I'm using HOMER Energy 3.9.1 and I want simulate an installation with two generators whose maintenance has been introduced in a table. But the results are not the same in the table of results and optimization.
Another question is whether we can change the program units and work in MW instead of kW.
Thank you in advance,
If you could send us your HOMER file, we could take a look at the results mismatch. Also, the units cannot be changed from kW to MW in the software.
The excess electricity isn't exactly Total production - Total load in all the time steps. When the PV output is used to serve the load, HOMER considers the inverter output rather than the PV output to calculate excess electricity.
You are probably comparing the O&M costs in the Optimization table with the Net Present value in the Simulation Results window. In the Simulation Results window, under Cost Summary -> Cost type on the left, select Annualized and you can see the values match.