[RE-wrenches] Demand savings from PV FYI

[Joel Davidson]

Hello Daryyl,

California electric utilities base their monthly demand charge on the 
highest 15 consecutive minutes kW demand for each month. PV clients can have 
excellent mid-day demand reduction until 15 minutes and 1 second of clouds 
occurs. Then that high demand sets the monthly rate. However, demand 
management with or without PV can significantly reduce the monthly demand 
charge.

For more information see 
http://www.sce.com/NR/rdonlyres/DE3375D0-8402-43CC-ABE1-38C65682B6CF/0/527V10707TOUPAB.pdf

and 
http://communities.nrri.org/c/document_library/get_file?p_l_id=49730&folderId=49865&name=DLFE-2208.pdf

Joel Davidson


----- Original Message ----- 
From: "Peter Parrish" <peter.parrish at calsolareng.com>
To: "'RE-wrenches'" <re-wrenches at lists.re-wrenches.org>
Sent: Saturday, June 26, 2010 1:25 PM
Subject: Re: [RE-wrenches] Demand savings from PV FYI


> Darryl,
>
> I'm sure what you say is generally true, but unless your utility has an
> enlightened tariff, I still think we have a problem.
>
> Since the demand charges are based on the highest demand recorded on a
> trailing 12 month basis, what happens on that one sunny hot day when a 
> cloud
> passes in front of the sun for 15 minutes and the recorded demand for that
> time period is recorded and the demand then snaps back to historical 
> values.
>
> In SCE territory, I believe, the demand charge gets pegged at that value 
> for
> the next 12 months, regardless.
>
> Please explain to me anything I'm missing.
>
> - Peter
>
>
> Peter T. Parrish, Ph.D., President
> California Solar Engineering, Inc.
> 820 Cynthia Ave., Los Angeles, CA 90065
> CA Lic. 854779, NABCEP Cert. 031806-26
> peter.parrish at calsolareng.com
> Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
>
>
>
> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Darryl
> Thayer
> Sent: Saturday, June 26, 2010 7:21 AM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] Demand savings from PV FYI
>
> Hi all
> A while back we had a thread going on demand savings from PV.  I reciently
> viewed a 1 year data set.  The PV Savings were $36/ month on energy and
> almost $100 a month on Demand.  The company is a small business with lots 
> of
> computers and of course air conditioning  We are blessed with a diurnal 
> temp
> swing.  so morning are cool, and economizers are effective.  The builoding
> does not have building automation system.
>
> The summer demand is by far the highest, Every monthly peak occured in the
> afternoon, The highest peaks were on sunny days in the afternoon, the 
> solar
> reduced all the highest demand peaks.  The Demand fee structure is both a
> monthly charge and a ratchet that follows the highest peak for 11 months.
> The system is 12 Outback inverters.
>
> BTW the smud program with Silent Power should reduce both utility and
> customer demand charges.
>