Dynamic prices: only show solar % values when PV is configured

[naltatis]

replaces #15047

Is your feature request related to a problem? Please describe.
As described here evcc always assumes a PV is present, even if no PV-meter is configured. This leads to unexpected effects (non-zero solar %) for people that use evcc without PV (dynamic prices).

Describe the solution you'd like
We could, for new installations, change our default assumption that a PV is always present. We'll still support solar charging with only a grid-meter but make this opt-in. Config UI could show an "I have solar, but no PV-meter." to enable the existing behavior.

This would also properly solve the issue, that we currently show "PV" and "Min-PV" option (instead of the single "smart" option) even if no PV is installed.

Additional context
Since this is currently not a functional issue, I'll not see this implemented before we've fully migrated to web-based configuration.

[madkiss]

How much will it cost to bump this up in the backlog? For non-pv environments, this issue effectively renders the price display in the "previous charges" list unusable (as demonstrated by the attached screenshot).

[naltatis]

How much will it cost to bump this up in the backlog?

This is not how this works. 😄

Workarounds:
a) configure a feed-in tariff with the same settings as grid the price calculation. then the calculated price should be correct. just solar % is off.
b) remove the grid meter, then all values should be correct (but you obviously loose the visualizations based on this value). extra benefit: for installations without grid meter, we already have reduced mode UI: off, smart, fast. smart is functionally identical to pv.

[madkiss]

AIUI, feedin does not support tibber as type, does it?

[naltatis]

There are no type limitations for feed-in.

[andig]

How much will it cost to bump this up in the backlog?

We appreciate sponsorship in any case :)