Power grid pylons- more or less?

 The UK power grid will need upgrading as it tries to take on heat pump power demand and electric vehicle battery charging loads. And on the supply side, new grid links are needed around the country to link to new wind projects – including those in sensitive areas like the Highland of Scotland.  There’s also a need for new links across East Anglia to carry power from its offshore wind projects and from the proposed Sizewell C nuclear plant on the Suffolk coast to the rest of the country. It’s the same in some other parts of the country- new power links will be needed 

However, there has been strong opposition to new pylons in most places. In some locations it may be possibly to put power grids underground, but although views are changing (for example, given their possible role in starting wild fires) overhead cables have usually been strongly favoured. They can carry more power at higher voltages and, crucially, burying grid cables safely is a very expensive option. Typically the cost of constructing a high voltage underground transmission line varies from four times to more than 10 times the cost of an overhead transmission line. So except in cities (where there may be no choice), and in very sensitive rural areas, it’s probably not likely to happen, at least not extensively.  

We can redesign pylons to look more attractive, as (hopefully!) with the UK’s new T-shaped design. In another ameliorative response, there has been talk of offering local compensation payments. Another more radical response is to promote local wind and solar power, rather than giant offshore wind and nuclear projects. That would supply some power locally without the need for new grids, but not as much of it and it would not be able to make a national contribution. There would also need to be more local backup via storage or other supply, and for more capacity overall than would otherwise be required to meet average demand. So the overall package would be more expensive and possibly have a larger eco-impact. 

So, there are big issues with total decentralization and some hard choices to make about how the countryside should look.  Even with a lot of local storage, for viable round the clock and round the year operation, in most places some green power will have to be imported (and exported) at times, via grid links, not least to balance local variations in supply and demand. That might even include international links and trading- via long distance  HVDC supergrids. So lots of grids of various types.  

Of course we can and do also shift energy via gas and heat in pipes underground, and, once installed, they are arguably much less invasive than pylons. And for some purposes, and in some locations, that can be the best option, with gasses (e.g. green hydrogen) and heat being much easier to store in bulk and for long periods than power. Gasses can also be transmitted long distances with very low energy losses, unlike power, and heat can also be shifted over several kilometers in insulated hot water or steam pipes. 

However, with some exceptions, for good or ill, pipes are out of favour, with the trend these days being mostly towards an all-electric future, with that being seen as more controllable – enabling us to switch synchronous power around the county rapidly.  So you can perhaps see why, if you don’t like power grids, then, despite their prospectively high costs, you might look to micro nuclear projects as a ‘local’ solution, especially in isolated areas, with perhaps a small local grid. But then would local residents be happy to live near to the reactors? And who would deal with their wastes? And provide security against theft or the misuse of  nuclear material? 

Fortunately though, some green energy analysts have argued, we don’t have to adopt such extreme high tech measures, or face their unknown risks. They say we can and should go for a mix of mostly local renewables, with roof-top solar being the most obvious, along with some local storage (e.g. modern battery systems) and also focus of using the power they offer more efficiently, seeking to cut demand. That’s maybe socially attractive, but whether it’s technical and economic viability is debateable – for one thing it depends on location. Not everywhere will have good local green power resources, or significant long-duration energy storage options. So, to maintain security of supply, it may still be necessary to import power from some large offshore wind projects as well maybe as wave and tidal schemes. And to have  links to some large (and often geographically determined) longer-term energy storage facilities (e.g. pumped hydro and cavern storage of green gas) using surplus green power to ensure overall system balancing when local green power availability is low and demand high  Which means some more grids. But, as a matter of principle, we could nevertheless decide to aim for the maximum of green power decentralisation, commensurate with reasonable local economic returns and national level system stability. 

Of course, that’s essentially a political choice and that’s inevitable given there we are talking about key technology frameworks and major infrastructure. People and Nature recently ran a fascinating two part overview of energy policy, with Part II focusing of some of the political issues facing supporters of green power decentralisation.  Others may insist on maximum economic growth and will argue that this will come by investing in the larger scale technologies and also that this may be the fastest way to decarbonise. For example a recent critical study of degrowth arguments came up with some controversial conclusions. It said that ‘two main decarbonization pathways appear as possible. A low- or degrowth, slower but more fundamental transition, or a growth based, forceful and fast transition. The first risks to be too slow to avoid climate disaster or have intolerable social consequences, the second risks to be undermined by further economic growth’. The author says they find ‘the second more realistic and more likely to happen, and therefore worth fighting for, well aware of the likelihood for new contradictions between growth and environmental impacts to await down the road’. 

I’m not sure I agree with this portrayal of low growth as being ‘slow’, whereas  high-tech profit-led growth mania certainly can have real eco and social problems- and fast! But it is true that a purist zero-growth line can also have its problems. In the extreme it may be about resisting change. Some changes have to happen- and that may involve a few more grids!  And as a recent UKERC blog notes, then some  of the key strategic issues will be grid power curtailment and flexibility. Grids may be expensive and invasive, but they can help balance variable supply and demand and avoid losses due to congestion. Like them or loath them, they are not going to go away.