EVs and solar panels

spalpeen

Hi, new to this EV stuff.

I overheard recently that EVs aren't really particularly good of a deal unless you have a home charger with solar panels, which then makes them very much a good deal. I know there are lots of variables to be taken into account, but is this directionally accurate in Ireland today?

Gumbo

Nope incorrect.

It sounds like you heard the tail end of a conversation to be honest.

glen123

Having cheap night electricity and being able to charge mainly at home is more important than solar panels, I think. 

I have both.

For solar panels to charge your car, your car needs to be at home during the day. Mine is at home during the day maybe 3-4 times a week and not all day.

Looking at May at my own stats, my car used a total of 447kw (345 - grid electricity, 102 - solar). This covered 2600km of driving.

At the time I was paying 8c for night electricity so 2600km worked out at 27.60eur (345 from grid x 0.08)

Even if I had had no solar, that would have worked out at 35.76eur for 2600km (447kw x 0.08). Not much of a difference.

I am now paying 14c during the night, so the same distance will now cost me 62.58eur without solar. I think it's still an excellent value for 2600km distance especially if we take into account half price tolls which in my case I have on the way to and back from work twice a week so that's another 2.20 x 2 = 4.40eur saved per week)

JPA

Having an ICE car is not beneficial unless you have an oil field in the back garden.

the_amazing_raisin

https://www.boards.ie/discussion/comment/121072402#Comment_121072402

And even then you'd need to pay excise duty on it 😕

the_amazing_raisin

https://www.boards.ie/discussion/2058312377/evs-and-solar-panels

It's incorrect

Going on public charging alone is probably the hardest way to own an EV, but it can be done (and has been done by a few people here) and can be done for a cost generally lower than diesel. You sometimes need to sign up to monthly payment plans to avail of cheaper rates, but I'm fairly certain if I opened a petrol station and offered a significant discount for a monthly fee I'd have ever taxi and van driver biting my hand off 😂

Home charging is the most convenient way to own an EV. Just plug in when you need to and charge overnight. More suppliers are moving away from night rates to shorter EV charging times which give 3-4 hours at a very low price. This is typically enough to add several hundred kilometres of range so is likely enough for most users

Adding solar panels into the mix is the best way to own an EV IMO. It's hard to beat free fuel and that's exactly what solar panels give you. I've been tracking my driving and charging in the thread below, but the tldr version is I'm getting usually more than 60% of my driving this year from solar power, even in the miserable summer we've been having

https://www.boards.ie/discussion/2058294549/im-driving-on-sunshine-whooah

For September, I've yet to charge the car from the grid

Garzard

Leaf owner and planning to install solar next year, but didn't see the point of going on a night rate in the meantime as I mostly WFH anyway and have no need to charge at night for a commute. Most of my shifts centre around the day or early evening when the solar will be active and I'll probably only need to charge once a week, but that's just my own circumstances.

eltoastero

Solar Panels and a home charger is the optimum solution (I didn't pay to charge my car in July or so far in September for example). I charge off Solar when I can and then fill the car battery on the cheap night rate when I know I've a longer journey ahead.

Having an EV with a home charger but without Solar is still excellent (as I did for 1.5 years in a BEV and 2 previous years in a PHEV), just make sure you're on top of your electricity tariff to make sure you've a cheap charging time during the night.

Having an EV without a home charger would be more difficult I'd imagine, I see 5 or 6 ID4's with on street parking within a KM of my house and they just seem to take turns on the closest ESB AC charger (signing up to a subscription in this scenario to reduce the cost would be advised). But you still have the advantage of driving a comfortable, smooth, fast, cheaper to run EV.

unkel

Pinergy offer 5c incl VAT night rate for 3 hours per night.

Cost of EV in fuel over 30k km (year) €255

Cost of diesel car in fuel over 30k km (year) €3060

Paul Kiernan

https://www.boards.ie/discussion/comment/121075530#Comment_121075530

You can't really put it any clearer than that, can you? Then throw in the €120 per year road tax and 50-75% reduction on tolls and you're laughing even louder.

magicbastarder

so you save potentially 3k a year; but that doesn't take into account the purchase cost of the car.

but take a skoda octavia as an example (it's a PHEV rather than a battery EV)

you can get a diesel octavia for approx 28k. the PHEV octavia is 43k. that'd take over five years to save the fuel costs. it's not an open and shut case in terms of value for money.

