AT the time he led a management buyout of Spark Energy, chief executive Chris Gauld said the financial clout of his institutional backers would enable the firm to double in size in two years.

Given the company was at a scale where revenue was more than £100 million it was a bold claim but customer numbers at rental-sector focused Spark Energy have grown from 250,000 to more than 400,000 in the last two years and with private rentals alone expected to grow 25 per cent in the next five years, to 5.8 million, the potential is significant.

In unveiling plans to increase staff numbers by 40 per cent, Spark is not only prepping for expected growth, but ensuring it is in shape to meet the demands of this growing base.

It has not been a journey without its bumps for Spark. In 2015 the company paid £250,000 to Citizens Advice after an investigation by the energy regulator found it had “failed to treat its customers properly while establishing itself in the marketplace”.

And as Spark grows in size it comes under more scrutiny. In October the company was named as one of six suppliers which allow consumers to build up an average of more than £800 debt before stepping in to help them to pay it back.

The changing shape of the energy market provides companies like Spark with an opportunity for growth which can be sustained through not only prices but exceptional customer service.

As it celebrates the one year anniversary of its on-site training academy in Selkirk, Spark Energy has a platform to grow into a significant player, ensuring its customers are happy remains key to that.