Guest Article: Mike Gadd (Head of EV & Energy Department – YESSS Electrical)
Domestic charging – things to consider pre-installation and how to ready your home for future renewables
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An electric car charger for your house – no different than getting an outdoor plug fitted right?
Unfortunately not. Some may see that as a negative, surely you just need something quick, simple, and easy to plug your pure electric car or plug-in hybrid electric vehicle (PHEV) into when you arrive home.
Electric vehicle (EV) chargers are the perfect gateway to a low carbon ecosystem, to include renewables, battery storage, vehicle-to-grid (V2G) and more! An excellent first step into this ‘cleaner greener life’ is a plug-in electric car, along with a high quality residential electric car charging station.
Let’s say you’ve found your ideal city electric car, like the SEAT Mii Electric battery-electric vehicle (BEV); you’ve weighed up the environmental and fiscal benefits of ditching diesel (internal combustion engine) and ending your years long love affair with the filling station. You now need to charge instead of fill!
The first thing you need to evaluate when seeking to buy an EV charging station, is the power supply to your house. It will be either a single phase or three phase power supply. In the UK, it is mostly single phase, while in Europe it is usually three phase! You will also need to asses:
- Average duration for charging your electric vehicle (EV)
- The onboard AC converter in your electric vehicle (EV)
- EV battery capacity, WLTP range and the zero-emission range you intend to drive
So let’s say you’ve assessed your houses’ power and you know that you have a circa 8-9 hour charging window whilst parked at home. This is good, because on average a 3.6 kW home charger will deliver 9-10 miles per hour of charge. A 7 kW home charger will deliver circa 25 miles of range per hour of charging and should you be fortunate enough to live in a nation like Germany, who have the benefit of a three-phase grid (as if being amazing at penalty shoot-outs wasn’t enough?) then you can charge at 11 kW or 22 kW. Which gains you 40 miles and 80 miles per hour of charge respectively.
Whilst in a perfect world you’d always roll off the driveway with a fully charged battery, this may not always be possible. However, most offices, supermarkets and retail spaces are now investing in EV charging infrastructure, with ample options for a top-up. Of course, also keep in mind that the average journey in Europe is less than 30 miles and in the UK, just 12 miles.
The idea of charging quicker and going as big as you can with an electric vehicle dedicated charger seems appealing right? Well hold your figurative horses. We have to cycle back to how much power your house has got. Because if we take the UK example again, your average main fuse has a maximum of 60 A to give. Your 7 kW charger can draw 32 A of those precious 60 A. And draw them it will, for often 6-10 hours at a time depending on your electric vehicle battery capacity and how much charge you need. Then, throw into the mix your lighting, your electric oven, your electric hob, showers, heating system, hot-tub, kettles etc. You see where I’m going with this . . .
So your precious 60 A supply may not have 32 A to give. Now, in the electrical world there is a magical thing called diversity. Diversity is basically an educated guess that you aren’t going to be running all your electrical appliances at one time so you could, for example, have 85 A maximum demand but not everything is going to be on so your 60 A fuse is more than good enough. However, you do not spend 8 hours in your electric shower, but you do spend 8 hours charging your car, and that’s the kicker. Your car charger will likely be the highest and most continuous draw of power your home has ever seen.
So, step one is that you need your EV charge point installer to calculate your max demand and factor in the power of charger you want. There is then a decision to make:
- Install with no load management or fuse upgrades
- Speak to your network operator and upgrade your fuse rating
- Use load management to ensure your fuse is never going to be blown
The first scenario is become rarer. The reason, electric car batteries are getting bigger, people need more charge to fill them, and chargers need to be bigger. Coupled with this, because of COVID-19 we’re all working from home (and in turn using more power), we all have a vastly increase number of electrical items in our homes compared to 10, 15 or 20 years ago.
The second scenario isn’t a bad one to opt for at present, as network operators are often keen in countries like the UK to move people off 60 A fuses into the realms of 80 A. However, whilst power upgrades are commonplace at the moment, the amount of power available for this is not unlimited, and network operators will eventually say no. And even if you do upgrade, if you decide to splash out on say a hot-tub, maybe some new underfloor heating or a large new double electric oven, those precious extra 20 A are going to disappear faster than a Tesla in ludicrous mode.
So what will likely be needed is option 3, or a combination of options 2 and 3. Load management, in layman’s terms, is your charger monitoring what power your house has spare and turning itself up and down based upon that. It does so through small clamps placed on your mains supply that monitor the flow of electricity into your property. Let’s say your charger is on and you decided to hop in your electric shower, the charger spots this, turns down from 32A to maybe 20A or 16A. When you’re done in the shower, your charger ramps back up.
