Battery or no battery?

[Nickfromwales]

Long story short; PV is a no brainier, matched to export as little as possible (get near to 100% self consumption), and batteries need thought and effort for them to be decided upon as ‘beneficial’.

 

Each case is unique, so no copy / cut / paste. 

[JohnMo]

1 hour ago, torre said:

for just the battery sounds like 8200 / 650 = 12.6 years . That's pushing the lifespan of the battery to payback at all

But the battery allows a few things that you are missing - difficult to work out the cost benefit really.

 

One thing is ironing out bumps in usage. Using lots of electric over and above generation without import.

 

So generating about 4kW while actually using nearly 7kW. No import. (Heat pump, immersion and dishwasher washer all on)

 

Allows way higher PV utilisation, my last week figure was in the mid 90%. Without battery that could have been mid to low 70%.

 

Allows better utilisation of immersion, run at full 3kW output. Can run heat pump over prolonged time period without having to import or it stop/starting due to clouds passing by during the day on PV, and not having to import to keep it running. Most of my heat pump running since mid March has been free and getting a CoP of around 5 when heating. Plus cylinder has been circa 70 most days except the odd wet day.

 

1 hour ago, torre said:

'some time in the future' always ends up being the best time to install a battery.

Everything is always better buying later. My first Pioneer flat screen TV was £10k back on the late 90s, but that's life. I enjoyed it (still have it and it still works - could possibly heat the house with it).

Edited yesterday at 12:42 by JohnMo

[JohnMo]

1 hour ago, torre said:

heat pump dryer - can make those longer cycles work, esp off peak.

Or better still with the PV generated and stored in a battery 

[Nickfromwales]

10 minutes ago, JohnMo said:

Or better still with the PV generated and stored in a battery 

lol. Let’s all stay up and fight 😁.

[SteamyTea]

59 minutes ago, JohnMo said:

Allows way higher PV utilisation

Do you know your annual utilisations?

[Thorfun]

this week I have been paid £9.60 to run my house (and it’s only April!). We charge the batteries on the off-peak Cosy tariff times and get paid more for export than for the import costs during generation hours. It works for us and I’m hoping that we can earn enough over the summer to negate the majority of the winter costs leaving us with a very low annual running cost. 
 

payback time? Don’t give a s**t. Had the money during the build and is now part of my mortgage so I’m paying interest on it etc. but don’t care. I can absorb that into my monthly costs. All I care about is not spending my pension (when I finally retire that is) on heating bills so I can use it for holidays instead! 
 

man maths for the win. 
 

[JohnMo]

1 hour ago, SteamyTea said:

Do you know your annual utilisations?

Average is about 89%, but with recent changes to diverter (i.e. got rid of it), utilisation is running about 94-95%

[JohnMo]

1 hour ago, Thorfun said:

this week I have been paid £9.60 to run my house (and it’s only April!). We charge the batteries on the off-peak Cosy tariff times and get paid more for export than for the import costs during generation hours. It works for us and I’m hoping that we can earn enough over the summer to negate the majority of the winter costs leaving us with a very low annual running cost. 
 

payback time? Don’t give a s**t. Had the money during the build and is now part of my mortgage so I’m paying interest on it etc. but don’t care. I can absorb that into my monthly costs. All I care about is not spending my pension (when I finally retire that is) on heating bills so I can use it for holidays instead! 
 

man maths for the win. 
 

Well done - we don't (can't) have a smart meter, so that wouldn't work for us. Even if we could export we would only get 4p per kWh.without a smart meter.

[Thorfun]

3 minutes ago, JohnMo said:

Well done - we don't (can't) have a smart meter, so that wouldn't work for us. Even if we could export we would only get 4p per kWh.without a smart meter.

The “profit” we make from buying off-peak to exporting has reduced with the increase of prices the other day. But it’s still a profit! If prices go up any further I’ll need to make some changes. But it works for now. 
 

my battery inverter says it’s Octopus friendly so I might look in to moving to Agile over the summer to charge the batteries when it’s cheapest. But research is required 

[Pocster]

You guys !

if ONLY everyone hadn’t laughed at me buying a Tesla powerwall 2 all those years ago !  

Moaning about payback time but not factoring increased future electricity costs.

Ahhhh 😊