Having recently had a smart meter fitted there are apps out there that can tie into your meter giving you accurate half hourly monitoring without additional hardware.

For example I found an app called Octopus Compare that I can code to my smart meter and look at what different tariffs would cost me. I can also see from the Octopus dashboard my usage and export in half hourly blocks so this data should also be available with the right logins.

So there must be some cool apps out there that monitor, advise, correlate but when I search I'm mainly finding proprietary software that talks to specific brand inverters.

Any recommendations?

Those I've found are either for the manufacturer of the strong inverter (like Solis do, which might need Wifi connection) or the simple graphical ones showing current values and perhaps saving the values at the end of each day. For the latter kind, Monitor for Givenergy (could work for others?) and Richard Russell's Inverter app are both free.

Do you have a battery with its own inverter? There are usually free apps or cloud platforms for those which will give you more detail often in 1 to 5 min slots.

There are a few companies doing Smart Tariffs where you can handover some control for them to export excess at peak payment times and import with cheaper (any EV tariff will do cheap import for winter battery charging). AxleEnergy is the other one I've heard of.

Given what I've seen on my first year with solar PV I feel I'm getting the current info I need for decisions over the next few days very easily, and the string inverters are logging and summarizing meter readings of generation per day / month / year etc. Thanks to the shite state of the electricity network we are limited to 3.6kwh export rates, and the main gains for us are in winter doing laundry or EV charging on the better days, and in summer doing them and how water at peak light times. (Nice size battery helps in winter and we export daft amounts full May to Sep).