question

sinbad avatar image
sinbad asked

ESS with Time of Use tariffs?

Hi

SO I see some references to ToU tariffs in the ESS documentation, but it all seems to talk about external control (writing to MQTT or modbus registers).

I'm not scared of doing this myself, but I was wondering if there was any standard option in ESS (current or planned) to allow optimisation of costs when on ToU tariffs?

Eg, charge the batteries from grid up to xx% on the cheap tariff, then run off batteries during the expensive period...

ESS
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3 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @Sinbad,

The scheduled charging feature allows you to charge the battery when power is very cheap, or stop discharging the battery during certain times (to save it for when power is most expensive).

You can read about it more in the Scheduled Charging section of the ESS Manual.

I am working on the ESS training and documentation at the moment, so if any of the information could be clearer, I would appreciate the feedback and suggestions for improvement.

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sinbad avatar image sinbad commented ·

Thanks Guy! I don't know why I didn't think of that... I was getting ready to do all sorts of fancy stuff with homeassistant :D

:)

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Don't let the easy way stop you!!

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sanchuka avatar image sanchuka commented ·

@Guy Stewart (Victron Community Manager) Is more info Available?

I have a semi-industrial installation 3-phase from Grid. The Electrical company from 17:00 to 21:00 changes my kWh-value up to 20 times higher.

I want to have an ESS (from scratch) that can Stand All the electrical Loads from Batteries at that specific period of Time (4 hours) and during the Day recharging from PV (when available) and Grid at cheap kWh-value.

I'm Planning to do it using Quattro 3-Phase System, Cerbo GX, and Pylontech US-3000.

Data: Electrical Load per Hour 19kWh (From 17:00 to 21:00), so I'm planning to have 19kWh*4 hours = 76kWh equal to 24 batteries (90% DoD).

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sharpener avatar image
sharpener answered ·

Is there any progress on expanding ESS to cover ToU tariffs? IIRC there was some talk of updates in another thread some months ago, but no actual signs of progress.

The recent price rises in the UK would suggest that the following features would be well received:

  • allow Keep Batteries Charged to work only at specified times of day and default to Optimised at other times
  • Have a mode a bit like BatteryLife - but which adjusts the target SoC for an overnight charge at off-peak rates according to whether was there was enough sun to fully charge the battery the previous day
  • in the VRM Dashboard, display power taken from grid in more than one category, by time of day, so we can see the split of usage between peak and off-peak
  • Distinguish between scheduled charging times and scheduled non-discharging times (like cheap Chinese inverters can), so we are not prevented from using battery power that already exceeds the target SoC

What do others think? Are there similar ideas crying out to be implemented?

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Jay avatar image
Jay answered ·

in the U.K. electricity companies provide off peak rates or rates that change every half hour interval (octopus agile). Other ESS systems are able to take advantage of this to change impromptu when tariff rate is low. Battery usage should be optimised during these periods.

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