Battery Storage And Uk Regulatory Compliance

[sharpener]

Hello all,

I am thinking of adding battery storage to my existing setup to increase self-consumption and provide backup for power cuts. Currently I have 16 x 230W panels feeding 2 + 2 kW StecaGrid inverters installed in 2011.

If I were to add for example a Victron MultiPlus 48/3000/35-50 in their Hub 2 configuration (i.e. the inverter/charger is connected to the incoming grid and the StecaGrids connected to the AC out) what are the regulatory requirements and the implications for my existing MCS certification?

Specifically, do I need to provide external anti-islanding protection or is the transfer switch in the MultiPlus sufficient (the internal earthing relay alteady meets G59)? If the new setup still cannot export more than 16A is the work notifiable to the DNO? Does it need to be done by an MCS contractor? Will it affect my current FIT contract?

All contributions gratefully received!

 

[TedM]

I'm not sure of the exact set-up you are proposing but you would need to ensure that you were not charging the batteries from the grid and then putting the output through your FiT generation meter via your existing inverters.

You should check the terms and conditions in your FiT contract with your electricity supplier to ensure you follow any required notification procedure of changes to your system.

Nothing really to do with the DNO although it would be polite to send them an updated system schematic.

 

[sharpener]

Thanks for that Ted.

Am trying to find a good solution to

1. Maximise self consumption
2. Provide backup for power cuts
3. ideally with island operation so that solar power extends operating time when grid is down.

No, the proposed arrangement would not be able to put energy from the batteries through the solar TGM. It's the Hub 2 configuration on p5 of the following paper (sorry, I haven't found a way to paste their diagram here) http://www.victronenergy.com/upload...ce-with-the-Victron-Energy-Storage-Hub-EN.pdf i.e. the solar inverters (and meter) would be connected on the load side of the battery inverter/charger. So it would be for this latter inverter to determine when grid voltage is present and if not to automatically disconnect it, currently this functionality is provided by the solar inverters as a condition of their G83 approval hence the possible interest of the DNO (lest its personnel be electrocuted by my equipment!)

Confusingly Victron also make a Solarswitch for changing the solar inverters over from grid side to load side of the battery inverter. The brochure http://www.victronenergy.com/upload/documents/Brochure-Solarswitch-SAL064122020-02-1103-EN_web.pdf also says

"In some countries grid impedance measurement is required as an additional safeguard against islanding. The output impedance of the MultiPlus will not match the impedance of the grid. Therefore the grid impedance monitoring function of the grid inverter must be switched off for proper functioning of the system. In countries where grid impedance monitoring is required, an additional grid monitoring module must therefore be inserted betweenthe SolarSwitch and the PV feed-in meter."
which would I think also attract the interest of the DNO, is impedance monitoring a required feature in the UK?

Will follow up with Victron and my FIT contract and post anything of interest back here.