Solar Panels

[Gonewild]

[/quote]Here in AZ, we get a $2.15w rebate from SRP now, AND net metering/meter runs backward too! So, that means from 3-6PM every weekday, we get paid .34/kwh which most will be unused because that's peak time. [/quote]
I am on the other TOU 1pm-8PM I get more on peak so it is more savings because I am selling power when the sun is out. I get 2 more hours of on peak but loose 2 at the other end but it is also cooler in the evening.

 

[LEAFfan]

Here in AZ, we get a $2.15w rebate from SRP now, AND net metering/meter runs backward too! So, that means from 3-6PM every weekday, we get paid .34/kwh which most will be unused because that's peak time. [/quote]
I am on the other TOU 1pm-8PM I get more on peak so it is more savings because I am selling power when the sun is out. I get 2 more hours of on peak but loose 2 at the other end but it is also cooler in the evening.[/quote]

Ya, but I LOVE the 3-hour on peak time...our bill last month and this month (peak months) was only $150. That's over $100 cheaper than the houses down the street with the same sq. footage. But I did recheck on the net metering...the first person I talked to at SRP was incorrect so I wanted to be sure and called an 'expert' on the solar panels. She told me the 'buyback rate' is only .03-.04 a kwh. We're not really doing this just to save a little on the electric, but to help the environment and be greener. So now, I'm wondering what the minimum size we would need to charge the LEAF without using SRP's grid? Thanks!

 

[Azrich]

Here in AZ, we get a $2.15w rebate from SRP now, AND net metering/meter runs backward too! So, that means from 3-6PM every weekday, we get paid .03-.04/kwh which most will be unused because that's peak time.

My electric company is Tucson Electric Power (TEP). I was able to get $3.00 per watt rebate, but I hear it is now lowered to $2.50/watt. My Peak time is from 2 pm to 6 pm, with two hours of "shoulder rates" on either side. However, I chose the option to have Off Peak all week end.

I'll be interested to see what happens to our electric bill once the panels are installed. Our average use last year was 1150 kWh a month, but we have made changes to the roof, some of our appliances, and will soon get a new air conditioner/furnace (ours is 25 years old and not efficient.) We are also replacing our six skylights with double-pane, low-e glass skylights. They have cheap plastic on them now. We are doing what we can to lower our home electric use so the LEAF's charging will not be much of a change in our average use.

 

[LEAFfan]

[

Richard, do you have any idea how big a system we will need to charge the LEAF without using the grid? I want to tell people that this car is truly zero emissions. I'm planning on using thin-cell panels and since we don't have any obstructions, I don't think we need individual enphase inverters. I was hoping around 3KW which should only be around $6-7K after rebates and credits.

 

[lne937s]

[

Richard, do you have any idea how big a system we will need to charge the LEAF without using the grid? I want to tell people that this car is truly zero emissions. I'm planning on using thin-cell panels and since we don't have any obstructions, I don't think we need individual enphase inverters. I was hoping around 3KW which should only be around $6-7K after rebates and credits.

Current indications put the LEAF at ~5 miles per kWh (although some people have guessed 4/kwh). If you go 1000 miles per month, that's 200 kWh (250). So, with 3 kWh of solar panels, you would need to average 2.5-3 hours of peak sunlight per day to charge the car- you will probably have electricity left over. However, if you charge after dark, you still need the grid, you are just displacing your consumption.

 

[mwalsh]

However, if you charge after dark, you still need the grid, you are just displacing your consumption.

Sure, but someone else, somewhere, gets to use your solar generation during the day instead of "dirty power". So I personally have less guilt over using grid power after dark. Though I would obviously prefer that it be obtained from greener sources whenever possible.

 

[LEAFfan]

[

Richard, do you have any idea how big a system we will need to charge the LEAF without using the grid? I want to tell people that this car is truly zero emissions. I'm planning on using thin-cell panels and since we don't have any obstructions, I don't think we need individual enphase inverters. I was hoping around 3KW which should only be around $6-7K after rebates and credits.

Current indications put the LEAF at ~5 miles per kWh (although some people have guessed 4/kwh). If you go 1000 miles per month, that's 200 kWh (250). So, with 3 kWh of solar panels, you would need to average 2.5-3 hours of peak sunlight per day to charge the car- you will probably have electricity left over. However, if you charge after dark, you still need the grid, you are just displacing your consumption.

Thanks Ine...The only time I don't want to charge is the 3-6PM weekdays. All other times, holidays, and weekends are off-peak. So it sounds like I could charge before nightfall here in AZ (most of the time less than half charge needed)
So Ine, what do you think would be the minimum size of pv's...would you go lower than 3KW?

 

[greenleaf]

[

Richard, do you have any idea how big a system we will need to charge the LEAF without using the grid? I want to tell people that this car is truly zero emissions. I'm planning on using thin-cell panels and since we don't have any obstructions, I don't think we need individual enphase inverters. I was hoping around 3KW which should only be around $6-7K after rebates and credits.

