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 which is now being employed by a leading northwest electricity utility.

By installing cutting edge ‘voltage controllers’ in primary substations savings to customers in the North West is estimated in the region of £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 primary 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 a network of overhead lines, underground cables and substations
• Reduces costs for all electricity customers
• Can be rolled out on a national level.

The next stage

The CLASS project team since the trials have been developing and approving the new, cutting edge voltage controllers and the next stage now is to roll out these new voltage controllers which are to be installed in up to 260 primary substations across the region which serve nearly 2 million customers.

This will allow ‘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.

How did Acrastyle become involved?

Acrastyle was approached due to our reputation, technical expertise and services that we can offer to the required design and engineering elements required to come up with a design pack which will enable contractors to install and commission the voltage controllers into each substation on the CLASS project.

During the first meeting it was clear that there were going to be a few hurdles that would need to be overcome. Site visits were going to be required for each site as the existing voltage control equipment would need to be reviewed to see how the existing equipment is currently installed and how it would be removed. The existing voltage control equipment would need to be replaced using modified circuit diagrams and wiring diagrams. To achieve this, we would need carry out Drawing modification – Red, Green & Black methodology. To enable the new equipment to be connected to the rest of the substation Interface Engineering would be required as part of the design pack to detail all the required connections.

Existing connections on the left would need interface engineering to connect the voltage control equipment on the right.

During the first sets of site visits that were carried there were instances were existing drawings were either not available, missing or while verifying the drawings on site we found that drawings did not fully reflect the as installed state of the equipment. Substation Drawing Replacement service was required to redraw any missing drawings and Site Surveys & Drawing Audits would be required for each site to make sure all the required information is available to enable us to complete each design pack. The project is expected to be completed by 2021.