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thew
Posts: 233
Joined: Sat Apr 30, 2011 9:56 pm
Delivery Date: 14 Jun 2011
Leaf Number: 4514
Location: Gold Beach OR
Contact: Website

Re: 7.2 kw grid-tie system in Rhode Island

Wed Feb 13, 2013 11:45 am

That's why you don't want to forget the Batteries. We are Grid tied! To.

It makes no sense to Generate your own Power and not Keep it.. Our System charges our Batteries that Run our services 24hrs a day. The Grid is only their to Top off the Batteries if needed, and keep things going on those very overcast days and of course at night . Running the system this way gives us a 50 amp Surge protected very balanced and clean Power system that Feeds the most important systems in the House 24/7.

It makes more sense to invest money in a Good Battery system now.. And Size down the Array to make up for the Battery cost Difference.. You will be very happy you did. Having your Own Power and Backup Power is really the beauty of Going Solar. Also Because the Utilities have yet to start actually paying us Full market rate for our Power We push back to the Grid, again it makes sense to be storing as much as you can for your Future needs. And You will have a place to use your LEAF batteries when it comes time to replace it :)
Grid Tied or not.. It makes Sense to invest some $ in a Good Battery system capable of handling the Load you need. Including your LEAF..
sling wrote:
thew wrote:Don't Forget your Battery Backup~.. !!
I think this was a grid tie system ;)
QueenBee wrote:It might be a bit higher than other areas but it's pretty inline with pricing of under $4 per watt installed. Labor is very expensive unfortunately and that's something that is going to be hard to drive down as easily as the rest of the system prices have.
Wow, glad i'm a do it yourselfer... never even looked at installer costs. Oooooorrrrrrrrr, maybe i should volunteer to install panels for 1/2 the cost of the best offer. I'd still make a killing even doing it "right" - meaning installing boots and such, NOT putting bolts through the roof causing leaks like i imagine many do
2011 Nissan LEAF Silver SL w/ QC port.
Reserved 5/5/11
RAQ 5/6/11 Accepted, Confirmed
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User avatar
RegGuheert
Posts: 6419
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: 7.2 kw grid-tie system in Rhode Island

Wed Feb 13, 2013 11:55 am

thew wrote:Grid Tied or not.. It makes Sense to invest some $ in a Good Battery system capable of handling the Load you need. Including your LEAF..
Batteries in a PV system equals higher cost, lower reliability and lower efficiency. You can expect to replace the balance-of-system components (batteries, inverters, charge controllers) after only 10 years (or less) instead of having a 25-year guarantee like you have with microinverters.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

Smidge204
Posts: 940
Joined: Wed Nov 24, 2010 1:42 pm

Re: 7.2 kw grid-tie system in Rhode Island

Wed Feb 13, 2013 12:19 pm

RegGuheert wrote:Batteries in a PV system equals higher cost, lower reliability and lower efficiency. You can expect to replace the balance-of-system components (batteries, inverters, charge controllers) after only 10 years (or less) instead of having a 25-year guarantee like you have with microinverters.
If you have dramatic TOU or peak electric rates, batteries can save enough money to pay for themselves with surplus, even without solar! There is also no reason to believe adding batteries to a grid-tie system will decrease reliability.

If you're the handy type and willing to try making your own, or have lots of money to spend buying them, use Nickel-Iron storage batteries. They are extremely low maintenance and will gracefully survive even severe abuse.
=Smidge=

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RegGuheert
Posts: 6419
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: 7.2 kw grid-tie system in Rhode Island

Wed Feb 13, 2013 12:26 pm

Smidge204 wrote:There is also no reason to believe adding batteries to a grid-tie system will decrease reliability.
Sure there is. None of the components have a 25-year life like microinverters. Batteries can live between 5 and 15 years. Central inverters and charge controllers have a life of around 10 years.
Smidge204 wrote:If you're the handy type and willing to try making your own, or have lots of money to spend buying them, use Nickel-Iron storage batteries. They are extremely low maintenance and will gracefully survive even severe abuse.
I *have* 24 kWh of NiFe batteries and I used them to power my house for several years. They were anything but low-maintenance: they outgas more than other battery types, meaning they require frequent watering. If you don't keep up with it, they short out and overheat.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

