Nick,
50+% greater output with enphase than unshaded kWh estimates with a string
inverter?
That is what my comment referenced, the practice of some installers of taking
pvwatts with a 0.85 derate(no shading) multiplying it by 1.5 or more just to
get the sale.
A kWh performance guarantee
I'm now monitoring a 5.376 kW system we recently installed. The sun
is barely up, with light clouds, and a portion of the array is still
in shade. The system is putting out 700 watts. A string inverter
would probably be waiting to start.
My main problem with the Enphase is the 199 watt
Yes Jamie:
I understood what you were saying, and that is too bad. Maybe the sales
guys are complete fools, or they are dishonest, or the customer's are
misunderstanding what is being said. However, due to the major advantages to
offering Enphase, you should consider adding it to your
Matt,
The 5-minute delay is verified in the group of inverters sent to the test
laboratory. Then, as long as the software and hardware don't change, it's
presumed the delay in all production units meets the value(s) measured in the
tested units.
An alteration in either hardware OR software
Perhaps some day in the not too distant future, we will switch from tax credits
(like in Hawaii) to performance based incentives and this topic will be
resolved
from empirical evidence vs unsubstantiated claims.
Then the educated public can see a side by side comparison.
This would have to have
Hello Drake,
I have observed hundreds of PV systems in the early morning and can say without
doubt that string inverters are not inherently slow to wake up.
For example, today my 12 year old SW4048 with a single crystal PV array facing
south at 12 and 18 degrees tilt and my SB2100 with a
Hey there,
We have a string inverter system installation coming up that has a power
line suspended over the roof. The line is diagonal to the roof and about 20'
above the surface. It will be very challenging to configure the strings to
mitigate shading. Does anyone have experience with the
Hello Joel,
The issue is that over half the array was in shade. I don't think
there would have been enough string voltage to start a string inverter.
Cheers,
Drake
At 11:33 AM 10/11/2010, you wrote:
Hello Drake,
I have observed hundreds of PV systems in the early morning and can
say
Hey Eric,This was discussed somewhat back in early Sept under the subject line
Wiley Assett. This topic, with some great insight, should have been
discussed under its' own subject line but My bad!
benn
DayStar Renewable Energy Inc. b...@daystarsolar.ca780-906-7807 HAVE A SUNNY DAY
Eric,
I've got a photo essay about one incident that I prepared on just this
topic. It shows photos of the shadow from a triplex cable that is
about 5 feet from a PV crossing several modules. The shadow only lasts
for about 40 minutes very early in the morning, but it reduces the
output by
We are installing a 8kW grid tied PV system for a commercial client. There
is an auto start generator on the premises, therefore we will be utilizing a
supply side AC point of connection. Inverter is an SMA SB8000. System owner
plans on adding to system in the next few years. We are designing for
Dave,
I think you are reading the output current for 277V. The spec sheet lists AC
max output at 240V as 7700W and 32A. If you take that number at face value,
you can still just use a 40A breaker. If you do the math based on their
listed output (7700W/240V=32.1A * 1.25 = 40.1A), you might need
12 matches
Mail list logo
