solar upgrade assessment + overcast observations

The new-to-me 750w array has been in place about two weeks and I wanted to share some notes about that. But I wanted to wait for some overcast weather to stress-test the system. Et voila:

There has been no blue sky, no sun, no shadows all day. The bank didn’t hit Vabs == 14.7v until 1100, 1-2 hours later than usual.

  • 1000 - 181.83w. 24% of rated, 32% of the theoretical solar yield available at that zenith angle at that time (“available yield” hereafter)
  • 1020 - 208.74w. 28% of rated, 37% of available yield
  • 1030 0 223.72w. 30% of rated, 37% of available yield
  • 1100 - 220w <– at Vabs with current acceptance decreasing – system not operating at max anymore
  • 1130 - 273w <– big load applied for testing, system at max again. 36% of rated, 41% of available yield.
  • 1302 - local solar noon - [no observations - outing to Fort Stanton and Lincoln, NM]
  • 1555 - 71w (with 1.75A endAmps going into the bank – fully charged)

The system was entirely adequate for charging the bank from 50% DoD under full overcast, and appeared to be capable of delivering at least 175w 2 hours on either side of solar noon.

narrative version

The new 750w array has met my needs so far and I haven’t wished for more. I know this because I have 200w more (portable) panel which has been stowed since mounting the new array. I deployed them regularly when the 570w was in place, and constantly when only 380w was up top.

To be fair, I reduce demand when the sun is shy. Tomorow’s crockpot bread experiment #3 will be at LO settings because it will be overcast again.