PV Solar sizing with and without EV

[Ferdball]

I'm game. Send details.

 

[TonyWilliams]

I'm game. Send details.

Here's the breakfast this Sat:

http://www.myrav4ev.com/forum/viewtopic.php?p=289#p289


For the range test, just give me a jingle when you're avaialble.

858-245-8217

 

[Ferdball]

I'm still not completely digesting the math, but I think there is a consensus that I should size my PV system to my pre-EV use. Should I also add a panel or three, like the US Green Solar guy recommended?

We have an 1800 sq ft home and central air. We have an electric stove, but a gas dryer. We both work, and our kids are okay with the warmer afternoons in the house, so almost no AC during the three seasons. In the summer however, we may have some good AC use. Usage can get up to 850 kWh in a hot month. I do plan on getting a whole house fan though, to minimize the use of AC.

So, can I program a 40A charger to start charging at midnight?

http://www.sdge.com/clean-energy/ev-rates

 

[Ferdball]

Decision why B-class over RAV4EV? [I've never owned a luxury model before. The Mercedes has a lot of little touches that seem like someone really thought things through. One thing that stood out was its lighting: It has direct lighting everywhere, backlighting in some nice spots, and ever some mark lighting that I'm a little embarrassed to like. I'm talking about the "Mercedes Benz" in the door panel. On the flip size, we were not very impressed with the interior of the Rav. It doesn't have leather, and the rear seat was a little flimsy. The mechanical seats, both front and back just seemed imprecise. There are a lot more little luxury items that we're discovering, and its a nice surprise.]

Acceleration comparison, if you drove both. [They seemed to be about the same. I didn't remember to hit the Sport mode in either. The Mercedes seems to limit power just on accelerator pedal tip-in, so that people in the car don't get the head snap effect.]

Pricing of B-class. [$1500 down, $379/mo, 12k miles]
Range. Does it too have standard and extended charge modes? [No idea, but I hear it has 100 miles]
EVSE selection? [No idea. I'll put in a 50A socket when solar gets installed. Can any of these be programmed to start charging at midnight?]

Did you know that Tony Williams will eventually be offering a DC quick charge CHAdeMO connector for the B-Class? Might want to get on his list. [I actually don't know what this means. But if a 40A can charge fully in less than 5 hours, I should be good.]
Anything interesting about it that you didn't know beforehand? [yes, that they would match, and beat the Rav4 price.]

 

[smkettner]

The RAV has an end timer or departure timer only. You can adjust the departure time to fit the 5 hour window fairly easy. The only way to really exceed the 5 hours is to roll in on turtle mode and request an extended charge. That might even be doable with a 40 amp EVSE. I have never seen over 5 hr charge with my 30 amp evse.

You will typically be selling energy at the on-peak rate. You will still get a great rate of return on your solar investment even if you do not completely zero out your bill.

 

[Ferdball]

Sdge has a TOU with its lowest rate between midnight and 5am.

Stick with 4.8 max.

You will be selling a lot of electric at 48 cents in summer and buying at 16 & 22 cents. Car should charge fine at 16 cents.

Best to not use the air conditioner during on-peak hours so you can sell the max amount.
In summer you can cool the house a bit extra during off-peak and cruise through the day (6p).

http://regarchive.sdge.com/tm2/pdf/ELEC_ELEC-SCHEDS_EV-TOU-2.pdf

So, with Net Zero Metering, they don't base it by the amount of energy, but by the cost of the energy and the time of day? Ex. 100kWh at $.48 is not the same as 100kWh at $.16?

 

[fooljoe]

Range. Does it too have standard and extended charge modes? [No idea, but I hear it has 100 miles]

Get this - the B-class offers the ability to use a "temporary range extender" as a $600 option, which is exactly the same thing as extended charge mode in the Rav. :roll:

 

[miimura]

Sdge has a TOU with its lowest rate between midnight and 5am.

Stick with 4.8 max.

You will be selling a lot of electric at 48 cents in summer and buying at 16 & 22 cents. Car should charge fine at 16 cents.

