2 EVs, Solar System Suggestions?

[seany1212]

Hi All,

I've lurked around here for a couple of weeks, and I've tried going back through posts to this category for the last 6 months but I can't find anything that fits the ballpark I'm looking for in a suggested setup for Solar install.

I'm looking to get a solar installation performed soon, but I want to be sure I'm asking for the right thing and not just being sold what suits the company I'm buying from. The goal is to offset as much electrical cost charging cars and running the house during the day as possible, I work from home and my partner is office based, so we can rotate the cars on a daily basis in order to max sure the other gets a full vehicle. House is south-south-west facing.

We have a budget of about £8k, of which I'm not thinking of including battery (because I understand the battery will be a sizeable chunk of change and will dwarf the overall generation potential), from which I'm hoping that generating as much as possible during the day and having that feed into one of the EVs plus the house usage would greater maximise my savings vs what is used overnight with battery usage.

Is lack of battery considering the budget a better approach here? Is £8k a reasonable budget for a decent Kwh setup + inverter? I think from reading what @johnb2713 has been suggesting on a lot of other posts is that an inverter greater than 3.5kw would be wise, is this also the case here?

Any feedback would be greatly appreciated.

 

[NozSpark]

Solar, battery storage and EV’s can work quite well together,,, if the PV and battery storage are sized correctly (I dont know much about PV or battery storage I’m afraid)

BUT…. I do know that anything that saves energy is 0% VAT rated,,, this also includes any associated works under the same contract/invoice ….. so if you have battery storage and an EV charge point installed at the same time you pay 0% VAT on them too……. If you have these additional works carried out at a later date then you’ll have to pay the full VAT duty on them

 

[bladerunnerpv]

How many kWp (kWp = kiloWatt peak) of panels do you think you can fit on your roof ? 400W-ish panels are in region of 1050-1150 mm wide and 1750-1850mm long, suggest you have a look at a PV supplier and pick one and rough it out. Allow a border around them, I'm told MCS recommend 500mm border but not seen that in writing.

Then using something like PVGIS will give you a feel for the generation you can expect for you location using this kWp value.

Do you have any data for your current kWh p.a. usage to compare vs generation?

The common electricity usage profile has peaks in morning and evening and lull during the daytime when people are out, so a south facing system without battery isn't ideal as peak generation isn't consumed, the battery stores some solar energy for evening/morning use and can improve the ratio of self-consumption markedly. Your usage circumstances sound a bit different though which may work better for you.

If you can use solar to cover your peak and most expensive energy usage then that will probably help save the most ££

Solar will not provide much in the winter months though, a rule of thumb I saw was average illumination of 4hours/day summer and 1hour/day winter. A more detailed (free) tool like easy-pv would help you make better assessments

Bear in mind some energy suppliers have cheap EV rates overnight, worth doing some sums to see what effect this would have for you.

hope something here helps with the cogitations

 

[novelsmike]

Well, my installation cost about £10K. 16 panels, 10Kwt battery storage, inverter etc installed. I have two EVs but I just plug into the mains and charge overnight at the cheap rate times. There are various Octopus tariffs available targeted at EV households (e.g Octopus GO) and panel/battery installations. Make sure that the installer you choose is MCS certified. Down the road you might want to get something back from exporting to the grid and for that you need an MCS certificate and DNO letter both of which are supplied by the installer.

 

[seany1212]

Thanks for your responses.

@NozSpark do you know if you still get 0% VAT having a charger fitted without having a battery installed? Or is having the battery fitted what qualifies it for the VAT discount?

@bladerunnerpv thanks for the suggestions for EasyPV and PVGIS, it looks like my roof could take 12-15 400W panels depending on layout chosen which could then produce 5000-6000W. PVGIS then says I should expect to generate approx 4700kw for the year so this should knock a good 25% off my current energy costs alone as we're using about 18k Kw per year for whole household usage plus cars.

@novelsmike appreciate the insight on pricing and install, I'll have a look at the Octopus tariffs and will check whoever we end up with is MCS certified.

 

[johnb2713]

Thanks for your responses.

@NozSpark do you know if you still get 0% VAT having a charger fitted without having a battery installed? Or is having the battery fitted what qualifies it for the VAT discount?

