Over the last couple of weeks, I've been travelling the length and breadth of Scotland talking to colleagues about the future opportunities for our transmission business.

Last Thursday evening, I had the chance to pause for a few hours to attend the Scottish Green Energy Awards in Edinburgh which are organised every year by Scottish Renewables. During the evening, the Beauly-Denny project was recognised with a special Judges Award for its critical contribution to the success of renewable energy in the north of Scotland.

It's almost a year since the full length of the Beauly-Denny line was energised successfully, marking the culmination of more than a decade of work by a cast of hundreds. The achievement is a tribute to everyone who took the project from its earliest days on the drawing board, through the consenting process - and ultimately to its construction. It was the site team, working alongside our principal contractor Balfour Beatty, who took the line over the 2,526ft summit of the Corrieyairack Pass, working through the winters of 2013/14 and 2014/15 to achieve energisation. Their work continues to wrap up final mitigation activity, not least the removal of transmission towers from Cairngorms National Park, which will leave a lasting positive legacy on one of Scotland's most valuable natural landscapes.

Beauly-Denny was a landmark project for our business, but the award reflects its significance for the country as a whole. At 220km, it spans Scotland from the Highlands to the Central Belt. It was the first and the most critical piece of a jigsaw which is still coming together across the north of Scotland today. By the end of 2015, almost 1,500MW of additional renewable generation development had already been enabled. Today, the total generation figure has more than doubled from its pre Beauly-Denny level with over 4,000MW now connected. By the end of 2018, helped by further major projects like Caithness-Moray, that figure is expected to rise beyond 5,500MW.

This has been an extraordinary period of growth by any standard � and it has taken a transformative investment in our transmission network to make it possible. In the space of less than 4 years since the start of our current price control, the asset value of our network has risen by over 150%. Our transmission business is expected to go from being by some distance the smallest of Great Britain's 26 electricity and gas networks in 2010 to being the fifth biggest by 2020.

That work is far from finished and, alongside our supply chain, we continue to apply the lessons from Beauly-Denny to our work to deliver projects from Kintyre to Caithness. As a provider of essential infrastructure, we have to strive to deliver reliability and value for energy consumers; but as a responsible developer we also need to show care for the environment where we are working and to build constructive relationships with local communities and other stakeholders.

Looking further ahead, we have built a firm foundation for the future. Early next year, the second annual publication of National Grid's Network Options Assessment will seek to chart out the anticipated needs of the electricity transmission system across Great Britain. That process will be repeated annually to take account of the fast-changing energy landscape which we operate within.

The constant in all of this is our customers. Operating our expanded network reliably is our most fundamental responsibility. With almost 4,500km of cables and wires transmitting power to customers in the north of Scotland and beyond, that responsibility has never been greater and it will bring new challenges that we are already working to meet.

The network we inherited was built, first and foremost, to bring reliable electricity supplies to communities the length and breadth of the north of Scotland. I am proud that Beauly-Denny is at the heart of a new chapter in the north's energy story, unlocking economic potential and transporting low carbon electricity efficiently in our network area and beyond.