Driving on Sunshine

[Silicon Desert]

My system completely payed for itself in 4 years, not including charging my 3, not Including the savings for

yea, I don't doubt that fast payback. I put solar on my son's home down there in San Diego because I was shocked at the high electricity rates. Many places in California have crazy rates. We were paying an average of .47 per KWh in the San Francisco bay area for our energy usages (5 tiers) before we moved away. Up here, solar doesn't make as much sense and has a long break even period since we pay only 9 cents per KWh and no tiers, no TOU. Kind of weird that rates vary so much around the USA.

 

[BruceInFlorida]

This seems reasonable, 15,000 miles you will need around 4,000 kWh. So if you know how much you need for your house, if you add those up, then you will know total you would want to offset your house and car if roof size, budget, permits, main panel permits this. In your case, its around 3,000kWh for the house needs

As some said, for most, it is cheaper to charge at night, so technically if one charges their car at night to save credits, lower charges, then car charges from the power plant/electrical gride.

Some of those photos in this thread are very nice and gorgeous solar setups. I think it is just natural, if you own your own roof and you have electric car, it makes sense to get solar, to save money over long term and keep community green and in some cases where power is not stable, such as winds, snow, wildfires get a battery to run off the grid.

After this year, Federal Tax Credit for Solar will decrease again. good site to learn about solar, get quotes, etc
Why the Solar Tax Credit Extension is a Big Deal in 2020 | EnergySage

Thanks for your input!

 

[BruceInFlorida]

yea, I don't doubt that fast payback. I put solar on my son's home down there in San Diego because I was shocked at the high electricity rates. Many places in California have crazy rates. We were paying an average of .47 per KWh in the San Francisco bay area for our energy usages (5 tiers) before we moved away. Up here, solar doesn't make as much sense and has a long break even period since we pay only 9 cents per KWh and no tiers, no TOU. Kind of weird that rates vary so much around the USA.

We pay 23cents/kWh Thanks for your input

 

[BruceInFlorida]

yea, I don't doubt that fast payback. I put solar on my son's home down there in San Diego because I was shocked at the high electricity rates. Many places in California have crazy rates. We were paying an average of .47 per KWh in the San Francisco bay area for our energy usages (5 tiers) before we moved away. Up here, solar doesn't make as much sense and has a long break even period since we pay only 9 cents per KWh and no tiers, no TOU. Kind of weird that rates vary so much around the USA.

Thanks for your input

 

[gavine]

Up here, solar doesn't make as much sense and has a long break even period since we pay only 9 cents per KWh and no tiers, no TOU

It still makes sense from an environmental standpoint. Also, there's a "feel good" factor around driving on sunshine. I realize that's not important to everyone, but to some people it is.

 

[Beardley]

No, my system is designed for 100% of last year's power usage.

Most of the power consumption is from AC. Power bill is ~450 in the summer, and around $210 in the winter.

Wow that's a lot of juice. It's all perspective though. I may run my window ACs 30-60 days total in a year, and 95%+ of my heat comes from wood, so its a fairly low energy house. The cars are by far my biggest draw. W/O the cars, a typical daily usage only 13-14 Kw. At the end of the day, I'm just happy to see more panels out there offsetting non-renewables.

 

[gavine]

It still makes sense from an environmental standpoint. Also, there's a "feel good" factor around driving on sunshine. I realize that's not important to everyone, but to some people it is.

It also keeps your house cooler by shading the roof. Our upstairs was noticeably cooler after our solar was installed.

 

[stephenburns1]

Looks great!

 

[dgpcolorado]

It still makes sense from an environmental standpoint. Also, there's a "feel good" factor around driving on sunshine. I realize that's not important to everyone, but to some people it is.

That's my view as well. My 2170 watt system (tiny by the standards of this thread) was installed back when prices were higher and not remotely cost-effective — I budgeted it as part of the cost of a future electric car. I first became aware of the synergy of PEV solar and electric cars around the year 2000 and installed my first 700 watt array in 2008 as "phase 1" of a future electric car.

Once I was driving electric and had hard data on usage, I added a 1470 watt array in 2012. Haven't paid an electric bill, other than the monthly service charge, ever since. My 2170 watts of solar panels covers my car and house usage, although I do some opportunity charging at public charge stations (subsidized by a state registration fee on plug-in vehicles) when I can. I try to charge my car in the middle of the day so that I can use my solar, and that of my neighbors, "directly" as opposed to charging on coal overnight.

