I can see how small efficiencies would matter a lot in that sitation.

When I had 6 100W panels and was trying to keep my laptop (and lights) running off that, then I did a lot more trying to keep them clean. If I was having to burn fuel for electricity, I'd certainly be trying a lot harder to squeeze what I can out the array.

Anyhow, good luck.

I likely am in a similar position. My hope is to get a cistern buried this year so I can have more than 40L of liquid water on hand at any given time... and then maybe even a shower :D Washing myself with a bucket is starting to lose its charm.