Solar Panels – DNO, Zero Export and Regulations

theoldmiser

[Deleted User] said:

Reed_Richards said:

It used to be said that when a popular TV show was over there was a spike in electricity demand as many people who had been watching TV then put the kettle on.  I wonder how the number of people with solar panels compares with the number of thirsty TV watchers?  Can the DNO perceive a sunny day because of a drop in the normal level of demand around the middle of the day?  

This is not a DNO issue so much, however shock loads can trip sub stations. Managing network loading is down to National Grid who do an absolutely amazing job of keeping our Gas and Electricity available to us.

'National Grid' IS a DNO...

https://www.nationalgrid.co.uk/  "Western Power Distribution is now called National Grid"

I was surprised to find this out too. I always thought 'The National Grid' was 'the national grid', but now 'National Grid' is just another DNO.

theoldmiser

[Deleted User] said:

ispookie666 said:

I do not see what is incorrect in what MCS have said - their members are installing the panels and the inverter manufacturer has obtained required certification. At times the DNO might want to check the export limitations on site. 

Exporting power to the grid might help my service provider (SEG/FiT) add to this lower transmission losses. I'm yet to see a street where every house is full off solar panels ☺️.

Like I said previously the panels themselves do not connect directly to the DNO infrastructure the issue is one for the panel manufacturer. They want a competent install of their their panels which MCS provides if their their guarantee is to be protected.

Zero-export is different because it is so highly scaleable second hand panels may be used in a way that does not happen with SEG/FIT as these are usually lots of new panels to maximise output with a need to last for decades.

In parts of the world like the US, Philippines and Hawaii export to a pole transformer would damage it leaving the DNO with costly repairs so they do NOT allow exports to grid. You will however see streets full of zero-export installs and with panels of dubious origin but nevertheless affordable even in the poorest of neighbourhoods.

You are quite right about inverter certification. It is the inverter that protects DNO infrastructure wherever they are installed in the world not the panels themselves. As solar power matures more and more used panels become available and at an affordable cost. The requirement is not to export as much power as possible to maximise earnings it is quite simply to provide power for self consumption with power to spare. The needs of SEG/FIT and zero-export are quite different in these respects.

I don't see why the solar panels are the issue at all - it's the inverter(s) that control how much power goes into the house and back to the grid (if exporting). Solar panels cannot be a problem for the DNO, it's the INVERTERS that need to be G98, G99 or G100 compliant. How on Earth can some secondhand solar panels magically produce some sort of magic electricity that somehow gets around the inverter and into the grid?

Solar panels give out a known range of voltages and currents, according to their specifications. You have to use an inverter or inverters that are able to cope with that range of voltages and currents, especially to cope with the maximum possible voltage that the string of solar panels can give out.

5kWh Dyness batteries are now available for £985 from BimbleSolar (January 2024), this is unprecentedly cheap, and two batteries will allow most households to get through the night with no problems (if the batteries have managed to be fully charged during the day).

Qyburn

theoldmiser said:

Even QrizB didn't notice that part... LOL. And he seemed reluctant to explain what his supplier did with the electricity that he exports - LOL again. He says "My supplier does nothing in particular with it." 

I don't think the supplier will see the export at all, except as a reduction in their customers' consumption. At a local level the DNO might, if a particular local area has enough embedded generation.

I don't know if anyone has an figures to support or refute either.

Last time i actually spoke to a DNO guy on the matter he said they don't consider the affect on their network at all when assessing a microgeneration application. But that was rural, it might be different in say a new housing estate. 

[Deleted User]

You might be interested to learn that the role of MCS is accomodating change which will happen sometime soon. Their website article MCS Scheme Redevelopment: Consultation Outcome describes the journey undertaken.Please take the time to read about what they are hoping to acheive it as it does affect Solar Installs with the prospect of them taking on retrospective approval of non MCS existing installs.