DNO solar limit question

[caliden]

Hi
Ive had 6.8kw solar panels (18x380w) fitted but noticed the max id produce is approx 3.6kw. After much reading Ive discovered the DNO limits and it looks like the max ill get is 3.6kw

Ive had some difficulty researching if theres any way around this? im buying an EV and will be installing a 7kw charger. so my 6.8kw panels + 3kw from the battery "could" easily allow me to charge for free over summer, but with the above limit it appears I would still have to pay 50% of the charging cost (worse since i have the EV tarriff so cheaper night rate but higher date rates).
one way around this is to use the 3pin slow charger (2.3kw) - but ive read this is not ideal for regular use due to various safety concerns

im just wondering if there is a way to use the full power so the car can be charged for free? The car has a setting to force reduce the charging power from the 7kw charger - but even then its about 4.5kw.
I have a luxpower hybrid inverter rated at 7kw DC and 3.6kw AC.
is applying for higher power from the DNO simply a case of fill in a form, tick some boxes, and im good to go?
or is it more like- pay for application, pay for an upgraded inverter, pay for new wiring in the house etc...in which case I guess 3 pin is the only solution!

(zappi is another option but the additional cost vs others....im not sure its worth it)

 

[johnb2713]

Hi
Ive had 6.8kw solar panels (18x380w) fitted but noticed the max id produce is approx 3.6kw. After much reading Ive discovered the DNO limits and it looks like the max ill get is 3.6kw

Ive had some difficulty researching if theres any way around this? im buying an EV and will be installing a 7kw charger. so my 6.8kw panels + 3kw from the battery "could" easily allow me to charge for free over summer, but with the above limit it appears I would still have to pay 50% of the charging cost (worse since i have the EV tarriff so cheaper night rate but higher date rates).
one way around this is to use the 3pin slow charger (2.3kw) - but ive read this is not ideal for regular use due to various safety concerns

im just wondering if there is a way to use the full power so the car can be charged for free? The car has a setting to force reduce the charging power from the 7kw charger - but even then its about 4.5kw.
I have a luxpower hybrid inverter rated at 7kw DC and 3.6kw AC.
is applying for higher power from the DNO simply a case of fill in a form, tick some boxes, and im good to go?
or is it more like- pay for application, pay for an upgraded inverter, pay for new wiring in the house etc...in which case I guess 3 pin is the only solution!

(zappi is another option but the additional cost vs others....im not sure its worth it)

Your inverter size at 3.6 kW is too small INHO. You will have a background current feeding your house that is constant, mine is around 500w, as soon as you switch any 'heavy' appliance on, kettle, washing machine, oven etc you will be importing energy from the grid.
Ideally you need a bigger inverter or an additional inverter installed.
ZAPPI is a good wallbox for working co-operatively with solar. With your EV plugged in ZAPPI in ECO mode will wait until export gets to 1.4kW, it will then start the car charging at 1.4kW, if the export increases it will increase the car charge rate, if grid import starts it will reduce the car charge rate. Mine has just changed from 6.8 kW down to 3.1kW and now back up to 7.2kW after a cloud obscured the sun. You can of course use scheduled times and charge immediately if you so desire. ZAPPI is a good investment and in conjunction with EDDI works really well sorting out hot water and EV charging with excess solar.

 

[binky]

DNO have an obligation to allow 16Amps, which is roughly 3.6kw, backfeed to the grid. You can go over that, with their permission if the grid will allow it, but mostly we fit hybrid inverter with export limitation, so they can't argue with larger inverters and arrays. As there's no feed in tariff anymore, backfeeding the grid is generally best avoided, although some people like to take advantage of smart tariffs offered by the likes of Octopus to help pay for the system - not something I'm a fan of, especially when you have an EV to charge up. Some also charge battery and ev on off peak tariffs which are cheaper. Have a read of some of the other posts on here, there's loads of discussion about that.

Do you actually know what inverter you have, can you post a picture of the label on the side of it. It might be a larger inverter with a lower supply rate for feeding energy the battery.

 

[caliden]

Thanks for the replies!
so if ive understood correctly, I could have a second inverter, therefore max will be 7.2kw, and if I limit the export then I can do this without further permission?
unfortunately I didnt do my research properly prior to buying and this 3.6kw limit wasnt explained by the installers, ive attached a pic of the inverter I have

 

[binky]

Thanks for the replies!
so if ive understood correctly, I could have a second inverter, therefore max will be 7.2kw, and if I limit the export then I can do this without further permission?
unfortunately I didnt do my research properly prior to buying and this 3.6kw limit wasnt explained by the installers, ive attached a pic of the inverter I have

Definitely a 3.6, dumb ass installers! It will spend lots of time bouncing off the stops rather than creating usable power. To top it off, the max battery charge rate is also 3.6kw. Upside is winter performance will be better, but at nearly 50% undersized, it's not good.

 

[Murdoch]

How long ago was it installed?

 

[caliden]

How long ago was it installed?

installed december

 

[Murdoch]

installed december

Complain to them in writing

 

[caliden]

Complain to them in writing

This is what I was thinking, I had briefly spoken to them about it and they said they installed this size inverter as this is the limit required by DNO, so thought id ask here first to understand what my response should be to that and what he should have done
If he did fit a larger inverter, would the inverter automatically limit the export to 3.6kw but allow the house to use more?

 

[johnb2713]

This is what I was thinking, I had briefly spoken to them about it and they said they installed this size inverter as this is the limit required by DNO, so thought id ask here first to understand what my response should be to that and what he should have done
If he did fit a larger inverter, would the inverter automatically limit the export to 3.6kw but allow the house to use more?

Most inverters have an export limit setting where you can adjust the maximum export rate. So if for example a 7.2 kW inverter had been installed, the export limit could be set to 50%.

Locked to prevent being resurrected (again)