Battery system for solar PV

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I am considering installing a battery system as an addition to solar panels, however the cost is prohibitive. Have any of the sparkies on here any experience of this as I would like to use SLA batteries but have no idea how these link to the system to provide power when the sun is not shining. I have invertors but not grid connected as the solar one is. Any advice appreciated
 
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I am considering installing a battery system as an addition to solar panels, however the cost is prohibitive.
What makes you think that you'd be able to build your own system out of SLAs which would be cheaper than one you can buy? Obviously there is the profit margin to consider, but against that you have to consider that you'll be paying a lot more for your batteries than they will....
 
I find that comment difficult to understand, given that most commercial systems use Tesla batteries and cost upwards of £6,500
 
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There was a special inverter for boats where it supplemented the shore supply, idea was with a 4 amp shore supply you could use the narrow boat battery bank to allow 16A items to be used intermittently and it would recharge the batteries when not drawing full 4 amp.

There is also a system to monitor supply and when there is enough excess to run your immersion heaters.

Since never fitted either, I don't have more details.

However the inverter for boat will allow you to synchronise with mains supply so you can use the battery power, and the immersion heater thing would allow you to recharge batteries when you have excess power, so technically it can be done.
 
There was a special inverter for boats where it supplemented the shore supply, idea was with a 4 amp shore supply you could use the narrow boat battery bank to allow 16A items to be used intermittently and it would recharge the batteries when not drawing full 4 amp.

There is also a system to monitor supply and when there is enough excess to run your immersion heaters.

Since never fitted either, I don't have more details.

However the inverter for boat will allow you to synchronise with mains supply so you can use the battery power, and the immersion heater thing would allow you to recharge batteries when you have excess power, so technically it can be done.

The Viktron Multiplus inverter/charger that I installed in the narrow boat can do this:

"PowerAssist – Boosting the capacity of shore or generator power
This feature takes the principle of PowerControl to a further dimension allowing the MultiPlus
Compact to supplement the capacity of the alternative source. Where peak power is so often
required only for a limited period, it is possible to reduce the size of generator needed or
conversely enable more to be achieved from the typically limited shore connection. When the
load reduces, the spare power is used to recharge the battery."
 
It seems likely then it can be done, as to if worth doing is another question. The idea for solar panels was to use the grid as a big battery, however the tariffs kind of killed that idea. On one forum there was a link to a report where some one I think Austrailia had fitted solar panels and had carefully worked out costs using battery backup.

He came to the conclusion it all hinged on gpverment grants which vary across their country, without them not worth it.

I am sure on the Falklands where there is no national grid only Stanley has 24 hour power, it may be worth it, but in UK unlikely.
 
How does 30,000 homes for an hour relate to MWh? Dinorwig's six generating units can produce 288MW for 5 hours. It seems to say 30,000 home/hour is more than that. I would think most home average 10 amp per hour or less, that's around 70 MWh so for the battery to be bigger than Dinorwig each home would need to use 200 amp.
 
I'd look at some used Industrial UPS systems. They often go on Ebay for around £500, couple that with a solar output controller like https://www.marlec.co.uk/product/solar-iboost/?v=79cba1185463 and you might be able to use the boost to charge the UPS as well as heat your hot water.

The problem with a boat system is that they assume your panel is DC, so not ideal for a domestic Solar PV system. If the whole system is DIY, then a yacht system would be ideal
https://mrandmrshowe.com/lifestyle-blog/sailboat-solar-panels-go-power

Tesla power wall is overkill for UK domestic use.
 
Thanks for all the interesting comments, as my normal evening requirements are a couples of LED lights, TV and about 50watts for the oil fired cooker/boiler I have decided on a simple 2 socket circuit and a 3LED light circuit powered from a pure sine wave invertor with a 60 amp/hour SLA battery charged from the mains during daylight hours so it is mainly solar powered.
 

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