Yet another Solar installation quote post!

uk1

Screwdriva said:

QrizB said

Not wishing to rain on anyone's parade, but basing a 10-year-plus investment decision on a peculiar condition of the market that has lasted barely 12 months is a bold choice.

uk1 said:

I’m not sure you have fully understood the full discussion.  

A perfectly rational view of “the battery” is that during the months when PV output is inadequate then the possibility of off-peak battery charging is a potential advantage and has a viable place in the consideration. So on days that export is available and the price is right, then you export.  On those days when you aren’t producing enough then you charge at cheap rates.  It sounds rational to me.  

Both sides of the battery discussion cannot base their decision on certainties. It’s about instinct and risk assessments and the different sets of considerations that different people find most important.

From your post, I'm not certain you have understood the full discussion. You can export on Outgoing Agile OR benefit from a cheap, battery charging nighttime tariff, but not both. 

I think others have corrected you since your post, so I’ll just add that on the one hand in your later post you correctly criticise others and state that they cannot foretell prices which is both true of them but also obviously true for you as well when predicting future trends.

This discussion is about the future, not the past.  People are trying to work out how to hedge themselves against a turbulent and uncertain power supply market. Price trends have changed in a way that no one could have predicted pre-Ukraine and it seems to me that a logical response from the suppliers will be increasing numbers of new products that try to match differing usage patterns and emerging needs including EV and solar etc with a more competitive market for tariffs and niches with both export rates and off-peak download rates being fairly obvious features that we should see increasingly offered.  This might of course have another possible “benefit” and that’s to increase smart meter take-up. 

QrizB

Screwdriva said:

Sorry to share, we haven't been paid .15p per kWh (as a daily average) since June if not longer. It's almost always been upwards of .20p per kWh, sometimes nearly twice that.

Did you look at today and tomorrow's prices on your link? Well below 20p/kWh assuming a typical solar PV generation hump.

Screwdriva

uk1 said:

I think others have corrected you since your post, so I’ll just add that on the one hand in your later post you correctly criticise others and state that they cannot foretell prices which is both true of them but also obviously true for you as well.  

I don't see the correction you appear to. I stand by my earlier point and don't believe a battery makes financial sense with current Agile tariff + price cap. (EVs and heavy nighttime users may prove to be an exception - the number should highlight this) I have never claimed to foretell prices however, I did state that, were the variable export tariff to fall drastically, a battery could always be added at a later stage. This optionality does not exist if a battery purchase were made today. 

There are other concerns as well, namely battery life relative to the rest of the system, as well as the ethical concerns involved with using finitely available lithium in a home vs. in a car where it can offset more carbon.

uk1

Screwdriva said:

uk1 said:

I think others have corrected you since your post, so I’ll just add that on the one hand in your later post you correctly criticise others and state that they cannot foretell prices which is both true of them but also obviously true for you as well.  

I don't see the correction you appear to. I stand by my earlier point and don't believe a battery makes financial sense with current Agile tariff + price cap. I have never claimed to foretell prices however, I did state that, were the variable export tariff to fall drastically, a battery could always be added at a later stage. This optionality does not exist if a battery purchase were made today. 

There are other concerns as well, namely battery life relative to the rest of the system, as well as the ethical concerns involved with using finitely available lithium in a home vs. in a car where it can offset more carbon.

With respect you do seem to simply select any hook to hang your argument on that is convenient and ignore all others. 

You are also making assumptions along the lines that your opinions about battery purchases are true for all people in any usage situation and have now introduced another judgement that people that buy batteries are not only misguided but also potentially unethical.

Screwdriva

uk1 said:

You are also making assumptions along the lines that your opinions about battery purchases are true for all people in any usage situation and have now introduced another judgement that people that buy batteries are not only misguided but also potentially unethical.

With equal respect, I just shared that there are use cases where a battery may make sense, numbers supporting.

