Is solar battery storage worth it?

Martyn1981

Screwdriva said:

Martyn1981 said:

Happy for you to use a SCOP of 3, I actually suggested 2 when talking about running through the night, since that's a fair average, but obviously, you can't use 94%/95% for a boiler average, that would be extreme cheating. 90% is, I believe entirely fair and reasonable, is it not?

No need to get an old out of warranty EV, as I mentioned, a 3yr old would be great, lots of choice at ~£10k, for those that drive closer to the UK average of 7,000 miles pa..

Obviously depends on your requirments, but a battery and BEV of £5k each is possible, which appears to be well under your figure of £20k.

Wow 13k kWh of FF gas, we're down to around 6,000kWh, and that's with only limited use of an A2A. Hoping to almost half that via the cheap rate, 2x A2A and battery.

I suspect the reason your figures are somewhat questionable, is that you are taking worst case for one, and best case for the other, rather than my approach of trying to be fair and reasonable throughout.

I have used my own household's data shared above, as I can't speak to other use cases,. Our V200 routinely achieves the efficiency I've shared (this isn't just me stating this- there's a bucketload of Viessmann installers who attest to this as well).

There is no way a £5K BEV is pragmatic regardless of how possible it may be. For us, a minimum 200 usable mile driving range is a must have. Others may be different. 

Just emphasizing this to counter the accusations above. Again, please feel free to use the above numbers to highlight a superior running cost vs. capital cost ratio over the next decade for us. Granted the ASHP warranty probably won't be that long but 10 years is a nice round number). 

Hi, you still seem to be cherry picking. In your own words, the boiler routinely achieves that efficiency, but is it an average? So back to ~90% as a fair and reasonable number.

Nothing wrong with a £5k BEV, no idea how you can make such a generalised statement. Also you are making this about you, but my comments were in general, and for the poster's stated mileage of 6,000, possibly falling after retirement. Please read in context.

So again, going back to what I said, rather than your spin, I mentioned that for about £10k, you could get a nice 3yr old 180 mile range BEV. To which you have tried to argue against my statement on the grounds that it will be old and out of warranty, and that you need a minimum of 200 miles ....... neither statement has anything to do with what I said.

So, back to your original statement that a gas boiler unit cost can't be beat, can I please direct you to mine and RR's explanations on how it can be beaten quite significantly. [Please don't try to spin this, it won't work for everyone, it won't necessarily be a full time solution*, but it can be done, and the situation and options are only getting better. *In my case, I can cover heating outside of the coldest months (Dec -Feb), and reduce gas consumption, and heating costs during those 3 months too.]

You may want to try to obfuscate and spin outside of the discussion, but the thread is about PV and batts, and an A2A unit was mentioned. You may not see a solution, you may not see a solution for you, but we are all different with different needs and circumstances, and there are options out there for some of us, and sharing that info with others is a good thing.

Alnat1

@Screwdriva your Octopus quote of £2500 for the ASHP includes the cost of a replacement HW tank so there's no need to add an extra £2000. It also includes any necessary radiator changes.

Screwdriva

Alnat1 said:

@Screwdriva your Octopus quote of £2500 for the ASHP includes the cost of a replacement HW tank so there's no need to add an extra £2000. It also includes any necessary radiator changes.

Things have changed sadly but you’re right that it was previously all inclusive. 

Reed_Richards

I could be wrong but I don't think an installation to MCS standards would allow the installer not to replace the cylinder, unless by some fluke you already had one with a suitably large surface area coil.  The "cylinder upgrade" referred to could mean a large capacity cylinder than the one Octopus have offered.

greenbee

I've got a current quote from Octopus (pre-survey, so all bets are off as to what it would end up as), but it includes a compatible cylinder and any necessary radiators and pipework. I think the 'no upgrades' is the same as their 'no designer radiators - they will install the required size/capacity based on their survey from their standard stock and not give you a choice of make/model. They are currently doing an extra £250 off if you book before the end of October. 

I'm not currently ready to commit (for a start I'm on a break from trades for the sake of my sanity). 

Screwdriva

Reed_Richards said:

Because?  Do you frequently make journeys of over 200 miles without stopping anywhere long enough to recharge an EV.  That must mean you drive far further each year than the average 7000 miles. 

Personal preference aside, we drive from London to the Devon coast several times a year. It's a ~230 mile drive each way and we typically don't stop for more than a quick loo break. Our annual mileage is ~4500 miles. 

Martyn1981 said:

Hi, you still seem to be cherry picking. In your own words, the boiler routinely achieves that efficiency, but is it an average? So back to ~90% as a fair and reasonable number.

Nothing wrong with a £5k BEV, no idea how you can make such a generalised statement. Also you are making this about you, but my comments were in general, and for the poster's stated mileage of 6,000, possibly falling after retirement. Please read in context.