You have to have solar PV installed to get the 0% VAT

@bladerunnerpv thanks for the suggestions for EasyPV and PVGIS, it looks like my roof could take 12-15 400W panels depending on layout chosen which could then produce 5000-6000W. PVGIS then says I should expect to generate approx 4700kw for the year so this should knock a good 25% off my current energy costs alone as we're using about 18k Kw per year for whole household usage plus cars.

Analyse your usage pattern eg, car charging is no good if your cars are not at home when the sun is shining, having a large solar array isnt good on ROI if you cant use all of the power generated yourself.

@novelsmike appreciate the insight on pricing and install, I'll have a look at the Octopus tariffs and will check whoever we end up with is MCS certified.

Octopus tariffs are really good, I've just moved from GO onto Intelligent and pay 7.5p kWh. Consider carefully battery storage, I aimed to have enough storage to run the house 24hrs during winter time i.e. when there little / no solar generation. By sizing the batteries appropriately and making sure I have enough inverter power available i.e. not the often quoted 3kW, I dont use any peak tariff units, all of my energy is either 7.5p or free. The 3kW inverters will not cope with switching a kettle and toaster or hob and oven on without importing from the grid which is annoying and expensive when you have power sat in the batteries unable to feed the load.
You only need the MCS certified install if you intend to sell back to the grid. If you're not intending to export you may find a cheaper installer / electrician to do the work.
If you want to join Octopus, you should do this sooner rather than later, their rates are the best in the business, shout out on here and one of us will give you a code which gets you £50 credit onto your account and same for us for referring you.
I'm retired and run an EV and a PHEV, my 16 panel 6.7 kW PV with 32kWh battery and 9kW of inverter power has saved me an absolute fortune over the last 12 months. I monitor the system continually and the data is in a spreadsheet. From January to now we are over £500 better off including the loan repayments for the solar than if we hadnt installed it. The Break even point for our system is less than 3 years.

 

[user 36398]

I'm pretty new to solar / battery, but here are my 2 cents.

If your limited on funds, and you have 2 electric cars. I would actually argue that going battery only to start, is better than going solar only.

Reason:

Because you will be using EV's, you will be able to go onto Intelligent Octopus, this means you could charge your cars for 7.5p for 6 hours during the night (longer if you use the intelligent bit). Eg. I've plugged my EV in at home at 3pm and gone onto 7.5p tariff until 5.30am the next morning. This same 7.5p rate you could then of course charge the batteries and during the day instead of been charged 38.58p per kWh your using the energy from the batteries that you charged for 7.5p. Also if you have a dishwasher / dryer with a timer or some hot water storage system etc, you can also use this 7.5p rate too.

EDIT:
Forgot to mention another benefit of a battery system, most Inverters now have an EPS outlet, fancy systems will even do whole house EPS, (think Tesla is one). IOW: This allows you to use electricity during power outage, something that's not possible with solar only for obvious reasons.

EDIT2: ROI..
Out of curiosity I thought it might be interesting to see what the ROI on a battery only install.
Let's say after excluding charging cars, etc, the energy you use during the day might only be about 8kWh, so if we assume a 9.6kWh battery install. Here is a rough calc. batteries about £3K, inverter about £1.5k , installation maybe another £1k. Total £5.5k.

So 8kWh * 38.58p * 365 = £1126 cost of day rate electricity.
If we charge using 7.5p night rate.
8kWh * 0.075 * 365 = £219 cost of charging batteries during the night.

This means it will take £5,500 / (1126 - 219) years ROI = about 6 years.

 

[user 36398]

The Break even point for our system is less than 3 years.

Love to know how you get an ROI of 3 years, that's seems too good. You didn't by accident include Intelligent Octopus in that did you?, because you of course can get this without Solar / Battery.

 

[johnb2713]

Love to know how you get an ROI of 3 years, that's seems too good. You didn't by accident include Intelligent Octopus in that did you?, because you of course can get this without Solar / Battery.

