Considering solar panels to offset charging costs

[moonpoint]

Last week, I leased a new 2013 s(with QC). We have PGE(here in the bay area),and as my electric rate in E-1 is about 30c per kWh, am looking for ways to minimize daily charging costs.

I have signed up for the TOU rates in EV-A, but as I work from home somedays, we have a fair bit of energy consumption during the peak hours(2-7pm), so not very hopeful of reducing charge costs over all.

If I were to go solar, say with 2.4kWh capacity, what are the prevailing price-per-watt rates in the bay area. After tax incentives and all,
$3 or $4 or much more or less... (I looked at solar in 2011, I think it came to be about $3.25 ppw, which I didn't go for at that time...

 

[DNAinaGoodWay]

Just curious. 2.4 kW doesn't seem like much, it's what, 10 panels? Roof limitations? Would probably offset your LEAF usage at about 300 kWhs/month, but nothing left for the house. Anyway, good luck.

 

[iDriver]

You're in luck! I just so happen to have a 2.6kwh system (11 panels). Specifically chosen for my house and car needs. It's more than enough for my house and the car, provided you're charging your car at night on Off Peak. Keep in mind, my house is smallish 1500sqft and I live in Sacramento where it's sunny often. If my A/C isn't running, my house uses less that 500wth. My A/C doesn't run often due to my house being very efficient. So there was no need to get a larger system to offset my A/C on hot days.

I'm on the PG&E E9A rate, and my cost is $0.40 (roughly) per KWH during peak (2-9pm), Solar is actually going strong at that time because the sun is up, my Off Peak (Midnight-7am) is $0.04kwh.

So every kwh I pump into the grid is worth TEN off peak. Basically, as long as I can produce 2.5kwh MORE than I use DURING the Peak time frame I've earned enough to cover an entire empty-to-full charging session.

It's working just fine.

 

[GRA]

<snip>
Keep in mind, my house is smallish 1500sqft and I live in Sacramento where it's sunny often. If my A/C isn't running, my house uses less that 500wth. <snip>

I'm on the PG&E E9A rate, and my cost is $0.40 (roughly) per KWH during peak (2-9pm), Solar is actually going strong at that time because the sun is up, my Off Peak (Midnight-7am) is $0.04kwh.
<snip>

OT. You're in Sacramento but you get your juice from PG&E? What happened to SMUD?

 

[DeaneG]

I have a 3-year-old 2.5kWac/3kWdc system on a west-facing roof, producing about 4.2MWh per year. My goal was to keep my house out of Tier 2 and above during the summer. It would be nice to have 30% greater capacity, but we were roof-space limited (avoiding visibility from the street), and the higher-efficiency panels were very expensive at the time.

All in all I'm very glad we did it, but I may have been a year or two early in implementation.

 

[moonpoint]

Thanks for all the replies.
DNAinaGoodWay: Yes, I am limited by the roof size(some tiles have vents, so have space for 10x 230W panels only ).
Am also trying to keep my initial capital costs down. My goal is to keep myself out of tier-3 (>11kWh/day) in the most economical way.

 

[moonpoint]

I got a quote for $17k (before the 30% federal tax credit)

Not sure if this is a good deal.

The price per watt(I used the dc watt, should I use the DC or the lower A/C - which one do solar professionals mean when they talk about ppw)

$3.67 (after federal discounts - $12,079/3270 dc Watts)
Before estimated fed tax discount
$5.25 ($17,170/3270)

thanks in advance

--------------

System Details
Year 1 Estimated Production: 4,729 KWH
3.27 kW (DC), 2.80 kW (AC) SunPower System
10 x SunPower E20/327 Solar Panel

 

[swaltner]

I got a quote for $17k (before the 30% federal tax credit)
...
$3.67 (after federal discounts - $12,079/3270 dc Watts)
Before estimated fed tax discount
$5.25 ($17,170/3270)
...

Seems a little high to me. I'd definitely look for a quote from a different vendor to do some comparison shopping.

I just received a quote of $10,200 for a 3.5 kW (14x 250 W modules, 14x Enphase M215 microinverters) *expansion* to an existing installation. That price is before tax incentives and comes in at $2.91 per DC Watt. Note that this since this is an expansion, the costs are lower than typical. All the base electrical infrastructure is already in place and this is a straight-forward install on a metal roof (aircraft hangar). My initial 5 kW installation (completed July 2012) came in at $4.62 per W (before tax credits).

 

[smkettner]

That is about what I paid.

 

[moonpoint]

smkettner, swaltner: thank you.
I am going to get quotes from a couple more dealers. Hopefully, with a lower costs I can break even under 10 years. Otherwise it is hard to justify these costs for myself.

The EV1 rates at off peak hours from PGE here in California is about 10 cents/kWh.

At the current quoted install, the cost is 13 cents/kWh (estimated over 20 years per the solar quote)

 

[DNAinaGoodWay]

It's a big outlay. Always a good idea to take as many qoutes as you can get, 10, 20, or as many as you can stand. It's the only way you can discover and compare the market. Not just on price either, look at the quality, availability, and past performance of the installers. Would definately recommend Enphase over a string inverter, for performance, and warranty.

 

[todatsu]

In my opinion at the current time if you can get a system installed for around $2.50 per watt that would be a decent deal. You might as well use the AC watts since that is what you will be buying / selling. The rest of the DC watts are lost as heat.

Wow! How do you get PG&E to sell to you for $0.04 ? They are giving me a night EV rate of about $0.09 Did you pay for a separate meter? If so, how much did they charge for the meter?

The odd thing is (as was mentioned above) the daytime power costs 4 times more than the nighttime! When I found that out, no more air conditioning for the cat. He will just have to sweat it out in the afternoon.

One of your better alternatives (neglecting the cost of the equipment), besides selling your power during the day, is to charge a battery bank during the night and use that power for refrigeration and lights during the day. That way you get to sell all that you can make at peak, and your own use during peak drops to zero. This idea is starting to gain some limited traction.

:?:

 

[moonpoint]

I signed a contract for the PV install.
$3.88 dc ppw ($5 ac ppw) Before taxes
After taxes:
$2.72 dc ppw and ( $3.5 ac ppw) After the federal tax credit.
Hopefully the contractor will finish the work this year itself.

2.89 KW(AC) system 3.7 DC = 14 panels x 265
with 14 micro inverters

thanks for your feedback!

 

[DNAinaGoodWay]

Sounds good! Congratulations.

More power to ya!