Additionally, what you term judgement, I call fact. If you are able to share any to disprove what I have shared, by all means please do.

uk1

Screwdriva said:

uk1 said:

You are also making assumptions along the lines that your opinions about battery purchases are true for all people in any usage situation and have now introduced another judgement that people that buy batteries are not only misguided but also potentially unethical.

Additionally, what you term judgement, I call fact. If you are able to share any to disprove what I have shared, by all means please do.

Hello again, I am more than happy to oblige.  You have made a criteria for not buying a battery for the home an ethical one.  You said. 

“There are other concerns as well, namely battery life relative to the rest of the system, as well as the ethical concerns involved with using finitely available lithium in a home vs. in a car where it can offset more carbon.”

If as you fear that the available lithium  is finite and therefore given the choice then the ethical choice must be that it must go into a car battery instead of my home because it offsets more carbon.  Whether it is more or not you seem to know and I do not have a clue.  All I know is that people tend not to drive for very long in these cars before they spend a lot of time not driving very much and being stressed (have you factored in the number of stress related deaths caused by regular daily "range anxiety" by people that weren't stressed  in their petrol or diesal cars?) and they certainly aren't driving for the same amount of time I plan to use the battery.  But I think we can at least agree that both using the battery in the home or a in a car offsets carbon to a greater or lessor degree. And we do know that either way is a good thing.    

You are however proving the opposite and that it is clearly the more ethical choice is to use the lithium in a home battery rather than a car battery as it directly saves more lives.

At the moment I have not ever read of a single person ever been killed by someone else’s home battery.  If you have any evidence to disprove this then please share it.  However every day many millions of innocent men, women and children are killed in every single country of the world by other people’s cars and those deaths are not reduced by whether the car is petrol or diesal or peddle or battery.  Their deaths are caused entirely by completely fuel blind lethal weapons and those events wouldn’t have happened at all if that vehicle had not been there in the first place.  So every EV car that is not on the road is potentially lives saved.

It therefore follows that there is a moral and ethical imperative that we all buy home batteries to ensure that we reduce the number of cars on the roads to save lives of  innocent men women and children in every country of the world.

QED.

Magnitio

This discussion appears to have turned into a farce.

Whilst there are people for whom a battery will make financial sense, I am sure that there are many purchases where it looks to be a good idea, but they will not get a return on their investment. Generalised arguments for either case can be made. I can certainly make a justification for my battey purchase, and am happy with it, but if I look at the detailed financials, I would have been better off without it.

Alnat1

I used this calculator Solar Panel & Battery Storage Calculator - Great Home (great-home.co.uk)
which I found a couple of months or so ago and appears to be able to factor in better variables than any other out there.

My ROI without a battery comes out at 6.6 years. With the battery I have, it claims 7.2 years so not a huge difference. 

uk1

Magnitio said:

This discussion appears to have turned into a farce.

Whilst there are people for whom a battery will make financial sense, I am sure that there are many purchases where it looks to be a good idea, but they will not get a return on their investment. Generalised arguments for either case can be made. I can certainly make a justification for my battey purchase, and am happy with it, but if I look at the detailed financials, I would have been better off without it.

There is a tendency for this to happen when one side of an argument with extremely fixed opinions who shoe-horn their version of “hard facts”  who seem to disrespect others and insist that they are obligated to justify a different opinion.  But no one died.

Screwdriva

Alnat1 said:

I used this calculator Solar Panel & Battery Storage Calculator - Great Home (great-home.co.uk)
which I found a couple of months or so ago and appears to be able to factor in better variables than any other out there.

My ROI without a battery comes out at 6.6 years. With the battery I have, it claims 7.2 years so not a huge difference. 

Thanks for sharing! Such a relief to see someone post actual numbers (vs. amateurish opinion) . In the case of our household, the difference is far more substantial (6 year vs. 11 with battery, assuming it lasts that long)

Perhaps the more pertinent question to ask is what could one do with the funds instead? The opportunity cost could instead supply a heat pump or better insulation, both of which may have the potential to reduce environmental and financial costs more than a battery could!