Residential solar in 2023

[whoaru99]

In the charging aspect it depends quite a lot at what expectation of charging speed one needs (wants?).

A Level 1 (L1) charger that connects to a typical 120V 15A or 20A circuit is not all that much of a demand on your house main panel. L1 gets you ~3 miles per hour of charge time.

Stepping up to a Level 2 (L2) charger typically is a 240V 30A or 50A circuit. Certainly a lot more demand on the panel than L1, but it's not a huge burden for a readsonably modern panel 100A or higher. L2 gets you ~25 miles per hour of charge time.

L3 chargers are the big ones like you'd find at a Tesla charging station. These are not really practical for at home unless maybe you are like Bill Gates, Elon, very wealthy folks. The big ones use one or more 460V three-phase feeds.

For mainly local running around errands a L1 system might be all you need majority of time.

If you want to leave every morning with a battey 80% or more and typically return to the house with a mostly discharged battery then one of the higher output L2 chargers is likely what you'll need.

Now, trying to power it with solar is another layer and of course how fast you need (want?) to be able to recharge is a really big factor.

 

[Thorrak]

Charging from solar without net metering is weird. That’s where battery infrastructure (and net metering) starts to become important…

 

[mashdar]

Stepping up to a Level 2 (L2) charger typically is a 240V 30A or 50A circuit. Certainly a lot more demand on the panel than L1, but it's not a huge burden for a readsonably modern panel 100A or higher. L2 gets you ~25 miles per hour of charge time.

Fwiw, a lot of 100A level 2 chargers are popping up. It started with commercial (Blink etc), but I've seen private residential grade units lately. (IMO new custom installs should get 100A wiring.)

Probably needed for electron guzzlers.

 

[whoaru99]

Yeah, I suppose that makes sense if you need to take a large capacity battery from 20% to 80% (or whatever) on a frequent, short time cycle. Or, maybe if like here there is no Level 3 charger for a quick blast in an odd case.

Not that it would be like Level 3 but hopefully noticeably faster than 30 or 50A. That said, I think one has to be aware of what their car can handle from AC charging vs. Level 3 DC fast charge where it's more or less direct to battery than through the car's on board charge controller.

 

[passedpawn]

In the charging aspect it depends quite a lot at what expectation of charging speed one needs (wants?).

A Level 1 (L1) charger that connects to a typical 120V 15A or 20A circuit is not all that much of a demand on your house main panel. L1 gets you ~3 miles per hour of charge time.

Stepping up to a Level 2 (L2) charger typically is a 240V 30A or 50A circuit. Certainly a lot more demand on the panel than L1, but it's not a huge burden for a readsonably modern panel 100A or higher. L2 gets you ~25 miles per hour of charge time.

L3 chargers are the big ones like you'd find at a Tesla charging station. These are not really practical for at home unless maybe you are like Bill Gates, Elon, very wealthy folks. The big ones use one or more 460V three-phase feeds.

For mainly local running around errands a L1 system might be all you need majority of time.

If you want to leave every morning with a battey 80% or more and typically return to the house with a mostly discharged battery then one of the higher output L2 chargers is likely what you'll need.

Now, trying to power it with solar is another layer and of course how fast you need (want?) to be able to recharge is a really big factor

What happens when the average family (2 working parents, 2 high school kiddies) all get home and want to charge their cars. How does the future handle that? Is that 4 chargers? Or do they daisy-chain or something? I'm really having trouble envisioning the amount of power required into that average home to make that happen overnight.

Also, a lot of people don't park in their garage (I get 3 cars in there, but that's not typical). How does the one or two in the driveway get charged? I guess you have the charging station outside somewhere? I really don't know.

 

[day_trippr]

This is stupid simple stuff to implement, but I would hope that chargers and cars can be told "when to charge" such that one could arrive home from their evening commute, plug in their charger dongle, and go about their business, while the car knows how many hours of charging it needs to reach [% target] and will attempt to use the cheapest hours possible to do so...

Cheers!

 

[Kent88]

Some of this could be good discussion to have here:

Poll: Do you have, or plan to get, an electric car?

 

[Thorrak]

It’s all in your commute, and willingness to look for a solution.

In the future, I’ll have a 6 mile commute (round trip). My partner will have a 60+ mile commute (one way). She’ll charge ~30-40kWh, and I’ll charge 2-3. We can get a pair of chargers that communicate to give my car the 20 minutes it needs, and gives her car as much time as it requires - switching between the cars on a single circuit. I will park outside and use a charger that is weather-resistant, she will have a charger that expects to live in the garage.

If you and your partner have long commutes then you may have a problem. For most households, I would expect this to be far more reasonable.

 

[mashdar]

I believe level 2 tesla chargers have some kind of max total power setting if networked. Other brands probably do too. It's definitely a thing for commercial installations (e.g. 10 level 2 chargers at a venue).

I'm sure as having 4 chargers becomes common, such a system will be commonplace.

I did hear someone point out that (by 2023 NEC) such a setting must be accessible to qualified people only, e.g. not a homeowner.

 

[Thorrak]

I believe level 2 tesla chargers have some kind of max total power setting if networked. Other brands probably do too. It's definitely a thing for commercial installations (e.g. 10 level 2 chargers at a venue).

I'm sure as having 4 chargers becomes common, such a system will be commonplace.

