Why are plans for the energy transition so complicated?

As with all things that at first sight appear to be really complicated, it is worth trying to simplify them to help you find the best ways to approach the problem.

It doesn't make complexity go away but it helps you navigate it. But if you do that with energy transition you will start to ask yourself what it is that is so complicated? Why are transition plans so labyrinthine?

Let's boil the problem down to its very basics. There are three dominant forms of energy we need to transition away from – burning fossil fuels to generate electricity, burning fossil fuels to heat buildings and burning fossil fuels to propel vehicles. If we manage each of those three transitions the vast bulk of our task is complete.

How hard is it to achieve each of these in technical terms? There are a number of factors which define the level of difficulty in each, and for each it is different. The first is where you are doing it; the narrative about it being a "global problem which needs global solutions" is utterly false. In almost every occasion you can stand and point to the source of the CO2 emissions. They're place-based and need place-based solutions.

That makes the first of the challenges really easy for Scotland. Scotland needs about three times the total installed renewable capacity that there was in 2019 to completely decarbonise electricity and expand that provision to cover increased demand (especially from electric vehicles). Scotland can comfortably achieve that with only onshore and offshore wind. We don't even need our vast marine energy potential.

There is a condition though. We need to build plenty of energy storage as well. Battery and gravity systems are perfectly capable of managing local resilience and 'load smoothing' and hydrogen can provide inter-seasonal grid-level storage. It shouldn't take long to put all of that infrastructure in place if there is a will to do it.

The picture for the UK as a whole is a bit different because of the density of population in the South East and its much lesser capacity for renewable energy. In comparison to renewable energy, nuclear generation produces very expensive electricity, has very long construction lead times and is much more dangerous.

But Britain as a whole may be reliant on nuclear, which may prove to be a major stumbling block in meeting its targets, and it has bet a lot on nuclear. Scotland shouldn't touch nuclear; we don't need to. Opinions clearly differ on Scotland's constitutional future but as a geographical entity, decarbonising Scotland's electricity is easy.

The same cannot be said for heating. More than any other single task, decarbonising heating is difficult. Put simply, heat is very cheap to produce but very difficult to transport while energy that is easy to transport produces expensive heat. Any version of heat transition is a major exercise, and any version is expensive.

Common Weal's calculations suggest that the cost of replacing the heating systems in every gas-heated home with a non-emitting equivalent is going to fall in a range of £30 billion to £50 billion. This is a massive investment, and so rather than working out the quickest way to do it (there isn't one) or the cheapest way to do it (there isn't one), we should ask what is the best way to do it.

By far the cheapest heat is renewable – solar thermal panels generate heat at very little cost and there are lots of options for forms of heat recovery (rivers, old mine works, industrial waste heat and more).

But you need to store and distribute that heat, so you need inter-seasonal heat-store and heat networks that take hot water to every house.

That is an enormous amount of work but creates a very large economic impact. Trying to achieve the same with air source heat pumps would cost not much less but would produce more expensive heat and put much greater strain on the National Grid. Plus the technology will need replaced regularly at substantial cost while heat networks, once built, can keep working for centuries.

Either way we need mass retrofit of houses to achieve better thermal performance – that alone will remove 40 per cent of the heating load required in one go.

Again, the pictures in Scotland and across the UK as a whole are different because of the difference in density of population, and it is likely that the south of England will now want heating systems that can also provide air conditioning (though heat networks can do that too).

Either way, this is the most difficult bit of energy transition. It must be planned coherently and action taken quickly.

The final part of the picture is transport. Here the issue are markets, supply and infrastructure. We can be pretty sure what the technologies will be – battery electric for smaller vehicles, hydrogen for large vehicles (like ferries) and potentially a mix of both for intermediate-sized vehicles (large trucks or lorries). We also have a good understanding of the charging and refuelling infrastructure we need.

Here the big issues are really about supply – how many and how quickly electric vehicles can be supplied to drivers – and market ability to absorb the supply. This latter point is important; people in the market for new cars are probably well served, even at this comparatively early stage in the development of electric vehicles.

But for those who rely on the secondhand market there just isn't supply. That will change over time but if we're serious about transition it can't be left to the market alone. Governments must intervene, particularly on charging infrastructure but also to facilitate faster development of the electric vehicle market.

What are the priorities? Heating is by far the nastiest one to deal with (particularly in Scotland) and needs grown-up decisions to be made, quickly. But that must go along with a matching commitment to house retrofit.

So where are the big oil companies in all of this? That is the point, they aren't. They aren't relevant to this transition, despite the phenomenal sums spent on PR trying to persuade you of the opposite. They aren't partners in the transition, they are the targets, they run businesses based on what we have to transition away from.

It is their influence which adds a lot of the complexity back in, touting technologies like Carbon Capture and Storage. We have simple tasks ahead and the oil and gas businesses will keep 'doing their thing' until we can get the work done and they can quietly go out of business.

Like the businesses that made horse-drawn carriages did when we transitioned into modernity.

Robin McAlpine is head of Strategic Development at Common Weal and a speaker at Holyrood's Next Steps in Scotland’s Energy Transition event which takes place on 1 September.