QueenBee
Posts: 1564
Joined: Sun Aug 08, 2010 5:14 pm
Delivery Date: 20 Jun 2011
Leaf Number: 2062
Location: Bellevue (Seattle), WA

Re: 7.2 kw grid-tie system in Rhode Island

Wed Feb 13, 2013 12:43 pm

RegGuheert wrote:
thew wrote:Grid Tied or not.. It makes Sense to invest some $ in a Good Battery system capable of handling the Load you need. Including your LEAF..
Batteries in a PV system equals higher cost, lower reliability and lower efficiency. You can expect to replace the balance-of-system components (batteries, inverters, charge controllers) after only 10 years (or less) instead of having a 25-year guarantee like you have with microinverters.
Definitely agree unless you have no gird to tie to, or you live somewhere with really unreliable power it's not worth the price. I think a high quality trifuel generator would be a wiser investment, especially if you have natural gas service.

AndyH
Posts: 6388
Joined: Fri Apr 23, 2010 3:43 pm
Location: San Antonio

Re: 7.2 kw grid-tie system in Rhode Island

Sun Feb 17, 2013 11:24 am

QueenBee wrote:
RegGuheert wrote:
thew wrote:Grid Tied or not.. It makes Sense to invest some $ in a Good Battery system capable of handling the Load you need. Including your LEAF..
Batteries in a PV system equals higher cost, lower reliability and lower efficiency. You can expect to replace the balance-of-system components (batteries, inverters, charge controllers) after only 10 years (or less) instead of having a 25-year guarantee like you have with microinverters.
Definitely agree unless you have no gird to tie to, or you live somewhere with really unreliable power it's not worth the price. I think a high quality trifuel generator would be a wiser investment, especially if you have natural gas service.
You're missing the point. Talk to the people on the East Coast that make a generator decision based solely on the assumed availability of either a fuel station or a functioning natural gas line.

A battery bank doesn't need an electrically-supported gas line, and keeps the homeowner out of the other electrically-supported "gas line".

My Midnite Solar charge controller is expected to live beyond 20 years. A properly sized bank of industrial batteries in back-up service will do the same.
"The stupid become extinct."-Bill Mollison
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User avatar
RegGuheert
Posts: 6419
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: 7.2 kw grid-tie system in Rhode Island

Sun Feb 17, 2013 2:12 pm

AndyH wrote:You're missing the point. Talk to the people on the East Coast that make a generator decision based solely on the assumed availability of either a fuel station or a functioning natural gas line.

A battery bank doesn't need an electrically-supported gas line, and keeps the homeowner out of the other electrically-supported "gas line".
No argument. I'm just pointing out that there is a cost associated with taking this approach.
AndyH wrote:My Midnite Solar charge controller is expected to live beyond 20 years.
By whom? Not by Midnite Solar. Here is their latest warranty statement from the Classic manual:
Warranty
MidNite Solar's Classic comes with a standard 5 year warranty we will repair or replace the Classic at no charge to the consumer during this 5 year period
Microinverter manufacturers warranty their inverters for 25 years. Not 5 years. 5 years is the length of warranty you offer on a product which you do NOT expect to last for over 20 years. My guess is the MTBF is on the order of 5-10 years like other hand-crafted multi-kilowatt power electronic item like the Midnite Solar Classic Controller.

Your multi-kilowatt inverter also likely has a similar 5-year warranty.

Note that just two years ago they had an additional offer in the manual which is now removed:
End of Warranty tune up
MidNite Solar offers a industry first Tune up / Extended Warranty. 6 months prior to the end of the
warranty period Customers can ship their Classic back to MidNite Solar with a check for $125 dollars and
we will replace any wearable items like the fans and the capacitors and in general tune the Classic up.
This will also extend the warranty by 2 additional years as well.
If I combine this old statement with recent firmware updates that Midnite has released which aim to reduce fan runtime, I will make the extrapolation that they are experiencing fan failures which of course leads to failure of the electronics.

Finally, I will note that the latest firmware reduces the maximum current for some modes by more than 5% than what was allowed 2 years ago. Again, I believe this is indicative that Midnite Solar is experiencing some warranty failures and is having to reign in their SOA limits on this controller.

