We didn’t, but, my goodness, we do now.
DNO stands for Distribution Network Operator – your DNO is the company responsible for delivering electricity to your property. They manage and maintain the wires, transformers and all the other infrastructure needed to deliver electrical power to end-users. You can find out who your DNO is here: https://www.energynetworks.org/customers/find-my-network-operator
Your DNO needs to know if you are installing solar panels, a heat pump, a battery or even an EV charge point. The installer should do it but it’s your responsibility so you need to make sure.
When our solar panels were installed one of the many bits of paper supplied by the installers afterwards was ‘proof of DNO notification’ – a letter from the DNO saying it was OK to connect up the new equipment to their network. The letter may contain conditions, for example the following is taken from the DNO letter about our Solar panels.
“You may connect the micro generation unit to our distribution system providing it complies with: National Engineering Recommendation G98/1-3 entitled: Requirements for the connection of Fully Tested Small-scale Micro-generators (up to and including 16A per phase) in parallel with public Low Voltage Distribution Networks on or after 27 April 2019.”
It’s not mindless bureaucracy or red tape – all the above devices can significantly change the amount of power used by your home – batteries and solar can even export power. The DNO needs to be able to plan and manage their network to cope with the changed demand.
Everything worked fine for the heat pump installation – the proof of DNO notification turned up with all the paperwork after installation. Chatting to the heat pump engineer he told me that EV charge points also require DNO notification. Ours had been installed 6 months earlier and we hadn’t received anything.
Took another 9 months to get it sorted with Pod Point but eventually they did what they should have done right at the start.
What happens if you don’t have proof of notification? Probably nothing until you come to sell your house. The purchaser’s solicitor is going to want to see that all the rules have been followed. If you don’t have proof of notification then at minimum it’s extra hassle at time when you really don’t need it. Could also cause extra costs if the purchasers insist on you paying for an indemnity policy to insure against any issues arising in future.