This is one of those blog posts where I’d wondered something, looked it up, and am now sharing what I’ve found out. When it comes to charging your electric car, you may hear the terms ‘level 2’ or ‘level 3’ charger being used. They’re not common terms in the UK, but you may encounter them in other countries – especially the US.
Level 1 chargers
A level 1 charger is, essentially, just a standard 3 pin plug like you have at home. Your electric car will probably come with an adaptor cable, with a 3 pin plug on one end, and a Type 2 plug on the other end. There’s usually a chonky box on the cable, known as an EVSE (Electric Vehicle Supply Equipment), that regulates the power flow. Colloquially, these are known as granny chargers.
In the UK, our standard power supply is 240 volts and 13 amps. Going back to GCSE Science, we know that power is the product of voltage and current (amps), so the maximum output is 3.1 kW. An electrician may be able to fit a waterproof external plug socket for you which is rated at 16 amps, upping the maximum power output to 3.8 kW. One of our neighbours had this done for charging their plug-in hybrid as it was cheaper than a dedicated car charger (level 2, as we’ll encounter in a bit).
In the US, the voltage is lower (typically 120 volts) but the current can be as high as 20 amps, depending on how it’s been wired. However, even a 20 amp socket in the US can only output a maximum of 2.4 kW due to the lower voltage.
A level 1 charger is therefore going to charge your car quite slowly – especially if you have a big battery. I have also seen photos of plug sockets that have melted due to continual use for charging electric cars. And it’s (probably) the least efficient; some tests suggest that 25% of the electricity doesn’t make it into your car’s battery and is lost as heat.
Level 2 chargers
Level 2 chargers are the dedicated electric car chargers that you can get fitted at home. In our case, we have a Rolec EVO unit, and this will be fitted to the outside of your house. In the UK, it’ll have a Type 2 connector, and will be capable of much higher current – up to 32 amps. That equates to (almost) 7.7 kW, which is the maximum that you can get on a single-phase electrical supply that is standard in UK homes.
My Rolec charger lets me vary the current, so I can set it below 10 amps if I’m not in a hurry and want to make the most of my solar panels. Level 2 chargers also incorporate EVSE inside them, so the cables just tend to have a standard type 2 plug on each end.
Many public chargers are also level 2 – especially older ones. Some may be connected to a three-phase electrical supply, which triples the power output to 22 kW. You’ll generally find these at places where you can park your car all day.
I personally describe level 2 chargers as ‘medium’ speed, but a full charge at 7 kW will take a long time for larger vehicles. For our Nissan Leaf, a full charge (from 0 to 100%) would take 6 hours and 30 minutes, although that’s partly because it can only accept 6.6 kW from level 1 or 2 chargers.
Level 3 chargers
Level 3 chargers are the rapid and ultra-rapid chargers that can output 40 kW or more – some can do up to 150 kW. Unlike level 1 and 2, these chargers use DC (Direct Current) rather than the standard AC (Alternating Current) that you would get from a standard 3-pin plug. They also use different plugs – CCS2 is the most common, but some cars, like our Nissan Leaf, use a competing standard called CHAdeMO. You’ll also find that these are almost always ‘tethered’ chargers that include their own cable, so you won’t need to plug your own cable in.
I doubt you would be able to get a level 3 charger installed at home, as they’re expensive and would probably need planning permission and authorisation from the electricity distribution network operator (DNO). But increasing numbers of these rapid chargers are available when out and about, and especially at places like motorway service stations where you need to charge quickly whilst en-route somewhere.
How fast your car will charge will again depend on its maximum charging speed. Our Nissan Leaf, when using CHAdeMO, can only accept up to 46 kW. Still, that means a full charge in less than an hour.
DC chargers are also more efficient, in that you’re less likely to lose power as heat than AC chargers. As these chargers are generally the ones you pay a premium for, that’s a good thing as almost all the electricity you pay for will make it into your car’s battery. However, regular use of rapid chargers can degrade the battery more quickly.
Somewhat annoyingly, our smart electric meter stopped being smart on the 26th March. I’m not entirely sure what happened, but since then, we’ve not had any automatic electricity readings sent to our energy supplier.
After a week, I reported the issue to Octopus, who are our energy supplier. We exchanged some emails back and forth, and tried various things, but apparently to no avail. What was weirder was that the gas meter still submits regular readings.