Finelli

Is there a case to be made for charging the car at night on the low rate and using the solar energy in the house and sending excess back to the grid during the day?

unkel

https://www.boards.ie/discussion/comment/121075735#Comment_121075735

And near zero maintenance. And insurance is generally cheaper for EVs. And depreciation will prove to be much lower than the depreciation we used to suffer on petrols and diesels

It is an open and shut case in terms of value for money. EVs that is, not (plug in) hybrids.

Both my own EVs have been charged purely from solar PV for the last 4 months now BTW. It's not just about money here, we need to stop burning stuff asap...

graememk

https://www.boards.ie/discussion/comment/121075794#Comment_121075794

Yeah, if your feed in rate is higher than your night rate, export during the day and charge at night.

magicbastarder

https://www.boards.ie/discussion/comment/121075757#Comment_121075757

Also, worth mentioning. The 30k a year quoted in that example is approx double what the average Irish car does in one year. So halve those savings for the average car.

I'm looking at replacing the car, I have an 11 year old Octavia. Getting to the point where yearly maintenance bills are pretty much expected. I am looking at EV options, but it's due to environmental concerns rather than an expectation of saving money, we do about 12 or 13k a year so fuel costs a little over a grand a year.

Calahonda52

https://www.boards.ie/discussion/2058312377/evs-and-solar-panels

BS**2

In fact it is flip side of the new sales patter from PV installers if they find out you have an EV: free driving all summer long (iff the car is at home plugged in, factor 50 applied and ray bans in place)

An of course to avail of the night rate/ free Saturday/Sunday etc mumbo jumbo you need to keep the car plugged in again

so just get a bus pass

crl84

https://www.boards.ie/discussion/comment/121075757#Comment_121075757

Indeed.

Plus the cost of installing solar.

unkel

Nobody sane would spend €43k on a PHEV Skoda Octavia. That is mad money. PHEVs were only a tax dodge, worst of both worlds. Feel sorry for most people who bought one.

unkel

https://www.boards.ie/discussion/comment/121072503#Comment_121072503

And employ some child slaves in the congo to mine you some cobalt that you need to refine the oil into petrol or diesel😂

the_amazing_raisin

https://www.boards.ie/discussion/comment/121077844#Comment_121077844

Let's not forget the enormous amount of electricity you'd need for the refinery

magicbastarder

https://www.boards.ie/discussion/comment/121077839#Comment_121077839

yeah, possibly a bad example - but as per my (real world) one. my car does probably 70% what an average irish car does, and fuel costs me approx 9c per km. say €1,200 per year on fuel. there's no slam dunk financial argument for me to change to an EV, but on the assumption that i do change, the cheapest battery EV out there (new) seems to be an MG at €29k new. a hyundai i30 would be about 9k or 10k cheaper.

it'd take a long time for me to recoup that difference even if fuel costs were zero with the MG.

the_amazing_raisin

https://www.boards.ie/discussion/comment/121077919#Comment_121077919

Could get a 2nd hand ID.3 for €23k, much easier to recoup the price difference

magicbastarder

Yes, but if you're going to introduce secondhand into the equation, you'd have to allow it for an ICE option too?

unkel

https://www.boards.ie/discussion/comment/121077919#Comment_121077919

There's simply no denying that. The less miles you do per year, the less favourable an EV is financially. People with huge commutes have huge savings. People used to buying cheap second hand cars, not doing much mileage, might be better off with a combustion car financially. That said there are some great bargains out there in older second hand EVs too, provided the car's range would suit your driving circumstances.

MojoMaker

Since when was it only about financials though?

