Energy plans place costly burden on power networks

A timely reminder about how much strain our energy networks can be put under was provided by David Clarke, Energy Technologies Institute chief executive, when he gave the Bridge Lecture last week. He noted (see news story, page 4) that domestic gas usage can increase sixfold between summer and winter.

It’s a key reminder for future energy scenarios. In some of these, electri­city eventually bears much of the burden of domestic heating, but as Clarke pointed out, the cost of providing a network that could accommodate such a wholesale shift would be prohibitive. Electric heating could viably be installed, he said, only in new developments where the electricity network could be sized accordingly.
Clarke’s lecture came as climate change minister Greg Barker announced ambitious new targets for photovoltaic (PV) installations in the UK. By 2020, Barker said, he wants to see 22GW of PV. In simple capacity figures, that’s not far off the average 30GW or so that we currently draw on in the summer. But capacity does not reflect actual use. In practice, that solar power will spill on to the system during summer days and disappear during the long, cold winter nights. Therefore it will have to be stored.
Are electric cars a storage solution? The couple of thousand vehicles on the roads today could turn into 100,000 by 2020 and could be charged using the solar surplus. It’s possible. But it doesn’t make the network issues go away.
PV, electric cars and electric heating will inevitably result in a huge number of new suppliers accessing the distribution networks, and a large number of new or bigger demand points. The usage – from both the supply and demand side – will not just be much bigger, but will have a less forgiving profile.
We will need a new electricity distribution network.
Distribution network operators are keen to evolve their networks. They have seed funding, from Ofgem’s Low Carbon Networks Fund, to research innovative ways of managing their networks. They have investigated new ways of introducing flexibility, such as interruptible or variable contracts. And they will take the opportunities offered by smart meters and the smart grid to use price signals to manage demand.
This is all helpful in managing the system, but it doesn’t address the fundamental issue. The volume being managed is going to be many times bigger than it is now, and in the end the networks under all our streets will have to be sized to carry it.
Clarke estimates the cost of replacing the distribution network, like-for-like in its current form, at £95 billion. But to upgrade the network for electric vehicles, PV and the rest, you have to talk multiples of that – and that’s before we start to think about the disruption, the streetworks (and let’s not forget the cost of permitting and lane rental). Nor can we spread that cost too far – not with all our targets converging on 2020.
The challenge of strengthening the transmission network for renewables is often given space in the media. But the cost and difficulty of remaking the electricity distribution networks, which will be much greater, is rarely afforded many column inches. We had better start facing that uncomfortable reality, and taking it into account in our planning.
Janet Wood

This article first appeared in Utility Week’s print edition of 17 February 2012.
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