This web site has loads of information about smart meters, including how they work and how they communicate with your energy supplier. As well as the gas and electric meters, all homes with a smart meter have a ‘communications hub’ that sits on top of the electric meter, and it’s this that sends the data. So even though it was sat on top of our electric meter, it was only sending data from the gas meter. Weirder still is our ‘in home display’ (IHD) – the small black screen that sits away from our meters in our dining room. That was still accurately displaying data from both gas and electric meters.
With Octopus unable to fix the problem remotely, we’ll need an engineer to come out. And right now, there’s a long wait for smart meter engineer visits, as energy companies are currently prioritising those with a ‘radio teleswitch’ (RTS) meter. These older meters were used for (for example) Economy 7 tariffs, and listen for a radio signal to switch to a cheaper tariff – they’ve been around since the 1980s. Alas, the radio signal is being switched off at the end of next month, and there’s an estimated 400,000 RTS meters still in use. That doesn’t leave very long to have these replaced with smart meters.
Going back to manual readings
So whilst our gas readings are being sent automatically on a regular basis, we’re back to doing manual readings for electricity. As we have solar panels, we have to do two separate readings – an import reading, for the energy we use from the grid, and an export reading, for the energy that we sell back to the grid.
For the import readings, we can just use the IHD – press a few buttons, and it’ll give us our usage. But the IHD doesn’t display export readings. For that, we have to take a reading from the screen on the meter itself.
Our electricity meter is in our cellar, under the steps down from the kitchen. After we had our kitchen renovated, we also improved the access to the cellar, but it’s still in an awkward place. I have to move our tumble dryer out of the way, and crouch in the small space under the steps to take the reading.
It’s also not the most straightforward process. The meter itself has a small screen and two buttons, and you need to know which combination of button presses are required. Thankfully, Octopus offers this excellent guide to how to read various types of meters, and so I was able to submit both import and export readings. The next day, we were credited £116 for all the electricity we’d exported since the 26th March.
Hopefully, it won’t be too long before an engineer visits and fixes the issue for us. In the meantime, I’m also waiting to see if we can get an Octopus Home Mini, which bridges across to your home Wi-Fi network and sends data in near real-time.
We’ve had our solar panels for a couple of years now, and, as a thought experiment, I’ve wondered if it would be possible to go ‘off grid‘. This would mean having no connection to the electricity and gas networks, and potentially the water network too.
Now, I’m very much aware that this is a classic example of Betteridge’s Law of Headlines, and indeed, the short version of this is pretty much, ‘no’ when it comes to electricity and water. Especially if the person reading this is my wife, Christine (love you sweetheart). It is intended to be a thought experiment after all.
Getting off the gas grid
We’ll start with the easiest one – getting off the gas grid. This is actually a long-term of ours, and many homes are now getting disconnected from the gas grid.
When we bought our house, which will have been 10 years ago this summer, it was a very gas-reliant house. There were three gas fires, a gas central heating boiler and water tank, and a gas cooker. We got two of the gas fires out before we’d even moved in, and the remaining one followed when we had the very old gas boiler replaced with a more energy efficient condensing boiler in 2016. Next to go was the gas cooker, when we had the kitchen renovated in 2022, so now we only need gas for heating and hot water.
Now our boiler isn’t quite nine years old, but it’s likely to have a few years left in at least. When it’s due for replacement, our plan is to switch to an air source heat pump, which will be electrically powered. That will mean there’s no need for a gas connection to our home, and we can have it completely removed. As well as meaning that we don’t need to pay the daily gas standing charge, we’ll no longer have pipes carrying an invisible and highly flammable gas running into our home. And it’ll reduce our carbon footprint too.
Off-grid electricity
So that’s the easy one out of the way. Going off grid for electricity, however, is likely to be much harder.
We’ve made a start, at least, with our solar panels. In the summer months, with longer days and more sunlight, we generally generate enough to be self-sufficient. We also have a battery attached to the system, so the solar panels can charge the battery during the day, and then the house can run off the battery overnight.
However, at this time of year, we are very much not self-sufficient. This is especially true as I write this on a very dull Sunday afternoon, where our solar panels are contributing a mere 7 watts of power. That’s about enough to run a couple of LED light bulbs, but certainly not enough for our freezer, for example. We would therefore need other ways of generating electricity on dull days, or at night.
Ovo Energy have a useful guide here. Generally speaking, a roof-mounted turbine would be capable of generating 1-2 kW of electricity, which is less than half the peak capacity of our solar system. And that’s based on a lot of assumptions about wind speed that may or may not apply to your property.
