My Solar Generation History – 7 Years Real UK Home Data

My Solar Generation History (back to 2018)

In previous blog posts I’ve explained about both my 5.1kW Solar Array and my Battery Install (now 16 kWh).

In these two articles I detail the specifications about the installs; size, direction of panels, photos etc.

Recently I’d been asked how much solar do I generate and how does the recent addition of battery and our EV impact the export numbers, so here you go.

As detailed in the Solar post, my system was installed in September 2018. But it took me a month or so to get my monitoring system all up and running. So the first full month data I have is November 2018 onwards.

I create all these stats and figures by using the data from my Open Energy Monitor emonPi system. This CT clamp based is constantly monitoring the ins and out of my solar setup (and import/export, to/from battery and even EV).

Any device you attach a CT clamp to can be monitored individually.

You can read all about their open source hardware and software here: https://guide.openenergymonitor.org/applications/solar-pv/

If you’re into system stats I can’t recommend the emonPi system highly enough. It is absolutely top notch.

Table of Contents

Use the Table of Contents below to jump straight to the section that matters most or scroll through at your own pace.

Installation and Renewable Timeline

Here’s a quick summary of our hardware installation timeline.

• Sep 2018 – 5.1kWh of Solar Installed on a 3.68kWh Solaredge inverter
• Feb 2020 – Installed 4.8kWh Lux and Pylontech battery system (2 batteries)
• Aug 2020 – Took delivery of EV and installed Myenergi Zappi Charger
• Oct 2020 – Installed a third battery taking total capacity to 7.2kWh
• Feb 2021 – Installed a further two batteries taking total capacity to 12kWh
• Feb 2022 – Mixergy water cylinder installed and myenergi Eddi PV diverter
• Oct 2022 – Vaillant Arotherm 5kW heat pump installed
• Nov 2022 – Upgraded from Pylontech batteries to Hanchu
• Aug 2023 – Expanded battery system to 16kWh usable capacity

Heat Pump Performance History

The details in this Solar Generation History page is a very similar layout to my Heat Pump Performance History page, where you can find annual and monthly heat pump performance and consumption figures going back to October 2022.

Heat Pump Performance History

Details Provided in the Tables

Here’s a short description of the columns shown in the tables below. Note, all figures are kWh unless otherwise stated.

• Gen – the total amount of solar generated (in kWh) for the whole month
• Avg Gen – the amount generated divided by number of days in month to give a daily average

• Cons – the total amount of electricity consumed within the home for the whole month (regardless whether from generation or solar)
• Avg Cons – the total amount consumed divided by number of days in month to give a daily average

• Import – the total amount imported from the grid for the whole month
• Avg Import – the amount imported divided by number of days in month to give a daily average

• Export – the total amount exported back to the grid for the whole month
• Avg Export – the amount exported divided by number of days in month to give a daily average

• Export % of Gen – the amount exported compared to generated shown as a percentage

Full Whole Year by Year Solar Stats (2019 to 2024)

Monthly Stats 2018

Monthly Stats 2019

First full year of the system generating 4244kWh through the year. I was delighted with that.

This was before batteries and the EV, so you can see that I exported a whopping 68% of what we generated, so only 32% used in the house? Grrrrr!!

Even in darkest December, over 40% of what I generated went back to the grid.

Monthly Stats 2020

The second full year shows we generated another healthy 4324kWh, but we only exported 35% of it back to the grid.

So 65% used in the house because of the batteries and EV coming into play throughout the year.

But despite onsite usage going up, so did energy imported. This will be charging the EV at off peak times.

You can see this in the jump in consumption figures too.

Look at December this time around, just 5kWh sent back to the grid. That’s better!!

Monthly Stats 2021

Lower than average generation, but exports now down to just 12%. Goal for 2022 is reduce that further.

Monthly Stats 2022

Feb 2022 sees a massive hike in consumption and import as we install a Mixergy water cylinder that we are heating on a combination of overnight electricity and surplus solar.

Still delighted that the exports are low though, with the myenergi Eddi diverting lots of surplus solar into the Mixergy.

July and August exports not as low as hoped, but we were away for a few weeks, so no hot water or EV dumping available.

