Re: [RE-wrenches] Monitoring split system
Holt, I see that nobody has jumped in to respond to your question, so I guess that I will. I don't know of any off-the-shelf monitoring system that would directly integrate the two systems. Fat Spaniel Technologies might be able to put together a combined system, but it would likely be expensive and complex. However, the vast majority of the time the SB6000 would just be in standard grid-tie mode, so you can just use the SMA WebBox and Sunny Portal to monitor the SB. Even if the grid is down, the SB output could be monitored. It just wouldn't tell you where the energy is going - to run loads or to charge batteries. But do you really need to monitor that? Most of the time the OutBack will be doing nothing but waiting for a grid failure, but If you want to also monitor that inverter, you can use the FLEXnet DC and the MATE to connect to a PC. Right Hand Engineering makes nice Windows-based PC software that works with the OutBack equipment to monitor and display status, with data logging and system control: http://www.righthandeng.com/hm_wvmob.htm Brian Teitelbaum AEE Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of hol...@sbcglobal.net Sent: Tuesday, October 20, 2009 6:45 AM To: RE-wrenches Subject: [RE-wrenches] Monitoring split system Have residential grid-tie system as follows: 6kw direct grid-tie w/SB6000, 2kw battery base back-up w/OutbackGT3648. Been waiting for Sunny Beam, have kwh meter on OB - Any way to coalesce the two into single monitoring station? Web-based prefered. Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.comhttp://www.holteksolar.com ___ 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
[RE-wrenches] Outback f ware
That is one of the reasons we didn't do a lot of outback stuff. You are right Midnite makes it so easy and if they don't have it they will make it they listen that's for sure Next time you do a multiple stack outback get ahold of Midnite and look at ther Nottagutter combined with the Epanel light's makes for a simple sweet and cooler inverter's install Sent from my BlackBerry® wireless device from U.S. Cellular ___ 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
Re: [RE-wrenches] AC Coupled Re-visited
Jeff, How would the battery based inverter control the charge? Most modern control algorithms are based around some version of pulse width modulation -- PWM. You open the circuit for a tiny fraction of a second, and as the battery voltage rises the open (off) pulses get wider, and the closed (on) times get shorter. To those of us living in meat time, it looks like the current is magically tapering. However, the GT inverter isn't a generator that can have loads unplugged and plugged back in -- it's a current source. *If *you could open the circuit for a millisecond without tripping the anti-islanding protection, the voltage on its output terminals would begin to rise as the BB inverter tapered the current. You may have seen a similar reaction if you've ever measured the voltage on the PV side of an old-fashioned PWM charge controller when the batteries near full and the charge controller begins to regulate -- the voltage on the PV side begins to drift towards module open circuit voltage. Once the voltage on the GT inverter's output terminals rose to the UL1741/IEEE high limit, the inverter would trip offline. Therefore, the only practical way to regulate the charge is to either tell the GT inverter to stop making power (ie, shut it down by forcing a blackout), tell the GT to throttle back power output via communication (ala Sunnyboy/Sunny Island RS485 and frequency shifts), or to divert that power and absorb it doing some other work. Per my other post, I now think this latter solution is the better idea if you're going to mix brands. Allan asked what would I recommend to accomplish this. There's a couple ways. 1. DC diversion, using standard PWM controller and DC resistance load. Advantages: temperature compensated PWM charge regulation. Disadvantages: difficult to source and size diversion load, and you need to ensure the regulation voltages don't interfere with normal charging and sell back voltages. I can share a good technical bulletin written by Morningstar on sizing DC diversion loads, if you contact me off-list. No magic bullet on keeping regulation voltage out of the way of charging voltages -- it's probably the one aspect that you will spend the most time getting right. 