So again, going back to what I said, rather than your spin, I mentioned that for about £10k, you could get a nice 3yr old 180 mile range BEV. To which you have tried to argue against my statement on the grounds that it will be old and out of warranty, and that you need a minimum of 200 miles ....... neither statement has anything to do with what I said.

So, back to your original statement that a gas boiler unit cost can't be beat, can I please direct you to mine and RR's explanations on how it can be beaten quite significantly. [Please don't try to spin this, it won't work for everyone, it won't necessarily be a full time solution*, but it can be done, and the situation and options are only getting better. *In my case, I can cover heating outside of the coldest months (Dec -Feb), and reduce gas consumption, and heating costs during those 3 months too.]

You may want to try to obfuscate and spin outside of the discussion, but the thread is about PV and batts, and an A2A unit was mentioned. You may not see a solution, you may not see a solution for you, but we are all different with different needs and circumstances, and there are options out there for some of us, and sharing that info with others is a good thing.

When accused of cheating, spin and obfuscation in the same thread, I realize I must have pricked a nerve somewhere.

While we're on the subject, I did not say a gas boiler can't be beat. I said that a "Viessmann (paired with the Gas tracker tariff <5p) remains hard to beat financially, even with panels".  TBH, I hadn't read any of your posts when I responded directly to pensionpawn's comment (and still haven't).

Let's say that you are correct on all of the above: Viessmann boilers are no more efficient than 90% and that I should only consider a cheaper 180 mile range EV.  

Even with the £10K BEV, charger and home battery, you will struggle to justify the upfront capital spend of £16K against the consumption numbers I have shared. There are low consumption, low mileage households that simply do not save enough  (< £1K including fuel savings in my case) to justify the upfront capital spend. Please share calculations showing otherwise and I will be the first to admit I am wrong. 

Does that mean heat pumps are a bad idea? Far from it. They have their place and are a great replacement for inefficient gas set ups, Calor (LPG), oil boilers and for off grid applications etc. I have never claimed otherwise during my time on MSE (quite the opposite) nor have I ever suggested that sharing information about their merits is a bad thing. 

Martyn1981

Screwdriva said:

Reed_Richards said:

Because?  Do you frequently make journeys of over 200 miles without stopping anywhere long enough to recharge an EV.  That must mean you drive far further each year than the average 7000 miles. 

Personal preference aside, we drive from London to the Devon coast several times a year. It's a ~230 mile drive each way and we typically don't stop for more than a quick loo break. Our annual mileage is ~4500 miles. 

Martyn1981 said:

Hi, you still seem to be cherry picking. In your own words, the boiler routinely achieves that efficiency, but is it an average? So back to ~90% as a fair and reasonable number.

Nothing wrong with a £5k BEV, no idea how you can make such a generalised statement. Also you are making this about you, but my comments were in general, and for the poster's stated mileage of 6,000, possibly falling after retirement. Please read in context.

So again, going back to what I said, rather than your spin, I mentioned that for about £10k, you could get a nice 3yr old 180 mile range BEV. To which you have tried to argue against my statement on the grounds that it will be old and out of warranty, and that you need a minimum of 200 miles ....... neither statement has anything to do with what I said.

So, back to your original statement that a gas boiler unit cost can't be beat, can I please direct you to mine and RR's explanations on how it can be beaten quite significantly. [Please don't try to spin this, it won't work for everyone, it won't necessarily be a full time solution*, but it can be done, and the situation and options are only getting better. *In my case, I can cover heating outside of the coldest months (Dec -Feb), and reduce gas consumption, and heating costs during those 3 months too.]

You may want to try to obfuscate and spin outside of the discussion, but the thread is about PV and batts, and an A2A unit was mentioned. You may not see a solution, you may not see a solution for you, but we are all different with different needs and circumstances, and there are options out there for some of us, and sharing that info with others is a good thing.

When accused of cheating, spin and obfuscation in the same thread, I realize I must have pricked a nerve somewhere.

While we're on the subject, I did not say a gas boiler can't be beat. I said that a "Viessmann (paired with the Gas tracker tariff <5p) remains hard to beat financially, even with panels".  TBH, I hadn't read any of your posts when I responded directly to pensionpawn's comment (and still haven't).

Let's say that you are correct on all of the above: Viessmann boilers are no more efficient than 90% and that I should only consider a cheaper 180 mile range EV.  

Even with the £10K BEV, charger and home battery, you will struggle to justify the upfront capital spend of £16K against the consumption numbers I have shared. There are low consumption, low mileage households that simply do not save enough  (< £1K including fuel savings in my case) to justify the upfront capital spend. Please share calculations showing otherwise and I will be the first to admit I am wrong. 

Does that mean heat pumps are a bad idea? Far from it. They have their place and are a great replacement for inefficient gas set ups, Calor (LPG), oil boilers and for off grid applications etc. I have never claimed otherwise during my time on MSE (quite the opposite) nor have I ever suggested that sharing information about their merits is a bad thing. 