So let’s say you’ve done the above, you like the idea or protecting yourself with load management to avert any nasty main fuse blow-outs and to ensure you won’t be unable to add extra electrical items to your house in coming years – you’ve made a good choice.
Now however, the next question – smart vs dumb. I’m not talking about your IQ here before you write in to complain. I am on about the chargers. Smart chargers are those defined as being internet connected with remote controllability (generally via smartphone app). Whereas dumb are often referred to as “plug and play”. They have no brains, you plug a car in, it delivers charge, that is it.
So why smart? As you will expect they do cost a little more, but what do you get for that?
Government grants and incentives for one. Most EU countries offer grants to encourage uptake of electric vehicles and these grants extend to your domestic EV charger. Now many of these grants have criteria attached (because free money without conditions is only a scenario we see in our dreams), and these criteria often mandate a charger must be smart. Before you believe this is just another Orwellian form of surveillance where somehow MI5, the BND or AISE are interested how many miles it took you to do your weekly shop at Lidl, it’s actually for a positive reason.
The grid’s in most countries do not possess the power for us all the plug in millions of electric cars on top of our usual demands, they especially don’t have the power for us all to do that at 6.30pm when we arrive home from work. So smart chargers are mandated so that we can set schedules, turn our cars on later in the evening when the grid has more power which means we all do our own little bit to help the countries lights stay on.
Beyond government grants, there are also numerous personal benefits to having a smart charger, such as:
- Saving money by using the scheduling features to use cheaper electricity rates during the night
- Locking your charger so your neighbors can’t steal any power whilst you’re on holiday
- Track power consumption and cost in real time
So although smart chargers may cost more, you will likely save money in the long term by being able to access extra grant funding and save money on electricity with smart tariffs and scheduled charging.
The next big question, and this one is going to require some thought, is how your car charger is going to operate in conjunction with both your home, your potential second or third electric cars or other renewables.
It has been alluded too several times in my article so far, we do not have an unlimited source of power. So, as we all need more electricity, the grid will come under huge strain in the next few years. Our energy production will also become more seasonal as we look more to solar farms and wind turbines as opposed to coal power stations. This again, is not a negative, just a new way. And with all new things, there will be some adjustments needed to normal life, but ultimately, they will be worth it.
These adjustments are likely going to be the solar panels on your roof, your heat pump and your battery storage system, potentially even the ability to peer-to-peer trade electricity with your neighbors via smaller sub-grids between rows of houses, streets and cul-de-sac’s. So why, in an article about EV chargers, am I taking about solar panels? Battery units? Heat pumps?
Because in the next 10 years your home is highly likely to become it’s own micro-generation point. You will, through the power of the wind and sun, generate your own electricity (exciting right?) and then, whilst the sun is out and you’re at work, all of this self-generated power will feed a battery storage unit in your home. Meaning when you arrive home at 6.30pm and plug your car in (which because you’ve gone for a smart charger won’t start drawing power until 12AM) and then turn the oven on to cook your food, you’ll be powering your oven off power generated and stored by and within your own home. When you turn the TV on, the power to do so will have come from the sun.
This is a whole other topic for another article, another time. But the reason I mention it, is you would not call your house finished if your windows didn’t work? Or your door didn’t open? And it is the same for your charger. For many of us, the car charger is the first piece of renewable hardware we will place into our homes, so it needs to still work in 5, 8, 10 years’ time when we install much more renewable hardware. It needs to have internet connectivity to receive software updates and keep it relevant, it needs to be able to seamlessly know what power your house is generating, what power you have stored in batteries and to know what power the grid has available to give.
So, I urge you, when considering your first car charger, it may be easier to opt for the simple option. But please, do not. Opt for the charger which will be just as good, innovative, and technologically capable in 5 or 10 years as it is today. Because, if you don’t, that plug and play charger you have strapped to the side of your house today, will need replacing in years to come. As a Yorkshireman it seems at odds with my thrifty nature that I would ever consider spending a penny more than I need too, but even I can see the benefits of a marginally higher upfront investment now, to make myself ready for a greener, cleaner future.
Current Role: Head of EV & Energy Department – YESSS Electrical
In July 2019 Mike Gadd joined YESSS Electrical to head up their expansion into providing solutions in the EV charging and renewables space. The beauty of this role is the exposure to every tier and layer of the UK’s transition to green energy and electric vehicles. Be that installer training, B2C engagement, B2B rollout projects and seeing the vast enthusiasm in all people of all ages about the biggest overhaul to our society since the industrial revolution. YESSS now work with a huge array of partners providing solutions from domestic chargers, PV systems and batteries all the way to underpinning the supply, delivery and rollout of some of the largest charging and renewable projects in the UK and Europe.
For those of you seeking to buy EV home charging points, we offer a vast range of high quality and high performance electric car charging points at competitive prices. We also offer EV charging cables, EV leasing and green energy.