I just did a very quick calculation:-

14,000 kWh per annum of peak rate electricity, saving of 38.58p - 7.5p = 31.08p per kWh = £4351.20

My solar has generated 5,100 kWh of the above so add 5100 * 7.5p = £382.50

Gives a total saving of £4733.70

I spent around £12k on my system therefore payback is around 2.53 years

 

[user 36398]

I just did a very quick calculation:-

14,000 kWh per annum of peak rate electricity, saving of 38.58p - 7.5p = 31.08p per kWh = £4351.20

My solar has generated 5,100 kWh of the above so add 5100 * 7.5p = £382.50

Gives a total saving of £4733.70

I spent around £12k on my system therefore payback is around 2.53 years

So you are including Intelligent Octopus, 7.5p. Like I said you can get that without Solar / Battery. For true ROI, you need to compare what you save during the day, not what you save by paying 7.5p during the night.

For example, lets assume you didn't get battery / solar, and we can assume majority of your usage is charging car during 7.5p rate during the night, your then maybe left with 8 kWh during the day, maybe even less if your savvy and put dishwasher etc on during the night. You say your usage is 14,000 kWh per year, this is about 38 kWh per day, so Night time 30 kWh & daytime 8 kWh.

Night: 30 * 0.075 * 365 = approx £821
Day: 8 * 0.3858 * 365 = approx £1126
Total = £1947

IOW: Your total needs on Intelligent Octopus = £1947 excluding standing charge of course, so even if your solar & battery generated 100% of your needs, it's not even £2K. Even if your usage was 50% night 50% day, it's only about £3K.

Remember Intelligent Octopus has nothing to do with your ROI, you need to compare apples to apples, not apples to oranges.. Currently I believe ROI on Solar / Battery is very good, even without FIT, but expect at lease 6/7 years ROI. Of course this could go up / down depending on what happens to electricity prices, go down ROI years will increase, go up ROI years will decrease.

EDIT: ps: Your usage of 38 kWh per day seems really high, is your heating using electricity (heat pump etc)?, or are you doing 32K+ miles in your car each year, or maybe some workshop with high power tools, just curious, as you could save even more money if you have some vampire usage you didn't know about.

 

[johnb2713]

So you are including Intelligent Octopus, 7.5p. Like I said you can get that without Solar / Battery. For true ROI, you need to compare what you save during the day, not what you save by paying 7.5p during the night.

Which is exactly what I did

For example, lets assume you didn't get battery / solar, and we can assume majority of your usage is charging car during 7.5p rate during the night, your then maybe left with 8 kWh during the day, maybe even less if your savvy and put dishwasher etc on during the night. You say your usage is 14,000 kWh per year, this is about 38 kWh per day, so Night time 30 kWh & daytime 8 kWh.

I need to charge during in the day at times, youre making too many assumptions.

Night: 30 * 0.075 * 365 = approx £821
Day: 8 * 0.3858 * 365 = approx £1126
Total = £1947

IOW: Your total needs on Intelligent Octopus = £1947 excluding standing charge of course, so even if your solar & battery generated 100% of your needs, it's not even £2K. Even if your usage was 50% night 50% day, it's only about £3K.

Not relevant, all incorrect assumptions

Remember Intelligent Octopus has nothing to do with your ROI, you need to compare apples to apples, not apples to oranges.. Currently I believe ROI on Solar / Battery is very good, even without FIT, but expect at lease 6/7 years ROI. Of course this could go up / down depending on what happens to electricity prices, go down ROI years will increase, go up ROI years will decrease.

Your advice appreciated........

EDIT: ps: Your usage of 38 kWh per day seems really high, is your heating using electricity (heat pump etc)?, or are you doing 32K+ miles in your car each year, or maybe some workshop with high power tools, just curious, as you could save even more money if you have some vampire usage you didn't know about.

Jesus, you really are on the case LOL, I do use heat pumps, I also have a laser cutter and we are heavy users of electricity for several other reasons eg bitcoin mining etc.

At the end of the day the real measure of ROI is whats happening at the bank and strange as it may seem to you, my bank balance pretty much coincides with my spreadsheet figures. So, in another couple of years I will pay off my loan with the money saved.