 

[ZsoZso]

My new passive-solar design house construction is nearing completion, the solar PV was installed in June, battery backup and web-monitoring went online on July 1st. Here is a picture of the solar array (the larger array on the left is facing SE, the smaller on the right is facing SW):

The size of the system (15kW) was calculated based on estimated projection of my yearly energy needs (house + charging 3 EVs), all energy use of the house is electric (stove, water heater, HVAC is a heat-pump), there is no fossil fuel consumption in the house or on the property at all, even my BBQ is solar powered instead of propane

It is a grid-connected system with net-metering setup with Wasaga Distribution Inc. in Wasaga Beach, Ontario, Canada.
I have just received my first bill from them since the net-metering started. It had a few surprises to me:

• They measure the energy (kWh) I push onto the grid in 3 separate time-of-use tiers and calculate the value with 3 different unit prices and record my surplus in $ value instead of kWh
• They also include negative "delivery charge" and "regulatory charge" values just like when customers buy energy from them, so these also accumulate $ value for me to balance my usage costs later (in winter time when my production will be lower than my usage).

I am not really happy with the $ based accounting instead of kWh, because my system size was designed to allow me to reach net-0 in terms of total energy production and usage. However, by accounting in $ instead, the power company can easily screw me over by raising the prices during winter and lowering them during summer (which would make sense for them if there are / will be a lot of solar sources on the grid). On the other hand, they are being generous by accounting me credits for delivery and regulatory charges on top of my "exported" energy, instead they could make me pay for those as cost (they need to maintain the gird, which gets extra load from my energy being pushed onto it).

Is this normal for net-metering arrangement in other areas / power companies, or do others account in kWh ?

 

[nicedrum]

I try to charge my car in the middle of the day so that I can use my solar, and that of my neighbors, "directly" as opposed to charging on coal overnight.

You've probably heard this before, but in general the best thing you can do for the environment is to charge overnight. Even though the solar-generated electrons are flowing during the day, other loads are also much higher and so the dirtiest and least efficient coal/NG power plants come online to top off the system. Maybe in your area they're the same as the night-time generators, but generally here in the northeast it's the dirtier or less efficient sources of energy. It's not that the electrons flowing into your car aren't from your panels, but it's more that instead of giving someone next door your clean electricity you're forcing them to use the least efficient source.

I've had the same thought as I have solar as well and can choose when to charge my car (just a Prius prime at this point), but thinking it over I choose to charge overnight (our utility also encourages the same -- their base rate is affected by how much juice our town uses during the "highest load" 3-hour-period in a given year), even if it feels a little strange to let someone else use "my" solar generation during the day. But again, it depends where you live and exactly how dirty or clean the nighttime vs daytime NG/coal/wind generators are.

 

[SageBrush]

But again, it depends where you live and exactly how dirty or clean the nighttime vs daytime NG/coal/wind generators are.

this ^^

@dgpcolorado 's co-op is PV friendly so it would not be surprising if they already have excess clean energy during the peak PV hours

 

[gavine]

You've probably heard this before, but in general the best thing you can do for the environment is to charge overnight. Even though the solar-generated electrons are flowing during the day, other loads are also much higher and so the dirtiest and least efficient coal/NG power plants come online to top off the system. Maybe in your area they're the same as the night-time generators, but generally here in the northeast it's the dirtier or less efficient sources of energy. It's not that the electrons flowing into your car aren't from your panels, but it's more that instead of giving someone next door your clean electricity you're forcing them to use the least efficient source.

I've had the same thought as I have solar as well and can choose when to charge my car (just a Prius prime at this point), but thinking it over I choose to charge overnight (our utility also encourages the same -- their base rate is affected by how much juice our town uses during the "highest load" 3-hour-period in a given year), even if it feels a little strange to let someone else use "my" solar generation during the day. But again, it depends where you live and exactly how dirty or clean the nighttime vs daytime NG/coal/wind generators are.

Well said and very true, but it still feels good knowing that you're charging directly from your own panels. That said, still better to charge overnight.