Get rid of the damn nags @magicbastarder and the financial picture suddenly looks a lot healthier 😂

spalpeen

https://www.boards.ie/discussion/comment/121078792#Comment_121078792

Why is low mileage less favourable for EVs? Is it because it takes longer to recoup the extra purchase cost compared to ICE vehicle?

the_amazing_raisin

https://www.boards.ie/discussion/comment/121149793#Comment_121149793

To some degree yes, although I think people get a bit hung up on recouping the price difference between EV and ICE

It's pretty rare that buying a car is a profitable enterprise anyway, so why do we suddenly all become accountants where EVs are concerned?

This kind of leads into my main point, which is that generally speaking it's more economical to keep a car running than replace it with a new one regardless of the purchase price

Maybe if you're doing bangernomics it's cheaper to replace but then you're spending a few grand evey couple of years on a new car

So for most people it becomes a situation where they want a new car. And since we're in the situation where it's a want rather than a need, I think it's fair to say that not every subsequent decision needs a thorough financial analysis and justification

magicbastarder

It's pretty rare that buying a car is a profitable enterprise anyway, so why do we suddenly all become accountants where EVs are concerned?

For two reasons; one is that an explicit selling point of EVs is the lower running cost. So that brings the financials into focus very quickly. Which is linked to the second point, the higher entry price point.

the_amazing_raisin

https://www.boards.ie/discussion/comment/121149842#Comment_121149842

It's one of several selling points, not the only one

I agree that for a low mileage driver it's going to be very difficult to look at spending €9k more on an EV and say that makes sense financially

My point is that it's also going to be difficult to justify spending €20k on a new car as a good financial decision

CoBo55

https://www.boards.ie/discussion/comment/121075530#Comment_121075530

And the day, peak and night rates are? Just asking for people like me who don't have a zillion solar panels and batteries around the house and are using 9000 plus units per year.

unkel

https://www.boards.ie/discussion/comment/121150691#Comment_121150691

Not quite sure, something like 47c outside the 3 hours cheap rate. You don't need any solar panels to make the most of this, but you would need to use a lot of your units during this period, I'd say you need both an EV and a home battery, the bigger the better. But even if you only use 60-70% of your units within this 3 hour period, it will work out cheaper than any other provider

But I'm the first to admit this isn't perfect for everyone. I have said it many times: do your own sums. For me, this is pretty much perfection, the only better (and greener) system is fully flexible agile rates that could completely change every 30 minutes, with rates between minus €0.25 (you get paid for using electricity) and plus €1.00 at peak time when there isn't enough wind / sun, like they are with Octopus Agile in the UK. Hopefully we will get that soon here too. My entire system would then pay for itself within a couple of years.

CoBo55

https://www.boards.ie/discussion/comment/121151218#Comment_121151218

Hmmm, battery storage with no solar... that's worth considering especially with that rate.

the_amazing_raisin

https://www.boards.ie/discussion/comment/121152055#Comment_121152055

Tbh the battery and hybrid inverter are pretty expensive by themselves so it'd be hard to justify the cost without the panels

No SEAI grant either to soften the blow

unkel

https://www.boards.ie/discussion/comment/121152131#Comment_121152131

I sold a no-name 5kWh battery pack a few months ago for €895. Buy a Sofar ME3000SP for about €600 and have an electrician hook the inverter up to your consumer unit for €150. The battery is click and play with the inverter. Take in 5kWh into the battery every night for 5c and release it for 28c on a timer. That's a revenue of 23c * 5kWh * 365 days or €420 per year, say 20% conversion losses for both ways, so €335 per year (tax free if 2 people on the bill), that's a pay back period of under 5 years, or a tax free return on a low value low risk investment of over 20%

Imagine what the pay back period is if you have a bigger system, buy your equipment much cheaper than that, build your own batteries and have a mate RECI who hooks things up for free. I bet you believe me now when I tell you it is more like 2-3 years

Dayor Knight

Even if you don't charge your car using the solar it can make some of the smart plans more advantageous. E.g. charge the car at night or weekend (free Sat/Sun with EI/BG) and use the solar to reduce the impact of the higher rates you will likely be paying the rest of the time..... everyone needs to run their own numbers.....

graememk

https://www.boards.ie/discussion/comment/121152131#Comment_121152131

I've run the numbers, and the payback is surprising

Say 2500 for 14kwh, 5-600 for an inverter, even at flogas community rate at 33 day 14.75 night, cycle to 20% is 11 and change

20% losses, (I've measured that over 2 yrs now)

Buy 13.2(€1.94) to get 11 out (€3.63)

1.68/day that's over 600/yr.