 

[bladerunnerpv]

@bladerunnerpv thanks for the suggestions for EasyPV and PVGIS, it looks like my roof could take 12-15 400W panels depending on layout chosen which could then produce 5000-6000W. PVGIS then says I should expect to generate approx 4700kw for the year so this should knock a good 25% off my current energy costs alone as we're using about 18k Kw per year for whole household usage plus cars.

You're welcome. 12x395W panels in SSW, 30deg tilt, in S.E. England suggests about 4500kWh generation in easy-pv. The inbuilt usage profile indicates about 3300kWh would be used directly, with the rest exported - in summer months at peak generation you may not be able to consume all the available PV in daytime, but your daytime usage profile may be higher than average as you wfh - kettle, PC, screen etc.

I'm not aware of any (free) tools which have different or customisable consumption profiles, it would be handy to be able to import smart meter usage history for example.

In PVGIS you can select different years irradiance profiles IIRC to get a feel for variability in PV generation.

Higher wattage panels are available ~600W, they are heavier though, need suitable inverter as they can have significantly higher Isc or Voc, compared to 400Wish panels from what I've seen, and are not necessarily as good efficiency-wise for converting irradiance to kW. The optimum is to get as much kWp per meter squared on the roof as poss., sometimes you can fit more narrower panels, you just need to do the sums and balance the costs. An immersion diverter may also be worth considering, it sends spare PV to heat the water.

 

[user 36398]

Not relevant, all incorrect assumptions

Then adjust for correct ones. I explained the calculations.. How much @7.5p are you then, 70/30 80/20. As I'll explain below it still doesn't add up.

Ok, lets try a make this even simpler.. let's assume your electric is on capped 0.34p, 38 * 0.34 * 365 = £4715.80... <- In other words NOT on Inteligent Octipus.

Are you really trying to tell me that with your solar / battery system over the year, including obviously winter when solar is really low, your pretty much generating nearly 100% of everything you need. Crikey, you may as well go off-grid and save the standing charge..

Anyway, if you really think your ROI is 2.5 years, good for you. But for me your calculations are not adding up.

Like I've already said, you will likely find your biggest ROI, is going onto Intelligent Octopus, that you could have done regardless if you had installed Solar / Battery. And yes, of course your bank will then pretty much coincide, but again your not splitting the difference between the installation of Solar Battery & been on Intelligent Octopus. IOW: Your saying your ROI is the difference of not been on Intelligent Octopus, and then been on Intelligent Octopus + Solar / Battery, it's not the way you compute your ROI.

Anyway, I'm not going to argue with you on this one. The main thing is your happy with your install..

 

[johnb2713]

Then adjust for correct ones. I explained the calculations.. How much @7.5p are you then, 70/30 80/20. As I'll explain below it still doesn't add up.

The split is irrelevant. As I stated above 14,000 kWh per annum of peak rate electricity why is that so difficult to take onboard? Now I dont use any peak rate electricity so those 14000 kWh come from my solar and my battery storage. Taking that as a given why do you think the saving I've stated arent justified.

Ok, lets try a make this even simpler.. let's assume your electric is on capped 0.34p, 38 * 0.34 * 365 = £4715.80... <- In other words NOT on Inteligent Octipus.

You need to simplify it so you can understand it because clearly you don't.

Are you really trying to tell me that with your solar / battery system over the year, including obviously winter when solar is really low, your pretty much generating nearly 100% of everything you need. Crikey, you may as well go off-grid and save the standing charge..

Incredible I clearly showed that my battery system supplies my peak energy and showed the saving from that.

Anyway, I'm through with this, go and figure whatever you want. My spreadsheet shows my predictions, my bank account confirms theyre correct.

END OF

 

[max.oldfield]

If one installs panels and a battery it makes sense to to install an inverter larger than prescribed in case you wish to add to your system

 

[user 36398]

The split is irrelevant. As I stated above 14,000 kWh per annum of peak rate electricity why is that so difficult to take onboard? Now I dont use any peak rate electricity so those 14000 kWh come from my solar and my battery storage. Taking that as a given why do you think the saving I've stated arent justified.


You need to simplify it so you can understand it because clearly you don't.


Incredible I clearly showed that my battery system supplies my peak energy and showed the saving from that.

