Solar Powered EV Charging

MouldyOldDough

OK I will admit to not exactly liking EV's (I have posted several anti-EV posts in the past) - but now it appears that an EV "may" be the way for me to go.....from Motability

If I did get an EV - Would it be possible for me to charge it purely from solar panels mounted on the garage roof ?

I know that there are lots of questions - such as direction (garage spine North/South) - Size of Apex roof (enough for 4 * 2by2metre panels each side) - but would solar panels produce enough juice to fully charge say a 50kWh battery - in a few days in summer ?

How long would it take to pump out 50kWh in average UK weather ?

We would not be using the car every day - sometimes only once a week with occasional motorway trips (that could not avoid additional charging costs)

sk2402005

Yes in theory, but you woud be better off getting the panels grid tied, and switch to an electric tariff that has a cheap charging rate over night. this will also drastically reduce your household eletcricity bill.

My 4kw 10 panel array can push out 25 Kwh per day in the summer. but i get an average of 4Khw in the winter.

You should be able to get a 4kw array fully installed for about £4K, or DIY if you can do it for about £2K (Inverter connection must be done by a sparky) if you want to get paid for any export, octopus do a diy route for £250.

The motability EV deal is absolutly fantastic if you can get it, the charger is also installed for free, its actually more expensive to own your own ICE car in most circumstances.

born_again

You could. But having batteries would help, so you can store energy when it's generated & used when you need to top up car.

End of the day. The cost of install etc will not be cheap.
Especially when you can only pay 7p kWh to charge a EV.
Yes your daily rate is higher. Not a high mileage user at all here. Average unit cost across the month is around 13p kWh

MouldyOldDough

sk2402005 said:

Yes in theory, but you woud be better off getting the panels grid tied, and switch to an electric tariff that has a cheap charging rate over night.

My 4kw 10 panel array can push out 25 Kwh per day in the summer. but i get an average of 4Khw in the winter.

You should be able to get a 4kw array fully installed for about £4K, or DIY if you can do it for about £2K (Inverter connection must be done by a sparky) if you want to get paid for any export, octopus do a diy route for £250.

The motability EV deal is absolutly fantastic if you can get it, the charger is also installed for free, its actually more expensive to own your own ICE car in most circumstances.

The problem is the distance from the garage to the house and meter is about 10 metres !

hence the idea of having it as a separate non connected entity

born_again

10 meters would be a standard install. Unless it requires a trench for cable.

Instal charger on wall of house, rather than in garage.

sk2402005

MouldyOldDough said:

sk2402005 said:

Yes in theory, but you woud be better off getting the panels grid tied, and switch to an electric tariff that has a cheap charging rate over night.

My 4kw 10 panel array can push out 25 Kwh per day in the summer. but i get an average of 4Khw in the winter.

You should be able to get a 4kw array fully installed for about £4K, or DIY if you can do it for about £2K (Inverter connection must be done by a sparky) if you want to get paid for any export, octopus do a diy route for £250.

The motability EV deal is absolutly fantastic if you can get it, the charger is also installed for free, its actually more expensive to own your own ICE car in most circumstances.

The problem is the distance from the garage to the house and meter is about 10 metres !

hence the idea of having it as a separate non connected entity

If you dont want to run in a cable, an option for you might be a home battery without solar, your car charger will need to be at the house though. a cable is probably the way to go though - run in a 6mm armoured or somthing like that.

you would need it big enough to supply all your normal daily usage, then charge both the car and battery overnight at the 7p rate from Eon/Octopus.

A 10Kwh home battery would set you back about £4K

You would save more with solar, and it will last probaby at least twice as long though  - the BMS in a battery probably will last 15 years, solar panels 30+

WellKnownSid

MouldyOldDough said:

The problem is the distance from the garage to the house and meter is about 10 metres !

hence the idea of having it as a separate non connected entity

The distance from our distribution board in the middle of the house to the outside wall where the EVSE went is about 40 metres, didn't seem to be an issue. 

Keep_pedalling

Unless you are going to export your surplus energy it is a rather costly solution since charging over night from the grid is so cheap. I have solar panels but still charge from the grid as I get paid twice as much to export than is cost to charge the car from the grid. 

WellKnownSid

MouldyOldDough said:

We would not be using the car every day - sometimes only once a week with occasional motorway trips (that could not avoid additional charging costs)

Tip: download the Tesla app and see if there are any public superchargers near your route.  They may be just off the motorway network but are significantly cheaper and they 'just work'.  We use the ones at Trentham Gardens near Stoke as our 'one stop' when we go from Dumfriesshire to London.  Just gives you enough time to grab a wee break and a scone.

QrizB

Everyone over in the Energy forum (or Green & Ethical) will point out that, if you don't connect your solar panels to the grid, you'll be missing out on the benefit of export payments. Meanwhile by not connecting your car charger to the grid you'll be missing out on preferential EV tariffs.

By all means put solar panels on your roof - as many as will fit, or as many as you can afford if fewer - but connect them and your EV charger to the mains.

I can give you some illustrations of costs and savings if you really want.

Related, will the Motability scheme contribute towards the cost of the EV charger?

sheenas

QrizB is spot on.