Solar powered Hybrid DC Bi-Directional Fast EV Charging

[Bandersnatch]

I have decided to post this in the alternative energy forum rather than in my EVs in Thailand discussion over in the Thailand Motor Forum as it is quite technical and we would probably get more discussion here.

https://aseannow.com/topic/1257405-electric-vehicles-in-thailand

 

I am not sure how many readers of this Forum are EV owners or are considering an EV, but this has been my experience powering an EV from solar in Thailand:

 

Overnight I power my house from my home batteries.  As soon as the sun comes up my solar panels start to produce power and start to meet the power needs of the house along side the batteries until there is enough sunshine to meet the power needs of the house and start to charge the home batteries. By mid morning my home batteries are full and I can start to charge my electric car and electric motorbike. All good so far.

 

First problem is that domestic EV wall chargers (yes I know they are not really charger) are AC. Solar DC is converted to AC by the home inverter (power loss) then sent to the car where the car’s on-board inverter converts AC back to DC (power loss) to charge the batteries. So a lot of power loss due to inefficiency.

 

Second problem is that the speed of AC charging is determined by the EVs on-board charger  - normally 7kW although some cars have higher 3 phase charging of 11kW - I am not going to pay for 3 phase. My home solar makes more power than the house, home batteries or EV can use, so my excess solar is curtailed, because I can’t put into the car fast enough.

 

 

Solution: There is now a way to have a switch to switch DC power from the home inverter into the car and charge the car at up to 25kW and so not waste any solar production. This technology has not been released yet but it looks very promising..

 

https://enteligent.com/dc-coupled-dc-evses

 

 

 

 

 

[JBChiangRai]

Some cars have as much as 22Kw AC chargers (3 phase, 32 amps per phase).

 

It was a >100,000 baht option on one of my cars, I didn’t specify it, my home solar will charge at 7Kw but it doesn’t like it when the car stops charging and the inverters error and reset, I only charge at 24 amps (circa 5Kw).

[jcmj]

I don’t have nor want an electric car but would love to have solar panels and subsidize some of my electric consumption, however, all the quotes are extremely high and don’t seem economical. I wish they had government subsidies for solar panels installed to offset the cost and make it more viable. My house is large so I know it wouldn’t cut out the electric bills but it certainly would help. Last month’s bill was over 22,000. Hopefully they will come up with some help soon like they have in other countries. If anyone knows of a decent priced place in Pattaya I’d still consider looking into it again. 

[mistral53]

On 4/15/2023 at 10:59 AM, jcmj said:

I don’t have nor want an electric car but would love to have solar panels and subsidize some of my electric consumption, however, all the quotes are extremely high and don’t seem economical. I wish they had government subsidies for solar panels installed to offset the cost and make it more viable. My house is large so I know it wouldn’t cut out the electric bills but it certainly would help. Last month’s bill was over 22,000. Hopefully they will come up with some help soon like they have in other countries. If anyone knows of a decent priced place in Pattaya I’d still consider looking into it again. 

I am certain you could get a grid-tied solar system with a payback of less than 5 years, even without subsidies. It's a no-brainier really, what keeps you from doing it? roof space?

I am in the 3rd year and on track to get my investment back in another 1.5 years, latest - best investment I ever made in Thailand. Another way of looking at a it is payback in 10 years and ROI of 10% - what's not to like about this?

BTW - if you have difficulties finding an installer, we have plenty of them in H-H that do installations nationwide, pm me if you need contact info.

Edited April 16, 2023 by mistral53
sp

[sharksy]

Can't really help much technically, but recently had a holiday in the island of Grenada as a guest in a villa with a couple of old friends from years back.

They had about 48 solar panels on the roof plus a swimming pool and were completely self sufficient in terms of water and electric.  It was explained to me, but a bit over my head I'm afraid.  I'm sure each inverter had a raspberry pi attached to monitor / control things.

The electric also ran their Gen1 Nissan Leaf which was perfect for this island which was generally low speed everywhere and lots of steep roads.

 

I was very impressed, especially with the old, high mileage war-horse of a car which had a gruelling life over there - sometimes carrying 8 people(yes, 2 in the boot - it's not illegal there, but just because you can, doesn't mean you should!)

 

I hope OP gets where he wants to be.

[driver52]

On 4/15/2023 at 4:59 AM, jcmj said:

Last month’s bill was over 22,000. Hopefully they will come up with some help soon like they have in other countries. If anyone knows of a decent priced place in Pattaya I’d still consider looking into it again. 

holy doodoos that is a helluva lot for leccy!! how many aircon uniits?? I'm not an electrician but I understand technology and I do know this stuff isn't expensive now......ie 335watt panels are 3800baht a piece and you can buy cheap inverters......search suoer we've been talking about it on another thread....

if i was me I'd just buy the stuff and rig it up myself with the help of some 'cheap labour' to 'have a go' lol

ie try say 6 panels to begin with, that'll give you 2kW of panels for not a lot of cash and that's a fair amount of electricity imo

panels here https://globalhouse.co.th/product/detail/072203095763