Thanks for the report, Steve. I'm also a huge fan of the European SI. We need to be careful when we start to compare operations across the ocean. The US version of the SI is a bit different from the European version. SMA in Germany decided that the full-featured SI would be too expensive for the US market, so they sent us a stripped down, cheaper version. The US version still has some nice features, but it has some limitations when compared to the full-featured European version. One of the brilliant aspects of the full-featured SI is the multi-master operation. I wrote a little bit on the SI for AC minigrids and the multi-master operation in HP 109 - Oct/Nov 2005. It's frustrating to me that SMA hasn't UL listed a full-featured SI for us in the States, but they must figure it doesn't make financial sense for them.
Dana -- Dana Brandt Ecotech Energy Systems, LLC www.ecotechenergy.com [EMAIL PROTECTED] 360.510.0433 On Wed, Nov 26, 2008 at 10:20 AM, <[EMAIL PROTECTED]> wrote: > Hi Tump, > > Yes, the SI & SB system is all it's cracked up to be! > > I'm not sure what is possible in the US but we've been running a 60kW > Sunny Island system for over a year now which powers the Scottish > Isle of Eigg and uses PV's with Sunny Boys, wind turbines with Windy > Boys, 100kW hydro turbine & back-up diesel generation. Power is > distributed around the island at 3.3kV three-phase using step-up & > step-down transformers. The generation is located at various parts of > the island (as are the houses & loads) with the Sunny Islands/Battery > Store & back-up diesels roughly in the middle. > > See our website for a full description: > http://www.windandsun.co.uk/projects_eigg.htm > > The Sunny Island inverters use 'Frequency Shift Power Control' - > variations in island grid frequency to communicate control signals to > the generation sources and to bonus loads. If the batteries cannot > absorb the renewable power being generated onto the network (if they > are full, or the power generated exceeds the inverter/charger > capacity), the Sunny Island inverters raise the system frequency. > Sunny Boy & Windy Boy inverters are set to 'Off-Grid' mode to respond > to this frequency rise and back off power being fed into the system. > Other renewable generation (eg. hydro turbines) that is able to > respond to this frequency rise to restrict their power output can > also be incorporated in the system. > > The raised frequency can also be used to trigger switching on of > bonus loads when there is surplus renewable energy output. > > The great thing about using this frequency shift for control is that > no communication cabling, special circuits or dedicated switching is > required and distance is no problem. > > The other great thing about using the Sunny Island system is that it > allows use of the Sunny Webbox for remote monitoring. This means > every morning I can check on the internet to see how the system is > performing, view state of charge of batteries, and dial in to change > things if needed. Furthermore, several people can do this at once - > eg. system owners & SMA technical support - so we can all look at > what's been happening and discuss any events. (I'm sure you all know > how useful this can be!) > > As an example the attached Word document shows how the frequency > shift works in practice (Hope it's Ok to send attachments on this > list) > > Regards > Steve Wade > > > > From: "Tump" <[EMAIL PROTECTED]> > To: "'RE-wrenches'" <re-wrenches@lists.re-wrenches.org > > > Date sent: Wed, 26 Nov 2008 08:33:38 -0500 Subject: > Re: > [RE-wrenches] More on AC coupling Send reply to: RE-wrenches > <re-wrenches@lists.re-wrenches.org> > <mailto:[EMAIL PROTECTED] > wrenches.org?subject=unsubscribe > > > <mailto:[EMAIL PROTECTED]> > > > Matt, I have long been interested in installing the SMA SI & SBs but > > I have a VERY tough time selling $9ks worth of inverters, just to > > get things started. In the system below I would not of hesitated in > > installing the SMA SI & SB! I too agree that w/this type of scenario > > described below, I would have given quite a bit of thought to using > > the SMAs. Can't beat the battery charging, no charge controllers & > > expandability. > > Please if there is someone out there that has had experience w/ the > > SMA SI > > & SB let us know if it is all that it is cracked up to be! > > With passport in hand, I offer my help if someone out there has a > > large system like this, that will be using the SI & SB/WB type of > > set up. TUMP > > > > Wind & Sun Ltd., Humber Marsh, Stoke Prior, > Leominster, Herefordshire, HR6 0NR. > Web: www.windandsun.co.uk > > Tel: 01568 -760671 > Fax: 01568-760484 > > The latest edition of the Wind & Sun Design Guide & Catalogue is now > available. > This has 112 pages detailing our product range and is packed with > information > and advice about setting up or using a wind or solar electrical > system. > Price is £5.00 + £1.00 p&p. > > Wind & Sun Ltd > Registered in England & Wales, Company Number 3403803 > VAT Number GB 448 5458 14, > Registered Office: Humber Marsh, Stoke Prior, Leominster, > Herefordshire, HR6 0NR > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > >
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