Anyway, I'm through with this, go and figure whatever you want. My spreadsheet shows my predictions, my bank account confirms theyre correct.

END OF

But, and this is a big but, you can go on Intelligent Octopus without having Solar / Battery, so you surely cannot claim the 100% savings your making on the installation of your Solar / Battery alone. It certainly helps in making the most use of that 7.5p rate during the day, as I clearly stated in my comment on installing a battery only system. Your calculation is claiming your saving the whole 14,000 using 7.5p, but it's not is it?, think about it for a while. IOW: without solar / battery is would be very easy to use 7000kWh @ 7.5p, does that make sense now?.

Jesus, you really are on the case LOL

Really, I was just been curious, as it just seemed a very high amount. Your answer clearly explained the reasons, so I have no idea of the flippant response. The Bitcoin one is something I did wonder about myself, as some days I'm generating too much, and having a dump load would come in handy.

The one thing I will say, because of your high usage, I do actually think your ROI is maybe better than the 6/7 years, but I just don't believe it's 2.5 years, the calculation you showed me proved that, as it excludes a really important part. If you adjusted your ROI to take into account the comments I've made about it, I'd say it's maybe 5 years, and that is nothing to be sniffed at. Amazing return.. Also your £12K install cost seems really good, and that will certainly help ROI too.


Ok back on topic ->

Your high use does make me think of another example of a battery only install for high usage like yourself. Making some assumptions, you own an EV so can go onto Intelligent Octopus (important).

40 kWh daily usage, lets assume a constant usage, in a real scenario you would want higher usage during the 6 hour window. But lets keep the calculation dead simple, IOW: no ratio of usage.. So to cover the 18 hours peak rate, you would need a 30kWh battery, but you should never drain the battery to 0, so maybe a 38.4kwh battery install.

Install Cost (estimate): Unfortunately this is not going to be cheap, battery storage is pretty expensive. A quick google and it appears £16K+ without install costs, so with installation it's maybe about £17K.

So first to work out our ROI, we need to calculate how much would it cost without the battery. Pretty important bit this..

Off Peak = 10 kWh * 7.5p * 365 = £273.75
Peak = 30 kWh hrs * 38.58p * 365 = £4224.51
Total = £4498.26

^^^^^^ note: 0.34 protected this would be about £5000, so already a saving, IOW: EV drivers save £500 for just having an EV, again no solar battery yet.

Please note I've not included standing charges here, that BTW I find a massive rip of by the energy companies, a gripe for another time maybe:

So with our new battery install, what do the numbers come out as. Well assuming we can charge the whole 30kWh within the 6 hours window, I believe 2 inverters will be able to do that.

Off Peak = 40 hrs * 7.5p * 365 = £1095.00

So total saving per year = £4498 - £1095 = £3403 , pretty descent savings indeed.

But what is the ROI,. £17,000 / £3403 = About 5 years. Not bad at all.

Of course the numbers can be tweaked here, making more use of the 6 hour window, so allowing for a smaller battery install etc, will make things even better. Unfortunately adding solar to this won't help reduce the ROI faster, because at the end of the day the solar you generate will only be saving 7.5p per kWh. Not saying a solar install is bad (I have one myself), but just do be aware the biggest saving are made by been able utilise that 7.5p cheap rate, the solar part will of course take longer to get it's ROI.

Anyway, final thoughts.. I believe an ROI of less than 10 years is amazing. Getting 5/6/7 years is absolutely insane. Why there is not a massive rush to get solar / battery installs baffles me,..

 

[user 36398]

If one installs panels and a battery it makes sense to to install an inverter larger than prescribed in case you wish to add to your system

If your certain you will upgrade in the future, but do be aware using a larger inverter than your panels could mean it's slightly less efficient, it's common for solar installs to overclock, the advantage of overclocking is that it will start generating sooner, IOW: will need less sun to start up and run for longer, and of course the cost is less. The disadvantage is clipping on those rare days the UK has full sun and maxes out your panels.

You might find if you plan to upgrade, another idea is just get another inverter, you can get ones that are designed to link and talk to each other. This is something I've been thinking about,. Our current install is on our East (pointing slightly South), as such that's the roof we installed too first. But one idea is in the future placing on the West, and we would just get another inverter for this.

