First trip well out of range!

[EVsince2016]

Element 3 - batteries

There is currently no viable financial return on energy usage for a battery system.

The costs are too high, losses from charging & discharging are 10% each way, so 20%

My options above achieves the same for 10% of the cost of a battery.

The current batteries have a limited life too short for a financial return.

Will this change?

Yes - when cheap LFP battery packs are available.

 

[EVsince2016]

Element 4 - Investment return

Currently solar panels do not increase the value of your property by much if at all. In fact a friend sold her house with solar panels on and the £1500m pa income from the old FiT rates but wanted a discount because they were there. Odd eh?

This will change a lot in the next 5 years, so if you move it's not £10k down the drain!

 

[AdamMGEV]

Apologies for hijacking this post, without having looked in to it seriously before I was surprised at the 14p/mile that I saw on here, which is comparable if not more expensive than my current diesel. Personally, like I mentioned in one of the posts, I'm just trying to get a handle on the costs at the minute, as the main reason I'm looking at electric was cheaper running. I appreciate now that that should be a rare occurrence for me, (commute is around 100miles round trip).
I think I'll be waiting till at least next year anyway to change car to see what happens at the next energy cap review and go from there.
I'm also looking for second hand as well, so there should hopefully be a bit more availability by next summer and the 2nd hand car market might have eased off a bit as well, and redo the figures with the capital cost of the cars taken in to account.
Thanks.

How does it cost you 14p a mile? If you can charge at home it would cost nowhere near that.

 

[Rocinante]

" was surprised at the 14p/mile that I saw on here.... I appreciate now that that should be a rare occurrence for me"
I worked out the costs as presented by OP, but as per my post (quotation above) I now understand that the the rapid chargers are an expensive way of running the car. I hadn't really appreciated how expensive the chargers were. Charging at home at the 3.0m/w as per the OP, it seems to work out at 6.8p/mile, which is still a little more expensive than I thought but obviously a lot less than 14p and less and an ICE.

 

[smokie]

Just out of interest EV, what size is your array and, if you have the data and just for comparison, how much did you generate on Sat, Sun and yesterday, and say the whole of November? Only asking as we aren't a million miles apart and I don't see how solar can do anything much at all for me at this time of year. I only have a 4kw system though.

My figures were
Sat 6.4
Sun 0.3
Yesterday 0.5
November 107.5

It's been fairly consistent over the years so I don't think there's anything wrong with my system but maybe there is..?

 

[EVsince2016]

Just out of interest EV, what size is your array and, if you have the data and just for comparison, how much did you generate on Sat, Sun and yesterday, and say the whole of November? Only asking as we aren't a million miles apart and I don't see how solar can do anything much at all for me at this time of year. I only have a 4kw system though.

My figures were
Sat 6.4
Sun 0.3
Yesterday 0.5
November 107.5

It's been fairly consistent over the years so I don't think there's anything wrong with my system but maybe there is..?

My figures were - 6.75 peak capped at 6.0kw
Sat 6.4 = 8.1
Sun 0.3 = 1
Yesterday 0.5 = 1.1
November 107.5 = 184.9

 

[Deleted member 3150]

Am I reading this right your journey was 760 miles and took 21hrs?

 

[smokie]

Interesting, thanks. There's a lot to be said but this isn't really the place - but e.g. on Sat I took about 17.5 kWh out of the grid with about 11 of that being a modest charge to the car.

So for me, the contribution of solar to running the car at this time of year is unexciting, to say the least - but, I suppose, better than nought!!

 

[bwanamdevu]

Am I reading this right your journey was 760 miles and took 21hrs?

The original poster stated that his journey was 260 miles and I believe he didn’t state how long he was driving. He did have a couple of stops along the way to recharge.

 

[defeatedbythecat]

Have a look at the taxi driver on YouTube, he charges at home and is paying something like £30-40 a month in electric

He's absolutely loving it

 

[Gomev]

Element 3 - batteries

There is currently no viable financial return on energy usage for a battery system.

The costs are too high, losses from charging & discharging are 10% each way, so 20%

My options above achieves the same for 10% of the cost of a battery.

The current batteries have a limited life too short for a financial return.

Will this change?

Yes - when cheap LFP battery packs are available.

