Solar-Panel to Controller Loss
Much has been made of the lower losses on the panel to controller path with MPPT because the amps are less. So once you have your loss measured, how valuable is it to improve on that if you don't lik...
Forum Discussion
Going back to Salvo's chart of pwm vs mppt;
mppt did indeed do better than pwm, earlier and later in the day... twice as good, in fact. But it was like 2a mppt vs. 1a pwm. Overall, IIRC, mppt pulled in an extra 8ah for the day, by being anywhere from 0-1a better than pwm... 1a better early and late, and about even at noon. If that extra 8ah's/day is worth the extra two to six hundred bucks, go for it.
mppt does considerably better than pwm in cool cloudy conditions... cooler panel temps, and it's ability to convert (excess)voltage into amps, vs the fact panel Isc takes a dive in such conditions.
pwm does as well, and perhaps a little better than mppt in hot sunny conditions due to panel voltage drop, and an increase in Isc.
So, mppt does do a little better in some conditions, considerably better in other conditions, and about the same, or even less than pwm, in certain conditions. Remember, most rv'ers don't use their panels in cold, sunny conditions... conditions that highly favour mppt.
And then there are controller efficiencies to consider, which are effected by both temperature, and the amount of bucking involved.
mppt did indeed do better than pwm, earlier and later in the day... twice as good, in fact. But it was like 2a mppt vs. 1a pwm. Overall, IIRC, mppt pulled in an extra 8ah for the day, by being anywhere from 0-1a better than pwm... 1a better early and late, and about even at noon. If that extra 8ah's/day is worth the extra two to six hundred bucks, go for it.
mppt does considerably better than pwm in cool cloudy conditions... cooler panel temps, and it's ability to convert (excess)voltage into amps, vs the fact panel Isc takes a dive in such conditions.
pwm does as well, and perhaps a little better than mppt in hot sunny conditions due to panel voltage drop, and an increase in Isc.
So, mppt does do a little better in some conditions, considerably better in other conditions, and about the same, or even less than pwm, in certain conditions. Remember, most rv'ers don't use their panels in cold, sunny conditions... conditions that highly favour mppt.
And then there are controller efficiencies to consider, which are effected by both temperature, and the amount of bucking involved.
