Adding an EV charger - existing PV setup

ecraig

Hi all
I am looking for some guidance regarding some EV chargers to add to my home to supplement my PV setup.

Here’s what I have so far:
SolarEdge inverter
Growatt AC management box
Growatt battery

So far I’ve received some quotes to supply and fit a Zappi.
Some installers would go straight into my consumer box. 

Some installers would take a feed from my main feed supply meter and use CT clamps and a Harvi to control the inverter and the battery accordingly.

This is my initial wish list:
I ideally want to be able to charge the car using solar during the day, but I’m not fussed about drawing from the growatt battery to the Zappi, as I’d quite like the battery to serve the house during the night and not quickly discharge the whole amount to the Zappi.
Most of the charging is going to happen overnight. 

My conundrum:

So this is where I’m now wondering if a cheaper and simpler charger might be more appropriate - such as an Ohme epod.
I appreciate this will take energy from the grid, but that would be fine since I would therefore charge overnight at a cheaper rate.
It’s almost more cost effective to charge overnight where I can purchase <15p kWh, and therefore export excess solar generation at 15p. 

It seems it would be more cost effective to save the money buying an Ohme (or something else) and profiteering from a better solar export rate.

> Am I thinking straight?
> What would you knowledgeable people recommend, please?

Reed_Richards

ecraig said:

It’s almost more cost effective to charge overnight where I can purchase <15p kWh, and therefore export excess solar generation at 15p.

It seems it would be more cost effective to save the money buying an Ohme (or something else) and profiteering from a better solar export rate.

> Am I thinking straight?
> What would you knowledgeable people recommend, please?

I'm not certain that there is a tariff which allows you to both purchase at <15p per kWh overnight and export at 15p per kWh.  If such a tariff exists it IS more cost effective, there's no "almost" about it.  And unless you do a lot of driving each day it may be more cost effective to just use a "granny charger" than even a cheaper wall box like an Ohme.  

ecraig

Thanks Reed.
Import is on the basis and hope that I can continue to import cheaply using Agile overnight.
Things may be different come summer, though..

noitsnotme

Reed_Richards said:

ecraig said:

It’s almost more cost effective to charge overnight where I can purchase <15p kWh, and therefore export excess solar generation at 15p.

It seems it would be more cost effective to save the money buying an Ohme (or something else) and profiteering from a better solar export rate.

> Am I thinking straight?
> What would you knowledgeable people recommend, please?

I'm not certain that there is a tariff which allows you to both purchase at <15p per kWh overnight and export at 15p per kWh.  If such a tariff exists it IS more cost effective, there's no "almost" about it.  And unless you do a lot of driving each day it may be more cost effective to just use a "granny charger" than even a cheaper wall box like an Ohme.  

Intelligent Octopus Go is 7.5p/kWh import between 23:30 and 05:30 (sometimes extra smart slots outside of that).  Pair that with Octopus Outgoing and you can export at 15p/kWh.

Many people with a qualifying EV or charger, solar and batteries do this, myself included.  My house battery is fully charged overnight, along with the EV when it’s needed.  The house battery then powers the house all day while 100% of my solar is exported at the 15p rate.  99%+ of my import is at 7.5p/kWh.

Screwdriva

ecraig said:

> What would you knowledgeable people recommend, please?

Hi again Craig! 

While I'm a big fan of the Zappi, in your case, given the SolarEdge inverter, I would consider placing an order for the SolarEdge bi directional charger when it is launched soon. 

It will substantially increase your home's storage / export capability!

https://www.pv-magazine.com/2023/06/16/solaredge-unveils-bidirectional-ev-charger/

P.S. Incase you have any spare roof real estate, installers are most amenable to negotiate fitting an extra panel or two to expand your existing system when they are booked in to visit your property for another job like a charger/ diverter etc.

noitsnotme

Screwdriva said:

ecraig said:

> What would you knowledgeable people recommend, please?

Hi again Craig! 

While I'm a big fan of the Zappi, in your case, given the SolarEdge inverter, I would consider placing an order for the SolarEdge bi directional charger when it is launched soon. 

It will substantially increase your home's storage / export capability!

https://www.pv-magazine.com/2023/06/16/solaredge-unveils-bidirectional-ev-charger/

Interesting.  I wonder how many EVs that will be compatible with.

The new Octopus Power Pack V2G tariff is currently only compatible with 3 cars (Nissan Leaf, Nissan e-NV200, Mitsubishi Outlander PHEV).

https://octopus.energy/power-pack/

Reed_Richards

But for Intelligent Octopus Go you need the right make of EV or the right make of charger.  If you don't have the right make of EV then the right make of charger will cost in the vicinity of £1000, I think.  So you have to pay a lot up-front to save.  You would have to export 6667 kWh of electricity before you paid-off £1000.

noitsnotme

Reed_Richards said:

But for Intelligent Octopus Go you need the right make of EV or the right make of charger.  If you don't have the right make of EV then the right make of charger will cost in the vicinity of £1000, I think.  So you have to pay a lot up-front to save.  You would have to export 6667 kWh of electricity before you paid-off £1000.

I did say “with a qualifying EV or charger”.  The Zappi (and possibly the Ohme epod) which the OP mentioned, happens to be one of those.  We also don’t know what EV the OP has.  They might already qualify.

I went for the Zappi because for me it was the best option for working with a solar install and its integration with Intelligent Octopus has been flawless.

Don’t forget I’m also saving hundreds of pounds a year on IOG by almost never using peak rate electricity, as well as making money on the export.

Screwdriva

noitsnotme said:

Interesting.  I wonder how many EVs that will be compatible with.

All TBD at this stage. But it is very promising! 

Reed_Richards

noitsnotme said:

Interesting.  I wonder how many EVs that will be compatible with.

The new Octopus Power Pack V2G tariff is currently only compatible with 3 cars (Nissan Leaf, Nissan e-NV200, Mitsubishi Outlander PHEV).

https://octopus.energy/power-pack/

Nissan Leaf - has been discontinued
Nissan e-NV200 - it's a van!
Mitsubishi Outlander PHEV - maximum battery capacity 20 kWh

Not exactly a wide range to choose from!

Netexporter

That's because Chademo was designed as bi-directional from the get-go. Unfortunately, it has become the Betamax of charging systems.

There are V2G-ready cars already available, from BYD and others, but the chargers are not yet available to exploit the capability.