Is it just me? (Poor solar weather)

[m4rmite]

Think yourself lucky pal! ?

I live completely off grid and am only powered by the Sun (read rain) at the moment.

But, no problem at all powering my home.

Granted I wouldn't use all my high power appliances at the same time while the weathers this poor, but I manage much better than I would have thought before I started this venture. (5 years ago)

Also a 500AH battery bank, means I can go quite a few days without any meaningful Sun.

You might be better off fitting a water wheel for generation

 

[QLeo]

Lead acids? For crying out loud, again! One day you're going to have to save up for some hands-off, labour non-intensive LFP chemistry.

The big difference is I can make my mistakes with the system without ruining the battery (or at least, I can make new mistakes...!) Short of flattening it to 0%, lead-acids are nice and hardy. And half the cost of a similar LFP system, even now. At the time I got the battery, it was more like 8x cheaper.

 

[Rolfe]

Wow, I didn't realise the difference was that much.

Here, the forecast is for wall to wall sunshine tomorrow, but the car got to 100% about 4.30pm this afternoon. So what could I do, but go out joyriding? Well, I drove 16 miles to the supermarket first, bought some bread and stuff, then went joyriding. A703, Peebles, Traquair, St Mary's Loch, Megget, Talla, Tweedsmuir, then a distinctly circuitous route home involving Skirling, Dawick and Dreva. 100 miles all told. The Borders countryside looks gorgeous in the golden evening sunlight.

Caliban is now on 46%, and I'm running a fan heater to keep cosy in the conservatory while I watch Tristan und Isolde by video stream. I'm not going to export any more of tomorrow's sunbeams than I can help. It just better be sunny, after all that!

 

[Bam Bam]

The big difference is I can make my mistakes with the system without ruining the battery (or at least, I can make new mistakes...!) Short of flattening it to 0%, lead-acids are nice and hardy. And half the cost of a similar LFP system, even now. At the time I got the battery, it was more like 8x cheaper.

It sounds like LFP overtook lead acid for lifetime comparative cost at some point after you got your system.

LFP should provide 10x times the number of cycles, so you'd have to replace the lead acids multiple times. That's according to this analysis at any rate.

Lithium battery costs have dropped to an amazing extent.

 

[GaryMG4]

I've just looked back over the last 8 years and this quarter is panning out to be the worst since 2016 and looks as though it might even be worse than that with only 6 days left.

Well July just about redeemed itself, the last few days sunshine have pushed the the generation amount for the quarter over the miserable total for 2016 although its still 20% less than 2018.

 

[QLeo]

It sounds like LFP overtook lead acid for lifetime comparative cost at some point after you got your system.

LFP should provide 10x times the number of cycles, so you'd have to replace the lead acids multiple times. That's according to this analysis at any rate.

Lithium battery costs have dropped to an amazing extent.

Yes, I think that's right. In our case, we could afford to over-spec the battery, so it never discharges to less than 50% SOC, which is important to lead-acid lifespans, and it's very different to, say, a car 12v battery* (they're actually huge forklift cells). We expect them to last well north of 10 years. So we have some years to go before we need to think about replacement.

* - full disclosure. I bought a Land Rover Defender Heritage 90 in 2000, new. 17 years later, I sold it with, I think 180000 miles on the clock. It still had its original lead-acid battery under the passenger seat. They can last if treated well.

 

[Rolfe]

So far so good on the solar front today. Panels generating the max, car saying it should be charged by about 4.15. We need a few more days like this. (Preferably after I have that MPAN, of which still no sign.) Weather forecast says today is a one-off though.

 

[gazza487]

So far so good on the solar front today. Panels generating the max, car saying it should be charged by about 4.15. We need a few more days like this. (Preferably after I have that MPAN, of which still no sign.) Weather forecast says today is a one-off though.

Not sure how it all works as it’s not complete yet but I had to take a picture of my meter with the export reading on (it was at 275kwh) and send that with the forms and everything.

I’m assuming the payments will start from the 275 reading.

 

[Rolfe]

I don't know either. I suppose it will be another round of delay to get Octopus on board even after the MPAN comes through.

 

[gazza487]

I don't know either. I suppose it will be another round of delay to get Octopus on board even after the MPAN comes through.

Ahhh I’m with the British Gas of doom so their methods are a smidge archaic (a paper form to fill in and scan back along with photos and installs paperwork plus mcs).

As it’s the first registration I had no export mpan to give so they apply for it by all accounts.

 

[Rolfe]

My MPAN is said to be here "by the end of the week at the latest". Not holding my breath.

 

[Bam Bam]

My MPAN is said to be here "by the end of the week at the latest". Not holding my breath.

I vaguely remember this experience from 13 months ago. Felt like ages to wait because once you've done thing you have to move on to the next one. Octopus are usually pretty quick with things at least.

Once you've got it this frustrating period will be forgotten.

 

[STG]

My MPAN is said to be here "by the end of the week at the latest". Not holding my breath.

Has it arrived yet?

 

[mikgle]

Lovely clear blue sky here in Norfolk, just waiting for the excess to reach 2kW so I can turn on the granny charger to see what I can gain today.

Have you got an evse? you can plug it in if so and set the car input to 8A.. this is a lower threshold than the granny charger, which I reckon is about 10A.

 

[GaryMG4]

Have you got an evse? you can plug it in if so and set the car input to 8A.. this is a lower threshold than the granny charger, which I reckon is about 10A.

No I currently just use the granny, I could use the AC limit anyway, which I did in the winter, in the summer I try to use all my excess into the car.

 

[mikgle]

No I currently just use the granny, I could use the AC limit anyway, which I did in the winter, in the summer I try to use all my excess into the car.

so youre not on a smart tariff, like octopus go?

 

[GaryMG4]

so youre not on a smart tariff, like octopus go?

Recently switched to Go after a year of having the car with the standard tariff, so a change of mindset needed. I've gone from any solar excess reduces the overall cost to the excess needs to be above around 1.7kW to be cheaper than Go, although like today I'm still sending to the grid whilst using the granny, except when the odd cloud appears so it will be almost free.

 

[gazza487]

Recently switched to Go after a year of having the car with the standard tariff, so a change of mindset needed. I've gone from any solar excess reduces the overall cost to the excess needs to be above around 1.7kW to be cheaper than Go, although like today I'm still sending to the grid whilst using the granny, except when the odd cloud appears so it will be almost free.

Wouldn’t it be better to send as much back to the grid, forgetting the car for say 15p/kWh export then charge at night for 7ish pence?

Obviously that’s assuming you are getting the export (still waiting for BG to set me up at 15p) and you can squeeze enough in the go window?

 

[GaryMG4]

Wouldn’t it be better to send as much back to the grid, forgetting the car for say 15p/kwh export then changer at night for 7ish pence?

Obviously that’s assuming you are getting the export (still waiting for BG to set me up at 15p) and you can squeeze enough in the go window?

I'm on FiT so I get paid even if nothing is exported.
Not been a bad day, I've generated 20kWh (£4.60 earned), purchased 7 (£1.70), put 8.5 in the car, done 1x dishwasher, 2x washing and cooked Sunday lunch.

 

[mikgle]

I'm on FiT so I get paid even if nothing is exported.
Not been a bad day, I've generated 20kWh (£4.60 earned), purchased 7 (£1.70), put 8.5 in the car, done 1x dishwasher, 2x washing and cooked Sunday lunch.

Yeah it's a bit of a balancing act without a battery. A storage battery acts like a sponge and mops up any surplus, then outputs when sun goes down. It depends on your electrical loads of course, I've just had a heat pump installed and done away with gas so everything is electric now..