Category Archives: ev

Walking the environmental high wire

I’m a bit of a hippy. It’s no secret. I juggle, I have multiple pairs of harem trousers, and am currently sporting an undercut. I’m also a bit of a capitalist though, so when I installed solar panels on my house in 2014 it ticked the boxes of reducing my carbon footprint (over the lifetime of the panels, there is obviously an environmental cost in the production of the panels just as with my electric car) and being a sound investment.

The cost of battery storage solutions has come down since my original install and with the launch of the Tesla Powerwall 2 I figured I had better revisit the situation and see what was up. I have a 1.96kW PV install, and over a year I generate on average 5.4kWh a day, of which I export 4.1kWh (though the feed-in-tariff assumes I only export 50% I actually export around 76%). I obviously also have to import electricity on those occasions when the sun is not hitting the panels hard enough (so, at night), which I currently do from Ecotricity (a bit more costly, but they generate from renewables themselves and it gives me access to their rapid chargers for my car).

So I fired off a couple of enquiry emails to local installers of battery storage systems and received responses the same day (good customer service there). The second company just pointed me at their twitter and facebook pages and didn’t give me any idea of an installation cost (which is what I had enquired about, points lost there), but the first company Ecocetera sent me back a considered reply (within a couple of hours) specific to my install. They included a summary of the different battery storage systems available in terms of both capacity and cost per kWh over the expected lifetime of the battery. They also included cost estimates including labour and delivery (what I had asked for).

They also prompted me to think about how much spare capacity I had to charge a battery, on how many days per year. All of the battery storage solutions assume the ability to charge on 250 days of the year, so I downloaded the numbers from my install and started crunching. For my specific install I probably wouldn’t be able to keep a larger battery like the Powerwall sufficiently charged up (which isn’t good for the battery), so I would be a looking at a smaller capacity battery. Unfortunately the smaller the battery, the higher the cost per kWh (there are a lot of additional gubbins that go along with the battery to manage it, so it’s not just the cost of the physical battery that goes into the overall cost).

All of this number crunching led me to conclude that given there is an environmental cost in the creation of any battery storage system, it actually makes both environmental and financial sense not to add battery storage to my existing PV system. Instead I will keep buying in electricity from renewable sources, keep trying to use as much of my excess solar during the day (luckily I am in a position to run high-drain items such as the washing machine and dishwasher, and charge my car then), and keep investing in green energy projects locally. It also means I don’t have to worry about where to put a physical battery, as well as saving me some money to put towards my Tesla Model 3.

Ecotricity and electric cars

When I was first considering switching from my hybrid (Prius) to a full electric (Leaf) car last year, one of the factors was Ecotricity’s Electric Highway: a network of rapid chargers at most motorway service stations that could take my car’s battery from 0-80% in 30 minutes. I was switching from hybrid to full electric because the majority of my journeys are well within the Leaf’s 90-mile range, but it was good to know that there was this network so that I could undertake longer journeys (such as the round trip I made to Heathrow earlier this year). The best bit about the Electric Highway? It was powered by green energy and it was free.

I was so taken by Ecotricity’s green credentials and their free Electric Highway that I was tempted to switch to them as my energy supplier, but when I looked at the rates and what I use it would have been about £100 more expensive a year (and I already get a lot of my own electricity from my solar panels). A couple of weeks ago, however, I got an email from them (as an Electric Highway cardholder) saying that they were changing the scheme so that a 20 minute charge would now cost £5 and the change was going to start on 11th July (the email was sent 7th July, so not a massive amount of notice), but that if you were an Ecotricity energy consumer then it would continue to be free.

Consultation followed as a lot of people gave feedback about the short notice and the substantial change in cost. On 12th July another email came around to state that the pricing structure had changed to £6 for a 30 minute charge, so 50% more charging time for 20% more cost. I think that most people accept that it is fair for Ecotricity to start to charge for this service that they have been providing for free since 2011, but the extremely short notice for the change and the pricing structure has left a bad taste in many mouths. In comparison, Charge Your Car has a £4.50 fee for a 30 minute rapid charge using identical units (sometimes it’s £4.50 for an hour, it depends on the owner of the unit).

Ecotricity are offering a discount on your annual energy bill of £40 if you register your electric car with them, which is going to be leading a lot of people to be running a lot of calculations as to whether to switch in order to continue having free access to the chargers. Unfortunately with the very short notice given between announcing the plans to charge and implementing the charges, this smacks of a way of forcing people to change their supplier, especially if you use the chargers a lot. I had been a regular user of the Ecotricity charger at my local Ikea (until I finally got a fast charger installed at home), and had only used the Electric Highway once on the Heathrow round trip. I stopped 4 times on that journey, so would have incurred a £24 fee for a journey of around 200 miles. If I made the same journey in the Prius it would have cost around £20 in fuel (assuming a per litre price of 110p and consumption of 52mpg).

Add into the mix that I am on the waiting list for a model 3 Tesla and things get more complicated again. Tesla are also rolling out their supercharger network in motorway services (and elsewhere). They have already announced that the model 3 will be supercharger capable, but will not get free charging (unlike the model S, X and roadster), though a charging fee structure will be available (yet to be announced) to be able to use them. With an adapter (costing around £450) a Tesla can also charge from the CHAdeMO connector on the Electric Highway rapid chargers, though will take longer than 30 minutes to reach 80% from empty as they have a larger battery. So, do I switch energy suppliers now to grant free access to the Electric Hghway, and then buy an adapter with my Tesla and stick with the Ecotricity machines, or eschew the Electric Highway entirely and rely only on the supercharger network? Hard to calculate without knowing what Tesla are going to charge for the use of their network. Faster charge from Tesla, but where is the power coming from?

I mostly charge from home these days, which means charging from my solar panels (so green energy that I also get paid for generating). The model 3 is going to have a minimum 215 mile range (more than twice my Leaf), so would need fewer rapid charges on a longer journey. I haven’t actually made a super-long journey, just the Heathrow round trip, so how much am I likely to use either network? My best bet is probably to have another look at Ecotricity’s prices as an energy supplier, with the £40 discount for having an electric car, and if that gives me free usage of their network too, then that’s an unexpected bonus. If I do decide to change, I know that Ecotricity offer a referral fee for existing customers, so I’ll keep people posted on that. Time to crunch some numbers (as I’ve just had an energy bill through). Luckily none of this affects my feed-in-tariff payments, as while I am registered with my current energy supplier for them the two departments don’t talk to each other (I sent them a copy of my energy bill as proof of address).


ETA: I did just run the numbers and it would cost me £59 per year to switch from my current supplier to Ecotricity. Interestingly I could switch to local Bristol Energy (which is planning on moving towards more green energy but is currently mixed) for a saving of £102 per year but on a 12 month fixed contract so that could change drastically after that.

UPDATE: an added wrinkle is that I have just found out that Ecotricity has a ‘fair usage’ limit of 52 free charges a year for their energy customers (it is buried at the bottom of their FAQs). So, do I pay more to switch energy suppliers to a 100% green supplier (Ecotricity) and also get limited free access to their rapid charger network (potentially also incurring a £450 adapter cost when I get my Tesla)? Or, do I stay where I am, charging primarily from my own green solar panels and pay according to whatever Tesla brings in for their charging plan, but not having 100% green energy? Or so I change to another, cheaper, energy supplier? Given that I have barely used their network so far, this is probably still a decision to be made on price vs. green energy and which is likely to be important to me now and in the future (plus what I can realistically afford).