Don't get me wrong, I hope your Classic Controller lasts over 20 years. This controller uses a very innovative power stage design which exceeds all the predecessors. But the manufacturing techniques and build quality are similar to what has been used in renewable energy for many years. I simply do not think there is much chance that it will show a step change in MTBF like has been achieved with microinverters.
AndyH wrote:A properly sized bank of industrial batteries in back-up service will do the same.
Agreed that a battery bank in float service can last 20 years. But I thought I was responded to someone who was using the battery in daily cycling service. I may have understood.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

QueenBee
Posts: 1564
Joined: Sun Aug 08, 2010 5:14 pm
Delivery Date: 20 Jun 2011
Leaf Number: 2062
Location: Bellevue (Seattle), WA

Re: 7.2 kw grid-tie system in Rhode Island

Sun Feb 17, 2013 2:41 pm

RegGuheert wrote: I'm just pointing out that there is a cost associated with taking this approach.
AndyH wrote:My Midnite Solar charge controller is expected to live beyond 20 years.
By whom? Not by Midnite Solar. Here is their latest warranty statement from the Classic manual:
Warranty
MidNite Solar's Classic comes with a standard 5 year warranty we will repair or replace the Classic at no charge to the consumer during this 5 year period
Microinverter manufacturers warranty their inverters for 25 years. Not 5 years. 5 years is the length of warranty you offer on a product which you do NOT expect to last for over 20 years. My guess is the MTBF is on the order of 5-10 years like other hand-crafted multi-kilowatt power electronic item like the Midnite Solar Classic Controller.

Your multi-kilowatt inverter also likely has a similar 5-year warranty.

Note that just two years ago they had an additional offer in the manual which is now removed:
End of Warranty tune up
MidNite Solar offers a industry first Tune up / Extended Warranty. 6 months prior to the end of the
warranty period Customers can ship their Classic back to MidNite Solar with a check for $125 dollars and
we will replace any wearable items like the fans and the capacitors and in general tune the Classic up.
This will also extend the warranty by 2 additional years as well.
If I combine this old statement with recent firmware updates that Midnite has released which aim to reduce fan runtime, I will make the extrapolation that they are experiencing fan failures which of course leads to failure of the electronics.

Finally, I will note that the latest firmware reduces the maximum current for some modes by more than 5% than what was allowed 2 years ago. Again, I believe this is indicative that Midnite Solar is experiencing some warranty failures and is having to reign in their SOA limits on this controller.

Don't get me wrong, I hope your Classic Controller lasts over 20 years. This controller uses a very innovative power stage design which exceeds all the predecessors. But the manufacturing techniques and build quality are similar to what has been used in renewable energy for many years. I simply do not think there is much chance that it will show a step change in MTBF like has been achieved with microinverters.
Oh man, not this debate again! Unless something has changed I don't think you'll be able to convince Andy of your points.

But for me the odds are the power is going to go out in the winterish months, and it's likely going to not be sunny when it does go out so you average my worst 6 months I'd get 164kwh per month of production or 5.4kwh per day or 220 watts an hour. Going to get a little bit of a headstart with whatever is stored in the batteries but that's what my little house uses to run it self when no one is home. A portable generator costs a fraction of a system to harness my PV to batteries and could power my entire house (But only being able to charge the car, run the heat pump, or run the dryer one at a time) using natural gas as the primary fuel and propane/gas as backups. I could even help out the near by neighbors with it.

AndyH
Posts: 6388
Joined: Fri Apr 23, 2010 3:43 pm
Location: San Antonio

Re: 7.2 kw grid-tie system in Rhode Island

Sun Feb 17, 2013 3:33 pm

RegGuheert wrote:
AndyH wrote:You're missing the point. Talk to the people on the East Coast that make a generator decision based solely on the assumed availability of either a fuel station or a functioning natural gas line.

A battery bank doesn't need an electrically-supported gas line, and keeps the homeowner out of the other electrically-supported "gas line".
No argument. I'm just pointing out that there is a cost associated with taking this approach.
AndyH wrote:My Midnite Solar charge controller is expected to live beyond 20 years.
By whom? Not by Midnite Solar. Here is their latest warranty statement from the Classic manual:
Warranty
MidNite Solar's Classic comes with a standard 5 year warranty we will repair or replace the Classic at no charge to the consumer during this 5 year period
Microinverter manufacturers warranty their inverters for 25 years. Not 5 years. 5 years is the length of warranty you offer on a product which you do NOT expect to last for over 20 years. My guess is the MTBF is on the order of 5-10 years like other hand-crafted multi-kilowatt power electronic item like the Midnite Solar Classic Controller.

