Heat Pumps and Electricity Supply – What you Need to Know

The process of adopting a heat pump involves switching from fossil fuels to using electricity to run your heating system. 

Firstly let’s do a little ‘myth-busting’ It’s been claimed that:

A mass roll out of heat pumps will over stretch the grid because they draw a lot of power all the time.

The truth – the electrical ‘requirements’ that must be allowed for are a kind of maximum start up draw.  Confusion can be caused by installers saying to homeowners ‘let it run’ don’t turn it on and off. This advice is correct, but the unit doesn’t run all the time and when it is running it is rarely using anywhere near the ‘start-up’ load being allowed for. The unit will use more power if being asked to continually heat the property up from a low temperature i.e with an on and off thermostatically controlled method (more on that in the chapter Living With a Heat Pump).

District Network Operator (DNO) Required Information

Checking that there is sufficient electricity supply is an important prerequisite of having a heat pump installed.

The person carrying out an initial site visit, heat loss survey etc should ask to look at your electricity supply and take photographs.

The installer should help you provide the relevant details about the electricity demand of the unit they are proposing to install at your property. This will be unfamiliar territory for many homeowners- it is worth asking the Company you intend to use about making this application and satisfying yourself that they have a robust procedure and can support you.

Summarised below is information from the MCS website:

Distribution Network Operators (DNOs) are responsible for delivering the power from transmission networks to the nation’s homes, businesses, and industries. There are 7 DNOs across 14 different districts that handle the distribution of power across the country.  These are listed below:

• Northern Ireland Electricity – https://www.nienetworks.co.uk/home
• SSE – https://www.ssen.co.uk/Home/
• SP Energy Networks – https://www.spenergynetworks.co.uk/
• Electricity Northwest – https://www.enwl.co.uk/
• UK Power Networks – https://www.ukpowernetworks.co.uk/
• Western Power Distribution – https://www.westernpower.co.uk/
• Northern Power Grid – https://www.northernpowergrid.com/

As the deployment of low-carbon technologies increases, it is important that network operators are aware of the number and location of energy assets within their network. DNO notification allows operators to record installation numbers of low-carbon technologies, which is critical for maintaining safe and efficient operation of the electricity network.

If you are planning to install any of the below MCS technologies there is a requirement to inform the network operator of installations. 

• Heat pumps
• Solar PV
• Wind turbines
• Battery storage

You can find out your DNO and how to contact them by using the Energy Network Association’s (ENA) DNO search tool on their website: https://www.energynetworks.org/operating-the-networks/whos-my-network-operator. Just enter your postcode.

Your DNO can also be determined by checking the Meter Point Administration Number (MPAN ) which can be found on your electricity bill. The first two digits (distributor ID) of a property’s MPAN number corresponds to a network operator. The document linked here provides a list of the DNOs according to distributor ID: https://www.energynetworks.org/industry-hub/resource-library/low-carbon-technologies-heat-pump-and-electric-vehicle-network-operator-contacts.pdf

What You Need to do as The Homeowner

Your installer should advise you on their quote if an upgrade to your fuse is needed based on the information they have about the power requirements of the unit they are quoting for. We include a link and explain: “Existing utility supply – 60A fuse cut out will require upgrading ideally to 100A prior to commissioning.” To request this upgrade you would follow this link and click apply: https://www.ukpowernetworks.co.uk/i-already-have-electricity-domestic/adding-more-power/fuse-upgrade

What Your Installer’s (or your) Electrician Needs to do

Each time a heat pump is installed on a premises, the relevant DNO must be informed. However, there are two different connection scenarios.

1. Apply to connect – if a new or upgraded connection is needed

This applies to premises with new Maximum Demand (MD) between 60A and 100A inclusive. In this scenario, a connection must be applied for prior to installation by completing the heat pump connection form. The DNO will subsequently assess the supply capacity within 10 working days – this ties in with the information above where you need to request an upgrade.

2. Connect & notify – if your connection seems adequate for the quoted heat pump unit

This scenario applies to properties with new Maximum Demand (MD) ≤60A and meeting all other relevant requirements. In this scenario, the device(s) can be connected and the DNO should be notified by completing the heat pump connection form within 28 days of the installation. 

Your installer should have determined which connection scenario will apply during their survey visit and informed you in their quote documentation as I have shown above. 

If you are using your own Electrician rather than your heating installer’s Electrician it is important to note that your Electrician will be responsible for informing the DNO of your installation – this is required for compliance with MCS Standards. It is important you assist your heating installer with this by asking your Electrician to comply with this requirement. if they do not normally work on heat pump installations they may not be aware of this.

The process if you already have an EV Charger

If you already have an EV charger there is a slightly different process to follow:

A helpful flow chart produced by the ENA covers the EV charge point and heat pump connection process: https://www.energynetworks.org/industry-hub/resource-library/low-carbon-technologies-combined-installation-process-flow-chart.pdf

The same form for both connection scenarios is used and can be found in the ENA resource library and is linked here: Single Electric Vehicle Charge Points & Heat Pump Installation Application Form

What is the process for notifying a DNO if a heat pump installation is being installed where there is an existing connection?

In scenarios where a heat pump is being installed in a premises with an existing DNO connection electricity supply, your installer can submit the multi-installation application form for heat pumps and EV charging equipment. The form can be accessed via this link: Electric Vehicle Charge Points & Heat Pump Multi-install application form

If the installation meets all the notification criteria (detailed in the form), they will need to notify the relevant DNO within 28 days of installing the new equipment. If the installation does not meet all the notification criteria, your installer must submit an application to the relevant DNO on your behalf, using the form, before connecting new equipment.