It's now been 9 month since we had our solar panels installed. Since they were installed I've noticed there has been many changes and advancements in solar technology and tariffs.
What has changed - tariffs
One of the biggest changes has been the availability of solar tariffs. When I first considered solar the SEG tariffs available were quite poor, the best being the Octopus Outgoing SEG tariff at 7.5p. When our solar panels were installed we were able to apply for the Octopus Energy Outgoing tariff which had by this point increased to 15p per kWh exported. At the time this was much higher than any other energy company would offer and was the reason why we moved to Octopus Energy.
Quite soon after our SEG export was confirmed and working Octopus surprised everyone by releasing their Octopus Flux tariff. this tariff increased the SEG export kWh unit rates even higher than Octopus Outgoing. Since being on Octopus Flux our SEG export kWh unit rate has averaged 23p per kWh exported. This is much higher than I expecting when we ordered solar panels back in October 2022.
During writing this blog Octopus Energy have stunned everyone by changing how SEG export Octopus Outgoing worked. They've made it so the Intelligent Octopus EV tariff is now eglible for their Octopus Outgoing SEG tariff. This means you can import your electricity to charge your EV at 7.5p per kWh, and export your excess solar energy at 15p per kWh. That's a big difference to solar and EV owners as they can finally get a great deal on both worlds.
What has changed - Technology
I've noticed there has been an improvement in battery technology. Recent releases of new home storage batteries such as the MyEnergi Libbi home storage battery and the Giv Energy All In One home storage battery have changed the home storage battery.
This new battery technology are a step above the previous rack mounted DC batteries I'd researched. The ability of these home batteries is much closer to the market leading Tesla Powerwall home batteries.
One thing I'd not considered before ordering our solar was how good solar app's are and how a good app makes your life easier. It wasn't until I got the MyEngergi Zappi and started to use their app that I found a good app makes a big difference. Its just so much easier to be able to make changes via an app rather than have to go to the inverter or EV charger to make the changes. This is of course more important if your solar inverter is in a more inaccessible place such as a loft.
I also hadn't considered how different batteries have a different peak output power. Our home batteries can provide up to 3.8kW of power at any one point. This means if the house is putting more load we will draw the additional power required from the grid. This means at certain times of the day we have to consider what appliances we are running or soon be running. It mainly means we can't cook dinner and have the washing machine on at the same time. Some of the newer home storage batteries will give a higher power output so this isn't such an issue.
The whole ecosystem of solar generation, EV charging, water heating and home central heating really needs to be considered up front. I hadn't really considered much beyond solar panels initially. This may complicate things in the future, especially if we change away from gas for home and water heating in the future like we plan to.
Has getting an EV changed things?
I'd not considered how an EV would changed things regarding the solar systems before getting one. I had thought about getting a Myenergi Zappi EV charger as I knew it would work great with our solar panel as it could transfer just the excess solar generation to charge the EV. I hadn't really thought about if the EV charger was compatible with certain EV tariffs such as Intelligent Octopus. With the recent Intelligent Octopus SEG export eligibility change its made me think that excess solar transfer to an EV is now pointless as its worth more exporting than it oil to import into the EV via Intelligent Octopus.
One thing I hadn't considered was how the EV would interact with our home storage battery. The biggest issue is that it's currently seen as a house load. This means the EV will drain the home battery when fast charging as it takes some power from the electricity grid and some from the home storage battery. I have found a work around to stop the home storage battery drain, I've set the home storage battery to charge during the scheduled EV charging period. This effectively switches off the home battery for a set period every night. Whilst this solves the home storage battery draining issue does mean there is a period of time where the home storage battery isn't able to meet home loads, causing electricity to be imported from the grid to meet house loads.
EV Tariff or Solar Tariff?
EV's work best when you have an EV tariff with a low overnight rate. Whilst up to now I've charged our `EV using the low Flux period a specific EV tariff would be better for us over the winter months when solar generation is lower. During summer I'd say we are very slightly better off on the Octopus Flux tariff due to the higher export unit rates.
