Having been marginally involved in warm/coolspace stuff wait for

"I'm sorry but we'd have to put the batteries out to a proper tender if we did that"

"Is the product in question certified for medical usage as our legal team think we might be making a promise of medical suitability"

Posted by: @etchedpixels

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Having been marginally involved in warm/coolspace stuff wait for

"I'm sorry but we'd have to put the batteries out to a proper tender if we did that"

"Is the product in question certified for medical usage as our legal team think we might be making a promise of medical suitability"

 

I suspect you are right.  In our litigiousness society (imported from the USA) it's far safer to do nothing than to do something that has a good chance of having a positive outcome, but may fail.

Every time I hear of someone suing the NHS or a care professional because the outcome of some incident wasn't what they wanted, my suspicions are immediately aroused.  Was it genuinely a failure, or was it an honest judgement based on incomplete (IE real world) evidence which turned out to be wrong, for reasons that are clear only with 20:20 hindsight.  I would be willing to bet that most of the time it's the latter.

Posted by: @jamespa

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Ok so let's start off by saying that anyone who reads the high level blurb and thinks they will get continuity of home electricity supply when the grid fails will be disappointed. 

Bother: that's me! Thank you very much for pointing that out.

I would like a system like this, no hassle, plug and play, but I shall not feed any back to the grid with fancy apps. I would like to use is more or less/mostly off-grid.

Can anyone advise me on alternative systems like this? Or would there be a work-a-round with this Indevolt set-up?

Posted by: @hanno

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Can anyone advise me on alternative systems like this? Or would there be a work-a-round with this Indevolt set-up?

All the plug in systems are required to island for safety so no plug in system will provide power through the sockets into the house with the grid out. Some of the units sold in Germany etc have sockets on the unit itself which continue to operate - and are often also outside of the 800W limit. Thus you plug devices directly into the unit to continue to operate on a grid fail. Some people for example keep them plugged between the fridge and the wall. I don't know if the Indievolt has the feature.

Any system that can keep the house live has to ensure that the house is either connected to the grid or to the local supply (ie your battery, generator, whatever) and it's physically impossible to end up connected to both. That can be done wired in but not plugged in.

Some wired in systems have the functionality built in (eg Sunsynk), others have a limited version of it built in (eg some of the Solis and other kit that supports a couple of sockets of backed up power). For some systems that feature is sold as another add on box - often called a "gateway".

At minimum though, you would need a transfer switch, a suitable grounding arrangement and a generator input if you wanted to use an existing grid forming battery box to power the house by being able to switch between the two. That's not often done in the UK - in part because grid tie has advantages and export rates are good, but it isn't uncommon in the USA for example.

Even with backup your ability to run stuff is usually quite limited. You can't exceed the peak power of your inverter, and if you try and run a lot of stuff you'll either need a very big battery or it'll go flat pretty fast.

Agreed, these plug-in systems are little more that a portable battery into which you may be able to plug in and run your fridge/freezer during a power outage. They are not full home backup systems. If you want full home backup, you really should be looking at something like a Tesla Powerwall 3 (11kW inverter, 13.5kWh battery) and Gateway which starts at around £7k installed. With my Tesla PW3 and solar, I could disconnect from the grid in March and not need to reconnect until October, assuming it didn't rain heavily for 3 days straight in summer.

If you are considering one of these Indevolt systems, I'd also wait to see what Octopus are offering with their 2kW stackable plug-in battery system (a rebranded Fox ESS model). They haven't announced pricing yet, but it's rumoured it may be around £500 at launch which would substantially undercut Indevolt's £799 pre-order pricing.

Posted by: @hanno

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Can anyone advise me on alternative systems like this? Or would there be a work-a-round with this Indevolt set-up?

There won't be a workaround.

I looked in some depth at systems that provide backup and, as others have said, they exist but are high end price wise and don't always power the whole house (so you have to decide up front which circuits will be backed up). 

I decided not to bother and instead to wait for plug in, 90% of the utility for 25% of the cost.  Fortunately power cuts are rare where I live and I already have my network equipment and computer on a ups.

Posted by: @old_scientist

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Agreed, these plug-in systems are little more that a portable battery into which you may be able to plug in and run your fridge/freezer during a power outage

In terms of backup I agree with this assessment.  But for ToU optimisation, storage of excess solar and for a few solar panels they are spot on.  I suspect that is what many people will settle for given the marginal cost of adding a house backup capability.

Certainly for me it's a no brainer, roughly a 3 year payback time at current tarrifs compared to 10 with a fitted battery.  It's not even worth waiting 6 months for prices to drop unless they are likely to drop by 50%.

