Disable PV mode base on price

[enboer]

You can set a price for energy in EVCC. Charger will switch to fast when tariff is below this. But what would be usefull is an option to disable solar charging if current price is above a certain level. So you can still plug in the care and it will only charge in PV if the price is in this price range.

I created a screenshot how this could look like.

[andig]

What is the use case for this feature?

[andig]

From what I understand you have just described "smart grid charging". What's the difference?

[enboer]

when I come home the price maybe 30ct. When plugging in the car it starts charging in PV mode, so not returning the left over to the grid. However during the night a normal charge could be cheaper (eg 20ct). It will be better then to keep feedin in the PV power to the grid at 30ct and pay during the night at 20ct. With the additional setting I can set the boundary until when I want it to allow charging in PV mode.
You are mentioning smart grid charging, do you mean I should set the charger to Off and set a plan for the next morning? Evcc with select the cheapest hours?

[andig]

I'm sorry. I don't understand.

[Lako-Unbekannt]

@enboer Why do you want to return electricity to the grid if the price is high? As far as I know the end user gains the same amount per kwh independ of the market price.

[enboer]

Here you get the 30ct (this is including taxes (0.12ct/kwh). See this screenshot of yesterday, Average 29ct from grid, 18ct feed in.
on yearly basis the tax is settled (Salderen in Dutch) between grid/feedin. If you have taken 5000 from grid and 6000 feedin, only on the 1000 you pay tax. So when prices are negative I should not switch off the Solar to soon (at about -12ct) as this has influence on this ratio and there is not enough feed in to settle.
This settling will however end in 2027.

There is a Dutch video on this topic: https://www.youtube.com/watch?v=EZgHEpuuhqA There is a lot info in the video, but at 34.02 he explains that initially he switched a boiler based on the PV return, but now switches based on energy prices.

Currently I implemented this enhancement by using the MQTT to switch of the charger based on the energy price.

[RenatusRo]

Ah, now I kinda understand: it's a deadly combination of the salderingsregeling en dynamic tarrif. In-com-pre-hen-sable (for my German mind).

[andig]

This settling will however end in 2027.

We're already building this but I'm wondering if that's actually useful. Is there any other market besides Netherlands that would benefit?

[tomvanswam]

Only the tax return on dynamic contracts will stop after 2027. So only the feed-in price to act on will be higher after 2027. Every other thing will still be applicable for any dynamic priced contract in any country. Only till 2027 Dutchies will benefit even more due to tax returns.

[andig]

Great, then let's continue building this!

[andig]

You can set a price for energy in EVCC. Charger will switch to fast when tariff is below this.

Can we please have a simple, understandable sentence, what the request here is?

"As a user, I want to ..., in order to achieve..."?

After two pages of discussion I can't find that. No diagrams, no screenshots. Thank you.

[andig]

As explained before, this is a special case. We won‘t build special cases.

[VolkerK62]

@enboer
I'm thinking about a dirty hack to use load management for your purposes.
In loadmanagement you can configure an individual MaxPower depending on special rules.
So you can configure the price within the loadpoint and compare it with the actual price. If the actual price is above, MaxPower ist set to a very low value, so charging doesn´t start.
But than, charging will start with max power, if the price is below. Not sure, if you want this?
As an option, if you do not have a battery, you can configure a fake battery, to use the price for the grid charge option for that.

[enboer]

That a shame that this wil not implemented. I will continue with my crontask which switches off based on price.
Just a question, if the charger is set to off, but if there is a planned schedule this schedule will normally start I assume?

[andig]

You got me wrong. All I‘m saying is that making this dependent on grid tariff is not the way to go.

[enboer]

I do not understand what you mean with your last comment: 'making this dependent on grid tariff is not the way to go'
That is in my opinion how EVCC works by selecting the cheapest hours when a plan is set. Also if the current tariff is below a certain level it switches from PV mode to Fast charging (my suggestion is to extend this with an Upper limit). This is all based on tariff.

[tomvanswam]

I'm in the same boat as @enboer, dynamic contract (in NL) and as you can see grid tarrif equals feed-in tarrif:

What I'm looking for is maybe a more general applicable feature "price optimized charging".
I'd like to be able to charge at maximum capacity (taking into account available PV and grid load not to overload the mains) on the cheapest hours (combination of grid tarrif and feed-in tarrif) to get my car charged to the set charge level on the time required by the plan.

This would also make @enboer's charging work the way he likes, as during expensive grid tarrifs (and thus rewarding feed-in tarrifs) there will not be charged, as this is to expensive.

