apctjb
Solar Enthusiast
- Joined
- Jun 16, 2020
- Messages
- 471
In the summer months my off grid system (5.5kw PV; 32kwhr battery, 6kw inverter) has the capacity to produce more energy than my system consumes. On most days my batteries are fully charged by 11am and my PV MPPT charger (2- Growatt 3000 LVM) will start limiting energy harvest for the remainder of the day.
To increase energy harvest I have been experimenting with running my mini split AC's during the day to utilize the excess power my array can produce. On the graph below you can see AC's coming on in the morning and off in the evening. (Load (red line) is 2x what is shown on graph as there are 2 inverters). The second graph is without running the AC's to illustrate the difference in energy harvest.
But here's the rub, I don't really need the AC's on during the summer as this is a second home and I am not there much in the summer, so one could argue that the extra energy harvested is going to waste anyway. Running the AC's keeps humidity levels in the house lower, and minimizes daily temperature fluctuations (inside gets hot during the summer, really hot at times). The downside is it puts extra load on the inverters and more hours of operation on the mini split. (I have no idea if running inverters or mini splits more hours a year materially shortens their useful lifetime, or not)
So curious to hear what others think about running AC's as a method to increase energy harvest and the tradeoffs of running AC's more time than they really need to run.
One last comment; these new inverter based mini splits are pretty amazing. Soft start, variable power levels, programable, and Wi-Fi enabled so I can control them with an app on my phone 2000 miles away. Never thought I would would have AC's running on a simple off grid solar system...
To increase energy harvest I have been experimenting with running my mini split AC's during the day to utilize the excess power my array can produce. On the graph below you can see AC's coming on in the morning and off in the evening. (Load (red line) is 2x what is shown on graph as there are 2 inverters). The second graph is without running the AC's to illustrate the difference in energy harvest.
But here's the rub, I don't really need the AC's on during the summer as this is a second home and I am not there much in the summer, so one could argue that the extra energy harvested is going to waste anyway. Running the AC's keeps humidity levels in the house lower, and minimizes daily temperature fluctuations (inside gets hot during the summer, really hot at times). The downside is it puts extra load on the inverters and more hours of operation on the mini split. (I have no idea if running inverters or mini splits more hours a year materially shortens their useful lifetime, or not)
So curious to hear what others think about running AC's as a method to increase energy harvest and the tradeoffs of running AC's more time than they really need to run.
One last comment; these new inverter based mini splits are pretty amazing. Soft start, variable power levels, programable, and Wi-Fi enabled so I can control them with an app on my phone 2000 miles away. Never thought I would would have AC's running on a simple off grid solar system...