I wouldn't call Sunsynk high end, at least not price wise but it's got all the backup stuff built in - just add an earth rod and transfer switch (so you can take it out of line if it failed). A 3.6/5kW Sunsynk is about a grand trade and can have 35A on the protected load side (so for many houses everything except a water heater, EV charger and oven). As it'll take standard batteries it's definitely also in the sensible priced end on battery too. Can even support a generator - which is why they are sometimes used on very rural properties, and also why they are so popular in South Africa.

For a lot of people though an Aferiy or Bluetti or similar battery pack between the fridge and the wall is probably all you need, as you can fish it out and charge phones etc off it in an emergency as well. EV people probably don't even need that as you've got V2L on the car for emergencies.

Posted by: @jamespa

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Posted by: @hanno

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Can anyone advise me on alternative systems like this? Or would there be a work-a-round with this Indevolt set-up?

There won't be a workaround.

I looked in some depth at systems that provide backup and, as others have said, they exist but are high end price wise and don't always power the whole house (so you have to decide up front which circuits will be backed up). 

I decided not to bother and instead to wait for plug in, 90% of the utility for 25% of the cost.  Fortunately power cuts are rare where I live and I already have my network equipment and computer on a ups.

 

Posted by: @old_scientist

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Agreed, these plug-in systems are little more that a portable battery into which you may be able to plug in and run your fridge/freezer during a power outage

In terms of backup I agree with this assessment.  But for ToU optimisation, storage of excess solar and for a few solar panels they are spot on.  I suspect that is what many people will settle for given the marginal cost of adding a house backup capability.

Certainly for me it's a no brainer, roughly a 3 year payback time at current tarrifs compared to 10 with a fitted battery.  It's not even worth waiting 6 months for prices to drop unless they are likely to drop by 50%.

I agree, for their target market of renters with no solar, they are great and most will consider full home backup a luxury given the price differential. Before I retired, I worked from home (online) since Covid and can only remember one brief power outage in that time, and for anything pre-planed I could arrange to work in the office.

I'm really interested to see what features are integrated into the Octopus offering, like integration with tariffs such as Agile, or IOF.

Posted by: @old_scientist

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I agree, for their target market of renters with no solar, they are great and most will consider full home backup a luxury given the price differential. 

Maybe I'm a mean git, but given 5k price differential I consider home backup a luxury, even though I could afford it.  

Posted by: @etchedpixels

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I wouldn't call Sunsynk high end, at least not price wise but it's got all the backup stuff built in - just add an earth rod and transfer switch (so you can take it out of line if it failed).

It's not the inverter that's expensive, it's the fitted package with whatever overpriced batteries and various add one the installer insists on including, plus any 'gateway' necessary to make it work in backup mode, plus then subdividing circuits to designated which are backed up.  All this allows the installers to heap on the cost, or in my case it doesn't because I'm buying plug in.

40kWh battery is 3350 trade, inverter is a grand, no gateway nonsense needed so it's about 5 grand in hardware for a 5kW, 40kWh, most of house backup installation plus electrician time - which including splitting the CU won't be cheap for sure.

There is basically a size point at which the vastly lower prices for the battery per kWh, the better inverter power and so on makes it work versus things like plug in when we get it next year for batteries. Much the same as solar - there's a fixed cost element that vanishes in a large install but doesn't in a small one.

But then if you blunder into a "package" without having done research you will get fleeced. You only have to look at all the people pushing high end product tied to vendor specific batteries, pretty much none of whom when challenged can explain why it's actually "better" than the basic stuff. A lot of the UK solar/battery/inverter market is powered by ignorance and opportunity.

Posted by: @jamespa

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Posted by: @old_scientist

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I agree, for their target market of renters with no solar, they are great and most will consider full home backup a luxury given the price differential. 

Maybe I'm a mean git, but given 5k price differential I consider home backup a luxury, even though I could afford it.  

Not at all. Many people simply won't need home backup. We don't need it. It is nice to have, but that is not the reason I bought a Tesla Powerwall. Full home backup was simply in the nice to have bonus feature column. We needed the larger capacity, outdoor IP weather rating and cold weather performance and access to the highly lucrative IOF tariff, for which only four brands were approved at the time (which allows us to achieve net zero annual costs as well as being net zero in our annual generation and consumption).

Posted by: @etchedpixels

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But then if you blunder into a "package" without having done research you will get fleeced. You only have to look at all the people pushing high end product tied to vendor specific batteries, pretty much none of whom when challenged can explain why it's actually "better" than the basic stuff. A lot of the UK solar/battery/inverter market is powered by ignorance and opportunity.

All understood, but if you want it installed 'professionally'  there doesn't currently appear to be a choice, at least not where I am.  There is clearly a large margin being made. 

Hopefully the advent of plug in will force prices down to something more reasonable, which is presumably why the industry tried so hard to block it with their un-evidenced scare stories.