 

[johnb2713]

But, and this is a big but, you can go on Intelligent Octopus without having Solar / Battery, so you surely cannot claim the 100% savings your making on the installation of your Solar / Battery alone. It certainly helps in making the most use of that 7.5p rate during the day, as I clearly stated in my comment on installing a battery only system. Your calculation is claiming your saving the whole 14,000 using 7.5p, but it's not is it?, think about it for a while. IOW: without solar / battery is would be very easy to use 7000kWh @ 7.5p, does that make sense now?.



Really, I was just been curious, as it just seemed a very high amount. Your answer clearly explained the reasons, so I have no idea of the flippant response.

The flippant response was due to your arrogance of offering to make simple for me to understand.

The Bitcoin one is something I did wonder about myself, as some days I'm generating too much, and having a dump load would come in handy.

The one thing I will say, because of your high usage, I do actually think your ROI is maybe better than the 6/7 years, but I just don't believe it's 2.5 years, the calculation you showed me proved that, as it excludes a really important part. If you adjusted your ROI to take into account the comments I've made about it, I'd say it's maybe 5 years, and that is nothing to be sniffed at. Amazing return.. Also your £12K install cost seems really good, and that will certainly help ROI too.


Ok back on topic ->

Your high use does make me think of another example of a battery only install for high usage like yourself. Making some assumptions, you own an EV so can go onto Intelligent Octopus (important).

40 kWh daily usage, lets assume a constant usage, in a real scenario you would want higher usage during the 6 hour window. But lets keep the calculation dead simple, IOW: no ratio of usage.. So to cover the 18 hours peak rate, you would need a 30kWh battery, but you should never drain the battery to 0, so maybe a 38.4kwh battery install.

Install Cost (estimate): Unfortunately this is not going to be cheap, battery storage is pretty expensive. A quick google and it appears £16K+ without install costs, so with installation it's maybe about £17K.

So first to work out our ROI, we need to calculate how much would it cost without the battery. Pretty important bit this..

Off Peak = 10 kWh * 7.5p * 365 = £273.75
Peak = 30 kWh hrs * 38.58p * 365 = £4224.51
Total = £4498.26

^^^^^^ note: 0.34 protected this would be about £5000, so already a saving, IOW: EV drivers save £500 for just having an EV, again no solar battery yet.

Please note I've not included standing charges here, that BTW I find a massive rip of by the energy companies, a gripe for another time maybe:

So with our new battery install, what do the numbers come out as. Well assuming we can charge the whole 30kWh within the 6 hours window, I believe 2 inverters will be able to do that.

Off Peak = 40 hrs * 7.5p * 365 = £1095.00

So total saving per year = £4498 - £1095 = £3403 , pretty descent savings indeed.

But what is the ROI,. £17,000 / £3403 = About 5 years. Not bad at all.

Of course the numbers can be tweaked here, making more use of the 6 hour window, so allowing for a smaller battery install etc, will make things even better. Unfortunately adding solar to this won't help reduce the ROI faster, because at the end of the day the solar you generate will only be saving 7.5p per kWh. Not saying a solar install is bad (I have one myself), but just do be aware the biggest saving are made by been able utilise that 7.5p cheap rate, the solar part will of course take longer to get it's ROI.

Anyway, final thoughts.. I believe an ROI of less than 10 years is amazing. Getting 5/6/7 years is absolutely insane.

Whatever…..

Why there is not a massive rush to get solar / battery installs baffles me,..

You need to take a look around, solar and battery installs are going crazy over the last year.

 

[user 36398]

You need to take a look around, solar and battery installs are going crazy over the last year.

No, I agree there has been a big uptake. Just not as big as I would expect, like more media coverage, more people I know thinking or doing it. etc. you get the idea..

arrogance of offering to make simple for me to understand.

Because making it more complicated to understand would be the correct thing to do?.. 14,000 * (38.58p - 7.5p) does NOT equal your total savings, so my attempt at trying to simplify things still didn't work anyway. But your solar generation I agree with. If you was only on Intelligent Octopus, you would be out of your mind to not make use of that 7.5p, your calculation seems to imply you wound't. Very strange!! Your savings should compare what you would save not having a solar battery / and having a solar battery.

