Baseload or baseless: Does the UK really need 'always on' generation?

By Richard Black, ECIU Director

Of the many statements that Energy and Climate Change Secretary Amber Rudd has made this week, the one with the most profound implications is probably one that appears pretty uncontroversial: ‘We have to secure baseload electricity’.

Ms Rudd was defending the government’s intention to give the proposed Hinkley C nuclear power station financial support until 2058 while insisting that most renewables be subsidy-free kinda now.

That we need nuclear, coal or maybe gas-fired stations chugging away 24 hours a day, 365 days a year (except for maintenance) is a commonly held belief, certainly among British politicians and media commentators.

I used to assume it was true too. Now, I’m not so sure.

Last week the Energy & Climate Intelligence Unit hosted a public event at which we saw a very different vision of an electricity network put forward by a German expert, Malte Jansen, from the Fraunhofer Institute in Kassel.

His project is called Kombikraftwerk. It has nothing to do with evolving electro-pop bands from the 70s, and everything to do with modeling the energy systems of the future, particularly as Germany pursues its own 100% renewables goal.

Kombikraftwerk is an evidence-based simulation of how the German grid might run at some point in the future on 100% renewables.

It uses real-world data on when and how much the wind blows and the sun shines, how much biogas can be generated and stored for winter use, how demand varies across the day and the year, and so on. It uses real-world data on factors such as available land to forecast how much wind and solar capacity is likely to be built in which areas of the country, and how the regions can be linked together.

As time runs forward in their simulation, electricity comes into the grid from various sources – onshore and offshore wind, solar PV, biogas plants, hydro dams, and so on. Power flows between different regions of the country, and over the national border in both directions.

When demand exceeds supply, non-essential demand is reduced and backup storage systems activated. When supply exceeds demand, the spare power is used for things like producing hydrogen for use later on or for heating, or is exported.

The exact solution for any given situation is largely worked out by the market: wind and solar power take precedence when they're generating because they produce basically free electricity, and other supply- or demand-side measures come in depending on price. Smart technology oils the decision-making wheels.

The level of detail in Kombikraftwerk goes far deeper than just how much electricity there is, probing detailed issues of concern to engineers such as how precisely the frequency in the grid is controlled.

And, in the simulation, it works.

The Kombikraftwerk boffins aren’t the first to claim that a 100% renewables system can work but as far as I can see their simulation is by far the most detailed. It hasn’t received any publicity outside Germany largely because they haven’t published anything in languages other than German until very recently.

So, could the same conclusions apply in the UK? ‘Yes’, said Malte Jansen – and he expands on the hows and whys in this week’s New Scientist.

Blown away in the wind?

The first question that always arises when such ideas come under discussion is ‘but the wind doesn’t blow and the Sun doesn't shine all the time’.

True; and the first answer is ‘but there isn’t peak demand all the time either’. (Clue: It’s called ‘peak’ demand.)

The key to making the flexible grid work, said another of our speakers, Professor Catherine Mitchell from Exeter University, is to ‘reduce, flatten and flex’ – first bring down overall demand by making energy use more efficient, secondly flatten the daily profile of demand by shifting peak load to other times of day or using storage, and thirdly build enough short-term flexibility into the system that random fluctuations can be caught.

The second question that always comes up is ‘so what happens for the two-week period in winter when the wind doesn’t blow and the sky is all cloudy?’

In the Kombikraftwerk scenario, long-term troughs are primarily filled by burning biogas – produced during the year through anaerobic digestion on farms, stored underground (as natural gas is now), and delivered to generators that run on demand.

That’s one aspect that might not work quite so well for the UK, given that anaerobic digestion is way less developed than in Germany and that there’s extra pressure on land – but other solutions might well be available, such as increased interconnection with hydro-rich Norway.

Carbon out, not lights out

We set up last week’s event largely because a crunch question may be about to arise in UK energy policy.

The government’s statutory advisor, the Committee on Climate Change (CCC), calculates that the most economically sound route for the UK to meet its legally binding target of cutting emissions by 80% by 2050 includes ‘virtually decarbonising’ the power sector by around 2030.

The government, the CCC and research groups such as the Energy Technologies Institute (ETI) all foresee doing this with a mix of nuclear, renewables, and fossil fuel-burning with carbon capture and storage (CCS).

But the first scheduled new nuclear reactor, at Hinkley Point, is increasingly troubled. Treasury officials think it doesn’t offer value for money, the hardware is afflicted by 'anomalies', and just this week Lord Howell, George Osborne’s father-in-law, described it as ‘one of the worst deals ever’.

And CCS? Well – as they used to say about nuclear fusion, it was five years away 10 years ago and still is.