Should I go off-grid?

zeupater

Hi

Re : ".... are vastly more expensive for broadly the same energy storage capacity. What do you think?"

Don't really follow the logic there ... for example, your batteries at £230 for 1280Wh work out at ~18p/Wh whereas some examples below seem to be in a similar ballpark per unit storage and include additional features such as BMS etc .... 

• Pylontech US5000 = £1164/4800  ~24p/Wh
• Fogstar 15.5kWh = £2500/15500  ~16p/Wh
• Seplos assembly kits (eg14.3kWh = £1700/14300 ~12p/Wh

... of course, they'd all need inverters etc, but on a pure unit based storage cost there doesn't seem to be a anything approaching a 'vast' difference ...

HTH - Z

HertsLad

zeupater said:

Re : ".... are vastly more expensive for broadly the same energy storage capacity. What do you think?"

Don't really follow the logic there ... for example, your batteries at £230 for 1280Wh work out at ~18p/Wh whereas some examples below seem to be in a similar ballpark per unit storage and include additional features such as BMS etc .... 

• Pylontech US5000 = £1164/4800  ~24p/Wh
• Fogstar 15.5kWh = £2500/15500  ~16p/Wh
• Seplos assembly kits (eg14.3kWh = £1700/14300 ~12p/Wh

... of course, they'd all need inverters etc, but on a pure unit based storage cost there doesn't seem to be a anything approaching a 'vast' difference ...

I agree I probably went a bit far by using the term 'vast difference' but the battery packs units used for a typical household solar installation are still significantly more expensive per Wh than my latest lithium batteries.

Generic lithium 100AH = £169/1280 is 13p/Wh compared to your figure of 24p/Wh for Pylontech, presumably if you buy the pack yourself for a DIY type installation. It's almost twice as expensive and would become even more expensive, presumably, if the batteries were part of an installation deal by 'accredited' solar installers.

The Fogstar battery is more competitive in terms of cost/Wh but, if the 'entry level' is a 15.5kWh battery, then it's a bit large, and involves shelling out £2500.

All my 100Ah batteries have BMS built in. I also need to add inverters and charge controllers, of course, but there are big savings there, too, compared to the kit used by typical solar installers.

ed110220

HertsLad said:

zeupater said:

Re : ".... are vastly more expensive for broadly the same energy storage capacity. What do you think?"

Don't really follow the logic there ... for example, your batteries at £230 for 1280Wh work out at ~18p/Wh whereas some examples below seem to be in a similar ballpark per unit storage and include additional features such as BMS etc .... 

• Pylontech US5000 = £1164/4800  ~24p/Wh
• Fogstar 15.5kWh = £2500/15500  ~16p/Wh
• Seplos assembly kits (eg14.3kWh = £1700/14300 ~12p/Wh

... of course, they'd all need inverters etc, but on a pure unit based storage cost there doesn't seem to be a anything approaching a 'vast' difference ...

I agree I probably went a bit far by using the term 'vast difference' but the battery packs units used for a typical household solar installation are still significantly more expensive per Wh than my latest lithium batteries.

Generic lithium 100AH = £169/1280 is 13p/Wh compared to your figure of 24p/Wh for Pylontech, presumably if you buy the pack yourself for a DIY type installation. It's almost twice as expensive and would become even more expensive, presumably, if the batteries were part of an installation deal by 'accredited' solar installers.

The Fogstar battery is more competitive in terms of cost/Wh but, if the 'entry level' is a 15.5kWh battery, then it's a bit large, and involves shelling out £2500.

All my 100Ah batteries have BMS built in. I also need to add inverters and charge controllers, of course, but there are big savings there, too, compared to the kit used by typical solar installers.

There are also the DIY 15.2 kWh Seplos kits for £1350 or £1500 if you're up for assembling them yourself. 

pete-20-11

1.39 Os today 

HertsLad

ed110220 said:

HertsLad said:

Generic lithium 100AH = £169/1280 is 13p/Wh compared to your figure of 24p/Wh for Pylontech, presumably if you buy the pack yourself for a DIY type installation. It's almost twice as expensive and would become even more expensive, presumably, if the batteries were part of an installation deal by 'accredited' solar installers.

The Fogstar battery is more competitive in terms of cost/Wh but, if the 'entry level' is a 15.5kWh battery, then it's a bit large, and involves shelling out £2500.

All my 100Ah batteries have BMS built in. I also need to add inverters and charge controllers, of course, but there are big savings there, too, compared to the kit used by typical solar installers.

There are also the DIY 15.2 kWh Seplos kits for £1350 or £1500 if you're up for assembling them yourself. 

Thanks but I probably can't justify 15.2kWh more lithium at present. My first battery bank, put together only a few years ago, was lead acid being primarily so-called leisure batteries bought from Euro Car Parts when they were heavily discounted for a while. I'm not sure if I should believe the implied claim the voltage can go lower than standard lead acid batteries but, if looked after, I hope they will last a long time. My 6 x lithium batteries (7,680Wh) provide power 24/7 for my fridge and freezer. 14 or more lead acid batteries (usable 6,132Wh) are also kept topped up from my solar panels but power is only drawn when I use my desktop computer, like right now. I keep my eye on a voltage meter to check the voltage doesn't drop too low. It's most unlikely. In addition, I have 4 x 36Ah lithium batteries (1,844Wh) which I charge from solar and use for various LED lights and a DAB radio.

How do you add the footnote with your system details? Is it added for each and every post, or more likely via an account setting? I looked at my account and couldn't see anything.