Currently I cannot configure (by lack of knowledge how to configure or it is not possible) such a charging plan.
Fast seems to charge regardless of the pricing at max capacity, also during expensive hours
Min+PV only during PV is available and posibly adds charges the min level from grid, also in expensive hours, and not max capacity in cheap hours
PV only charges when PV is available
And off, well, it does not charge during expensive hours, but also does not charge during cheap hours. It does what the chargepoint wants.
Expensive hours can be limited, however when you set the price limit to low it is possible that you're not at home during the limited hours, or that there are not enough available hours to charge to the set charge setpoint in time. Only way around this I see is to manually change the max price every day.

To me it looks like al charging settings are based around using as much PV as possible, however I would like to charge when it is most economically feasible, independant of the availability of any PV power. And not limited by a manually set max price. This way you're always ensured to have a charged car, for the least amount of money.
I can imagine this mode will suite more users than only some Dutchies with a dynamic energy contract.
Currently this is possible with Tibber's (my energy provider) own app. However it lacks a lot of other functionality that evcc gives me. So I'd like to stick with this awesome project!

It could be that I'm not understanding the workings of the different modes exactly and the "price optimized charging" mode is already possible with a proper config, please let me know when this is the case.

Edit: read some code and learned that off mode is not off, but is putting the chargepoint in control of energy usage.

[krispek]

I have the same request, and this works even without the ‘salderingsregeling’. I would say: even better.

To write it in a story:
As a EV-owner, I want to disable charging the surplus of my PV-energy, so that I can return that energy to the grid for a profit. At a later time, I want to charge the surplus of my energy, because returning it to the grid does not offer any value.

This works quite well in situations where you do have solar panels to the east or west (latter in my case). At the end of the day prices rise significantly and I rather return that energy to the grid. Next day I can continue charging.

I see this as an extension for solar charging. The whole idea of solar charging is that this is very cost effective. However, this can be even more cost effective.

An image as example. These are prices ex taxes. The whole idea is that taxes to not matter, as long as you can delay charging, even when you are on solar mode. In this case, I don’t use my car today or tomorrow.

[krispek]

Correct, the determinator is the feed-in price.* And in my opinion the functionality is exactly the oppositie from the ‘Cheap Grid Charging’ functionality. And thus I agree one can automate both parts: disable charging when prices are higher than a setting, enable solar mode when the price drops below the same setting.

I made some gherkins, that makes the assumptions more explicit (assuming you like to use them):

Given EVCC in solar mode
And a connected car that is charging
When feed-in price becomes higher than [setting]
Then stop charging

Given EVCC in solar mode
And a connected car that is not charging
And the feed-in price is higher than [setting]
When the minimum threshold for charging is exceeded
Then do not charge

Given EVCC in solar mode
And a connected car is not charging
And the minimum threshold for charging is exceeded
When the feed-in price drops below [setting]
Then start charging (immediately/after the delay time has passed?)

Given EVCC in solar mode
And a connected car is not charging
And the minimum threshold for charging is not exceeded
When the feed-in price drops below [setting]
Then do not charge (until the threshold is exceeded)

Not sure whether charging should start immediately or that the system should respect the delay that is normally used. I’m indifferent on this.

Given the chart above, I would use the price setting 0,1€ct, which disables charging (at 17:00) and allows charging in solar mode again at 10:00 the next day. Hopes this clarifies the chart and the feature. :)

*In the Netherlands, the feed-in price is a price ex taxes (f.e. VAT). The only difference with the normal grid price is that taxes are added in the normal grid price (energy tax + VAT). In the chart, prices ex taxes are shown.

[andig]

What exactly does the chart show? Feed-in prices?

[enboer]

I think the chart is feedin price excl taxes. Adding the tax to the chart just moves the chart up by eg 12ct.
I would suggest to use the specified feedin price from the EVCC setup.

[krispek]

Day ahead market prices, which is equal to the feed-in price. I thus agree that the specified feed-in price should be leading. A user tries to optimize the time of feeding in energy to the grid. The normal grid prices are not relevant here.

[JeeDeWee]

I am also in NL and I am using Dynamic energy prices via Tibber. I have very disabled PV surplus charging by setting the enable threshold on the load point to -10000.

loadpoints:
  - title: Oprit
    charger: my_charger
    circuit: main
    enable:
      threshold: -10000 # Effectively disabling PV surplus charging

Since my solar produces maximum 6kWp I will never reach the threshold and the PV surplus charging will never start.

I leave the EVCC setting to PV and set a default charge plan. EVCC will select the hours with the lowest electricity price regardless of the PV surplus as suggested above.

[andig]

Will be implemented in #21813

[andig]

This has now been merged.

[RenatusRo]

works great!
(only a matter of time until someone will ask for:
'disable PV for the most profitable 20 hours per day')