Solar Charging an EV

[dpeilow]

The system in the picture above is 9.1 kWp. We did 4.7 kWh today, 147 for the month so far. I think our worst day was boxing day which was 1.4 kWh.

The question about batteries etc relates to a different planned system though.

Your solarlink is interesting. What inverter is it connected to? I know SMA make a webbox that does similar, but it's pretty expensive.

[JRP3]

Because it's cheating...

PV is great for removing the daytime demand peak (it's about 55GW day, 30GW night in the UK), but it would be a shame if night charging EVs just moved the problem there. It's great to have a PV system contributing electrons to the grid during the day, but I don't want to have to fire up another coal or gas plant to charge cars at night when possible. I don't think that is truely solar charging your EV.

Yup, that's the dirty secret that many people don't really understand. Plus with a battery system you also have emergency backup power if the grid goes down, or your local line. I can imagine it would be rather frustrating to look at your solar panels when the grid is down with a grid tie only system.

[Mitrovic]

Because it's cheating...

PV is great for removing the daytime demand peak (it's about 55GW day, 30GW night in the UK), but it would be a shame if night charging EVs just moved the problem there. It's great to have a PV system contributing electrons to the grid during the day, but I don't want to have to fire up another coal or gas plant to charge cars at night when possible. I don't think that is truely solar charging your EV.

You are right, but. here in Switzerland no coal or gas plants it is hydro power during night. Maybe instead of investing in batteries, you should invest in a windmill?

What panels did you use?
My system has Suntech 180

I'm thinking about buying some left overs of Solyndra

[jcstp]

After 36,000 solar-powered miles, MiniE driver ready to make the switch to BMW ActiveE (and an SUV)

[VolkerP]

regarding PV system supervision and web visualization of harvested energy, I recommend Homepage. Connects to many brands of string inverters, comes with email problem notification, and free web space for viewing results.

[dpeilow]

So I've been thinking about how to solar charge an EV that is away during the day. Seemingly some lead acid batteries and appropriate inverter/charger are the easiest cheapest way to do this, however I'd like to:

- Charge the battery during the day unless the EV is plugged in, in which case the solar power should charge the car and blend with grid power if necessary.

- If the battery bank is charged and the car is not drawing power, the PV should supply the grid.

- At night the car should draw power from the battery bank then switch to the grid if that gets depleted.

OK I found that this can be done exactly as I described with a Xantrex XW charger/inverter and XW Solar Charger Controller.

Why didn't I find this before? Because for some reason the XW range is sold by Schneider Electric...

Renewable Energies - Schneider Electric

[jcstp]

WOW Interesting
Shame I don't know anything about electronics!

[dpeilow]

Drive a Solar-Charged Electric Car, Save $263,000 On Fuel Over 50 Years?




It does seem to leave out the cost of a new set of panels (or additional ones to bolster the first set) at 25-30 years. Nevertheless the gap is still huge.

[JRP3]

It also makes the unreasonable assumption that you don't move in 50 years, or you take your panels with you. But as you say the gap is so large you'd still come out ahead even if you had to purchase the solar system a few times over.

[PV4EV]

Drive a Solar-Charged Electric Car, Save $263,000 On Fuel Over 50 Years?

It does seem to leave out the cost of a new set of panels (or additional ones to bolster the first set) at 25-30 years. Nevertheless the gap is still huge.

... and if you rework that for UK fuel prices, the difference is not just huge, its ridiculous and looks like a major error in my maths ... except it isn't, its real.

The use of a 50 yr extrapolation also makes this seem extreme because compound percentages over such along time distort everything, so even if you took the original 3.5% petrol inflation and applied that to a 50 yr chart you still get a total petrol cost of £ 406,000. And both BP and Shell state in their shareholders documents that oil will have run out by approx 2050-5052, even allowing for marginal processes like shale extraction.

Basically, powering and EV from PV is a long term financial no brainer. However ... 50 yrs from now what ever oil is left (if any) wont be worth extracting and governments will have adopted road taxation based on miles travelled / monitored, and there will have been radical changes to energy harvesting / storage / use / modes-of-transport etc etc ... so all this goes out the window ...