elma wrote: ↑
25 Aug 2017, 15:50
Mandrake wrote: ↑
25 Aug 2017, 15:42
An 11kW (or 22kW) EV charger needs a 3 phase supply - which almost no residential UK property even has. .
That isn't strictly true.
For example if you look at a terrace of houses usually the first one (relative to the electric supply) has 3 phase coming to a box. From the box each single phase will supply 1/3 of the terrace.
There might be 3 phases going to the terrace as a whole, but within each house there will only be one phase going to the meter and consumer unit of that house. So you only have one phase at your disposal to connect an EV charger to, so it doesn't really change my point - the vast majority of residential UK properties will only ever get single phase EV chargers which are limited to 7.2kW, but that's OK as its more than enough.
A 7.2kW charger can add up to 30 miles of range per hour of charging - 10 hours of charging would completely charge a battery that could do 300 miles. So unless you're doing 300+ miles per day in a car with a 100kWh battery, not an issue! Of course if you only did say 60 miles a day, it would only take 2 hours of charging to top up, which could easily be done after midnight on a timer. Going above 7.2kW doesn't really offer much benefit - I'd argue that its better to spread out a lower load over more hours than have everyone trying to charge really rapidly at the same time when they get home.
Older large houses often have 3 phase as well but only one is brought to the meter. It's very cheap and easy to comission the other 2.
This isn't always the case but with EVs looming it may well become a factor in valuing a house soon. It's also possible to use capacitors to convert 1ph to 3ph, having not investigated I'm not sure if this offers reduced amps/watts but I expect so.
That's interesting, but I don't think 3 phase charging at home is necessary unless you were a real road warrior, see my calculation above.
Of course the media have taken that horribly out of context. Each phase would have its own fuse so they are implying that domestic properties have 3ph with 20-30amps available per phase. I might look at ev charger installer certification actually. Could be a good certificate to have.
There's probably good money in it while the grants last - if you are OLEV certified the UK government will pay you, the installer, up to £500 directly towards the installation cost, also in Scotland there is an additional grant of up to £500 on top of that which the Energy Savings trust will pay the owner who is getting the installation done. (in the form of a re-reimbursement)
It looks like most installers pad the cost up to take full advantage of the grants...
For example the installer I originally looked at who can only do the OLEV part was going to charge me about £200 for the installation, (so they get £700) but I found one in Scotland who can also apply for the EST grant, and they padded the non-OLEV part of the quote up to £499 for pretty much the same charger unit.
So I pay £499 up front but get it all back a few weeks later instead of paying £200 for the same thing and not getting anything back. Craziness....