As well as the installation cost, we would probably also need planning permission, as our house isn’t detached. We’re therefore looking at around £2000-3000, and it would probably take quite some time to recoup that investment.
Dull days with no wind
So, a solar system backed up with a wind turbine might cover our electricity needs. Unless it’s a dull day and there’s no wind.
I’m in a few Facebook groups for people who use Home Assistant and who have solar and battery systems, and quite a few other members have the Agile Octopus tariff. On this tariff, electricity prices change by the half hour, based on wholesale prices. If it’s forecast to be a particularly sunny and windy day, electricity prices can be very low. Indeed, they occasionally go negative – in other words, Octopus will actually pay you to take electricity out of the grid, rather than the other way round. It’s great for people who have battery systems that can charge from the grid, or who can plan their days to use more electricity at the times when it’s cheap.
Though we are Octopus Energy customers, we’re not on Agile Octopus, because prices can also shoot up on dull days with no wind. Our fixed tariff means we pay 21.10p/kWh, regardless of the weather, but on Agile Octopus, the electricity unit price can go up as high as £1 per kWh. And if you haven’t been able to charge up your home battery by then, it could get very costly.
As an aside, if you’re not already an Octopus Energy customer, here’s my referral link. You get £50 off your bill if you join, and their customer service is better than any other energy company that we’ve been with so far. There’s also an unofficial Home Assistant integration that uses their API.
Therefore, if we were to disconnect from the grid, we would need a third source of electricity. This is where it gets a bit more tricky. The options I have looked up so far include:
A wood burning stove, with a thermoelectric generator. However, in my research, I’ve yet to find anywhere in the UK that would sell such a system. And those that I have seen for home use would only be able to generate a few watts – not even enough for our house’s ‘base load’ (fridge, freezer, devices on standby etc). We have a chimney that we could use, but we would also need filters to stop particulate matter getting into the air.
Some form of hydro generation using water collected from rainfall on our roof. This would only really work when it rains; although we live in the Pennines where it rains quite a bit, I doubt this would power much more than a couple of light bulbs.
Therefore, we would probably have to fall back on a diesel generator, which would be noisy, smelly, and not good for local air quality or the environment.
No Smart Export Guarantee
The other benefit to being on the electricity grid is that you can be paid back for any excess electricity that you export. Even though it’s January, we’ve exported around £1 of electricity this month, and that’s only after our battery has been fully charged. In June last year, we were paid £46 for the electricity we exported, against £36 for the grid energy that we used. So that was a net payment to us that month. Indeed, over the whole of 2024, we were paid £227 for the excess electricity that we exported.
If we’re not on the grid, then we can’t export. So if our battery is full, that electricity is essentially being wasted. Of course, if I was serious about going off-grid, then I would probably invest in another battery to prevent this from happening, but then that’s another expense.
What about water?
Going off the water grid would be the most difficult. Although ironically, we’ve been inadvertently off the water grid four times so far this month, due to supply issues. I have an active complaint with Yorkshire Water about that, but let’s imagine that I want to willingly disconnect from the water grid for a moment.
Clearly, we would need some other way of getting clean water into the house. Rainwater is the most obvious, but we would then need somewhere to store it. In 2023, I read The Climate Change Garden(sponsored link) by Sally Morgan and Kim Stoddart, and the book shows you how you can store water in tanks underneath your garden to cope with water shortages. During the 2022 heatwave, we had a hosepipe ban for several months, and so I’m considering whether to get a water butt to store rain water for use in the garden. You may be eligible for a subsidised water butt from Save Water Save Money – you’ll need to pop in your postcode to see if your water company participates.
But even a butt, or huge tanks under our lawn, are unlikely to be sufficient. We would ideally need to have access to a constant flow of running water, such as a stream. And we would need the means to filter the water so that it’s fit for drinking.
And what about sewage? We don’t have a particularly big garden and so we probably wouldn’t have room for a septic tank, or any other means of storing and/or treating waste.
A case study: Gibson Mill
Up above Hebden Bridge is Hardcastle Crags, a National Trust property which is home to Gibson Mill. The Mill is off-grid, because of its remote location – it’s about a mile away from the nearest electricity cables, for example. So, electricity is instead generated on site, using solar panels and a hydro-electric generator. Mills were typically built next to watercourses and Gibson Mill is no exception, being served by Hebden Beck. Whilst this would have driven a waterwheel in years gone by, nowadays it drives a turbine to produce electricity. The solar panels have recently been replaced with newer, more efficient models, and there are huge batteries to store energy.
