Future Energy Scenarios 2025: The pathway to net zero or the road to nowhere?

The four waves

• Foundation wave (2005–2025): We’ve just completed this one—developing wind, solar, EVs, and heat pumps. Though Scotland built its first electric carriage in 1830, so arguably this metaphorical wave is over 200 years long but has now finally crashed onto the shore
• Acceleration wave (2025–2030): Innovation is mostly done. We know which technologies are dominant: wind, solar, biogas, nuclear. The challenge now is policy and scale. Think of this as pushing down the loud pedal in a Porsche
• Growth wave (2030–2040): The difference between this and the preceding wave is slightly vague, but this is also when mass adoption and grid investment kick in. It’s also when the bulk of the 200 GW is supposed to be built
• Horizon wave (2040–2050): The final push—focused on decarbonising hard-to-abate sectors like aviation, construction, and shipping

The report also outlines four different routes to the 2050 summit:

1. Holistic – A bit of everything: wind, solar, nuclear, hydrogen, demand reduction, and load-shifting
2. Electric – A world run mainly on electrons
3. Hydrogen –Fewer electrons, more H₂ molecules. A little gas elevated to playing a big part in the energy mix
4. Falling behind – The plan fails, we don’t ‘summit’, but we get a decent view on the way up

So: 4 policies x 3 waves x 4 scenarios = 48 possible futures. Hopefully that’s clear.

Renewable deployment: the real numbers

It is easy to poke gentle fun at how overly complicated NESO has made describing what is quite a simple concept. But the challenge of getting to net zero by 2050 is enormous and our reading of the numbers works as follows:

• Offshore wind: 80 GW (from 15 GW)
• Onshore wind: 36 GW (from 14 GW)
• Solar: 57 GW (from 16 GW)
• Nuclear: up to 12 GW (from 6.5 GW)
• Other technologies: 20 GW (from 5 GW)
• Biogas: 18 GW (from 2 GW)

And alongside that, heat pumps are expected to grow from 250,000 to 19 million by 2050, and EVs from 1.5 million to 30 million.

It’s heady stuff. But I’m older now, with less hair and more kids than I had in 2005, and I have three concerns:

1. Is there public and political support?

2050 is five general elections away. At present, only Labour, the Lib Dems, and the Greens are fully committed to net zero. Other parties are ambivalent or outright sceptical. Reform UK, for example, has promised to cancel offshore wind contracts if elected.

With 20,700 politicians in the UK, it’s fair to guess that at least 5,000 are not fans of net zero. Betting that this plan survives five government changes feels well, let’s say, optimistic.

2. Can we build it?

We’ve got 9,125 days to install 200,000 MW, so that’s about 22 MW per day, every day. Last year, we managed about 11.5 MW/day. We need to double that overnight and hold it at that rate for 25 years.

Given the UK’s planning system, this feels deeply unrealistic. The UK is a small densely-populated island with 22,000 people employed as town planners, and understandably, these people tend to create work for themselves.

A good example of this is the Lower Thames crossing, which you will recall is a new tunnel under a river that already has a lot of existing tunnels and bridges. But still, the planning process has now taken 10 years and cost GBP 300 million so far, all without a single spade in the ground. The total documentation required by various authorities aggregates to over 60,000 pages. All of this to build a tunnel. Under a river. A river that already has 17 tunnels.

Thinking that somehow the same planning system is going to allow 200,000 MW of wind farms, solar parks, interconnectors, and most critically nuclear power stations to be built in 25 years is unrealistic, unless the system radically changes almost beyond recognition.

3. What will it cost—and who pays?

NESO doesn’t say much about the costs of their ambition (less than a page in 170), but states that a detailed appendix will follow, albeit conveniently during the Parliamentary summer recess.

Our own rough numbers (2025 prices):

• Offshore wind: GBP 3m/MW → 65 GW = GBP 195 billion
• Onshore wind: GBP 1.5m/MW → 22 GW = GBP 33 billion
• Solar: GBP 1m/MW → 41 GW = GBP 41 billion
• Nuclear: GBP 12m/MW → 5.5 GW = GBP 66 billion
• Biogas: GBP 3m/MW → 16 GW = GBP 48 B

Total: ~GBP 383 billion, or GBP 39 million a day for 25 years.

The Government presumably hopes the private sector will foot the GBP 383 billion bill. But the UK is a small, damp island competing with the rest of Europe for capital. Our gilt yields are now the highest in Europe, which is not a great sign for investor appetite. A key part of our role at Green Giraffe Advisory is to bash UK projects into some form of investable shape, because we know the competition for capital is both global and fierce.

Secondly, of course, the impact of the planning process described above is likely to increase costs way beyond the GBP 383 million we calculated above. The much-maligned managers of HS2 have recently complained that over 100,000 people objected to their plans to build 135 miles of new railway track (in a country that already has 9,584 miles of track), over which Parliament reviewed 827 petitions. Nearly every petition subsequently required a change to their design, which massively increased costs. Eventually, they paid about GBP 350 million for each mile of track. Yes, you read that right: GBP 350 million per mile of track whereas the equivalent French TGV cost circa GBP 40 million per mile and a Chinese railway maybe costs as little as GBP 20 million. So, given our collective experience of building HS2, I think it is a fair assumption that the GBP 383 million set above will be an underestimate.

Conclusion: From scenario to reality

The NESO report is impressive, exhaustive, and physically exhausting to carry around. But as Prussian General Helmuth von Moltke the Elder put it: no plan survives contact with the enemy.

The plan is clear: 200 GW of new capacity, 19 M heat pumps, 30 million EVs, and a fully decarbonised grid. But 9,125 days is a long time, and as my own life illustrates, a lot can happen.

Building all of that on a small, densely populated island with 22,000 town planners reporting to 20,700 politicians is at best challenging. Add in an ageing grid designed around long-demolished coal-fired power stations serving long-demolished factories, and ‘challenging’ suddenly becomes ‘really challenging’.

At Green Giraffe Advisory, we’re fully committed to achieving net zero in the UK. It is pretty much all we talk about all day, every day, and we have raised GBP billions so far to build projects. But we work at the coal face of project finance, and we know what it takes to turn strategy into steel, mission statements into megawatts, and business plans into biogas.

It’s easy to write 170 pages about what should happen. Making it happen is another story, and that bit is still only partly written.