**I don’t understand how to use/fill in the column of ‘size to consider’ in application for battery, wind turbine, converter, solar panel & diesel genset.**

You must enter one or more sizes in the ‘sizes to consider’ table for each system component. In the typical case where you don’t know the best size (or quantity) in advance, we recommend that you enter several sizes covering a reasonable range.

Sometimes I will use a geometric scale for this, so for example if I have no idea how to size the battery bank, I will try 0, 2, 4, 8, 16, 32, 64, 128, and 256 batteries. If it turns out that 256 batteries is the best of those sizes, HOMER will issue an ‘edge of search space’ warning message saying that you should really try larger numbers, since the optimal number may be larger than 256. Then I might try adding 512 and 1024 batteries to the sizes to consider, and if that showed that 512 batteries was the optimal size, I would probably the sizes to consider to 200, 300, 400, 500, 600, 700, and 800, or something like that.

In such a way, I would refine the search space with multiple runs of HOMER, letting the results from one run guide how I set up the next.

By the way, if HOMER eventually told me that the optimal number of batteries was 400, I would change to a larger battery because that’s an impractically large number of batteries.