However, if in 1965 you’d been standing on the banks of the River Thames, just downstream of the Dartford Crossing, you would have seen something equally significant if slightly less exciting. A pair of 190m tall electricity pylons being assembled to take power across the Thames. This crossing was part of what would become a two decade long period of intense activity by the Central Electricity Generating Board (CEGB) to build the Electrical Transmission Supergrid.
Over half a century later, and we are now in an age of mobile phones and Alexa (although sadly no warp cores but who knows, give Elon Musk time). Some things though, haven’t changed, you can still head down to the Dartford Crossing and see the same pylons carrying power across the Thames. We still rely on over 4,000 miles of electricity transmission line built by the CEGB to power our modern world. However, the world has changed greatly in the last five decades and the Supergrid we rely on, now faces numerous challenges if it is to support our needs for another fifty years.
The first challenge is age. Some of the UK’s oldest electricity lines were built in the 1930’s, and many run through remote and exposed landscapes. Nothing lasts forever and even diligent maintenance and refurbishment can only extend the life of a steel structure so far. Many structures are reaching the end of their lives.
The problem of age is compounded by the second challenge of increasing demand. Our appetite for electricity is ever increasing and will only increase further if the government’s plans to replace out petrol and diesel cars with electric cars succeed. To meet this demand, our electricity lines will need to carry more power than ever envisaged by their designers.
Our third consideration is generation. Gone is the era of large coal fired power-stations sitting at the centre of sprawling web of power lines. An increasing amount of power is generated by small gas fired plants, widely distributed windfarms and interconnectors to our neighbours in Europe. The current Supergird wasn’t arranged for the decentralised structure that is evolving in the UK generation market.
Finally we must consider climate change. Much has been written on the subject and whilst projections vary, it seems very likely the UK is heading for a wetter, warmer and windier future. How this will impact on the thousands of miles of existing powerlines up and down the country is difficult to predict but the risk cannot be ignored.
These challenges suggest that in the not too distant future, the engineers of today will, like their predecessors, have to turn their talents to building a new electrical grid fit not only for today but also tomorrow. Add in the potential of ‘smart’ technologies and the necessary roll out of electrical car infrastructure and we could be looking at electrical infrastructure investment programme to rival the creation of the Supergrid.
Which leaves one final challenge. How are we going to pay for it? The situation at Hinckley Point C has shown the challenge of attracting private investment for infrastructure that may not offer a return for decades. Two things are however certain, the future of the country depends on our ability to meet these challenges and it probably won’t be Mexico paying for it.
This blog has been written by Stuart Flint, WSP Senior Engineer