Your multi-kilowatt inverter also likely has a similar 5-year warranty.

Note that just two years ago they had an additional offer in the manual which is now removed:
End of Warranty tune up
MidNite Solar offers a industry first Tune up / Extended Warranty. 6 months prior to the end of the
warranty period Customers can ship their Classic back to MidNite Solar with a check for $125 dollars and
we will replace any wearable items like the fans and the capacitors and in general tune the Classic up.
This will also extend the warranty by 2 additional years as well.
If I combine this old statement with recent firmware updates that Midnite has released which aim to reduce fan runtime, I will make the extrapolation that they are experiencing fan failures which of course leads to failure of the electronics.

Finally, I will note that the latest firmware reduces the maximum current for some modes by more than 5% than what was allowed 2 years ago. Again, I believe this is indicative that Midnite Solar is experiencing some warranty failures and is having to reign in their SOA limits on this controller.

Don't get me wrong, I hope your Classic Controller lasts over 20 years. This controller uses a very innovative power stage design which exceeds all the predecessors. But the manufacturing techniques and build quality are similar to what has been used in renewable energy for many years. I simply do not think there is much chance that it will show a step change in MTBF like has been achieved with microinverters.
AndyH wrote:A properly sized bank of industrial batteries in back-up service will do the same.
Agreed that a battery bank in float service can last 20 years. But I thought I was responded to someone who was using the battery in daily cycling service. I may have understood.
Sorry for the disconnect, RegGuheert - I was replying to QueenBee's suggestion that a generator is better than a battery for a grid-tied backup.

I'm not concerned about the warranty terms - I'm interested in how long the equipment will actually last. Before I chose my components, I spent some time with the designers/engineers. Because I'm the system designer/installer, I'm able to size and locate components to maximize life. My focus is completely off-grid anyway, and I'm capable of swapping capacitors when they reach end of life, so I'm much happier self-insuring/self-warranting a single charge controller and a single inverter. I'm not suggesting anyone should make the same choices for the same reasons.

But I'd still highly recommend at least some battery capability in the system as our power grid isn't getting any more stable or hacker-proof, and weather isn't going to be back to normal in our lifetimes...
"The stupid become extinct."-Bill Mollison
2018 Outlander PHEV
2015 smart Electric Drive (lease ended Feb, 2018)
OpenEVSE Plus DIY

AndyH
Posts: 6388
Joined: Fri Apr 23, 2010 3:43 pm
Location: San Antonio

Re: 7.2 kw grid-tie system in Rhode Island

Sun Feb 17, 2013 3:46 pm

QueenBee wrote:
But for me the odds are the power is going to go out in the winterish months, and it's likely going to not be sunny when it does go out so you average my worst 6 months I'd get 164kwh per month of production or 5.4kwh per day or 220 watts an hour. Going to get a little bit of a headstart with whatever is stored in the batteries but that's what my little house uses to run it self when no one is home. A portable generator costs a fraction of a system to harness my PV to batteries and could power my entire house (But only being able to charge the car, run the heat pump, or run the dryer one at a time) using natural gas as the primary fuel and propane/gas as backups. I could even help out the near by neighbors with it.
None of the battery proponents are suggesting anyone include a battery capable of powering the entire house - I know I'm certainly not. A decent generator designed to deliver a long life won't be much less expensive than an emergency back-up battery. The rule of thumb is similar for both - if one can pick up the (generator, battery) then it's not a good choice for backup power...

In the old off-grid days, everyone used 'pure' DC systems. When early inverters hit the streets, folks started adding AC circuits to their buildings. As things evolved, the pendulum ran to 100% AC with no DC circuits. There's renewed interested in DC circuits again. There's a similar pendulum swing with grid-connected power - turn of the last century some houses had generators and battery banks. A desire to provide some level of disaster proofing is bringing more interest in some level of home-scale uninterruptible power. I think that people that prepare are wise - they tend to not be stuck in overfilled shelters when things go wrong.
"The stupid become extinct."-Bill Mollison
2018 Outlander PHEV
2015 smart Electric Drive (lease ended Feb, 2018)
OpenEVSE Plus DIY

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