Have a look at this video from EVM

 

[Gomev]

" was surprised at the 14p/mile that I saw on here.... I appreciate now that that should be a rare occurrence for me"
I worked out the costs as presented by OP, but as per my post (quotation above) I now understand that the the rapid chargers are an expensive way of running the car. I hadn't really appreciated how expensive the chargers were. Charging at home at the 3.0m/w as per the OP, it seems to work out at 6.8p/mile, which is still a little more expensive than I thought but obviously a lot less than 14p and less and an ICE.

There is a whole expanse of things to check out.

 

[EVsince2016]

Have a look at this video from EVM

Thee are some good points but some serious omissions in his calcs

I am on Go, so 5p/kw at night, but with battery losses the output from that battery is 6.5p/kw. With my current day rate the saving is just 7p/kw or 84 p a day but for half the year only due to solar! A whole £153 pa

With my solar, I use the energy on diverters to charge the car and heat the hot water so none is free for charging a battery as the benefit would be less, a smaller £££ return.

As far as rates are concerned I disagree with his assumptions: -

• Day & night rates will remain relative and the % gap will not grow substantially.
• Yes day rates are high now, but as more wind etc come online with their much lower generation rates costs will fall again
• As more EVs charge at night & V2G in peaks, the rates over A day will balance. Instead the variation will change to between different days / seasons / weeks due to wind / sun amounts.

Also, the limited life of these batteries & degradation in that type of operation results in no financial return within their lifetime of ~15 years. LFP changes that.

He may make savings this year but I doubt in the lifetime of his battery.

Must admit thought, £3.9k is a good price versus £10k for the powerwall 2, but not power gateway for off grid?

 

[biffo]

Ah its far more complicated than that!

Element 1 - Solar panels. Size really matters here and bigger the better

As much of the cost is fixed, extra panels do not greatly increase the costs. A small system offers very little in returns, can rarely offer the minimum 1.4 KW/h rate to activate your car charging etc so the minimum size recommended is a 4 kw system. I recommend though that you go for panels of around 6.5kw on a 6 kw inverter system.

The reason suppliers suggest 4kw is because its easy for them (not you) because they have to apply for DNO consent above 4kw but DNOs have to accept 6kw without good reason. Above that could be tricky. The reason you oversize the panels is for losses and the fact it only uses the peak in the summer so mine has a flat topped output curve thus getting more total daily power.

This is what I calculated to give the best overall return

All of this might be better in a dedicated thread about solar - but I'm contemplating solar panels (undecided about solar battery) just now - need to get my home energy report done to apply for Scottish Government 0% loans. I'm single tariff and don't charge my EV much but do have a lot of daytime usage due to WFH, tumble drier, etc.

I have limited south facing roof space due to loft conversion/velux windows but have unobstructed east and west roofs too. The question I keep coming to is - am I better to buy high efficiency panels with a 25 year guarantee and 90%+ efficiency after this period - or work on the assumption that cheaper panels with a 10 year warranty (and lower efficiency at end of warranty) will work with the view that technology will improve in 10 years+ and replacement would be sensible anyway?

The difficulty comes down to buying the best in an attempt to future proof without knowing where the future is going to end up - versus being mid range and expecting technology to advance by their end of life

 

[EVsince2016]

All of this might be better in a dedicated thread about solar - but I'm contemplating solar panels (undecided about solar battery) just now - need to get my home energy report done to apply for Scottish Government 0% loans. I'm single tariff and don't charge my EV much but do have a lot of daytime usage due to WFH, tumble drier, etc.

I have limited south facing roof space due to loft conversion/velux windows but have unobstructed east and west roofs too. The question I keep coming to is - am I better to buy high efficiency panels with a 25 year guarantee and 90%+ efficiency after this period - or work on the assumption that cheaper panels with a 10 year warranty (and lower efficiency at end of warranty) will work with the view that technology will improve in 10 years+ and replacement would be sensible anyway?

The difficulty comes down to buying the best in an attempt to future proof without knowing where the future is going to end up - versus being mid range and expecting technology to advance by their end of life

The one rule that out does all others is that you need a viable sized PV array for it to be worthwhile.

Best is 6kw of cheap panels if you have the space. If space is limited yo need better panels to maximise your output and odd positions need better systems to maximise output.