Qyburn

HertsLad said:

A few people have suggested Octopus Energy as a good provider for exporting surplus solar energy. I looked at their website this morning and can't see how I could possibly make it pay. At present, I pay zero for electricity including no standing charge. But to sign up to Octopus, I would need to pay their standing charge of £175 per annum. If energy was exported at 15p per kwh, I would need to export 1.2kwh just to break even. . 

From your figures it doesn't make sense. I think one key question is whether you could cover your use 12 months a year without importing. If you can then, as you're implying, the sole reason for a grid connection would be financial.

Martyn1981

HertsLad said:

ed110220 said:

HertsLad said:

Generic lithium 100AH = £169/1280 is 13p/Wh compared to your figure of 24p/Wh for Pylontech, presumably if you buy the pack yourself for a DIY type installation. It's almost twice as expensive and would become even more expensive, presumably, if the batteries were part of an installation deal by 'accredited' solar installers.

The Fogstar battery is more competitive in terms of cost/Wh but, if the 'entry level' is a 15.5kWh battery, then it's a bit large, and involves shelling out £2500.

All my 100Ah batteries have BMS built in. I also need to add inverters and charge controllers, of course, but there are big savings there, too, compared to the kit used by typical solar installers.

There are also the DIY 15.2 kWh Seplos kits for £1350 or £1500 if you're up for assembling them yourself. 

How do you add the footnote with your system details? Is it added for each and every post, or more likely via an account setting? I looked at my account and couldn't see anything.

Hi, go to your account, and you will see to the right of your name a box with an image of head and shoulders and down arrow.

Click on that 'edit profile'. Then 'signature settings' on RHS list.

The best of luck.

HertsLad

Qyburn said:

HertsLad said:

A few people have suggested Octopus Energy as a good provider for exporting surplus solar energy. I looked at their website this morning and can't see how I could possibly make it pay. At present, I pay zero for electricity including no standing charge. But to sign up to Octopus, I would need to pay their standing charge of £175 per annum. If energy was exported at 15p per kwh, I would need to export 1.2kwh just to break even. . 

From your figures it doesn't make sense. I think one key question is whether you could cover your use 12 months a year without importing. If you can then, as you're implying, the sole reason for a grid connection would be financial.

Sorry, but I don't understand. Taking your first sentence in isolation, which figures don't make sense? 

On the second point, I already cover all my needs for electricity year-round without using any mains electricity. So, yes, the primary reason for a grid connection would be financial. But there are set up costs, too, if I moved from where I am at present to where I'd need to be to hook up to Octopus. For example, a grid tie inverter and a so-called 'expert' to wire everything up. I think most typical, domestic solar systems work on 48V. My system works at 24v so all my solar controllers would need to be changed. I'd be moving towards 'classic' domestic systems which I think are so expensive, the payback period is too long. A secondary reason for reconnecting to mains electricity again would be easier, occasional use of high power gear such as welding equipment.

zeupater

HertsLad said:

zeupater said:

Re : ".... are vastly more expensive for broadly the same energy storage capacity. What do you think?"

Don't really follow the logic there ... for example, your batteries at £230 for 1280Wh work out at ~18p/Wh whereas some examples below seem to be in a similar ballpark per unit storage and include additional features such as BMS etc .... 

• Pylontech US5000 = £1164/4800  ~24p/Wh
• Fogstar 15.5kWh = £2500/15500  ~16p/Wh
• Seplos assembly kits (eg14.3kWh = £1700/14300 ~12p/Wh

... of course, they'd all need inverters etc, but on a pure unit based storage cost there doesn't seem to be a anything approaching a 'vast' difference ...

I agree I probably went a bit far by using the term 'vast difference' but the battery packs units used for a typical household solar installation are still significantly more expensive per Wh than my latest lithium batteries.

Generic lithium 100AH = £169/1280 is 13p/Wh compared to your figure of 24p/Wh for Pylontech, presumably if you buy the pack yourself for a DIY type installation. It's almost twice as expensive and would become even more expensive, presumably, if the batteries were part of an installation deal by 'accredited' solar installers.

The Fogstar battery is more competitive in terms of cost/Wh but, if the 'entry level' is a 15.5kWh battery, then it's a bit large, and involves shelling out £2500.

All my 100Ah batteries have BMS built in. I also need to add inverters and charge controllers, of course, but there are big savings there, too, compared to the kit used by typical solar installers.

Hi

Smaller capacity Fogstar units start at ~£1050 for 5.12kWh, so ~21p/Wh ... that's a metal unit with integral BMS, display etc ... the Seplos DIY unit is similar in capacity to the original Fogstar mentioned, also comes with metal enclosure (+screen etc) and is still cheaper (per Wh) than the generic 100AH battery you mention .... and, as 'ed110220' mentioned, the Seplos options are priced depending on battery grades, capacities, cycle life expectancy etc .... 

Regarding your batteries having built-in BMS .... do you operate them as a bank or as stand-alone units ... if the former, how are the individual units balanced against each other and what is employed to achieve this .... also, having mentioned that you've expanded capacity, are you mixing batteries of different capacities, makes & age to make-up a single bank (or banks) ? 

Z

Qyburn

HertsLad said:

Qyburn said:. 

From your figures it doesn't make sense. I think one key question is whether you could cover your use 12 months a year without importing. If you can then, as you're implying, the sole reason for a grid connection would be financial.

Sorry, but I don't understand. Taking your first sentence in isolation, which figures don't make sense? 

Maybe I should have said that given your figures, a grid connection doesn't make sense. Financial sense.