Best to not use the air conditioner during on-peak hours so you can sell the max amount.
In summer you can cool the house a bit extra during off-peak and cruise through the day (6p).

http://regarchive.sdge.com/tm2/pdf/ELEC_ELEC-SCHEDS_EV-TOU-2.pdf

So, with Net Zero Metering, they don't base it by the amount of energy, but by the cost of the energy and the time of day? Ex. 100kWh at $.48 is not the same as 100kWh at $.16?

With Utility Net Metering, they add up all the usage, positive and negative, during each time window (Peak, Part-Peak, Off-Peak) multiply it by the price for that time period, then add up the dollars. They do this each month and accumulate the dollars through the year. If you owe them money at the end of the year, you have to pay that in a lump sum. If you have a bill credit at the end of the year, but you have still used more kWh than you produced, the credit balance is cleared and you start the next year accumulation from $0. If you have produced more than you consumed in total for the year, they will usually pay a fixed price per kWh for your net production. PG&E pays approximately $0.04/kWh.

Net Zero usually refers to a design goal for a home that produces as much energy as it uses. It has nothing to do with utility billing.

 

[miimura]

Range. Does it too have standard and extended charge modes? [No idea, but I hear it has 100 miles]

Get this - the B-class offers a "temporary range extender" as a $600 option, which is exactly the same thing as extended charge mode in the Rav. :roll:

I was told by a Silicon Valley MB dealer that they did not expect any cars to be available with the Range Package during this calendar year 2014. Model year 2015 cars are in transit already and those would be the first to have the Range Package. I don't know how accurate this information is. It came from a salesperson.

 

[Ferdball]

I was told by a Silicon Valley MB dealer that they did not expect any cars to be available with the Range Package during this calendar year 2014. Model year 2015 cars are in transit already and those would be the first to have the Range Package. I don't know how accurate this information is. It came from a salesperson.

No, its available now as a $350 option. Of the two cars on the lot, the other one had it.

 

[Ferdball]

So, with Net Zero Metering, they don't base it by the amount of energy, but by the cost of the energy and the time of day? Ex. 100kWh at $.48 is not the same as 100kWh at $.16?

With Utility Net Metering, they add up all the usage, positive and negative, during each time window (Peak, Part-Peak, Off-Peak) multiply it by the price for that time period, then add up the dollars. They do this each month and accumulate the dollars through the year. If you owe them money at the end of the year, you have to pay that in a lump sum. If you have a bill credit at the end of the year, but you have still used more kWh than you produced, the credit balance is cleared and you start the next year accumulation from $0. If you have produced more than you consumed in total for the year, they will usually pay a fixed price per kWh for your net production. PG&E pays approximately $0.04/kWh.

Net Zero usually refers to a design goal for a home that produces as much energy as it uses. It has nothing to do with utility billing.

Thanks. I signed up for TOU2.

Should I get the originally quoted system (4.8kW), or add a few panels?

 

[TonyWilliams]

Should I get the originally quoted system (4.8kW), or add a few panels?

Do you want to zero out your electric bill every year, or not?

The amount of power that you will "pull from the wall" to operate your MB B-Class ED is about 1 kWh per 2.5 - 3.0 miles.

So, 12,000 miles divided by 2.75 miles equals 4,363kWh per year divided by 12 months is 364kWh per month, assuming all the charging is done at home.

364kWh for the EV plus 639kWh that is your household use = 1,003kWh per month.

That would require about 30 of the 228w panels that I have, assuming lots of sunny days at 33 degrees north latitude, with a south facing array, etc.

That is a 6.8kW system.

 

[Ferdball]

Should I get the originally quoted system (4.8kW), or add a few panels?

Do you want to zero out your electric bill every year, or not?

Looks like the better idea would be to use TOU for my charging, and not spend the money buying extra PV capacity. Would you agree?

 

[smkettner]

Should I get the originally quoted system (4.8kW), or add a few panels?

Do you want to zero out your electric bill every year, or not?

