kick in at the same time, you'll get an overload disconnect on that power station & no fridge or freezer working until you discover it.

Unless I read that wrong & it's a fridge/freezer in 1 box with 1 pump doing both. Then it should be big enough to handle the switch on current. Then some new fridges with auto defrost that have heaters to evaporate & get rid of the defrost water, could add more to the max draw.

[peteramjet]

I’d check to see if there is a better plan available first, as those rates seem exorbitant.

I’m in NSW so prices will likely be different, but I have a single tariff of 25c/kw and a controlled load (for hot water, ect) of 14c/kw.

[PeterInSa]

pa just moved to Lumo in SA after a comparison with other providers

Off Peak 26.62
Shoulder 20.98
Peak 48.3

Service charge $1.02 a day.

All plus GST

AND SA has the Most Solar and Wind per population thats why we could have the higherst prices for power.

[Uncle Fester]

Constantly switching over refrigeration compressors while they are running can harm them.
And a Bunnings type timer switch is useless.
You would need an automatic transfer switch and that is where things get messy, unless you are a sparky and really know what you are doing.
There are motorised types that can be triggered with a control voltage that can be managed with a timing circuit but after I purchased one on Ebay and had a closer look inside it I decided to discard it.

You would need to speak to a sparky to look into this if you don't want your house to burn down one day.

Also consider/calculate the power consumed in the 10 hours the fridges are running at peak and how much you would REALLY be saving.
Use a power meter on those fridges for 10 hours and see for yourself.
My estimate is probably less than a dollar a day.
My old chest freezer actually uses only 0.5kWh in 24 hours... IN SUMMER !

[PeterInSa]

UF, I have an electrical/electronic background and apprecaite the need for accurate load/battery measurements. The question was along the lines of, I would like to, rather than I am going to, and wondered if there was a off the shelf package available that would do the job.. From your comment about a Frig/Freezer the system would need a movement detector to determine if the F/F was running and not switch Off.

Mate has 2Kw of Grid solar, 2 Kw of Home solar driving 10 x 135amp Gel cells and manual switches over at night ( Hot water, F/F, water pump and some lights)to run off his batteries, he is in credit with the power company. His system has been running for a couple of years. If he uses grid power its 40c/Kw plus GST.

He has a Heat Pump for house heating, great if its not really cold as its ices up in the morning ( Friends in Tassie leave there's on 24/7 year round I believe. Anyway he is going to install a 5Kw diesel heater that should do the job. ( Have seen some small businesses in Adelaide with the Heater in their workshops.

We used 100Kw hours in 15 days at 48.3 + Gst, would like to move that over to Shoulder at 20.9c we do all the cost saving things eg diskewasher/washing etc etc between 10am an 3pm,.