You can read all about the water cylinder install here: https://energy-stats.uk/plant-room-project/

October saw us ripping out our 32kW combi boiler and replacing it with a 5kW Vaillant Arotherm heat pump. This will obviously have a big effect on our electricity consumption moving forward. The figures will be very interesting how the batteries, solar and time of use tariffs play together.

November and especially December see a giant jump in consumption due to the cold spell (-3C) and the heat pump doing its thing. It sill managed a COP of 3.4 despite the cold weather.

Solar generation for 2022 turned out to be our biggest year to date, so that’s nice.

Monthly Stats 2023

Worst generation year to date, but not by much. I still generated over 4000 kWh.

This was the first full year of having the heat pump.  Strangely, figures are very similar to the previous year.  Likely because whilst the heating demand has come up, the hot water is no using the heat pump (getting 300% efficiency) instead of 100% using the immersion alone in 2022.

Monthly Stats 2024

Second full year with the heat pump. Be good to have year on year comparisons.

But these annual figures might be skewed by the fact that 2024 was the year we went gas free as we installed an induction cooker and said goodbye to the gas meter.

Note: Noticed from historical system stats than I lost output from a single panel in January. The SolarEdge optimiser failed, so I have been a panel down from January until it was fixed in September. Which goes some way to excuse why my overall output has been a little lower compared to recent years.

Also, I have decided to move my exports from FIT to actual exports. With a few to seeing if getting paid for everything I send back on 15p Octopus Fixed is more lucrative than old 50% deemed FIT.

Monthly Stats 2025

Update info about 2025

January Comparison

February Comparison

March Comparison

April Comparison

May Comparison

June Comparison

July Comparison

August Comparison

September Comparison

October Comparison

November Comparison

December Comparison

Thinking of Solar? Where you gonna dump the excess?

If you’re thinking about owning solar then I’d suggest that you also have to consider where you are going to dump the excess.

No matter how hard you try to do the washing and cooking when the sun is shining you will not be able to use all electricity you generate, especially from March to October.

Yes, you could try and make some money by exporting via an Octopus Energy Outgoing tariff.

UPDATE: Read my 5 years with solar PV article for more information about exporting back to the grid.

5 years with Solar PV

But for an easy life and use the energy within your house (and not pay import costs) you’d need somewhere to divert your spare generation.

The more of your generation you can use in the house the better your return in investment (ROI) will be.

So where could you dump that excess?

Hot Water Cylinder

Probably the best bang for your buck. At less than £400 a Myenergi Eddi PV diverter will dump any excess generation to the immersion in your hot water cylinder. This will likely pay for itself pretty quickly.

As well as a conventional water cylinder you could divert to a smart cylinder (like a Mixergy) or a Sunamp heat battery.

EV Charger

Very similar to the Eddi, the Myenergi Zappi EV charger will divert excess generation to your car.

The beauty of the Eddi is that it can put very small amounts of excess generation into the water cylinder, just a few 100W.

Whereas your EV needs 1.4kWh available to fire up the charging mechanism of the EV. This probably won’t be an issue on sunny days.

But don’t let that put you off as you can also part top up the Zappi with Grid (or battery) to get to the 1.4kWh minimum that your EV needs to fire up the charging mechanism (ie a mix of 900W Solar and 600W from grid or batteries for example).

Home Batteries

As detailed in my home battery blog post, batteries can be used two ways. Both for dumping excess PV into and also charging at off peak times for use later.

As you can see from the figures and stats above, the batteries have been a game changer for us.

Get a Heat Pump

If you’ve got solar and perhaps a battery, it’s a bit of a no brainer adding a heat pump.  My 2024 review shows how much benefit the holy trinity (solar, batteries and heat pump) bring to whole house running costs.

You may also be interested in; How much electricity does a heat pump use, which gives a good flavour for electricity usage and potential battery sizing.

Other options?

Bottom line is that any electrical device in your house could be used for dumping spare generation. But the ones listed above are the easiest and are sort of ‘fire and forget’ options that don’t need a great deal of user interaction.

Summary

My Solar PV system is brilliant, I absolutely love it. I’m actively investigating if I can extend the system too.

But it was very tough through that first full year seeing oodles of generation go back to the grid.

Adding the batteries and then getting the EV has totally changed the way I view my solar now. In fact, I love it even more now.

During the winter the batteries come into their own when we can load then up with off peak energy.