Octopus Energy have changed all of this now Intelligent Octopus os now eligible for Octopus Outgoing. This changes things as you can have low cost eV charging and get paid a great rate for solar export.
Comparison of August's actual use on Octopus Flux compared to Intelligent Octopus
Would I do anything differently now?
When I first researched solar I was mainly interested in solar panels and didn't really consider home battery storage. That meant I made a snap decision just after placing the order to upgrade to a hybrid inverter. My idea at the time was that it would future proof us and make installing a battery easier in the future. What this actually did was send us down the path of only DC batteries that were compatible with that specific hybrid inverter. When we finally installed home storage batteries 7 months later battery technology had moved on and we missed out on considering the newer AC battery technology options that were now available.
Don't get me wrong, our solar system and home storage batteries work well for us. Hindsight is a wonderful thing, sadly with solar you have to make a choice and stick with it for many years. If I was doing things again I'd likely not install our Solis Hybrid inverter and DC battery. I'd look at the likes of Giv Energy All-In-One and Myenergi Libbi batteries for battery storage.
I had considered our future would involve an electric vehicle as I loved driving the Toyota Prius on electric only mode. What I hadn't really considered was that it would happen much sooner than I thought it would, or how it would work with our solar system and tariffs. The EV and home storage battery now complicate matters now regarding solar export rates as many SEG export tariffs won't let you onto their export tariffs if you have a home storage battery due to 'brown export'. This means I miss out on the higher SEG export rates if I want to have an EV tariff, unless I'm eligible for Intelligent Octopus. I'd definitely install an Ohme Pro EV charger over the Myenergi Zappi now Octopus have changed Intelligent EV tariff SEG eligibility. That said the Myenergi Zappi will soon be compatible with Intelligent Octopus so that would be less of a concern if anyone is buying an EV charger in the future.
How all the components of the solar system and EV interact is actually quite important. With more manufacturers offering complete ecosystems inter compatibility of smart devices will become better. One example are MyEnergi's Zappi EV charger, Libbi home storage battery and Eddi solar water heating products. they are designed as an ecosystem to work seamlessly together. They've even thought about the EV/home battery draining issue as the Libbi battery won’t drain when an EV is plugged in unless you tell it to take power from the Libbi battery. That saves the whole hard wiring issue and lets you have the best of both worlds. The only downside is these new battery technologies do come at a higher cost than DC batteries I have installed. .
Actual changes in the future?
One thing I've decided I will look at again is the hard wiring option of the EV charger so it's outside of the house loads. Whilst the home storage battery drain work around works it means every month we are still importing around 1kWh per day from the grid despite the fact we have home storage batteries. I'd like to get to a point where our home imports minimal electricity from the grid during the summer when we're on Octopus Flux.
It also means we can't consider an EV tariff such as Intelligent Octopus. That EV tariff changes the times of the EV charging every night rather than have a charging window like Octopus Go. Having an EV tariff like Intelligent Octopus would be beneficial to us all year round due to the Octopus Outgoing 15p per kWh eligibility and low 7.5p import rate to charge the home batteries overnight all year round..
I now think having an EV tariff would be more beneficial during winter than being able to discharge the home batteries into the EV. My thinking is that 10kWh battery capacity doesn't really provide enough stored energy for both the house and the EV. I could add more battery storage capacity, but that would be quite expensive as it would need to double or triple our current 10kWh storage capacity. There is probably little to gain as during winter our current home storage battery can store the available solar generation and charge overnight during the low cost period, causing little to be exported. In summer the EV can be charged by low cost electricity overnight, which is slightly lower than the average export rate on the Octopus Flux tariff.
I do have time on my side regarding hard wiring the EV charger as the MyEnergi Zappi EV charger isn't yet compatible with intelligent Octopus but its rumoured that it should soon be. Once that's available I will be looking to do anything that's needed so I can move to Octopus Intelligent.