Not to be concerned, about 2 KWH a year. This week I achieved an improvement
of 2 KWH a day by changing connections to two inverters, to slightly reduce clipping.
The PVwatts prog HOURLY OUTPUT is useful for you because of your ideal weather. It isn't useful here in cloudy
NW IL, because the program arbitrarily inserts cloud losses on an hourly basis. Looking for the peak is moot when
clouds are present. This was immediately evident when I did hourly graphs of some days.
Number crunching programs are very useful, once their integrity and limitations are established. I do not care to
simply accept any output without a sanity check; the slide rule guys (of which I once was one) did well because
they had a pretty good idea of the answer before doing the calculations. My favorite check is the curves, and
programs that produces them give me infinitely more confidence.
The 5300 W DC unclipped limit was based on efficiency here: 1.2% DC losses
and 3.8% inverter losses give about 5040 W AC. Bruce Roe
of 2 KWH a day by changing connections to two inverters, to slightly reduce clipping.
The PVwatts prog HOURLY OUTPUT is useful for you because of your ideal weather. It isn't useful here in cloudy
NW IL, because the program arbitrarily inserts cloud losses on an hourly basis. Looking for the peak is moot when
clouds are present. This was immediately evident when I did hourly graphs of some days.
Number crunching programs are very useful, once their integrity and limitations are established. I do not care to
simply accept any output without a sanity check; the slide rule guys (of which I once was one) did well because
they had a pretty good idea of the answer before doing the calculations. My favorite check is the curves, and
programs that produces them give me infinitely more confidence.
The 5300 W DC unclipped limit was based on efficiency here: 1.2% DC losses
and 3.8% inverter losses give about 5040 W AC. Bruce Roe
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