solar cells for charging electric car.

[Douglas]

Has anyone on here been using a home solar system to charge an electric car or high bred. I would really like to hear how it is working out. How large your system is how long it takes etc etc.

[Mike90250]

I know several people with PV and EV. But they all drive their car away from the PV on weekdays, and so they backfeed the Grid daytimes, and use a timer on the charger from Midnight to 5AM, consuming the daytime credit.

[Sunking]

Has anyone on here been using a home solar system to charge an electric car or high bred. I would really like to hear how it is working out. How large your system is how long it takes etc etc.

Done everyday with Grid Tied system. Would be really silly to just use it to charge a EV and not get any credit and have to leave the car parked at home all day when the sun shines and you are at work.

[russ]

Douglas is gone thanks to his southern California queer comment - poor little tyke

I am not sure what the high bred he was talking about is - maybe hybrid?

[Sunking]

Douglas is gone thanks to his southern California queer comment - poor little tyke

Yeah he was a moron. He aimed that remark at me. Idiot does not know I am a Texan living in Panama.

[SunEagle]

Douglas is gone thanks to his southern California queer comment - poor little tyke

I am not sure what the high bred he was talking about is - maybe hybrid?

He has been on and off this forum for a few months and has used the "high bred" term before. I didn't want to call him on it since he is a little too thin-skinned and pointing out misspelling seemed petty to me.

He does seem to be very cynical with his responses to our feedback but has asked some good questions. I'm still not sure about his motivation or interest in solar.

[Battman]

Hello. First post here from not so sunny Derbyshire, UK.

I installed a PV self use system 3 or 4 years ago using a 5kw PowerRouter with 610 Ahr lead acid batteries. Having lived the previous 13 years without solar in San Diego, there is some irony there!

I am pretty happy with performance, although the system does seem a lot of time performing battery maintenance. With 7kw of SW facing panels, summer months see me exporting around a 3rd of my generated power. I have just got an electric car and want to play around and see just how much of its energy I can home grow. I also want a beefed up backup supply to run a well pump which the PowerRouter's backup output can't really support. The car can be charged for 9 hours off a 16 amp circuit or 4 hrs off 32 amp. As the car is often at home for a few sunlight hours most days, I am looking at spreading the charging requirement between a dedicated grid-tie inverter with 3.5 kWh lithium, a dedicated inverter with battery support and a grid input, and the excess PV energy from the PowerRouter.

I started off looking at an off-grid with grid support using Sunny Island, but it sounded to me as though that inverter can bridge between the generator support input (which I would connect to the supply grid) and vehicle charging grid which has the string inverter feeding it and the load being charged (the car). This could then feedback from the string inverter and the Sunny Island onto The supply grid.

After a lot of digging, the Victron Quatro looks like a better bet, and has a grid feed that can be configured to guarantee no feeding into the supply grid. The Victron seems to claim support for the LG-Chem lithium battery, but only fully supports their own lithium batteries and BMS unit. This works out very expensive for battery storage (like £5000 in batteries alone for 3.7kwh useable. SolaX use PylonTech Xtra2000 battery units which are also 48v with built in BMS. Even LG-Chem at £2500 for 5.8kwh looks like a way better deal.

Can batteries be hooked up to any inverter and the BMS be relied on to keep the batteries in good shape?

Any other comments on this set up would be appreciated.

Thanks.

[ChavaTarin]

Maybe this is not relevant enough, but I know a fellow who installed a 315W Sun Power panel on top of a golf cart, using a Morning Star charge controller and it works really nice! While other golfists have to exchange carts in order to finish a game, this guy goes on playing all day, and has never had to use the utility charge any more (as a matter of fact, in my profile pic, I am driving that same golf cart), but a full sized car, that's another story.

[SunEagle]

Maybe this is not relevant enough, but I know a fellow who installed a 315W Sun Power panel on top of a golf cart, using a Morning Star charge controller and it works really nice! While other golfists have to exchange carts in order to finish a game, this guy goes on playing all day, and has never had to use the utility charge any more (as a matter of fact, in my profile pic, I am driving that same golf cart), but a full sized car, that's another story.

Maybe that story is true and maybe not.

Most electric golf carts will have enough power to go twice around an 18 hole course. If they don't then their batteries are replaced. I know because I use to work at a golf club and customers get real pissed if their cart won't last a full round and not come back.

As for that 315 watt panel keeping that cart fully charged, that is pretty hard to believe unless the battery is very small and you are golfing on a 9 hole par 3 course.

Most golf carts run a 36volt battery system. A 315 watt panel will generate less than 10 amps for a couple of hours pointed directly at the sun. That is not enough for the battery to get charged and while mounted flat on top of the cart is never really pointed at the sun.

[Mike90250]

315w x 4 hours = just a bit over 1Kwh harvest, in a golf cart, maybe a couple hundred feet difference.

[ChavaTarin]

There are some things that help. He keeps the cart at home in the open, and does not go golfing everyday, so there is enough time for the battery to come to a full charge; however, it is a true story.

[Battman]

I just got a compact 5-door all electric car (a Renault Zoe). I was surprised that a full charge (typically 3 hours at 7kwh) is only 20-30kwh. With this, the car has a claimed range of 150 miles and more realistic 110-120 mile. Part of the deal is that with efficient regenerative braking, the car's average energy use is nearer to that of driving along a level road, since every climb has a descent and every acceleration has a deceleration. Special tyres / tires also reduce a significant energy loss through friction. If my typical use of the car for local journeys is 50 miles per day, then that equates to around 10kwh per day. 3 hours of 3kw is not unrealistic even for the UK between mid March and end August. Using an inverter / battery to shift grid consumption to night rate power (50% day rate cost here) does not justify a system by itself, but it is added value.

Of course the cost of batteries is a big deal. If lithium can deliver 4-5000 80% DOD cycles, then at least there is something to work with. Of course the value of using a discharge cycle to shift energy use has less value than for capturing self generated PV, so I will have to do some calc's to try and determine the optimum use pattern.

It is interesting to me that solar PV is able to (on the face of it) make a worthwhile contribution to running a pretty usable vehicle.

[Wy_White_Wolf]

315w x 4 hours = just a bit over 3Kwh harvest, in a golf cart, maybe a couple hundred feet difference.

3Kwh? I think a typo because it would be closer to 1 Kwh. That would get him 2 to 3 miles so if he only golfs once or twice a week that could get him by but would also destroy the batteries in about a years time.

WWW

[sensij]

ChavaTarin's profile lists Chihuahua, Mexico as the location, probably one of the better places in the world for someone to make this work.

[BattleCat]

Battman - You might want to check this link about using Nissan Leaf batteries as solar storage. linked removed. You can find written off Leaf's very cheaply on copart.co.uk and autotrader. I've seen them go for about £2k for a whole car, so the battery would be cheaper (24kWh). Hope this help to you finding a cheaper battery solution

Mod Note. The link to using batteries from wrecked Leaf vehicles was removed due to that not being a necessarily safe action and is not condoned by this Forum.