We last went back in 2023, and despite having more than one way of generating electricity on site, there was still a diesel generator at the back that was needed to top-up the electricity supply. Even then, they were unable to serve hot food in the café as a result of not having sufficient power.
Gibson Mill also has no connection to the sewerage system, so its toilets are composting toilets. Below the toilets are huge vats filled with worms, who digest our waste for us. It’s feasible at this scale because it’s a tourist attraction, and the alternative of laying pipes would be more expensive.
Conclusion – staying mostly on-grid
So, in summary: going totally off-grid would be difficult, although coming off the gas grid is achievable and something that we want to do eventually. We don’t live in a very remote area, and so going off-grid with electricity and/or water wouldn’t really make sense. Even if we could find the means to generate our own electricity, the upfront costs of installing the required equipment would probably outweigh the potential savings.
We’ve now had our solar panels for two years, so it’s probably time to review how much money they have saved us, and how close we are to getting a return on investment.
We have a SolaX system, which includes twelve 400 Watt solar panels, an inverter and battery. I’m using SolaX’s app to estimate how much money this saves us, based on the electricity unit prices from the grid, and also the amount that we get paid for exporting surplus electricity under the Smart Export Guarantee.
I’ve included a screenshot taken a couple of weeks ago. We only saved around five pence that day, as the solar panels spent most of the day under a thick blanket of snow. But you can see that, in total, we’ve saved around £1600 in two years.
I should note, however, that whilst this averages out at £800 per year, last year we actually saved closer to £900. Alas, 2024 was a less sunny year, on the whole, and so our solar panels couldn’t work as hard.
The total cost of the system was around £11,000, so after two years, we’ve recouped 14% of our outlay. Had 2024 been as sunny as 2023, then this would have been closed to 16%. Assuming that we have more years like 2023, then we should break even in around 10 years time. That’s a long way away, but we’ll still be paying the mortgage on the house then, and we have no plans to move.
Since we had our solar panels fitted, prices have dropped significantly, and so a comparable system to ours would probably cost closer to £9000. You could argue that we should have waited a little longer to get our system installed, but back in 2023, energy prices were at an all-time high. Still, it does mean that the economics of getting solar panels fitted now is even better than it was.
Most of the money that we used to pay for the solar panels was either savings, or money gifted to us by my parents. However, we did borrow around £4000 to cover the rest of the cost, and still have some of that to pay off. Provided that we don’t have any more major expenses (I’m glaring at our car as I write this), we should have this paid off this coming spring.
Erm, no. Because even though we’re not yet at the end of January, we’ve used the last of our savings, some money from The Bank of Mum and Dad, and a small amount of new borrowing to pay for the installation of solar panels.
I would show you a photo of them, but that’s hard to do without also sharing a photo of our house, which I’m loathed to do publicly. Instead, here’s a photo of the interior kit – namely, the inverter and the battery.
The battery is an optional add-on to solar systems and is designed to offer additional off-grid power at the time when the solar panels aren’t working – i.e. dull days or at night. It can store up to 6 kWh of electricity, and there’s a pair of plug sockets that are attached to the battery, meaning that we have backup electricty in the event of a mains grid power cut.
Here are our reasons for having a solar panel installation:
Saving money
Energy prices have increased everywhere recently, but especially in the UK where many of our power stations work by burning natural gas. Gas prices were already on the rise when Russia declared war on the Ukraine, and pushed prices even higher as countries started to reduce their reliance on Russian gas. So, switching to a renewable source of power that doesn’t cost money to generate (once the panels are installed and paid for) seems like a good idea.
January is a bit of an odd time to have them installed, though. The days are short, and we only get about 6 hours of usable daylight for generating electricity as I write this – normally 9:30am until 3:30pm. Yes, it’s light from around 8am but the sun needs to have moved around sufficiently to be shining onto the panels to get more than just a few watts of power.
Last week was very, very cold but with clear, sunny afternoons. That was enough for the panels to generate around 2.5 kW – and normally, when I’m working at home without any appliances on (e.g. washing machine, dishwasher, cooker etc.) we only use about 250 W of power. So, that’s a lot of overflow to also charge the battery and there were several days where it was fully charged at sunset. That then gave us enough power for teatime and up until beyond bedtime, meaning that we weren’t paying for grid energy.