Current indications put the LEAF at ~5 miles per kWh (although some people have guessed 4/kwh). If you go 1000 miles per month, that's 200 kWh (250). So, with 3 kWh of solar panels, you would need to average 2.5-3 hours of peak sunlight per day to charge the car- you will probably have electricity left over. However, if you charge after dark, you still need the grid, you are just displacing your consumption.

The numbers are pretty close to what I figured.

My commute each day is around 40 miles. Since battery cap is 24 kWh, I assume I need to top up about 12 kWh each night (allowing for some losses). If I commute 20 days a month, this is 240 kWh.

I added the 240 kWh / month to my current usage pattern into a spreadsheet. A 3 kW DC system would cater to the electric car with left overs to spare.

 

[Gonewild]

However, if you charge after dark, you still need the grid, you are just displacing your consumption.

Sure, but someone else, somewhere, gets to use your solar generation during the day instead of "dirty power". So I personally have less guilt over using grid power after dark. Though I would obviously prefer that it be obtained from greener sources whenever possible.

You put your unused power on the grid by day and use your power at night so you can say it not dirty because it was store for you earlier.

 

[Gonewild]

I bought a 5.16k system and it will off set all my daily used and any left overs will be used to charge my Leaf. I am not sure what my over all bill will be but it will be lower without all the changes I have done.

 

[LEAFfan]

[/quote]

Richard, do you have any idea how big a system we will need to charge the LEAF without using the grid? I want to tell people that this car is truly zero emissions. I'm planning on using thin-cell panels and since we don't have any obstructions, I don't think we need individual enphase inverters. I was hoping around 3KW which should only be around $6-7K after rebates and credits. [/quote]

Current indications put the LEAF at ~5 miles per kWh (although some people have guessed 4/kwh). If you go 1000 miles per month, that's 200 kWh (250). So, with 3 kWh of solar panels, you would need to average 2.5-3 hours of peak sunlight per day to charge the car- you will probably have electricity left over. However, if you charge after dark, you still need the grid, you are just displacing your consumption.[/quote]
The numbers are pretty close to what I figured.

My commute each day is around 40 miles. Since battery cap is 24 kWh, I assume I need to top up about 12 kWh each night (allowing for some losses). If I commute 20 days a month, this is 240 kWh.

I added the 240 kWh / month to my current usage pattern into a spreadsheet. A 3 kW DC system would cater to the electric car with left overs to spare.[/quote]

Greenleaf, so are you saying a 3KW system would be good? You wouldn't go lower since you would have some left over?
Here in AZ, I'm guessing our peak hours are right now 6AM-4PM. Does that sound right?

 

[greenleaf]

The price has come down some. The pricing I get is negotiated by 1BOG at $5.24 per DC watt (installed). Monitoring and micro-inverters are extra if I want them. There's no shade on my roof so I don't really need microinverters.

I am thinking of a 3.22 kW system. Gross cost is $16872.80. Net cost after all incentives is around $10600.

That exact system's net cost for me in AZ would be around $6300! The 30% fed tax credit can be taken over how many years? I was thinking at least 5? Oh, greenleaf, could you get me a GROSS cost on a 5 KW system? Do you know if 1BOG is in AZ? Thanks!

Leafan I missed out answering your question.

The 1BOG pricing is based on the DC watt you are installing (subject to a minimum of 2.4kW I think). There is an active campaign in Phoenix. I don't know the current pricing unless I sign up but the last campaign price was $5.70/DC watt with REC solar. So, if you put up a 5 kW DC system, your gross price is 5000 x 5.70.

http://solarphoenix.1bog.org/phoenix-solar-panel-cost/

I suspect the current price should be in the low five dollars.

Note $5.70 is the base price -- which typically means composite roof, single story, 1-array etc. You pay more if your conditions are different.

 

[greenleaf]

Greenleaf, so are you saying a 3KW system would be good? You wouldn't go lower since you would have some left over?
Here in AZ, I'm guessing our peak hours are right now 6AM-4PM. Does that sound right?

Electricity rates are in tiers. At the highest tiers (e.g. $0.40 per kWh), solar energy is very competitive to the local utility. But at say $0.06 per kWh, solar energy is expensive. My intention is to eliminate the high tiers and still depend on the local utility for the low tiers. My 3.22 kW system should be able to do that.

 

[greenleaf]

leaffan,

You can use this calculator

http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/US/Arizona/

to figure out the amount of electricity (in kWh) a system can generate in a year. The calculator takes into account the sun's position throughout the year.

You can match this to the commute you have in mind with your car (figure around 300 kWh per 1000 mile of commute each month).

Example, if you commute 1500 miles a month, the Leaf consumption would be around 450 kWh each month, or 5400 kWh a year. A 3.3kW DC system would produce 5500 kWh a year for a location in Phoenix (I assume your utility company allows you to net off your usage once a year).