OK, going to have to do this. You say that your needs are 14,000 kWh, if you was only on intelligent, would you agree that you would try offload as much as you can onto the 6 hour cheap rate window? If not, then it's a pointless tariff. Would you also agree by this definition you would try and get at least 50% of your usage into this 6 hour window, again if not your loosing out. So total cost = 7.5p * 7000 + 38.58p * 7000 = £3225.60, not £5401.20 that your calculation is implying. So your total savings would then equal => £3225.60 - 14000 * 7.5p = £2175.60 , so your ROI = 5.5 years. Again, I think that's a fanatic ROI, and you should be well happy. I'm not trying to make you feel bad or anything, but just trying to point out a slight miss calculation you made. You can call me arrogant if you wish, but I'm not sure how else I could have expressed myself. EDIT: oops, forgot to include you Solar generation -> £2175.60 + £382.50 = £2558.10, ROI: 4.7 years.

Ok, I've maybe said my peace here.. But I do have a genuine question for you, seen as you have some experience here. You know I said I was thinking of dumping some access solar for BitCoin mining, I've a PC with a 3060, (yes not the most powerful card for mining). But doing a cost analysis even if I did use the free solar, website calcs are giving numbers like 4p a day. Are you finding it still pays to mine?, have you any advice on what hardware, what to mine. As that 4p a day bit seems not worth it, unless I was to using the heat generated from mining to keep the house warn..

 

[johnb2713]

No, I agree there has been a big uptake. Just not as big as I would expect, like more media coverage, more people I know thinking or doing it. etc. you get the idea..

well there we go, solar installers are flat out, very long protracted dates for instal, but not what you anticipated......

Because making it more complicated to understand would be the correct thing to do?.. 14,000 * (38.58p - 7.5p) does NOT equal your total savings, so my attempt at trying to simplify things still didn't work anyway. But your solar generation I agree with. If you was only on Intelligent Octopus, you would be out of your mind to not make use of that 7.5p, your calculation seems to imply you wound't. Very strange!! Your savings should compare what you would save not having a solar battery / and having a solar battery.

OK, going to have to do this. You say that your needs are 14,000 kWh, if you was only on intelligent, would you agree that you would try offload as much as you can onto the 6 hour cheap rate window? If not, then it's a pointless tariff. Would you also agree by this definition you would try and get at least 50% of your usage into this 6 hour window, again if not your loosing out. So total cost = 7.5p * 7000 + 38.58p * 7000 = £3225.60, not £5401.20 that your calculation is implying. So your total savings would then equal => £3225.60 - 14000 * 7.5p = £2175.60 , so your ROI = 5.5 years. Again, I think that's a fanatic ROI, and you should be well happy. I'm not trying to make you feel bad or anything, but just trying to point out a slight miss calculation you made. You can call me arrogant if you wish, but I'm not sure how else I could have expressed myself. EDIT: oops, forgot to include you Solar generation -> £2175.60 + £382.50 = £2558.10, ROI: 4.7 years.

As before, whatever, think what you like I KNOIW what the reality is.

Ok, I've maybe said my peace here.. But I do have a genuine question for you, seen as you have some experience here. You know I said I was thinking of dumping some access solar for BitCoin mining, I've a PC with a 3060, (yes not the most powerful card for mining). But doing a cost analysis even if I did use the free solar, website calcs are giving numbers like 4p a day. Are you finding it still pays to mine?, have you any advice on what hardware, what to mine. As that 4p a day bit seems not worth it, unless I was to using the heat generated from mining to keep the house warn..

Bitcoin went to dedicated hardware a long time ago when they ramped up the difficulty level, etherium went the same way last year, you can no longer mine it with graphics cards. Theres still plenty around that use various technologies. We are currently running a hard disk farm mining Chia. We have HDD's readily available via our IT recycling division of our business and we have in excess of 350Tb of drives running. I'm not disclosing figures to you of what it mines because i have no intention of going through our returns on it, you can do your own research and decide the ROI is too long