LKK
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Re: Can I divert excess solar power to my LEAF?

Thu Feb 25, 2016 2:12 pm

After seeing how my utility treats solar user I've been thinking of taking my solar system off grid. Its not practical food me to go totally off the grid but I'm wondering if I could use the Powerwall or something like that to act as a buffer and a regulated voltage system for new circuits that are separate and isolated from the grid. The idea is to run a separate circuit from the Powerwall to my garage to plugin my EV. By doing this my solar system will be available when the grid is down.

miscrms
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Re: Can I divert excess solar power to my LEAF?

Thu Feb 25, 2016 2:17 pm

davewill wrote:It is technically possible. If you were to build an OpenEVSE and modify your firmware to monitor your solar output, you could indeed change the output level to match your output. Monitoring your current usage would be harder, but there are ways to do that, too, if you're dedicated enough. You could even install the OpenEVSE hardware inside your Blink case, replacing the smarts that are there now.
I was wondering about this. Has it been confirmed that the Leaf will react to a change in the EVSE's max current signal during a charge cycle?

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DaveEV
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Re: Can I divert excess solar power to my LEAF?

Fri Feb 26, 2016 1:38 am

miscrms wrote:I was wondering about this. Has it been confirmed that the Leaf will react to a change in the EVSE's max current signal during a charge cycle?
Yes, quite some time ago.

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Marktm
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Re: Can I divert excess solar power to my LEAF?

Fri Feb 26, 2016 11:47 am

davewill wrote:It is technically possible. If you were to build an OpenEVSE and modify your firmware to monitor your solar output, you could indeed change the output level to match your output. Monitoring your current usage would be harder, but there are ways to do that, too, if you're dedicated enough. .
I have the deluxe 30 amp model that I built from a kit and will be attempting to monitor a battery pack voltage to adjust the amp setting on the level 2 charger for my Leaf. This is purely experimental in nature to learn more about "programming" the OpenEsve with the hopes I can eventually charge my Leaf off-grid with a 48 volt DC/208 volt AC inverter that I have (re-purposed UPS). Would this be a major undertaking for someone not that familiar with arduino hardware/software development? I'm certainly up for the learning experience.

BTW, the solar off grid based system is already in place at a rural location where the Leaf will eventually reside. As a new Leaf owner, I've been posting about making this "100 mile trip" on this forum and feel confident at this point.
2012 Leaf SL; 46,000 miles. Battery replaced November 1st, 2016.

NeilBlanchard
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Re: Can I divert excess solar power to my LEAF?

Mon Feb 29, 2016 10:33 am

There are only two ways to use the actual electricity from your solar PV panels in your Leaf is to:

1) charge the Leaf while the sun is shining

2) get a home battery storage system, like the Tesla Powerwall.

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Marktm
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Re: Can I divert excess solar power to my LEAF?

Thu Mar 03, 2016 10:17 am

NeilBlanchard wrote:There are only two ways to use the actual electricity from your solar PV panels in your Leaf is to:

1) charge the Leaf while the sun is shining

2) get a home battery storage system, like the Tesla Powerwall.

Yes, my hope is to "opportunity" charge and get the max energy during a typical sunny day cycle from the panels. Since no one (that I can find) makes a high voltage MPPT charger that accomodates the EV type batteries, it is looking more like some type of HEMSx (Honda) or PowerWall will be required to fill the gap. The issue is grid-tied. My goal is off-grid emergency use of the EV, which presents another set of problems essentially requires DC/DC MPPT charging to get reasonable efficiencies.
2012 Leaf SL; 46,000 miles. Battery replaced November 1st, 2016.

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davewill
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Re: Can I divert excess solar power to my LEAF?

Fri Mar 04, 2016 7:22 pm

My feeling is that the electric vehicle doesn't make a good off-grid storage device...for a couple of reasons. First we usually like to drive around in the daytime more than we do at night. Kinda hard to charge it and drive it at the same time. Second, if you run the car's battery down at night, how will you drive anywhere? It's best, I think to get your off grid system going, but include enough renewable generation to keep the car topped up, too.

Besides, EV batteries degrade badly enough without putting them through extra cycles using them as daily storage. Now if you're talking about being grid tied, but being able to use the energy in the car if you get snowed in with no power, then it could work fine. Just get a good inverter and use it to keep your fridge and a couple of essentials going.
2014 Rav4 EV, Blizzard Pearl White
2011 LEAF SL w/QC, Blue Ocean, returned at end of lease

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Marktm
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Re: Can I divert excess solar power to my LEAF?

Fri Jun 17, 2016 2:13 pm

davewill wrote: Now if you're talking about being grid tied, but being able to use the energy in the car if you get snowed in with no power, then it could work fine. Just get a good inverter and use it to keep your fridge and a couple of essentials going.
Use of the Leaf's battery in emergency off-grid mode has a major missing link - the inverter. I don't know of any reasonably priced, efficient, high VDC to 240 VAC (split phase) inverter designed for off-grid use. Some of the UPSs operate in the range of 400 VDC, but require a center DC tap (which is accessible from the Leaf in the emergency plug). However the UPS "0" VDC appears to NOT be isolated from the AC neutral. Not being an electrical engineer, I'm not sure, but I believe that could be a real problem when connected to the Leaf's battery.
2012 Leaf SL; 46,000 miles. Battery replaced November 1st, 2016.

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davewill
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Re: Can I divert excess solar power to my LEAF?

Fri Jun 17, 2016 9:43 pm

Marktm wrote:
davewill wrote: Now if you're talking about being grid tied, but being able to use the energy in the car if you get snowed in with no power, then it could work fine. Just get a good inverter and use it to keep your fridge and a couple of essentials going.
Use of the Leaf's battery in emergency off-grid mode has a major missing link - the inverter. I don't know of any reasonably priced, efficient, high VDC to 240 VAC (split phase) inverter designed for off-grid use. Some of the UPSs operate in the range of 400 VDC, but require a center DC tap (which is accessible from the Leaf in the emergency plug). However the UPS "0" VDC appears to NOT be isolated from the AC neutral. Not being an electrical engineer, I'm not sure, but I believe that could be a real problem when connected to the Leaf's battery.
Nissan sold one in Japan that plugged into the CHAdeMO port, but that wasn't what I was suggesting. Most people who have done this use the 12v bus to feed the inverter. You have to leave the car on so that the DC to DC converter will operate. Only good for emergencies.
2014 Rav4 EV, Blizzard Pearl White
2011 LEAF SL w/QC, Blue Ocean, returned at end of lease

knightmb
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Re: Can I divert excess solar power to my LEAF?

Fri Jun 17, 2016 10:29 pm

If the goal to avoid sending extra power to the utility company because they are offering such terrible return rates, you could set a charge timer on the Leaf to just charge when the sun is brightest from the solar. I am not sure how it would work into your drive schedule though if you need to use it at the same time.

The best you could do with the Leaf as an extra power source is use the 12 volt system to power an inverter that runs under 2kW of power as either emergency power in an outage or custom systems in the home to draw and use the power. I use my Leaf to power a separate AC/Heat in my home for example. It won't run a stove or hot water heater, but it can keep the home warm/cool and power some outlets for TV, Microwave, Fridge, etc.
2013 Leaf SV

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