CoBo55

https://www.boards.ie/discussion/comment/121157552#Comment_121157552

I got lost after 14.75 night...

unkel

https://www.boards.ie/discussion/comment/121158190#Comment_121158190

I'll try make it a bit simpler, maybe that helps?

For Pinergy. Buy at 5c, sell at 28c

Graeme's system has 14kWh, of which he has 11kWh as usable (that's very conservative), so you can load up 11kWh per day and sell it. You will have about 20% losses, so 11kWh minus 20% is 9kWh. So you make 9kWh (28c - 5c) per day times 365 days = €755 per year

The system cost €3300 to install (including €200 fee for an electrician that Graeme didn't include), so a pay back period of about 4-5 years

Mr Q

https://www.boards.ie/discussion/comment/121158442#Comment_121158442

But you are leaving out some figures too. That €755 is taxable, less your €200 credit if one name on the bill. So it could be €755 less roughly €270 leaving €485.

Plus wear and tear or replacements in that time. That payback would get much closer to 8-10 years very quickly if accounting for everything.

And the the Pinergy buy at 5c, sell at 28c is great now but who knows what will be there in 18 months.

Saying that I have batteries and would buy again if doing it now for several reasons, payback being one.

unkel

https://www.boards.ie/discussion/comment/121158740#Comment_121158740

It's taxable but there is a €200 per person exemption on the bill. I have 5 people on the bill 

😂



Inverter and battery should last 10 years without maintenance. So after the system has paid off itself in 4-5 years, the next 5-6 years are pure profit of €755 per year. Also this cost was for an assembled system, paying an electrician and going rates for parts. Personally I buy a lot cheaper than market rates, build my own system and have a mate electrician, so go figure the payback period is more like a bit over 2 years rather than 4-5 years

And indeed, nobody knows where the rates are going, but it is near certain that the difference between peak rate and cheapest rate is getting bigger, not smaller. That is natural in the transition to renewables (feast or famine). Not so sure if this generous FIT regime is going to last though...

Mr Q

https://www.boards.ie/discussion/comment/121158784#Comment_121158784

But it is not realistic for most to put 5 people on their bill. I had thought it was a max of 2 but obviously not.

I'm surprised the FIT has got anywhere near as high is it is currently, fully expected the energy companies to pay a tiny amount per unit.

unkel

@Mr Q - "I had thought it was a max of 2 but obviously not."

Same. If you remember most of us here weren't expecting much more than wholesale rates of about 5-6c around the time just before the first providers started announcing FIT rates. That said, they make a lot more profit on all other rates these these than they did a few years ago. Looks at the profits of the utility companies.

@Mr Q - "But it is not realistic for most to put 5 people on their bill."

Any 16+ year old in the house with a job can be put on the bill as you can claim they pay towards said bill from their earnings

the_amazing_raisin

https://www.boards.ie/discussion/comment/121158810#Comment_121158810

I expect as solar becomes more popular then the FIT will begin to drop, like what has happened in pretty much every other country

It's important to remember the suppliers are still making a profit on the FIT, if they're buying it at 28c they're also selling at 47c or so back to the market

Same for that pump and dump that unkel is talking about, customer buys at 5c in the middle of the night and supplier makes a profit (albeit probably a very small one). Customer sells electricity at 28c during the day and supplier still makes a profit reselling that

cannco253

slightly off topic, but do we know how much energy FIT provides/has provided to the Grid - are those figures available or buried?

https://www.smartgriddashboard.com/#all/generation

System Generation

System Generation represents the total electricity production on the system, including system losses, but net of generators' requirements. It includes an estimate of the power produced by wind generators, but excludes some non-centrally monitored generation (e.g. small scale combined heat and power and microgeneration).

