The world is burning. At least, that seems to be the takeaway from the harrowing images of residents and tourists fleeing wildfires across the Mediterranean. Whilst climate change detractors (let’s call them “deniers”) have crawled out of the woodwork to point out that many of the headline-grabbing fires were started by arsonists, that European wildfires have been declining in intensity for decades, that cold kills nine times more people globally (and ten times more in Europe) than heat each year, and that global climate-related deaths per capita have fallen more than 99 per cent over the last century — you and I both know such people are wilfully missing the point.

His plan, unlike that of the Tories, comes with a detailed model

The point is that global temperatures are rising, with profound consequences. Indeed, Nobel Prize-winning climate economist prof. William Nordhaus, and most experts, warn that a 3–4 degree Celsius increase in global temperature could mean the global economy will be 2–4 per cent smaller than it would have otherwise been by 2100. (That we are still projected to be 10 times richer than we are now will, presumably, be scant consolation). With the world facing crises, the despairing masses cry out for a leader to deliver them to salvation.

That leader, it seems, is Ed Miliband. Under the sage guidance of the Once and Future Secretary of State for Energy, the Labour Party has committed to seize the means of generation and switch the UK’s electricity system to net zero by 2030. Bold, unsubstantiated climate pledges are fun to scoff at (guilty), but Miliband is no novice. His plan, unlike that of the Tories, comes with a detailed model.

That model was created by Ember, a think tank founded by Mr. Miliband’s former adviser and lead drafter of the Climate Change Act 2008, Baroness Worthington. Noting that Labour had effectively asked Ember to make the sums work, Ember’s Managing Director Phil MacDonald cautiously described the resultant plan as “ambitious but possible”. Exactly how much leg work are these two adjectives doing? Let’s take a look.

The first thing to say about Ember’s model is that the numbers don’t add up. In order to meet annual demand, the plans rely on 12.2 terawatt hours (TWh) of hydrogen-fired electricity generation. Without this, the country would have a -1.9TWh deficit (implying energy rationing and blackouts).

The problem with using hydrogen to plug this gap is that green hydrogen takes 3.3 ͘times more electricity to make than it produces. Maintaining 12.2TWh of hydrogen-fired generation would therefore require an annual non-hydrogen-generated electricity surplus of 40.7TWh — 42.6TWh more than under Labour’s plan.

Okay, that’s not a great start, but let’s cut Ember some slack here (it was clearly in a hurry). Let’s assume the hydrogen will be imported — an initiative which would cost bill payers at least £2bn a year. Does this save the model?

The answer turns on the question of storage. Miliband’s vision for 2030 has nearly 75 per cent of annual demand met by weather-dependent renewables, with “dispatchable” generation (i.e. generation which can be turned-on on demand) capable of meeting just 45 per cent of peak daily demand. As generation must match demand 1:1 every second of the year, and wind and solar output sometimes drop to near zero, Ed will require a lot of storage to avoid near-constant blackouts.

How much storage? It’s hard to say. Ember hasn’t deemed it necessary to give us an estimate, and day-to-day and season-to-season drops in wind output are complicated to model (not even National Grid has gotten around to doing so).

To give an idea of the scale, then, let’s side-step estimating weekly and seasonal variance, and look at a simple problem: wind drought.

In a wind drought year, European wind speeds are unusually low. In 2021, for example, UK wind farm output dropped almost 20 per cent. For any renewable based energy model to work, therefore, there must be enough inter-year energy storage (or backup dispatchable generation) to account for a 20 per cent drop in wind.

If you look below, I’ve altered Ember’s model to reduce wind inputs by 20 per cent. Doing so cuts annual generation by 42.2TWh, leaving us with an annual energy deficit of 32TWh. To avoid catastrophic grid failure, Ed’s plan would require an intra-year storage reserve of at least 32TWh. Without this, intra-day and intra-week storage will not be able to top-up between lows in wind, and it will be exhausted before the end of the year.

Where is this going to come from?

Pumped hydro is the most efficient means of backing up electricity; it ought to be our candidate of choice. Ember models hydro generation capacity increasing 180 per cent by 2030 — impressive, but nowhere near enough to account for the 119,850 per cent required increase in storage. Indeed, according to an extensive Europe-wide analysis conducted in 2013, the UK has a maximum viable potential of about 0.5TWh of pumped storage.

Is there any hope for our aspirant energy guru?

This leaves us with batteries, which Ember implies to be its primary backup asset.

Currently, installing one kilowatt hour (KWh) of battery storage costs between $300 and $650, with the UK’s largest grid battery, Chapel Farm, pricing in at £383.8/KWh. Do such projects benefit from economies of scale? Seemingly not. Australia’s world-beating 193MWh Hornsdale Big Battery cost £466.4/KWh, with the state paying a further A$2m a year to keep the project connected to the grid.

Let’s ignore land, maintenance and grid costs, and take the lower (£383.8/KWh) figure as an optimistic estimate. This translates to a cost of £383.9 billion for 1 TWh battery storage and £12.2848 trillion for 32TWh. That’s £437,181.49 per household, or over 500 per cent UK GDP. This isn’t a one-off payment, as batteries wear down and require regular replacement.

It is impossible to overstate the extent to which this plan is not going to happen. The price of batteries could halve, and it would not happen. They could drop by a factor of ten, and it would not happen. If they dropped by a factor of twenty, it would still be a rubbish idea.

Is the price of batteries going to drop by a factor of twenty any time soon? No. Battery prices have been rising for three years. This is partially because the dramatic decline in fossil fuel prices, which in-part underpinned the headline battery price drop during the 2010s, has gone into reverse. It is also because shortages of the key minerals they rely on have become more acute, just as extracting them has become more energy intensive. IEA analysis suggests that the current pipeline of mining projects is well below that needed to service demand, predicting acute shortages of metals such as lithium, cobalt, nickel and copper. Unsurprisingly, the IMF predicts prices for these minerals to rise 240 per cent, 400 per cent, 117 per cent and 66 per cent, respectively, by 2030.

Okay, so batteries are a dud, but what about other innovations? Whilst there are a number of clever ideas in the works, none have yet overcome the problem of scale. All such projects face the fundamental hurdle that any storage system, in which the majority of assets sit idly for years between discharges, is going to charge astronomical prices to recoup its capital and running costs.

With climate scientists predicting that European average wind speeds will fall by 8–10 per cent by 2050, this problem is only going to become more acute. Without a cheap backup, intermittent renewables appear doomed.

Is there any hope for our aspirant energy guru?

In a characteristically awkward slip of the tongue whilst talking to the New Statesman last September, Mr. Miliband said it was his ambition to “change the weather in this country”. Until our would-be saviour attains this power, I would caution readers to think twice before following him to the promised land. As it stands, Ed’s plan would cost five times the nation’s wealth and render most economic activity so expensive as to be unviable. On the upside, this would cut carbon emissions.

Onward, comrades!