 

[Gomev]

Thee are some good points but some serious omissions in his calcs

I am on Go, so 5p/kw at night, but with battery losses the output from that battery is 6.5p/kw. With my current day rate the saving is just 7p/kw or 84 p a day but for half the year only due to solar! A whole £153 pa

With my solar, I use the energy on diverters to charge the car and heat the hot water so none is free for charging a battery as the benefit would be less, a smaller £££ return.

As far as rates are concerned I disagree with his assumptions: -

• Day & night rates will remain relative and the % gap will not grow substantially.
• Yes day rates are high now, but as more wind etc come online with their much lower generation rates costs will fall again
• As more EVs charge at night & V2G in peaks, the rates over A day will balance. Instead the variation will change to between different days / seasons / weeks due to wind / sun amounts.

Also, the limited life of these batteries & degradation in that type of operation results in no financial return within their lifetime of ~15 years. LFP changes that.

He may make savings this year but I doubt in the lifetime of his battery.

Must admit thought, £3.9k is a good price versus £10k for the powerwall 2, but not power gateway for off grid?

I agree with some of your points, however as to the price of electricity in the future nobodies guess is any better than anybody else's.
As to wind power it's only good when the wind is blowing and there were periods this summer when there was virtually no input from wind.
Wind energy generation accounted for 24% of total electricity generation (including renewables and non-renewables) in 2020 so still a way to go yet.

Wind energy in the UK - Office for National Statistics

Exploring the wind energy industry in the UK, including energy generation, turnover and employment. Includes data from the Office for National Statistics and other official sources.

www.ons.gov.uk

 

[supermegamonkee]

I currently have an ICE, but am trying to weigh up Electric, so am unfamiliar with the terminology, and may have misunderstood this somewhere, but the way I figure it, (Google says Morrisons amble is 42p/kWh), you achieved, 3.0m/kw, so is that not 14p per mile ? Which doesn't seem to be markedly cheaper than an ICE vehicle. Could you confirm the costs for your journey ? If this is accurate you would seem to be better off going getting a diesel Ford Focus Estate ?

Granted, not the cheapest way of charging... 99% of my charging is done at home, way cheaper than running an combustion vehicle.

760miles using Instavolt rapids and genie point came in at £65ish... im not going to grumble at that!

 

[supermegamonkee]

Am I reading this right your journey was 760 miles and took 21hrs?

Hey, it was the trip up, touring round the week and back home.

 

[Tim Falkiner]

I've just switched to a standard tariff, as my deal has just come to an end and finding something better seems problematic at the minute, but my electricity is now getting charged at 20.40p per kWh. Again unless I'm doing something wrong that works out at 6.9p per mile. Cheaper than my ICE but not as big a margin by the time you take in to account cost of vehicle. With rates set to increase this looks set to get worse.
Where are you getting 5p/kw ?

The annual tax on my current diesel is £30 per year, so this aspect is negligible. Problems I've had with my car(touch wood) so far have been related to suspension/brakes/wheels, which will be the same for electric, if not worse, due to the increase weight, so the engine hasn't been too bad, although I appreciate increased maintenance on this aspect. Not trying to be negative, or have you persuade me electric is good, just trying to get a handle on the matter.

I live in Victoria, Australia and buy electricity on a general rate at around 25 cents per Kwh. I get around six kilometres per Kwh and that gives me a cost of around 4 cents per Kwh. Added to that is a tax of 2.5 cents per kilometre giving me a total cost of 6.5 cents per kilometre. Once I get solar panels I will charge from them as I am at home during the day. (A litre of petrol is rated at 9.1kwH. Electric vehicles use around (18.2 kwH) per 100 km (or better) and so have an efficiency of 2 litres per hundred kilometres in city driving and maybe a bit over 2 litres per 100 kilometres in the country.) In Britain I imagine it would make sense to put up solar panels and get a home battery when the prices come down so you can charge a car on solar at night.

 

[smokie]

To save others the effort - 1 Aussie dollar is about 54p. So if I'm not mistaken your 6.5c per kilometre is about 3.5p, which is about 5.6p per (UK) mile, and your tariff is about 13p.

Happy for anyone to check my workings out and provide corrections as needed

IF I'm right, your electricity is comparatively cheap Tim. Some of us here are on time-of-use tariffs where we get 5p (approx 10c) or thereabouts for 4 - 6 hours off peak but most regular tariffs are upwards of 20p i.e. about 50%+ more than yours.