puzzling performance [RE-wrenches]

[Jeff Clearwater, Village Power Design]

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Hi Mo and Christopher and all,

Here's the actual data on the Glen Ivy plant in Corona, CA.  Perhaps 
if we share S. Cal data we can establish some reality to counter the 
bad reporting or bad data or unreasonable expectations or propaganda 
or whatever it is LADWP is seeing.

Some minor corrections - it's 11.88 KW (STC) (72 Sharp 165s) not 11.2 
KW and the average for the actual calendar year of '03 was 1754 
KWH/month.

So Mo your calcs are right on. ( We actually thought we would see 
about a 19% increase due to single axis tracking however)

The panels were washed about once every 6-12 weeks.  More in summer 
as the plant is next to an active gravel pit.

11.880 KW STC System on Single Axis Tracker	  Year End
					  Average
Month	KWH	Days	KWH/Day	SunHrs/Day SHrs/Day

Oct-02	882	31	28.5	2.39
Nov-02	1411	30	47.0	3.96
Dec-02	1254	31	40.5	3.41
Jan-03	1195	31	38.5	3.24
Feb-03	1145	28	40.9	3.44
Mar-03	2024	31	65.3	5.49
Apr-03	2171	30	72.4	6.09
May-03	2309	31	74.5	6.27
Jun-03	2013	30	67.1	5.65
Jul-03	2280	31	73.6	6.19
Aug-03	2413	31	77.8	6.55
Sep-03	2134	30	71.1	5.99	4.90
Oct-03	1595	31	51.5	4.33	5.06
Nov-03	879	30	29.3	2.47	4.94
Dec-03	893	31	28.8	2.43	4.85

Total  03	21051	365	57.7	4.85

You can see that June was an unusually bad month for solar in S. Cal 
this past year.  Alot of rain and clouds. Also this particular 
tracker falls off sharply in the Winter months due to it being a 
horizontal single axis tracker (array is at 0 degree tilt when facing 
South).  It makes up for it in Spring, Summer, and Fall though. (see 
www.wattsun.com)

The only caveat is that the tracker power supply failed and was not 
noticed for the last two weeks of Nov and the first two weeks of Dec 
03.  So those numbers were a bit lower with the tracker stationary at 
0 degree tilt (Single Axis Horizontal Tracker).  So that skews our 
yearly comparison a bit but you can compare to last year those same 
months.

If anyone wants access to this plant's data for comparison or 
promotion purposes, contact me offlist and I can see about allowing 
you to call direct into the Sunny Boy Control Modem for this plant or 
share with you the ongoing spreadsheets it generates.

Best,

Jeff C.
Village Power Design


>Jeff Clearwater, Village Power Design wrote:
>>  I had predicted 2050 KWh/month for the Glen Ivy (Corona - near
>>  Riverside) 11.2 KW (STC) plant (has single axis tracking).  In
>>  actuality we harvested just under 1800 KWh/month. 
>
>So that works out to:
>
>1800 kWH per month / 30 days / 11.2 kW = 5.35 peak sun hours
>
>Pretty good performance considering were using the STC rating for the PV
>array.  I guess it never does rain in southern california...
>
>What was the december performance like? 
>
>Christopher Freitas
>OutBack Power Systems, Inc.
>cfreitas @ outbackpower.com 
>www.outbackpower.com
>Arlington WA USA
>Tel 360 435 6030 
>
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-- 
~~~~~~~~~~~~~
Jeff Clearwater
Village Power Design Associates
Sustainable Energy & Water Solutions for Home & Village
http://www.villagepower.com
gosolar at villagepower.com

877-SOLARVillage
413-256-6777,  Fax 413-825-0372
61 Baker Rd
Shutesbury, MA 01072

PO Box 115
Boonville, CA 95415
707-895-9015, Fax 707-897-0024
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`~

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