Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,660
When I look at the specs for SMA PV and battery inverters:
There is a small efficiency difference shown in graphs, 96% at 220 VDC vs. 98% at 480 VDC PV, and 95% at 63 VDC vs. 96% at 42 VDC battery.
As far as power production from PV or run time from battery, doesn't matter much.
But in terms of heat dissipation, those are 2:1 and 5:4 respectively, which would affect how long they could sustain that power for a given ambient temperature environment.
I was surprised that boosting 63VDC to 120 VAC is less efficient than 42VDC to 120 VAC. Maybe the transformer ratio is such that the least voltage reduction from battery to primary occurs when drawing from 42V battery and secondary is driving 170V peak. If this was high frequency boost architecture like SolArk might be reversed.
Unlike the transformerless Sunny Boy I linked above, spec sheet for my older transformer type shows lowest efficiency at 480VDC, highest at 300VDC PV.
Interesting the things we learn when critically studying specs of products.
There is a small efficiency difference shown in graphs, 96% at 220 VDC vs. 98% at 480 VDC PV, and 95% at 63 VDC vs. 96% at 42 VDC battery.
As far as power production from PV or run time from battery, doesn't matter much.
But in terms of heat dissipation, those are 2:1 and 5:4 respectively, which would affect how long they could sustain that power for a given ambient temperature environment.
I was surprised that boosting 63VDC to 120 VAC is less efficient than 42VDC to 120 VAC. Maybe the transformer ratio is such that the least voltage reduction from battery to primary occurs when drawing from 42V battery and secondary is driving 170V peak. If this was high frequency boost architecture like SolArk might be reversed.
Unlike the transformerless Sunny Boy I linked above, spec sheet for my older transformer type shows lowest efficiency at 480VDC, highest at 300VDC PV.
Interesting the things we learn when critically studying specs of products.