Charging with solar & off peak electricity

[AussiePete]

I am in the process of moving to Octopus Go to enable charging of my ZS during off-peak hours and I am also considering installing solar PV's to provide household electricity during the day as well as charging if there is sufficient solar capacity.

I know smart chargers can be setup to do timed charging, so overnight off peak charging is not a problem. However what I don't understand is how the charger knows to kick in a charge if there is sufficient solar to do it - or can this only be done manually?

Anyone have this setup and able to help educate me?

 

[Deleted member 2439]

The charger has smarts inside it which measure how much solar is being generated, how much is going to/from grid & adjusts what goes to the car accordingly.

Heres a snapshot from my system which shows what happened a couple of months ago. Nothing from the grid, car charging at 7kW from a combination of the solar PV system and my battery storage. I have a total of 7kW solar and about 19kWh of battery storage.

 

[AussiePete]

1

The charger has smarts inside it which measure how much solar is being generated, how much is going to/from grid & adjusts what goes to the car accordingly.

Heres a snapshot from my system which shows what happened a couple of months ago. Nothing from the grid, car charging at 7kW from a combination of the solar PV system and my battery storage. I have a total of 7kW solar and about 19kWh of battery storage.

19kwh of battery - wow!!

I’m presuming that your charger is a specific one for solar integration?

 

[Jomarkh]

The charger has smarts inside it which measure how much solar is being generated, how much is going to/from grid & adjusts what goes to the car accordingly.

Heres a snapshot from my system which shows what happened a couple of months ago. Nothing from the grid, car charging at 7kW from a combination of the solar PV system and my battery storage. I have a total of 7kW solar and about 19kWh of battery storage.

View attachment 4815

Hi, what sort of power levels do you get into the 19kWh, would you be able to charge the car and run the house after dark?

 

[Deleted member 2439]

Hi, what sort of power levels do you get into the 19kWh, would you be able to charge the car and run the house after dark?

The inverter part of the battery system, everything is AC connected, has a max charge & discharge rate of 3.6 kW. So, when the battery is full and the sun has gone in, I tend to go for long slow overnight charges @ 1.4kW using the ECO setting on the Zappi. I also have Octopus Go Faster, this gives me 5 hours @ 5.5p per kWh, which means that I can charge the car at the low rate and also charge the house battery if the weather the following day is forecast to be overcast. Charging the car for “free” needs careful planning as the energy in the battery would otherwise be used for cooking, washing etc - but it all helps. This weekend for example I’ve used a full battery in the car just running around locally and the total solar generation is less than the 40 or so kWh required - so some of it had to come from the grid - albeit at the cheaper price. Hope this helps .

 

[charliesjt]

You will not regret installing solar panels. Thanks to the wholesale price of electricity this year everyones bills are going to go through the roof.

To answer your direct question batteries and smart chargers use 'CT clamps' to make themselves smart. CT clamps connect around your meter tail and around your solar generation and then the systems know how much solar is being generated, how much the house is using and how much excess there is.

I use the same Myenergi system as Robert and I would recommend. I don't have a battery (yet) but I do have the hot water diverter as well, you can prioritise whether you heat the hot water or charge the car.

The system is also compatible with Octopus Agile so if we do ever see cheap electricity again like all of last summer then the system automatically downloads the cheapest 30minute slots of electricity and charges the car in the night with the very cheapest slots (It's v cool)

Note: The minimum rate at which an electric car charges is 1.4KW. So for a 100% free/green charge you need at least that in excess. I have 4.2KW of solar but wish I have gone BIGGER!

 

[SparkyEV]

When it comes to speccing your system it's worth getting a standalone inverter - we've got a hybrid inverter and so the zappi charger can't see the batteries as a separate entity to the solar panels as we can't put a CT clamp on the tails of the batteries. We can still use it but it takes some jiggery pokery with the zappi settings to get it working as we want.

 

[Deleted member 2439]

You will not regret installing solar panels. Thanks to the wholesale price of electricity this year everyones bills are going to go through the roof.

To answer your direct question batteries and smart chargers use 'CT clamps' to make themselves smart. CT clamps connect around your meter tail and around your solar generation and then the systems know how much solar is being generated, how much the house is using and how much excess there is.

I use the same Myenergi system as Robert and I would recommend. I don't have a battery (yet) but I do have the hot water diverter as well, you can prioritise whether you heat the hot water or charge the car.

The system is also compatible with Octopus Agile so if we do ever see cheap electricity again like all of last summer then the system automatically downloads the cheapest 30minute slots of electricity and charges the car in the night with the very cheapest slots (It's v cool)

Note: The minimum rate at which an electric car charges is 1.4KW. So for a 100% free/green charge you need at least that in excess. I have 4.2KW of solar but wish I have gone BIGGER!

View attachment 4869

Ours is a 7kW system, or actually a 4kW one and a separate 3kW one. I’ve not seen the Eddi symbol before as we don’t have one. We have something similar - albeit home made & running on an Arduino based microcontroller. The challenge was that all the CT clamp “gubbins” is a considerable distance from the hot water tank, so had to get creative with some twisted pair cable and opto-isolation. Works a treat though & has been in and running continually since 2013.

 

[Fokmg]

I am in the process of moving to Octopus Go to enable charging of my ZS during off-peak hours and I am also considering installing solar PV's to provide household electricity during the day as well as charging if there is sufficient solar capacity.

I know smart chargers can be setup to do timed charging, so overnight off peak charging is not a problem. However what I don't understand is how the charger knows to kick in a charge if there is sufficient solar to do it - or can this only be done manually?

Anyone have this setup and able to help educate me?

Hi
I have an MG 5EV and have solar panels
I have just had a zappi 2 wall charger installed, this has multiple modes of operation in particular the ECO modes which can be set so surplus energy can be routed to charging the MG rather than sending it backdown the grid.
I certainly recommend the Zappi 2 it works well with the MG and I have been able to leave the MG plugged in so it feeds almost entirely of sunlight ! Very green and very cheap!
I know the Zappi2 is not the cheapest EV charger but I think its one of the best
PS if you are having solar panels fitted and the location has shadin such as trees, chimneys other roofs etc make sure you use solaredge technology with your solar panels.

 

[Spinynorman]

This is a terrific thread!
I’m looking to install solar panels with a Zappi 2 charger.
Are there any gotchas to lookout for?
Having a think about batteries but don’t really have the space and would need to build some sort of outside brick extension to house it and I only live in a small 2 bed terrace house, so difficult to accomodate.
I have seen a company with some good reviews that do the charger at the same time as the solar panels which seems good but still doing the research for suppliers which - as usual - is a minefield.