Backup plan

In the context of the great energy debate concepts like ‘grid efficiency’, ‘demand-side management (DSM)’ and ‘infrastructure modernization’ can appear a little abstract and hard-to-sell politically when compared with shiny solar cells and spinning turbines.

But the experts have long recognised the importance of the former set of initiatives and their necessity to make the latter a viable reality. 

Part of the problem is lack of communication and broad assumptions of knowledge in discussions, so let’s first address some basics. The simplest aim is to reduce energy use at times of peak demand.

Traditionally at peak times the National Grid has switched on back-up power stations. In fact around 10% of electricity in the UK is produced by these peak power stations, which are more expensive and carbon-intensive than the regular ‘baseload’ plants. What’s more there may actually be a greater need to rely on them with the introduction of renewable energy, which is more ‘peaky’ and intermittent.

And so DSM is a way to curb peak demand with relatively simple measures. Already quite a developed industry has sprung up around DSM in the US – with various schemes and robust technologies in place – but it’s still somewhat lagging behind in the UK. Nevertheless, there have been some promising signs recently.

This week the first trial of a DSM system where companies are paid to turn off non-essential systems at peak times got under way in the North East.

Network Revolution, delivered by Northern Power Grid (NPG) is part of Ofgem’s £50m Low Carbon Networks Fund (LCNF) – a project to explore the feasibility of a national smart grid.

It will cover 15,000 homes and businesses who will be paid for units of energy that they do not use (sometimes called ‘negawatts’). At a practical level this means shedding energy demand such as lighting and heating in vacant areas and installing free energy management equipment. Consultancy KiWi Power will act as a go-between for participants and NPG. 

Also this week Southern Energy Power Distribution (SSEPD) and Honeywell, a US-based DSM specialist, announced the launch of a smart grid pilot project west of London near Bracknell. 

As part of the £30million New Thames Valley Vision (NTVV) project it will install automated demand response (Auto DR) technology in selected facilities.

The project builds on a successful Auto DR demonstration in Bracknell where Honeywell showed that a commercial building could quickly shed up to 45% of its electrical load during peak hours.

The full-scale project ultimately aims to give the local smart grid the ability to shave approximately 10MW of energy use when necessary.

The technology centers around a demand response automation server (DRAS) which alerts business customers when energy use is expected to peak and create grid congestion. At each facility, a framework-based controller automates load-shedding strategies during these periods. The controller listens for signals from the DRAS and communicates with the building management system, which then makes short-term changes based on parameters the customer sets in advance  e.g., turning off banks of lights or elevators, or cycling equipment on and off.

While this is all encouraging stuff, DSM is actually a rather small part of the puzzle.

On Monday Ofgem said that it has earmarked £7 billion for Scotland’s high voltage network by 2021, as part of a wider re-wiring project in Britain to replace ageing infrastructure.

It was a timely announcement, coinciding with a report by the Renewable Energy Foundation (REF; a charity with a history of scepticism of wind power it must be said) on Wednesday showing that the that National Grid paid £12.8m to wind farm operators last year to compensate them for having to switch off their turbines when the grid was overloaded. The Farr Wind Farm, near Inverness which has 40 turbines and is operated by nPower renewables, received the highest payment, of around £2.3m.

It’s helpful to look at the example of Germany here, which after phasing-out nuclear power in 2022 aims to go 100% renewable by 2050. Last week I spoke with a German engineer Dr Wilfried Goldacker who is researching grid technologies at the Karlsruhe Institute of Technology (KIT).

‘In Germany we have severe problems with our wind-energy generation in the North sea and Baltic sea — we need 8,000 to 10,000km of transmission lines to bring energy down to the centre to industrial areas and about one quarter of the wind energy cannot be fed into the grid because of instability, and we fear in Germany that we need more than 10 years to extend the grid and prepare for the upcoming increase in wind-power generation,’ he told The Engineer.

KIT along with RWE Deutschland and Nexans, recently launched the ‘AmpaCity’ project to highlight the advantages of superconductor technology in grid systems. In terms of renewable-energy generation, using superconducting current limiters and cables could create a more stable overall grid design.

The first stage of the project was to replace a 1km-long high-voltage cable connecting two transformer stations in the Ruhr city of Essen with a three-phase, concentric superconducting 10kV cable designed for a transmission capacity of 40MW.

So the bottom line is let’s not blindly march into enormous renewable schemes without first having the means to properly support them. The danger is that the generating technologies, though perfectly viable, are made to look ineffectual by a sub-standard grid set up and are effectively still-born.