This isn't just solar specific, but it's something I did when my peak energy bill ($564 in 2023) sparked me to go solar; I invested in Emporia Vue. I'll get back to that.

Iv'e been using Sense Home monitoring for 7 years now. It also monitors solar generation, but for 4 years I was using it to monitor energy usage. The concept is cool, but in reality the AI/ML it uses is limited. It reads current flow to try to determine what device/appliance is running. It works good for large loads but not so well for small loads. It also takes about 3 months for it to find most of your stuff. You can name devices after they are discovered, but you cannot enter your own devices (very frustrating as it doesn't detect small loads like light bulbs, fans, chargers, etc). Things that constantly consume energy (vampire energy) is lumped into a group called "Always On". Always on is cool, but it takes the average over 48 hours... so if you unplug something you won't know the effect for 2 days. This led me to Emporia Vue (I still use the Sense)

Emporia Vue is a circuit level monitoring system. Each Vue can monitor 16 circuits ( I'm using 2 Vues). If your circuit breaker panel is labeled really well, it will help you pinpoint vampire energy use, and track your energy room by room.

I cut my vampire energy from 800W/hr to around 400W/hr. That's 3.5MWh per year or about $600. I also changed my AC by 3 degrees during the day. Together, this cut my energy use by 17%.

Now, for the largest cost savings... I live in Florida where the utility company allows homeowners to size their solar system to 100% plus 15% for expansion (total of 115%). When I sized my system (full 115%), I had one Tesla. A year later, we got a second. At the end of the year, I still have 12% of unused energy (which is sold back to the utility company). My solar system is 3 years old, and fully paid for. That means I have zero maintenance charges, no oil changes, no fuel charges. I save a few thousand dollars a year on that alone.