eyeks
Posts: 6
Joined: Wed May 21, 2014 10:24 am
Delivery Date: 20 May 2014
Leaf Number: 340090

Graph: Impact of Nissan Leaf on Solar generation/consumption

Wed May 28, 2014 10:31 am

See the chart for a typical day of solar generation and use before and after acquiring the Nissan Leaf:

Image

Enjoy!
\eYeks
2014 Leaf-S 36-mo lease 36K $3K-down $180/mo
7.4KW Sunpower Solar Power
---
1992 Toyota Previa 200K miles
2001 Benz CLK430 Cab - 56K miles

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abasile
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Posts: 1922
Joined: Thu Sep 02, 2010 10:49 am
Delivery Date: 20 Apr 2011
Location: Arrowbear Lake, CA

Re: Graph: Impact of Nissan Leaf on Solar generation/consump

Wed May 28, 2014 10:48 am

Very nice. It looks like you are doing the bulk of your charging after arriving home in the evening. For battery longevity and grid friendliness, I'd recommend instead charging in the very early morning hours whenever possible. You can use a charging timer with an end time of, say, 7 AM and no start time.
2011 LEAF at 71K miles, pre-owned 2012 Tesla S 85 at 98K miles
LEAF battery: 9/12 bars and < 49 Ah (-28% vs. new)
Tesla battery: 250+ miles of range (-5% vs. new)

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

Re: Graph: Impact of Nissan Leaf on Solar generation/consump

Wed May 28, 2014 11:06 am

eyeks wrote:See the chart for a typical day of solar generation and use before and after acquiring the Nissan Leaf:

Image

Enjoy!


Nice!

Was there an issue in measuring on the second graph? Was your usage literally zero in the middle of the day?

eyeks
Posts: 6
Joined: Wed May 21, 2014 10:24 am
Delivery Date: 20 May 2014
Leaf Number: 340090

Re: Graph: Impact of Nissan Leaf on Solar generation/consump

Wed May 28, 2014 1:01 pm

QueenBee wrote:Nice!
Was there an issue in measuring on the second graph? Was your usage literally zero in the middle of the day?

I believe the '0' usage is due to separation of generation and consumption metering - when consumption is completely supplied by the panel the consumption goes to '0' - If the graph was single color (net metering) the orange bars would be inverted.
\eYeks
2014 Leaf-S 36-mo lease 36K $3K-down $180/mo
7.4KW Sunpower Solar Power
---
1992 Toyota Previa 200K miles
2001 Benz CLK430 Cab - 56K miles

eyeks
Posts: 6
Joined: Wed May 21, 2014 10:24 am
Delivery Date: 20 May 2014
Leaf Number: 340090

Re: Graph: Impact of Nissan Leaf on Solar generation/consump

Wed May 28, 2014 1:10 pm

abasile wrote:Very nice. It looks like you are doing the bulk of your charging after arriving home in the evening. For battery longevity and grid friendliness, I'd recommend instead charging in the very early morning hours whenever possible. You can use a charging timer with an end time of, say, 7 AM and no start time.
You are right. My off-peak hours on E-7 (grandfathered PG&E circa 2005 rate) start at 6 pm and run through noon M-F. The Leaf-S does not allow setting a start time even though you wouldn't think so if you read the manual (http://1drv.ms/1k18h2L). That's a real problem since I only have L1. The possibility of forgetting to plug in after 6 and being car-less the next day is finite.
Could you elaborate on your 'For battery longevity' comment? I believe I'm grid friendly after 6 pm.

Cheers,
\eYeks
2014 Leaf-S 36-mo lease 36K $3K-down $180/mo
7.4KW Sunpower Solar Power
---
1992 Toyota Previa 200K miles
2001 Benz CLK430 Cab - 56K miles

User avatar
abasile
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Joined: Thu Sep 02, 2010 10:49 am
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Re: Graph: Impact of Nissan Leaf on Solar generation/consump

Wed May 28, 2014 2:22 pm

eyeks wrote:
abasile wrote:Very nice. It looks like you are doing the bulk of your charging after arriving home in the evening. For battery longevity and grid friendliness, I'd recommend instead charging in the very early morning hours whenever possible. You can use a charging timer with an end time of, say, 7 AM and no start time.
You are right. My off-peak hours on E-7 (grandfathered PG&E circa 2005 rate) start at 6 pm and run through noon M-F. The Leaf-S does not allow setting a start time even though you wouldn't think so if you read the manual (http://1drv.ms/1k18h2L). That's a real problem since I only have L1. The possibility of forgetting to plug in after 6 and being car-less the next day is finite.
Could you elaborate on your 'For battery longevity' comment? I believe I'm grid friendly after 6 pm.

On the timer, you don't need to set a start time, just an end time in the AM just before you leave for work.

Li-ion battery longevity tends to be better if the battery spends most of its time at moderate SOC (state of charge) levels, generally at about 80% or below. The optimal "storage" SOC tends to be roughly 30%. By programming the car to wait as long as possible every night to charge, you lower the average SOC which is good for longevity. With the LEAF, this seems to be much less of a factor than battery temperature, however. And since you're leasing, longevity might be less of an issue to you.

"Grid friendliness" is relative. There's still a lot of grid demand in the evening hours when people get home from work. Charging much later at night is preferable since electricity demand is much lower then.

All of that said, don't take any of this advice too far! Above all, do whatever you need to do to make the car useful to you. Personally, I do not hesitate to add charge during peak hours if I need to do multiple drives in a day, given the LEAF's limited range.
2011 LEAF at 71K miles, pre-owned 2012 Tesla S 85 at 98K miles
LEAF battery: 9/12 bars and < 49 Ah (-28% vs. new)
Tesla battery: 250+ miles of range (-5% vs. new)

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

Re: Graph: Impact of Nissan Leaf on Solar generation/consump

Wed May 28, 2014 8:25 pm

eyeks wrote:
QueenBee wrote:Nice!
Was there an issue in measuring on the second graph? Was your usage literally zero in the middle of the day?

I believe the '0' usage is due to separation of generation and consumption metering - when consumption is completely supplied by the panel the consumption goes to '0' - If the graph was single color (net metering) the orange bars would be inverted.


So the "household use" label should really be "bought from the grid"?

Usually you measure generation and the connection to the grid and then add the production and connection to the grid values together.

So if generation is 5kw and power from the grid is 1kw your home is using 6kw.
If generation is 5kw and power from the grid is -2kw your home is using 3kw.

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