 

[dgpcolorado]

this ^^

@dgpcolorado 's co-op is PV friendly so it would not be surprising if they already have excess clean energy during the peak PV hours

Yes. Overnight is definitely fossil fuels except for some wind from the Plains (no wind here, one of the least windy parts of the country).

A couple of points specific to my area: This is not an AC zone, houses with AC are rare although commercial buildings have it. Also, although I don't have TOU billing, that option from my co-op has noon to 5 PM as OFF-PEAK! Peak is mornings and evenings.

So, I was aware that midday, when my solar is best, is also a lower demand period for my rural mountain co-op (and THEIR cost from Tri-State is based on that demand). Perhaps in national terms that isn't true, since all the grids except Texas (infamously) are connected, but I prefer to view it regionally.

 

[israndy]

You've probably heard this before, but in general the best thing you can do for the environment is to charge overnight.

I don't generate enough power to charge my car full speed from solar, but I do to charge from 110v. Also I have a switch on it so that when the clouds roll in I can have the power to the car cut so my remaining solar is still able to feed whatever else is running. Typically the car will be charged faster than I use the charge (maybe not in winter). Often not fully charged and never fully empty. I would think THAT is the best. I get that if you charge at night it CAN be beneficial to your grid not burning off power there is not demand for, but if EVERYONE is given that advice they are all gonna start charging at 9pm when the peak time ends and charge until full. There is NO way that can be as beneficial.

It's good that power companies are starting to implement storage batteries, but it would be best if there were a protocol for cars to submit a request for power overnight and a central authority says "You can draw 2.2kW starting at 11:38pm and stop at your charge setting which should be 4:20am at 75% state of charge"

This would allow the operators to avoid a spike at the end of peak time and avoid everyone charging at a full 48 amps when they have all night to charge. It would be really great too because they could back load it so people will finish early but if there is a strong unpredicted demand that requires a Peaker Plant to come online they could change their mind about the way all these cars are gonna charge and with all that extra power could ramp up the rate the cars finish at and then shut down the Plant after they charge as they were gonna be the bulk of demand overnight.

I don't think current electric cars are smart enough, but a smart EVSE could be built and funded by the Feds that has this and we all get retrofits or at least all new EV owners get them and this allows the CHEAPEST electricity rate and full utilization of the grid to power these cars.

 

[ItsNotAboutTheMoney]

I don't think current electric cars are smart enough, but a smart EVSE could be built and funded by the Feds that has this and we all get retrofits or at least all new EV owners get them and this allows the CHEAPEST electricity rate and full utilization of the grid to power these cars.

You mean a "smart charger" that are in common use for UK EV owners, with installation subsidized by the UK government.? Oh and all public chargers have to be smart chargers now/from a particular date.

Efficiency Maine has a smart charging trial, but unfortunately it required 32A+ EVSEs from a particular vendor and I was reusing a 30A circuit.
Other states/utilities might be running trials as well.

 

[Zaxxon]

I don't generate enough power to charge my car full speed from solar, but I do to charge from 110v.

Something to keep in mind is that 120V charging is *significantly* less efficient than 240V (~80-85% vs 90-95%), so it may be counterintuitively 'better' from an environmental perspective for you to charge at 240V and use your solar for other loads.

 

[iPlug]

Here in CA the greenest (ratio of renewables:fossils) time to charge is shortly after sunrise to late afternoon in Winter/Spring and shortly after sunrise to early afternoon in Summer/Fall.

CAISO has instantaneous supply (by source) and demand trends going back years. Not sure if such data is available in other States.

 

[thesmokingman]

The other weekend it was not hot in the afternoon so the batteries had a lot of charge. I topped off the MYP. It was surreal watching the powerwalls push 7kw to the car, only running a 30amp circuit.

 

[cali8484]

It's good that power companies are starting to implement storage batteries, but it would be best if there were a protocol for cars to submit a request for power overnight and a central authority says "You can draw 2.2kW starting at 11:38pm and stop at your charge setting which should be 4:20am at 75% state of charge"

JuiceBox already does this. Owners can opt-in to charge when utility power is most clean and get JuicePoints that can be redeemed for cash. I like it since it's flexible in that you can set a departure time for desired charge level so if necessary JuiceBox will charge the car with less clean power but you don't get JuicePoints then.