Right now, it’s saving us between £1 and £2 per day, depending on the weather and how much energy we’re using. Our savings will increase soon, once we have our Microgeneration Certification Scheme (MCS) certificate, which will allow us to be recompensed for the excess energy that we can sell back to the mains grid under the Smart Export Guarantee. Realistically it’ll be the end of next month before this is up and running, but it means that, once the battery is fully charged, we can make a bit of money back. Not much – at best, we can earn about 16p for kWh at present, which is less than half the 34 kWh we pay to use electricity – but we would already be a few pounds up by now if it had already been in place.
The app which links to the inverter can be configured to calculate your savings, so we have an idea of how much money we’re saving.
Doing our bit for the environment
You may choose to believe that climate change isn’t real, but I’m convinced, along with something like 99% of climate scientists that it is happening. So having solar panels means that we can actually do something tangible about it. Whilst renewable energy sources are forming an increasing proportion of Britain’s mains grid energy mix, burning natural gas is still the source of the majority of our electricity, and there are CO2 emissions involved. Also, gas supplies are finite, and so regardless of whether you believe in climate change, there will come a point when we run out of gas, or have to go to greater lengths to access it. Again, the inverter’s app approximates how much CO2 we’re saving, which is over 50kg in just over a week. I reckon that’ll be half a tonne by the end of the year, which seems like a staggering amount for just one household.
We are, of course, parents, and so by doing our bit, we can show our seven-year-old that we care about the planet that they’ll inherit.
International Geopolitics
I’ve mentioned Russia’s invasion of Ukraine, and I suppose this could be a small act of solidarity with the Ukrainian people. Whilst Britain only sources a small amount of its gas from Russia, if that could be reduced to zero then that’s a lot of money that Russia isn’t getting to fuel its war machine. I’d like to think we’re helping, even if it’s only a tiny contribution.
Resilience
I mentioned above that, attached to the battery, are a pair of plug sockets which draw power only from the battery. If there’s a power cut, then these sockets will still provide power, so long as there’s some charge left in the battery. Indeed, the inverter normally avoids depleting the battery completely – typically it’ll leave 10-20% charge behind.
Even it’s sunny and the panels are generating, should the mains grid go offline (i.e. we get a power cut), then unfortunately all the regular sockets and lights in our house will go off too. But this extra pair of sockets will keep going, and so we could, for example, run a long extension cable up from the cellar to the freezer, to keep that going. We’ve had a couple of short power cuts in recent months, but these have been no more than 10 minutes at a time thankfully.
What to consider if you want solar panels
Our system cost a low five figure sum to install, and was done by a local firm. We got three quotes and all were almost exactly the same, so this seemed to be the going rate. There’s a great guide on MoneySavingExpert about whether they’re worth it, and I suggest that you also read that, as well as my own experiences.
These are things you need to consider:
You need a pro-dominantly south-facing roof; ours faces south-west, which is okay but not perfect. If your roofs point east or west, then solar panels probably aren’t for you.
You will get more out of solar panels if you can use the energy whilst it’s sunny. So, you’ll need to use the delayed start on power hungry devices like tumble dryers and dishwashers, so that you’re using them when the panels are working. If you work at home, you may benefit more, and especially if you have an electric or plug-in hybrid car that you can charge at home during daylight hours.
Solar panels will help with electricity, but not with your gas bill. So, you’ll get less of a benefit if you have a gas oven, or if you don’t have an immersion heater in your hot water tank. Annoyingly, in hindsight, we ripped out our hot water tank in 2016 and replaced it with a combi gas boiler, although as part of our kitchen renovations, we bought new electric hobs and ovens. Conversely, if your heating and hot water is electrically-powered, perhaps using a heat pump rather than a gas boiler, you could benefit more from solar panels.
In a similar vein, to maximise your savings, you may consider boiling an electric kettle for hot water for washing up, or using an electric shower to fill a bath. Using a slow cooker during daylight hours may be more economical than a cooker in the evening.
The return on investment period for solar panels is about 11 years, so it’s probably best to install them in a house where you don’t plan to move any time soon.
It’s probably best not to borrow all of the money for solar panels. Whilst you can save hundreds of pounds per year, through less usage and selling back your excess to the grid, the interest payments on any borrowings will extend the return on investment period. We’re borrowing around £4000 to fund the panels, which I’m funding using a credit card balance transfer to keep the interest down, but the rest was savings and a parental gift.
You probably won’t need planning permission, unless your house is a listed building or you live in a conservation area.
I’ll aim to post again in the summer, once our Smart Export Guarantee is set up and we have some sunnier weather, to indicate how much we’re saving.
