PHEV, battery storage and back-up supply

[dspp]

All of us with solar pv are exporting large amounts of energy to the grid at the moment.....because it's wall to wall sunshine.

Add electric cooking, heating, bev, battery storage & winter months and see how much you won't be exporting. I think your 12 weeks is to optimistic..... 16 weeks would be nearer the mark.

One thing is absolutely for sure.....with a 4kw solar array you cannot......run a house, heat water, charge a bev and top up a storage battery.....there just ain't enough bright days in the year.I

Perhaps a move to the West coast of the USA or Australia might help !

I did not say I could charge the car. I do not overclaim.
- dspp

[88V8]

You don't have to amortise anything.......it's never compulsory is it. The expenditure is about return, an 8-10% return vs 1% means that the expenditure makes perfect sense.......provided you are not borrowing the money or using money earmarked for more important things.

No, one doesn't have to amortise. We all have a certain capacity for self-deception, so one can just ignore that small elephant.

But the 'money earmarked for more important things' can currently be invested at c6%. So one has to save the 6% just to break even.
And then one really should at least mentally put aside the money to replace the kit when it wears out.
Otherwise one is just kidding oneself about the 'savings'.

It would be like me looking at my thatched roof and congratulating myself on its insulating qualities, whilst ignoring the fact that it costs me c£2,000 pa.

On a more general note, I have little experience of solar panels, but do recall testing one to drive a circ pump. It was remarkable how the output fell off with just a slight veil of cloud, compared to blue sky.
Not much blue sky in the UK, on the whole.

V8

[richlist]

Clearly I don't understand this need to amortize.

Spending £6K on solar panels won't result in the value of your house rising by £6K anymore than spending £6K on some 'home improvements would generally. Spend the money on a new bathroom, a garden makeover or a new heating system and you are unlikely to ever see a return.....your property may be easier to sell but it's unlikely to affect the price much. I don't imagine Mr average would consider amortising the cost of his new bathroom or most other home expenditures so why do it for solar panels ?

Spend £6K on solar panels and get a good return year on year.....and I'm not going to be living there in 20+years time when it needs replacing I will almost definitely have moved on before then.

Are you suggesting preference shares are risk free ?

[richlist]

Getting night time electricity at 5p a unit isn't that useful for mr average......he doesn't use a lot of electricity at night.......most of his usage is during the day. How is that an elephant in the room ?

[scotview]

Thanks to everyone for your feedback. It has helped to give me a clearer idea for future backup supply requirements. The following are my two best cast scenarios for my circumstances (no solar).

I will assume existing gas boilers will be allowed after 2025. So in both scenarios I will probably install a new gas boiler at the end of 2024, with a new 5 year warranty.

Scenario 1 Dedicated Battery Backup. Based on a Solax 4.5kWh battery system , capital cost £3000, so over 5 years £600/year
Fully charged Nov to March, giving a backup duration of 4 days, for circulating pump, boiler and 4 zone valves, (50% use factor)
Electricity off peak cost saving £50/year, so backup storage costs £550/year.

Scenario 2 PHEV with vehicle to home technology (VTH). Additional monthly PPI cost £40, £500/year inc VTH installation.
PHEV 50% minimum battery charge (8 kWh) Nov to March, giving a backup duration of 8 days, for circulating pump, boiler electronics and 4 zone valves (50% UF)
Electricity off peak cost saving £170/year, so backup storage costs £330/year.

Additionally, the PHEV can be disconnected and run to recharge the battery giving some degree of extension. So PHEV wins. Await a vehicle to home (VTH) solution for PHEVs.

The above numbers are ball park.

[staffordian]

I will assume existing gas boilers will be allowed after 2025. So in both scenarios I will probably install a new gas boiler at the end of 2024, with a new 5 year warranty.

Not sure if affects your calculations, but there are, or certainly were until recently, several boilers available with a ten year warranty.

If nothing else, it perhaps delays any further decision making