PDQ Mobile wrote:No you don't charge from solar any night. The moon doesn't work.
And of course you don't need to charge it much if you don't use it much.
Who said anything about using solar at night?
The examples I gave are based on average mileage.
PDQ Mobile wrote:But then the much vaunted cost benefits don't look so favourable?
20 k odd for the vehicle plus a solar installation at 5k, if you don't do the miles then it's making a single mile very very expensive.
It's pretty simple really.
Average cost to me so far is around £10 per 1000 miles - sometimes more, sometimes less.
As we head into winter my guess it that could be as high as £15 assuming we don't get all our nuclear back online.
In terms of cost I've picked a "compact SUV" (which is apparently what folk want these days)
Taking numbers from the manufacturers website (which I know are inflated in the case of the EV by about £5k and about £2k for the IC version if you can be bothered shopping around) this is what I've got.
The EV is £345 a month, the IC £233 a month with no deposit (I can't be sure about the IC but I know the EV is available for under £300 if you shop around).
So in this scenario you're paying £112 a month more for the EV.
If you're doing the average 10,000 miles a year - 830 miles a month and you get 40mpg (based on the vehicle I'm using above) then you're paying around £100 in petrol (assuming £5 a gallon).
If we go for the worst case cheap electric I can find which is 8p fixed overnight then you need 200kwh @ 8p which is £16.
So worst case scenario the EV costs you £28, best case you're probably about the same in profit. Increase the mileage and the EV looks better and better.
Against this you've got no tax, cheaper servicing (no exhausts, brakes, timing belts), potential savings if you need to enter some low emission zones (the cost savings going in and out of London would be astronomical).
EV's are also better to drive, easier to sell on and in this case better specced. It's also more convenient for the majority of driving because you don't have the hassle of detours to the local petrol station, plus your own personal fuel station is always open.
Of course there may be reasons why the above may not apply to you but they apply to a significant proportion of the population.
PDQ Mobile wrote:Surely if what you say adds up, then you WOULD charge every day or at least every day when you can buy leccy cheaply. I imagine though you have to monitor pretty frequently to find the best rates?
What model did you go for that demonstrates such a built in sophistication that it can decide itself where and when to draw its charge?
No, you'd plug in every day - that doesn't imply charging. You let the charger make the decision, you simply tell it what the minimum miles you require are and it'll figure the rest out for you.
So if your commute is say 20 miles a day then you might be happy with a minimum of 40 miles, at weekends you might want 100 miles so you make that a condition of the weekend. If necessary you simply override it and tell it to charge up fully. It's just a simple app.
The charger I have is a Zappi, but other models are available and all modern chargers are smart. If you're an Octopus customer you can pick up an Ohme for half price which handles their pricing structure out of the box.
(I bought a Zappi so it'll handle my solar when I have it installed).
PDQ Mobile wrote:4p a kwh is a gift, under the actual price of generation and delivery I guess. Under a quarter of what I pay.
While I am no expert I cannot see how generating and delivering it at that can work without subsidy from other customers.
The price has been as low as -11p.
But you were paying the subsidy anyway. When too much power is generated those guaranteed prices we offer to generating companies have to be covered, or we pay them to shut the power station down.
You could argue that by preventing the cost of shutting power generators down EV owners are subsidising you by buying electricity when there are no other customers.
Electricity is sold as a bidding process, you buy electricity in advance and its price fluctuates. Sometimes the price is negative or very cheap.
My overall average since January is 7p/kwh.
Octopus tell you how the price is worked out, basically it's the wholesale rate multiplied by 2.2 with 13p added between 4pm & 7pm (capped at 35p). So despite the outrage I'm still paying more than the wholesale price.
It's not all good of course, tonight for the first time ever the price will hit the cap of 35p between 6 & 7 but for me all that means is I won't put the oven on during those times (or the dishwasher / washing machine).
(Which may well mean the wholesale price is above what you're paying - so I'd be subsidising you
PDQ Mobile wrote:And however you spin it, it IS 20 million odd cars drawing their energy from the grid. It is a huge amount of energy. I am sure you could work it out (back of an envelope) much better than me.
I don't think we are anywhere near covering that capacity at the moment or in the foreseeable future, no matter what anyone says, for I do watch Gridwatch and quite often we get close to full capacity.
No, it isn't 20 million cars drawing energy from the grid.
For a typical car of average mileage it's one hour a day - usually when energy is in surplus not when the grid is loaded.
If it was evenly spaced out that's less than a million cars, if the majority happens during the night then it's about 2-3 million cars, so about 15-20GW.
Looking on gridwatch that's about the same as the usual fall in overnight demand.
(Incidentally according to Ofgen our installed capacity is 75GW and it's not often I see us get even close to that, currently we're running about 40GW. On top of that our energy use has been declining for years as homes and industry become more efficient - or move abroad).
And lets not forget this is now - not in the 10-15 years it'll take to replace the car fleet.
By then we'll have more renewables and vastly more storage.
As an aside I noticed you can buy a 330w solar panel now for well under £100.
If you've got a roof (doesn't even need to be "suitable" now since solar generation is so cheap it'll still be a plus) then fitting solar is an absolute no brainer.
Even battery storage is almost affordable, smooth you over those 35p peaks and charge the car using solar overnight - no moon needed...