Calahonda52

https://www.boards.ie/discussion/comment/121150546#Comment_121150546

Once you get out to the high mileage end of the curve EVs are not at the races due to the finite life of the battery.

Am looking at a 25 year old 2.8 V6 l Volvo estate in Margate at the moment: 1,200 stg: in immaculate condition inside and out, full service record for the 450,000 miles on the clock: put up on blocks for for 5 years, till it gets to 30, beats 15% inflation

unkel

https://www.boards.ie/discussion/comment/121160714#Comment_121160714

There's no such thing as a set lifespan, finite life of a battery. They will last much longer than the rest of the car. They will degrade but this is a slow process (except in a Nissan Leaf). It is standard in the spec sheet of any battery cell to state the number of cycles of life. But this is not until the cell is dead, it is until the cell "only" has 80% capacity left. In the case of LiFePO4, this is generally 6000 cycles. Or in practical terms, a car with say a 60kWh battery that does two cycles a week, can have 3000 weeks until it is has lost 20% capacity. That's roughly 60 years and 2 million km

You've been a regular in this forum for many years, surely you would have picked up on this sort of stuff along the way?

the_amazing_raisin

https://www.boards.ie/discussion/comment/121160714#Comment_121160714

How many of the parts in that Volvo have been replaced in the 25 years? 😉

Because if it's had any significant parts replaced then that's going to be several thousands invested in repairs

And if it's okay to spend several thousand keeping an ICE running for 25 years (I think it is fine to be clear) then it's also okay to spend several thousand on replacing degraded battery modules in a 25 year old EV

unkel

https://www.boards.ie/discussion/comment/121161067#Comment_121161067

The whole point is that an old ICE need expensive maintenance / fixes to keep going. The old EV needs nothing. Nobody in their right mind is going to spend serious money to replace degraded battery cells with shiny new ones. If the range is no longer sufficient, you just sell it on to someone for whom the range is no problem

And yes I know there are loads of eejits queuing up to pay thousands for newer / bigger batteries for their old Leafs and anyone can do with their hard earned what they like, but those are not rational decisions...

the_amazing_raisin

https://www.boards.ie/discussion/comment/121161151#Comment_121161151

I think replacing modules could be viable if done for the right price

They won't be new batteries for sure, unless we see a shocking change in approach from manufacturers who don't make the modules available for sale

Just did some quick googling and a 2nd hand ID.4 module can be bought for €1,250 with a capacity of 6.82kWh when new

https://evshop.eu/en/batteries/339-vw-id3-battery-module-48v-12s-685kwh.html

Not the greatest price ever, but bear with me for a second

You could probably DIY the module replacement, hardest part is getting the battery pack out without getting squished

After that it's just pop the screws out of the cover, open the pack and disconnect the bad module

How many modules would it take to maintain 70% capacity in the car over 25 years? Could be zero, but two or three seems possible if some of the modules degrade faster

Let's say 4 modules because it multiplies easier and maybe you got a bit of a lemon of a car

So €5k over 25 years, €200 a year average to keep a lemon on the road

That's not bad when you think about it, could easily see a petrol car costing twice that and be considered cheap to maintain

So even in a bad scenario of the battery needing a bit of work it's still possible to do it cheaper

I do agree a full pack replacement is almost never going to make sense. Maybe if doing it DIY on a classic, but I don't really see the appeal of spending €9k to upgrade a 2011 Leaf to 200km of range

https://www.boards.ie/discussion/comment/121161605#Comment_121161605

Devil's advocate here: The classic EVs have advantages though and this is before thinking about sustanability of throw away tech including cars.

I find the 2016 leaf less annoying than the 2018 model due to lack of lane assist and collision warnings. The 2021 Model 3 doesn't seem to suffer though, but the new models introduced in 2023 now have speed warning pongs if you go even 1 km/h over the speed limit (that the car thinks is right, which may or may not be the correct speed) that have to be switched off at the start of every single jorney. That would be even more annoying.