What is CLASS?

What is CLASS?

CLASS (Customer Load Active System Services) is a low-cost solution which uses voltage control to manage electricity consumption at peak times.

By installing cutting edge ‘voltage controllers’ in our substations we could save customers in the North West around £100 million over the next 25 years – and £300 million across Great Britain.

During the 12-month trial, the new voltage controllers were installed at 60 substations serving 485,000 people. Detailed research carried out during the trial showed that customers didn’t notice any change in their electricity supply.

This ground-breaking approach can be used to help balance electricity supply and demand for the whole of Great Britain and brings a number of other advantages:

• Makes it easier to adopt low carbon technologies onto the electricity network such as wind and solar power
• Avoids or defers the cost and disruption of expanding our network of overhead lines, underground cables and substations
• Reduces costs for all electricity customers
• Can be rolled out on a national level.

The project was completed in September 2015.

Business as usual

Following a six month extension to the original CLASS project which demonstrated how the technology could be deployed commercially, we are rolling out the CLASS project into our business as usual processes.

Working with our project partner Schneider, we have developed new, cutting edge voltage controllers which are being installed in up to 260 primary substations across the region which serve nearly 2 million customers.

This means we are now able to offer ‘balancing services’ to National Grid which can help to maintain electricity supplies for millions of customers up and down the country and avoid the need for additional expensive sources of power.

CLASS trials

To demonstrate the CLASS approach and to understand if customers were aware of any effect on their electricity supply, we ran four trials on 60 primary substations during 2014. This represents 17% of our network and around 485,000 customers.

• Trial 1: Voltage increment and decrement over one year
• Trial 2: Voltage decrement to achieve a demand response at times of system peak
• Trial 3: Voltage decrement to provide a fast frequency response
• Trial 4: Reactive power absorption to redress high network voltages

Choosing the CLASS trial area

We developed a methodology for choosing the 60 primary substations which serve the trial area. This ensured that the trial area was representative of our geographic area and our different customers.

Find out more about our selection methodology.

Monitoring the CLASS trial area

As part of the trial we collected and analysed a varied and significant amount of data so that we could share our findings with the rest of the industry.

This included information on voltage and power quality so that we could quantify the effects of the CLASS trial on the regional and national electricity networks and our service to customers.

We carefully selected a number of locations across our network to install monitoring equipment to enable us to gather the data we needed.

Find out how we identified our monitoring locations.