Unfortunately it looks like you are still spinning and obfuscating. Possibly not cheating, though your wording on boiler efficiency does still appear to be 'a bit naughty' by the use of 'no more efficient than 90%', rather than appreciating what I've actually siad..

Para 1. The only nerve hit was to see you repeatedly try to undermine advice given, by the use of tricks. For example, how many times did you try to discredit RR's advice by requesting (demanding) he give you a figure for the cost of an EV? Many people are moving to an EV, but more importantly what you failed to grasp, was that it's not the cost of an EV, but the far smalkler difference in cost v's an ICEV. The difference may even be in the favour of the EV. I didn't read RR's comments as in any way throwaway, or dismissive of the cost of buying/owning a vehicle. Instead I simply saw them as providing options. 

Para 2. That seems to be the big giveaway, you made a statement without reading all thread comments, and being aware of the full discussion. You then proudly state that you intend to remain so informed.

Para 3. You seem to be spinning/obfuscating again. When talking about HP's you refer to the SCOP, so a seasonal average (perfectly fair)*, but for the gas boiler, you want to use the peak 'upto' figure for efficiency. All I've done, repeatedly, is to ask you to apply fairness both ways. 90% efficiency average would seem fair and reasonable. Certainly higher than my boiler.

*In my comments I tried to be fair and err on the side of caution, so I suggested a cost per kWh(t) of half for night use, and 1/3rd for day use, trying to roughly account for differing temps and therefore COP. That part of the discussion (and it's in my comments if you care to read them) was a mention of shoulder months, when the COP will of course be higher than the winter period.

Para 3 (cont). Never asked you to consider a 180 mile range, certainly never stated that you should only consider one. As mentioned, this isn't about you. Perhaps you should have read the thread.

Para 4. You again add the whole cost of the BEV, more spin and cheating. And once again, had you read my comments, you would see that I caveated them all, by suggesting that for some this may work, for others it may not it. It will depend on their circumstances. Whereas your comments attempt to portray only the negatives and worst case.

Para 4 (cont). Not asking you to 'admit you are wrong', since everyone's circumstances will differ, and thgis isn't about you / your circumstances specifically. I've simply pointed out that many of your statements and claims don't add up, within this discussion, and appear to be pushing a biased narrative, rather than an open discussion and consideration. [Requiring RR to give an EV cost, hard to beat gas unit cost, £20k not enough for a BEV and battery, 3yr old £10k BEV, would be cheap, old and out of warranty, use of average for HP, use of max for boiler, etc.]

Para 5. Good to hear, hope we can now discuss and consider merits and costs in a balanced manner, taking on board the comments of others, and any facts/data they provide.


So, it's clear that you (personally) are not yet convinced on the economics of batts, HP's and BEV's in all cases. I'm of the very same mind - in all cases. However, I do think that things are moving in the right direction, and that the economics (especially on a Green and Ethical basis) are shifting, and that for some, it's already the case.

Reed_Richards

Screwdriva said:

Reed_Richards said:

Because?  Do you frequently make journeys of over 200 miles without stopping anywhere long enough to recharge an EV.  That must mean you drive far further each year than the average 7000 miles. 

Personal preference aside, we drive from London to the Devon coast several times a year. It's a ~230 mile drive each way and we typically don't stop for more than a quick loo break. Our annual mileage is ~4500 miles. 

With your low annual mileage, an EV would be ideally suited to you, were it not for the sticking point of your 230 mile journeys.  But if you stopped for a loo break and a cup of coffee that would be long enough (say half an hour) to add another 14 kWh or so of charge to my car which would get me a total of 230 miles very comfortably if I started on a full charge.  I would need to do a full recharge when I got there and that would take around two hours, possibly less with a really fast charger.  My EV is very nice to drive and has a lot more oomph than my previous car, which was a self-charging hybrid (and 10 years old when I traded it in).  And although few people have noticed this, for some car models there really isn't a price premium for an EV over the ICE equivalent. 

Screwdriva

Reed_Richards said:

With your low annual mileage, an EV would be ideally suited to you, were it not for the sticking point of your 230 mile journeys.  But if you stopped for a loo break and a cup of coffee that would be long enough (say half an hour) to add another 14 kWh or so of charge to my car which would get me a total of 230 miles very comfortably if I started on a full charge.  I would need to do a full recharge when I got there and that would take around two hours, possibly less with a really fast charger.  

Just not worth the range anxiety given our requirements but appreciate that the we are fast approaching a time when we may be able consider this.

Reed_Richards

Yes, fortunately I am not an anxious person.  I once got home after a long car journey with less than 10 miles of nominal range to spare but I found that quite exciting! 

My EV has three driving modes, Eco, Normal and Sport.  Even Eco mode gives you fast pick-up when you put your foot down and in Sport mode the car takes off like a rocket.  This responsiveness makes EVs very pleasant to drive.