Posted by: @dansus

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Hi, can you remind me how to enable 3kW feed in when grid tied, do we need base unit plus two batteries? 

Posted by: @indevolt-tech

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Under existing ENA G98 rules, any battery system capable of grid discharge—whether throttled to 800W or operating at full 3.68kW—is classed as a grid-tied energy storage system. There is currently no special exemption under BS 7671 that treats an 800W battery discharge differently from a 3kW battery discharge when connected to home wiring. Both require standard G98 notification and BS 7671 compliance.

Not interested in a plug in device, or 800w. Just need to know from a hardware standpoint, what system config do I need to make sure I can feed in 3kW from this unit if i purchase it @indevolt-tech 

Obviously, it will be installed by a qualified solar electrician, and G98 submitted. 

@dansus 
To achieve a full 3kW (3000W / 13A) continuous AC feed-in into your home grid, you will need equip 1× PowerFlex 3000 and at least 1× Extra Battery module (e.g., PFA4000) (or 2× Extra Batteries for optimal storage capacity and battery lifespan).

Operating at a continuous 3000W output requires the discharge C-rate supported by adding at least one expansion battery pack. A single standalone base unit operates at a lower continuous output limit.

Once your electrician has completed the fixed AC installation (via a dedicated CU circuit / switched isolator):

1. Open the Indevolt App during initial system commissioning.
2. Select "Fixed Grid-Tied / Hardwired Mode".
3. Accept the in-app Compliance Disclaimer confirming that the system is hardwired according to BS 7671 and registered under G98.
4. The firmware will immediately unlock the full 3000W AC grid feed-in limit.

Hope this gives you the exact hardware list you need for your pre-order! Feel free to ask if you need any further specs for your electrician!

Posted by: @indevolt-tech

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Hope this gives you the exact hardware list you need for your pre-order! Feel free to ask if you need any further specs for your electrician!

This is very helpful, thank you. 

@transparent

I seem to recall that you may have suggested that, provided an appropriately registered electrician installs and certifies the circuit up to a suitable breaker, the final connection to the inverter can be made by a reasonably competent householder.  From my reading of Part P it is possible to infer that, the installation of the new circuit either requires a competent person or is notifiable under building regs, connecting up the inverter if done separately (unless its in a 'special location') is not at least to my reading.  Can you clarify your interpretation/correct my memory please?  G9x is separate of course, Im not asking about that just about the electrical installation itself.

Posted by: @jamespa

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I seem to recall that you may have suggested that, provided an appropriately registered electrician installs and certifies the circuit up to a suitable breaker, the final connection to the inverter can be made by a reasonably competent householder.

That depends on the inverter. Some require hard-wired 240v AC connections, whereas others have a plug & socket for the mains input.

Indevolt are using a circular 3-pin connector for grid input/output. If the electrician has installed a switched fused-spur and connected the Indevolt flying lead to it, then that's all that would be covered by his Part-P certificate.

Customers should be paying greater attention to the PV panel inputs rather than thinking that it's only the mains which can bite! There are no regulations to prohibit end-users from connecting MC4 plugs and sockets. But a typical solar panel might be outputting 40-50v DC (open circuit), depending on the model. Although the Indevolt Powerflex specification states 11v-60v for each MPPT connection, I can foresee people trying to put two in series.

Unlike AC electricity, the human body doesn't have a reflex action to a DC shock. It's rather like the DC connector 'sticks' to the skin.

This is another of those areas where the public have insufficient knowledge of energy matters to understand what is and isn't safe.

Posted by: @transparent

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Indevolt are using a circular 3-pin connector for grid input/output. If the electrician has installed a switched fused-spur and connected the Indevolt flying lead to it, then that's all that would be covered by his Part-P certificate.

Thanks, however that's an answer to a subtly different question.  What, in your view, is the situation if the electrician does wiring up to a breaker (other than in a "special place") certifies, and leaves?  To my reading Part P requires any connection of equipment (eg an inverter) to the breaker to be safe, but it does not require it to be done by a 'competent person' (in the technical sense) or notified.

Just wondering what we currently think may be good options for battery plugin in the uk. Just a simple system with a ct clamp and looking for a low £/kwh. 

I saw some around £370/kwh. Some of these systems are modular, like in 2kwh boxes. 

@batpred Plug in batteries are not yet legal so maybe best to hang on until they are if you want to be certain of compliance

Posted by: @batpred

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wondering what we currently think may be good options for battery plugin in the uk. Just a simple system with a ct clamp and looking for a low £/kwh. 

... and you're aware that Plug-in Storage is not yet permitted in the UK ?

You can buy such a unit, but it would need to be hardwired by a qualified electrician.
It's not OK to fit a 13A square-pin plug and connect it via a wall socket.

See this other discussion topic on battery storage without solar. There I provide an illustration of how the requirement for hard-wiring can be satisfied using a fused-switched-spur outlet.

The problem with giving an answer to your question is that there isn't yet an agreed definition of what might be classed as a plug-in battery when the Government does make it legal.

It may or may not be limited to an output not exceeding 800w, which is the limit presently applied to plug-in solar.

But there could be further constraints in order to provide a better safety margin for current being injected into an existing ring-main.

Government will need to consider dwellings which have already purchased the two plug-in solar kits which are permitted by law. How should a plug-in storage device 'decide' whether it is sharing the same ring-main as those two existing plug-in solar inverters?

Will there be a need for software to prevent three plug-in kits exporting at 800w simultaneously?

There's a lot to consider, quite apart from cost per kWh

Posted by: @transparent

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... and you're aware that Plug-in Storage is not yet permitted in the UK ?

You can buy such a unit, but it would need to be hardwired by a qualified electrician.
It's not OK to fit a 13A square-pin plug and connect it via a wall socket.

See this other discussion topic on battery storage without solar. There I provide an illustration of how the requirement for hard-wiring can be satisfied using a fused-switched-spur outlet.

To be honest, I was not sure about the status. I see that the approved solar DIY is without energy storage.. 

I will take a look at the link, thanks for sharing. 

It would be useful to understand what kit currently being sold for electrician install is likely to be best for DIY (once that is approved). 

I've got a podcast recording scheduled this week where we're going to tackle where plug-in batteries are and what's likely to happen to them in the UK from a regulation perspective.