I did hear someone point out that (by 2023 NEC) such a setting must be accessible to qualified people only, e.g. not a homeowner.

Our apartment was wanting to install chargers, but only has 200A service where they want to place it (and thus absent a new meter would be limited to a max of 3-ish chargers if everyone wanted to charge at full speed). The fact that most owners will rarely need to charge from 0 to full means it could work for more - but only if the chargers all communicate.

Definitely feels like an opportunity for either innovation or regulation.

 

[whoaru99]

What happens when the average family (2 working parents, 2 high school kiddies) all get home and want to charge their cars. How does the future handle that? Is that 4 chargers? Or do they daisy-chain or something? I'm really having trouble envisioning the amount of power required into that average home to make that happen overnight.

Also, a lot of people don't park in their garage (I get 3 cars in there, but that's not typical). How does the one or two in the driveway get charged? I guess you have the charging station outside somewhere? I really don't know.

As I mentioned, the depth of discharge and the time in which the battery needs to restored to X percent full all factors in.

Not every use case runs the battery near dead every time they use it and requires being back to full in a few hours. So, I don't see the four-car family where every car needs 80% charge every day necessitating 4 x 50A L2 charging. But, no doubt there are always outliers. Maybe they should consider proximity to Level 3 chargers if they have frequent high duty cycle use. Maybe that's the incentive to not drive the wheels off if you have to pay more for that fast blast L3 charge.

To really get a feel one needs to use relevant use case info, like how many miles per day one typically drives. For me, a typical weekday would be maybe 10 miles driving. Could go many days between charges at that. About the same for the fiancé so, most of the time charging requirements between us would be pretty light. But, that's us. Others have to pencil out the reality of their typical driving. If there is someone who racks miles and miles and demands quick turnaround then maybe EV isn't right for them quite yet, if they don't want to pay for Level 3 charging (if even available - nearest to us is 35 miles one way)

FWIW, I read the average household has ~2 cars.

Again though, we digress way from the actual thread topic of solar installation.

 

[whoaru99]

Our apartment was wanting to install chargers, but only has 200A service where they want to place it (and thus absent a new meter would be limited to a max of 3-ish chargers if everyone wanted to charge at full speed). The fact that most owners will rarely need to charge from 0 to full means it could work for more - but only if the chargers all communicate.

Definitely feels like an opportunity for either innovation or regulation.

I'd expect a professional grade multi-connection charging system would inherently distribute available current between the number of ports in use. As the batteries get closer and closer to 100% they inherently draw less current so that causes the other cars with lower charge levels to get a bit more of the share too.

The charger in my boat for the three marine batteries has done distributed charging since before EVs were a thing. I'm sure the level of that sophistication in that older thing is less but none the less it does it.

 

[Thorrak]

I'd expect a professional grade multi-connection charging system would inherently distribute available current between the number of ports in use. As the batteries get closer and closer to 100% they inherently draw less current so that causes the other cars with lower charge levels to get a bit more of the share too.

The charger in my boat for the three marine batteries has done distributed charging since before EVs were a thing. I'm sure the level of that sophistication in that older thing is less but none the less it does it.

Huh. Interesting idea!

I was going to make a comment about how with lithium Ion batteries, you generally dont want to charge them to 100% if you want to maximize the lifespan and that degradation is minimized when kept at a state of charge around 70%, with a negligible hit at 80% and a more-pronounced-but-acceptable hit at 90%, but I guess this still is achievable given that the software on the car would cut the charging rate once it detects you are at 80%

This would still prevent leaving an EV hooked up long term considering things like sentry mode - but maybe this is acceptable/desirable in a shared charger situation where you wouldn’t want someone leaving their car hooked up long enough that a 1 mi/hr drop in range would be noticeable/problematic.

 

[whoaru99]

There is some possibility to manage the charge details in the EV, but a lot of what happens with charge slowing at higher % is inherent to battery and charge/charger characteristics. One example, at a high level, is the difference between battery voltage and charge voltage. The closer together they get as the battery charges inherently means the charger can't "pump" as fast into the battery.

And, yes, I believe in some chargers you can set the charging time schedule to coincide with off peak rates or whatever reason.

I know in the Tesla I rented you could set the upper charge percentage to terminate charge at 80% (pick the number) rather than 100%. Maybe there were more sophisticated settings as well, but I wanted to drive it rather than explore every possible setting and configuration.

As you alluded to, it's not necessary nor really even desirable/recommended, to charge to 100% unless you really need every possible mile from that charge instance.

 

[whoaru99]

This would still prevent leaving an EV hooked up long term considering things like sentry mode - but maybe this is acceptable/desirable in a shared charger situation where you wouldn’t want someone leaving their car hooked up long enough that a 1 mi/hr drop in range would be noticeable/problematic.

If it's not already on the table, I'd strongly consider a formal Acceptable Use Policy that tenants/renters/residents have to sign.

A piece of paper in itself won't prevent someone from abusing the system, but it could provide means to deal with habitual offenders should the need arise.

 

[Thorrak]

If it's not already on the table, I'd strongly consider a formal Acceptable Use Policy that tenants/renters/residents have to sign.

Yeah, they’re going to have to figure that out. We had first mover advantage - our meter is our own, and gets the cheaper time of use rates.