As part of the discussions with Adam from LAMM Solar and Electrical, I mentioned that we were getting an electric vehicle and I was interested in getting a home charger for faster charging. After clarifying that I wanted nothing to do with a certain T*sla brand, they recommended taking a look at an Evnex charger.

We only have single-phase power in our house (and no immediate plans to change that), so that narrowed it down to one of their E2 range that can provide up to 7.4 kilowatts:

The Flex is the base model. It doesn’t have the ‘Solar smart’ feature that allows you to “schedule your charging to use only your excess solar power without drawing from the grid, giving you free kilometres from sunshine”.

The Core sounded like it was the one, but I took note of Adam’s advice to always get a longer cable than you think you’ll need, as you won’t regret it. Some chargers let you plug in your own cable, whereas unfortunately the Evnex ones don’t. That pushed me to the ‘Plus’ as rather than 5m it comes with an 8m cable. It also supports a client/server model which I understand would be useful if we wanted to get a second charger installed and they could be managed together.

I was also interested to see what kind of ongoing support they had - I found there’s an active support forum with prompt responses to queries, so that was also encouraging. They’re designed and manufactured in New Zealand. If I can’t buy Australian then New Zealand is the next best thing!

And so that’s what we got. We ordered directly from Evnex and it arrived a couple of weeks later, just in time for LAMM to install when they refreshed our solar panels (there was a small reduction in costs for doing both together).

Oh and Adam was spot on with the longer cable. 8 metres was enough that I could run the cable along the ceiling of our carport over to near the charging port on our car. Keeping it off the ground and avoiding a tripping hazard. 5m would have been too short to do that.

Mobile app

Evnex provides a mobile app that you can view and manage your charger.

For comparison, here’s the Kia app at the same time:

In the Evnex app you can view the details of the current charging session (and past ones too)

Like the solar inverter, the Evnex also uses a CT clamp to monitor actual electricity usage in your house. I’d say ‘current usage’ but that could be confusing🙂

You might just want to be able to charge any time, but for me I wanted to limit charging to when our electricity plan is cheapest. It is true that the Kia app provides simple scheduling for when to accept charging:

But the Evnex app has much more advanced controls:

The app has an advanced schedule setting, where you can configure when you want to allow charging and the costs that it would incur (from your electricity plan).

My current electricity plan has free power from 11am-2pm, so that’s the main time I allow the car to charge. But on occasion I may want to allow charging overnight (when it isn’t free but the cost is low) so I’ve created 1 hour intervals that I can selectively enable if needed.

You can add in different prices.

And for each time period you can assign one of three behaviours:

If we had a larger solar installation, then the Solar Smart feature could be useful too, to manage how much of your solar-generated electricity to allocate to EV charging.

Charging done (set to stop at 90%):

Home Assistant

Yes, there’s a really good Home Assistant integration for the Evnex chargers. It provides two devices:

There’s a number of controls and a bunch of sensors

You can use these to track usage and generate some nice graphs. I can imagine you could get quite clever with using Home Assistant to provide even finer control over how your car is charged. I could see something like monitoring the weather forecast to predict likely future solar generation to adjust how and when charging is offered. Not something I’m going to do now, but there’s all kinds of possibilities.

Money back

Narelle discovered that our local council were offering a number of sustainability rebates, including for installing your own EV charger! We just had to supply a before and after photo of the installation and then a week or two later we got $200 back. Nice!

So previously I described how our rooftop solar panels had a small failure that resulted in a reduced generating capacity. Now that we also have an EV, I was keen to get them back working as efficiently as possible. Ideally we’d be generating as much power as possible, not only to use in our house, but also to charge the new car.

Again, I contacted a few different installers, but ended back with LAMM Solar and Electrical again. There were a couple of constraints that they understood and worked with us on:

1. We’re still receiving a generous government feed-in tariff for power we send back to the grid (paid in addition to any input rate on our electricity plan)
2. We don’t have heaps of money to throw at a huge upgrade.

The first point is important. As I understand it, if you make any significant changes to your system, like increasing capacity or installing a battery, then the government tariff gets cancelled. So if at all possible, I’d prefer to keep that until it runs out in a couple of years.

Adam from LAMM patiently came up with a few different options to choose from that all kept any changes compliant. As long as the new system didn’t exceed the capacity of the original then the feed-in tariff would continue.

One thing I hadn’t considered was that solar panel technology has advanced a lot since our original panels were installed. The old system consisted of 24 x 190W panels.

The new system is 9 x 500W panels - and as it takes up a lot less roof space, it gives us physical room to expand in the future.

The alignment of the original panels was in two strings - with a longer one more north-aligned. It was great in Summer, but shaded by trees a lot more in Winter. The second string was at a slightly less north-facing angle, but not impacted by trees, so it could be relied on to keep generating through the whole year.

The replacement installation kept the second string. The plan was to put all 9 panels in that position, but on the day of installation we realised that they were just a bit too big to fit, so 3 panels were put on a different part of the roof. Those will pick up more afternoon sun and should also do well over Summer.

One slight annoyance was to discover that the government incentives for installing solar actually meant it was cheaper to put in a brand new inverter, rather than keep the perfectly fine one we had (it was only a few years old, having replaced the original inverter when that became faulty).

In a similar way, there wasn’t much that could be done with the remaining old panels. If I had a farm shed or something similar I might have been able to repurpose them in some off-grid system, but I don’t have any such thing. Even donating them to someone else would not be worth it, as I was informed that the cost of reinstallation would outweigh any savings compared to just putting in a new system. A shame but not much I could do about that.

Home Assistant monitoring

The new inverter is a GoodWe brand, and Home Assistant has support for that built in with the GoodWe Inverter integration.

I had read the documentation for that integration which mentioned you needed the Modbus TCP option enabled. That wasn’t on by default. I want to give an extra thanks to the LAMM installers (Liam, Ethan and Ben), as they not only completed the installation but were happy to stay on a bit longer and adjust the inverter settings for me until the HA integration worked. That was much appreciated.

One advantage to getting a new inverter is it comes with a CT (Current Transformer) clamp. This allows it to monitor the electrical current in the mains connection. With that in place, you are able to see the actual amount of electricity that is being consumed by the house (in addition to any that is being generated by the solar panels).

I wish I’d started using Home Assistant much earlier, as I would have had a much longer history to compare with. As it is, here’s a couple of months of the old system (and bear in mind it is Winter here in Adelaide, so any sunshine peaking through the clouds this time of year is a bonus!)

The new panels are already proving their worth. Whereas the old panels were lucky to get 6 kWh maximum, the new ones seem to have that as almost a daily minimum!

Replacing the panels was an unplanned expense, but the proceeds from selling the old Kia Sorento car ended up covering a good portion of the cost.

There’s one other thing that I got LAMM Solar and Electrical to install on the day. I’ll talk about that more in another post!