2. AC diversion, using relays driven by Aux Outputs and AC resistance heaters. I believe this is the most practical solution available today for grid tie applications. It's not PWM, but it's far more stable than 5 minute off cycles. Depending upon the brains driving your aux output, it's probably temperature compensated. AC heaters are commonly available in a range of wattages and voltages, and they're dirt cheap. Besides, it's AC power that you're trying to absorb, so why make your BB inverter go through the stress of having to convert that AC power to DC just to send it off to a heating element? If you want to get fancy and have multiple inverters (therefore multiple aux outputs) in the system, you can do staged diversion (1,000 watts of load come on at one voltage, an additional 2,000 watts comes on .2v higher, etc). Same complication of ensuring regulation voltage doesn't interfere with normal charging and sell back voltages apply, however. 3. Christmas Wish-list solution: I've been trying to talk the guys at Outback into creating a Diversion controller that can talk to the rest of the system, provide temperature compensated PWM control of energy flow to a diversion load, but most importantly know when grid power is present and then stay out of the way. That would ensure that there is no time where you're buying AC power from the grid and dumping it to the heater, and it eliminates all the gyrations of staggering voltage setpoints and hoping that the multiple temperature sensors and devices will all play nicely under all conditions. Bonus points if it can work with AC or DC. Extra bonus points if it can work with any brand of equipment (wind or hydro, anyone?). However, I'm just one voice in the wilderness -- if you would like to see a solution such as this come to market, send Outback an email. Let them know Phil sent you ;-) I think there is a lot of opportunity to add power reliability and stability to traditional grid tie systems -- what we need is a way to do it easily and effectively. Here's to looking for a way! Phil Undercuffler Conergy -- Forwarded message -- From: Jeff Yago jry...@netscape.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Wed, 21 Oct 2009 19:53:11 -0700 Subject: Re: [RE-wrenches] AC Coupled Re-visited There have been some good advice related to battery bank sizing and a better description of how Sunny Islands work with SunnyBoys, but I am afraid we are getting away from my original post that started this and that was: Since a battery based inverter has a battery charging section and all kinds of software control over the charging process when connected to the grid, why does the battery charging process go wild when the grid is
Re: [RE-wrenches] Name that solar module guessing game!
Mick, The predecessor to the K-51 was the J-51 which had round Jboxes as you describe. They were located about 1/3rd of the way down from the edge of the module. Before those were the J48 and before those were the J45. That would be circa 1988-1994. Haven't seen any recently, but I recall the EVA would brown right in front of the Jbox. Looked like a coffee cup stain. Dunno about the yellowing. Quite a few of us old grey beards sold them for some time back in the days when Al Panton ran Kyocera US. Then they had a bright idea, got into bed with Photocomm exclusively and quite selling directly to us. Japanese marketing 101. Pissed everybody off and worked out so well for Kyo that they had to eventually take over PComm to keep it from going under. Bonus points AND a history lesson! Cheers, Bob-O On Oct 22, 2009, at 2:59 PM, Mick Abraham wrote: Set the dials on the Wayback Machine, Wrenches! The modules which I wish to identify had bright blue polycrystal square cells, before the yellowing and discoloration occurred. They are 50' high on a 12:12 metal roof, and 45 minutes from the nearest emergency room. I am not anxious to make that climb but a friendly helper was going up anyway, so he took some photos. Unfortunately, the labels could not be read or photographed. Dimensions of the frames are, sadly, unavailable. There is one telltale clue, however, which will no doubt yield the Correct Answer from one of the Mechanics: The junction boxes are round with a bayonet mount cover that rotates to liberate the cover. The boxes are big and deep. (I hate to mention that because some of us liked things better when we had big and deep junction boxes, and I don't want this thread to go off topic.) My own guess is Kyocera brand, possibly earlier than the venerable K-51. Alas, my little gray cells are not what they used to be, so I'm polling the group. The yellowing does point away from my own guess because I had not seen that on Kyocera brand, nor on other polycrystal brands. All Correct Respondents have my permission to take the rest of the day off! Bonus Points if a Correct Respondent can also state approximate time of manufacture. Thanks for helping, Mick Abraham, Proprietor www.abrahamsolar.com ___ 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