The amount of power that you will "pull from the wall" to operate your MB B-Class ED is about 1 kWh per 2.5 - 3.0 miles.

So, 12,000 miles divided by 2.75 miles equals 4,363kWh per year divided by 12 months is 364kWh per month, assuming all the charging is done at home.

364kWh for the EV plus 639kWh that is your household use = 1,003kWh per month.

That would require about 30 of the 228w panels that I have, assuming lots of sunny days at 33 degrees north latitude, with a south facing array, etc.

That is a 6.8kW system.

Did you adjust for selling that extra on-peak and charging off-peak?

Big difference between monetary zero and energy zero.

 

[TonyWilliams]

Should I get the originally quoted system (4.8kW), or add a few panels?

Do you want to zero out your electric bill every year, or not?

The amount of power that you will "pull from the wall" to operate your MB B-Class ED is about 1 kWh per 2.5 - 3.0 miles.

So, 12,000 miles divided by 2.75 miles equals 4,363kWh per year divided by 12 months is 364kWh per month, assuming all the charging is done at home.

364kWh for the EV plus 639kWh that is your household use = 1,003kWh per month.

That would require about 30 of the 228w panels that I have, assuming lots of sunny days at 33 degrees north latitude, with a south facing array, etc.

That is a 6.8kW system.

Did you adjust for selling that extra on-peak and charging off-peak?

Big difference between monetary zero and energy zero.

No, I didn't because I don't have that data that is specific for every TOU and utility in the state. It's easy enough to figure out.

For San Diego, our "Super Off Peak" is midnight to 5am.

 

[Ferdball]

Okay, Stellar Solar just called me and said that it is power produced vs. power used. It doesn't use the cost tier structure when using net metering. He's going to send me the net metering rules. But this goes against what most others are saying here.

I wonder if everyone that says there is a time of day production vs. use reduction factor (for lack of a better term) is from Northern California.

Does anyone on SDG&E have specific experience with this?

 

[Ferdball]

With Utility Net Metering, they add up all the usage, positive and negative, during each time window (Peak, Part-Peak, Off-Peak) multiply it by the price for that time period, then add up the dollars. They do this each month and accumulate the dollars through the year. If you owe them money at the end of the year, you have to pay that in a lump sum. If you have a bill credit at the end of the year, but you have still used more kWh than you produced, the credit balance is cleared and you start the next year accumulation from $0. If you have produced more than you consumed in total for the year, they will usually pay a fixed price per kWh for your net production. PG&E pays approximately $0.04/kWh.

Net Zero usually refers to a design goal for a home that produces as much energy as it uses. It has nothing to do with utility billing.

The guy at Stellar directly refuted this. Again, there may be a difference in North vs. South methods.

Guys, would you mind adding your location to your profiles please? Thanks!

 

[Ferdball]

If you sell 100 kWh at 48 cents you get $48 credit, then use 100 kWh at 22 cents you have $22 in charges.
The net bill has a credit of $26 for zero net usage. (simplistic example)

You will not get a check at the end of the year. But you can save a bundle by installing about 30% less solar.

You may need to look at someone's actual bill that has TOU and solar to see how the credit works.

Which rate plan are you on? DR, DR-SES, or TOU-2?

 

[Ferdball]

I used 660 kWh more than I made last month and still had a $11 credit on my bill, my solar made 563 kWh. My credit for the year so far is $130.

What rate plan are you on?

 

[Ferdball]

Monthly Generation Credits

How do you calculate the dollar amount of my net generation credit?

First we start with the excess amount of energy you generated for the month, which is determined by subtracting the number of kilowatt hours (kWh) you used from the number of kWh you generated. Then we multiply the excess kWh by the price per kWh to determine the credit you will receive. Because the price of energy can vary, we perform this calculation separately for each month your system generates more electricity than you use. The dollar value of your excess generation is carried forward and used to offset charges for energy supplied by SDG&E.

https://drive.google.com/file/d/0BzLsErPbuVfWZGdSXzYteE93Umx5Y2FyUTZnX1VQdm0tdG5B/view?usp=sharing