Will a solar pv system that is grid-tied work during a power cut

+Sid · Nov 26, 2022

Hi,

I looked into installing a solar photovoltaic system 15 years or more ago and decided against it for cost/benefit reasons. I'm now taking another look and am finding that getting to grips with the details a challenge.

I can see how energy that is generated during the day can be used to power appliances and that any excess can be used to charge a battery and how any extra energy after that can be fed int the grid for which you get paid. I know that it's not a lot but even if it's enough to pay the daily standing charge at least it's something.

But what happens when there is a power cut - which for us happens more frequently than we would like. My questions are:

1. Will the electricity generated by the solar panels no longer be useable since the inverter is powered from the grid?

2. Can the power that is stored in the battery be utilised on all the domestic circuits?

These may seem like dumb questions, and I apologise if they are, but I am loath to fork out a shed load of money only to find that I am still at the mercy of the Energy Companies?

johnb2713 · Nov 26, 2022

+Sid said:
Hi,

I looked into installing a solar photovoltaic system 15 years or more ago and decided against it for cost/benefit reasons. I'm now taking another look and am finding that getting to grips with the details a challenge.

I can see how energy that is generated during the day can be used to power appliances and that any excess can be used to charge a battery and how any extra energy after that can be fed int the grid for which you get paid. I know that it's not a lot but even if it's enough to pay the daily standing charge at least it's something.

But what happens when there is a power cut - which for us happens more frequently than we would like. My questions are:

1. Will the electricity generated by the solar panels no longer be useable since the inverter is powered from the grid?

2. Can the power that is stored in the battery be utilised on all the domestic circuits?

These may seem like dumb questions, and I apologise if they are, but I am loath to fork out a shed load of money only to find that I am still at the mercy of the Energy Companies?

The short answer is no, it wont.

Most inverters have another output usually termed emergency supply or backup, this output does provide power in absence of a grid supply. People normally have it wired to an 'essentials' circuit eg fridge, freezer, heating and lighting or to a 13amp socket that can then be used to power a boiler and some other appliances. It is possible to make it automatically switch over the supply to this output for the whole house in absence of the grid supply but thats for another thread.