 

[LEAFfan]

Greenleaf, so are you saying a 3KW system would be good? You wouldn't go lower since you would have some left over?
Here in AZ, I'm guessing our peak hours are right now 6AM-4PM. Does that sound right?

Electricity rates are in tiers. At the highest tiers (e.g. $0.40 per kWh), solar energy is very competitive to the local utility. But at say $0.06 per kWh, solar energy is expensive. My intention is to eliminate the high tiers and still depend on the local utility for the low tiers. My 3.22 kW system should be able to do that.[/quote]

Here, we have only two tiers: .08 and .34...the .34 is ONLY between 3-6PM weekdays. All other times with holidays are .08. I want to do that too. Our EU is running out of solar monies, so she said to 'lock' it in as soon as possible and I have to have a KW figure to do that.

 

[lne937s]

leaffan,

You can use this calculator

http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/US/Arizona/

to figure out the amount of electricity (in kWh) a system can generate in a year. The calculator takes into account the sun's position throughout the year.

You can match this to the commute you have in mind with your car (figure around 300 kWh per 1000 mile of commute each month).

Example, if you commute 1500 miles a month, the Leaf consumption would be around 450 kWh each month, or 5400 kWh a year. A 3.3kW DC system would produce 5500 kWh a year for a location in Phoenix (I assume your utility company allows you to net off your usage once a year).

Where do you get 300 kWh per 1000 miles? Even if you use the full battery's capacity of 24 kWh to go 100 miles (worst case assumption- figuring there is no buffer zone in the battery), that is 240 kWh/month.

 

[greenleaf]

Greenleaf, so are you saying a 3KW system would be good? You wouldn't go lower since you would have some left over?
Here in AZ, I'm guessing our peak hours are right now 6AM-4PM. Does that sound right?

Electricity rates are in tiers. At the highest tiers (e.g. $0.40 per kWh), solar energy is very competitive to the local utility. But at say $0.06 per kWh, solar energy is expensive. My intention is to eliminate the high tiers and still depend on the local utility for the low tiers. My 3.22 kW system should be able to do that.

Here, we have only two tiers: .08 and .34...the .34 is ONLY between 3-6PM weekdays. All other times with holidays are .08. I want to do that too. Our EU is running out of solar monies, so she said to 'lock' it in as soon as possible and I have to have a KW figure to do that.[/quote]
At 0.08, I think it will take a very LONG time to breakeven (since I assume you can charge at times other than 3-6pm) unless rates are changed.

 

[greenleaf]

leaffan,

You can use this calculator

http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/US/Arizona/

to figure out the amount of electricity (in kWh) a system can generate in a year. The calculator takes into account the sun's position throughout the year.

You can match this to the commute you have in mind with your car (figure around 300 kWh per 1000 mile of commute each month).

Example, if you commute 1500 miles a month, the Leaf consumption would be around 450 kWh each month, or 5400 kWh a year. A 3.3kW DC system would produce 5500 kWh a year for a location in Phoenix (I assume your utility company allows you to net off your usage once a year).

Where do you get 300 kWh per 1000 miles? Even if you use the full battery's capacity of 24 kWh to go 100 miles (worst case assumption- figuring there is no buffer zone in the battery), that is 240 kWh/month.

I am allowing for losses. OK, losses of 25% is probably too much. Maybe you could figure in 10% losses in the charging system

 

[LEAFfan]

Greenleaf, so are you saying a 3KW system would be good? You wouldn't go lower since you would have some left over?
Here in AZ, I'm guessing our peak hours are right now 6AM-4PM. Does that sound right?

Electricity rates are in tiers. At the highest tiers (e.g. $0.40 per kWh), solar energy is very competitive to the local utility. But at say $0.06 per kWh, solar energy is expensive. My intention is to eliminate the high tiers and still depend on the local utility for the low tiers. My 3.22 kW system should be able to do that.

Here, we have only two tiers: .08 and .34...the .34 is ONLY between 3-6PM weekdays. All other times with holidays are .08. I want to do that too. Our EU is running out of solar monies, so she said to 'lock' it in as soon as possible and I have to have a KW figure to do that.

At 0.08, I think it will take a very LONG time to breakeven (since I assume you can charge at times other than 3-6pm) unless rates are changed.[/quote]


Oh, you may have missed a post on another thread...I don't really care about the payback on the system, I just want to drive a totally emissions free vehicle and help our environment. Our electric bill is way below the average already and I don't really believe the charging is going to add much with the pvs. I know it will be less than .02/mi. to charge.

 

[greenleaf]

Oh, you may have missed a post on another thread...I don't really care about the payback on the system, I just want to drive a totally emissions free vehicle and help our environment. Our electric bill is way below the average already and I don't really believe the charging is going to add much with the pvs. I know it will be less than .02/mi. to charge.

In that case, the calculator I posted earlier would work very well for you to estimate. The grid would funciton as a giant "backup battery" if you charge at night.