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energy per day from a 5KW system?

H

Harry B

I am thinking seriously about installing a 5KW photovoltaic system.
It will be grid connected.
The area I live in averages 7.5 hours of sunshine per day (taken over a
100 year period.)

How much outpout in kilowatt-hours might I average per day, year round.

One reference says maybe 20kW-hours per day average over a year.

Can anyone suggest some links that might help answer the question?
 
H

Harry B

Think again on the 7.5 hours. Useful time is typically 3-4 hours unless you
gonna' track the sun.

Check sun chart calculators for real figures.

Is this a waste money project?


I am thinking seriously about installing a 5KW photovoltaic system.
It will be grid connected.
The area I live in averages 7.5 hours of sunshine per day (taken over a
100 year period.)

How much outpout in kilowatt-hours might I average per day, year round.

One reference says maybe 20kW-hours per day average over a year.

Can anyone suggest some links that might help answer the question?

Is this a waste money project?
Good question.
Where I live the government is providing a huge incentive.
The incentive is a gross feed in tariff at 3 times the retail price of a
kWh unit.

Why do you say useful time is typically 3-4 hours as opposed to say 4-5
hours or 2-3 hours?
 
H

Harry B

I have a 5KW system located in Paso Robles, California, halfway
between San Francisco and Los Angeles. I've written an application
that show the production data for every day the system has been in
operation. Just go to the site and click on the app's screen image.
If you have a recent version of Java installed, the app will launch
and you can explore daily, weekly, yearly and lifetime data. Go to
the Custom Day tab and check the data for June 21 and December 21 and
you can see the shortest and longest power-generating days of the year
(although December is normally cloudy and rainy). My system peaks
around 35 KWH in the summer and drops to about 22 KWH on a clear day
in the winter. Let me know if you have any questions. I work for a
solar power company and can probably get you more in-depth data if you
need it. We use the PVWatts system from NREL among other tools to
predict our system's power output: http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version2/

http://www.mike-land.com/Solar_Power/solar_power.html

Mike Brown

Wow. You have some great info on this site. Congratulations.
I am trying to work out some of the scales on your graphs as to whether
you are talking gross or net, ow why your cumulative meter readings over
a year can have dips in them.
I will look more closely at a later stage.
 
Josepi said:
Think again on the 7.5 hours. Useful time is typically 3-4 hours unless you
gonna' track the sun.

Saying that typical sun time is 3-4 hours is no more reasonable than saying
it is 7.5 hours, unless there is a geographical reference supplied.

Someone else mentioned PVWatts version 2, but I prefer Version 1
http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/
Predicted solar energy available, based on real observation points around
the US and the world.

For my installation:
PVWatts for a nearby station, 4500 DC, 84%, 26 tilt, 214 az, 15.3 cents.
(kWh/m2/day) (kWh) ($)
Year 5.42 6777 1036.88
021506-021507 actual 6751 generated, 99.6% of NREL prediction.

http://cdold.home.mchsi.com/Solar-generation.htm $1775 avoided in 2008
 
J

Jean Marc

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