The new SMA grid tie inverters will make juice when the sun is shining even with the grid off. They have separate connections for a sun only circuit.
From: Harold Bledsoe Sent: Thursday, August 31, 2017 9:05 AM To: af@afmug.com Subject: Re: [AFMUG] OT Home Battery Array, Generator and Solar Readiness Agreed, Chuck! Will be interesting to see where it all ends up. One thing on my setup - I don't lose the grid. The grid is still connected as a backup to the islanded system, however the batteries and the power collected from the solar are first priority. -Hal On Thu, Aug 31, 2017 at 9:36 AM Chuck McCown <ch...@wbmfg.com> wrote: They were trying to add demand charges in Utah. That would have made me off grid. But they have backed away from that. I think net metering costs me something like $5 and it is worth it to have juice at night without batts. From: Harold Bledsoe Sent: Thursday, August 31, 2017 5:44 AM To: af@afmug.com Subject: Re: [AFMUG] OT Home Battery Array, Generator and Solar Readiness This. We do systems like this as well using Cenga: http://www.cengapower.com/ If you are doing pure backup, AGM is hard to beat because of zero maintenance, lower cost, and low cycles involved with backup only. If you want to island or go off-grid with part of the house with daily cycling, the best choices are forklift batteries or lithium ion. Golf cart batteries don't work out financially for daily cycling compared to those. The federal tax incentives makes adding panels essentially free. If you are lucky to live in a state friendly to solar with state incentives, the system gets pretty darn cheap! I personally am not a believer in netmetering anymore. I started out with netmetering and ended up taking most of the house islanded. Why? The power companies don't want to do it so they eventually will find a way to kill it. My power company added a netmetering fee of $10/kW installed per month. So I'm islanded now. Hal On Wed, Aug 30, 2017 at 8:30 PM Zach Underwood <zunder1...@gmail.com> wrote: 1 watt of lead battery does not equal 1 watt of lithium ion. With lead acid you can only take them to about 40-50% depth of discharge but with the lithium ion you can get like 80-90% depth of discharge. Also the number of discharge is only like 1000-3000 cycles where with lithium it can be as high as 9000 cycles. The number of cycles is less of a problem in a grid connected back up only but if off grid solar then with lead you would have to replace every 2-3 years where with lithium it could be every 5-10 years. When I was looking into solar this year the 10 year cost of lithium was cheaper then lead. Zach Underwood (RHCE,RHCSA,RHCT,UACA) http://ZachUnderwood.me advance-networking.com On Aug 30, 2017 9:13 PM, "Mathew Howard" <mhoward...@gmail.com> wrote: Tesla Powerwall looks to be 14kWh, so you'd be looking at about $2100 worth of batteries to get the equivalent. I don't see anything on Tesla's website about what size inverter it comes with, but from what I'm seeing on Google, it looks to only be 5kW. You'd also have to come up with some kind of a charger if you don't have solar. On Wed, Aug 30, 2017 at 4:17 PM, Chuck McCown <ch...@wbmfg.com> wrote: How many kWh is that tesla wall of batts or whatever it is called? BTW, you have until November to file a net metering application with RMP in Utah to get grandfathered into the better deal. -----Original Message----- From: Sterling Jacobson Sent: Wednesday, August 30, 2017 3:14 PM To: af@afmug.com Subject: Re: [AFMUG] OT Home Battery Array, Generator and Solar Readiness Ok. Is this easier to do with a APC Symmetra PC Power Array system? I found one for a good price for pickup 16Kva for $1800. -----Original Message----- From: Af [mailto:af-boun...@afmug.com] On Behalf Of Chuck McCown Sent: Wednesday, August 30, 2017 3:11 PM To: af@afmug.com Subject: Re: [AFMUG] OT Home Battery Array, Generator and Solar Readiness How many kwh is that? Batts can be had for 15 cents per watt hour - or - $150 per kWh. Inverters come in at 15-30 cents per watt. Lets say you want a 20 kWh battery, DIY it should cost $3K for the batts. 10 kW will run most homes unless you have all the AC and clothes dryers running at the same time. So $1500 for an inverter. -----Original Message----- From: Sterling Jacobson Sent: Wednesday, August 30, 2017 3:03 PM To: 'af@afmug.com' Subject: [AFMUG] OT Home Battery Array, Generator and Solar Readiness Looks like it’s about $6k plus installation for a TESLA Wall battery. Couldn’t I just get about 10 $165 batteries and put them in an array in my utility room? I’ve got a Generac transfer switch that I haven’t hooked up. Ideally I would like to have ‘clean’ power through some sort of whole home inverter/conditioner for regular utility power. Then if the power glitches I would like to seamlessly run off a battery array for a few minutes until the Generator comes online. Then have a whole home generator on NG for any extended power outages. But I’m having a hard time finding online any sort of DIY or sample/guide for electricians to make this. Is this not ‘normal’ now days? I don’t have solar, but would like to consider it in the future as well. Wife doesn’t like the look of panels on the roof ☹ -- Harold Bledsoe
