, September 24, 2021

The future of energy and why I am not worried about the intermittent nature of renewables


  •   4 min reads
The future of energy and why I am not worried about the intermittent nature of renewables

What is the future of energy? I think renewable energies is where the future of energy lies and I am not overly concerned by their intermittent nature.

The world, it seems is divided into three. Some like me, believe in climate change, but think renewable energy is a vital weapon in combating it. Some agree about climate change's seriousness, but are not fans of renewables and instead think the future lies with nuclear. The third group either don’t believe in climate change or think it is a problem without a solution and instead think we should carry on with fossil fuels.

I think the third group is wrong: the science of climate change is irrefutable, the climate change we see today is caused by us. But I do believe there are solutions. And this is where I do disagree with many scientists and economists in this field. I think there are economic benefits from the weapons we develop to fight climate change such that as a result, we could become better off.

I disagree with the nuclear supporters, for one main reason. I will come to that in a moment, but first, I need to explain two important concepts. They are learning rates and convergence.
A learning rate describes a technology that falls in cost while advancing in power with each doubling in its output. An early example is known as Wright’s Law, named after an aeronautical engineer Theodore Wright who  “observed that every doubling of production of US aircraft brought down prices by 13 per cent.
Another example of a learning rate is Moore’s Law.  Genome sequencing is following an especially marked learning rate. Both wind and solar power and indeed lithium-ion batteries are following learning rate trajectories.

The learning rates for renewables has been so significant that the cost of energy generated by solar has fallen from $76 a kilowatt-hour in 1977 to 36 cents in 2014. Since 2010, the cost of energy from solar has fallen by 82 per cent, and since 2019 it is down by 13 per cent to just five pence a kilowatt-hour.

This report: Why did renewables become so cheap so fast? And what can we do to use this global opportunity for green growth? provides an excellent detailed account.

This is why I am so excited about renewables. If the learning rate continues, within a decade or so, energy could become incredibly cheap. Without the threat of climate change, the investment in renewables might never have happened — but as a result, the dream of almost free energy could be realised.

Convergence, is something I will return to in a moment, it describes when different technologies, sometimes developed for various reasons, come together.

I am not a fan of nuclear, because while the cost of energy from renewables has plummeted, the cost of energy from nuclear has gone up. While renewables present the promise of really cheap energy, nuclear doesn’t. It seems to me that there is no learning rate in nuclear energy.

Some argue that you need nuclear to provide a baseload — but it is not complementary to renewables. The ideal technology to support renewables is one you can turn up and down with ease. Nuclear is not that technology.

I can see a use for nuclear in regions far from areas where solar is effective, such as in the Arctic Circle, but am cynical about its applications for the mass market. The exception could be small scale nuclear reactors, but I am not convinced. The learning rate is most effective when applied to technologies made in thousands, or even hundreds of thousands of units. Small scale nuclear reactors are smaller than traditional nuclear power reactors, but they are still massive and will never be made at the scale seen with wind turbines, and solar panels.

What about the intermittent nature of renewables?

Renewables cynics —whom you can normally identify the moment they refer to wind turbines as windmills — think that renewables' intermittent nature means they can never be viable on their own.
I disagree with that. It’s a problem now, for sure, but convergence and learning rates hold the answer.

The solution to the intermittent nature of renewables

It is essential to understand there isn’t one answer to the problem of intermittent renewables. There are multiple answers; some are cheaper than others. The key is only to have to use to the more expensive solutions rarely.

Solutions are:

  • Mix of renewables — it’s often too dark for solar, it’s often not windy, but less common for both.
  • Broader coverage — the larger the area, the less risk from the vagaries of unpredictable optimal conditions.
  • Hydropower — a cost-effective and established form of storage, but requires quite a lot of land and favourable terrain, such as that seen in Norway.
  • Lithium-ion — lithium-ion batteries' cost for grid-level storage remains high, but this technology follows a learning rate and the cost is falling. The biggest drawback lies with how long a battery can stay charged. They might work to correct variability lasting a few hours but are less effective at dealing with seasonal variability.
  • Vehicle to grid; this will use the fleet of electric vehicles, so it could be relatively cost-effective as it will use technology that already exists.  But the technology will still use lithium-ion batteries, so has the same seasonal drawback as described above.
  • Redox flow batteries, especially using vanadium. These may be more suited for grid-level storage and can retain the charge for longer.
  • Other forms of storage, such as molten salt and gravity batteries.
  • AI/automation technologies/smart grids. This is where convergence enters the story. By channeling energy at times when conditions are optimal into less time-sensitive uses, it is possible to even-out the use of energy to more closely match supply. For example, apply energy when it is cheap to storage heaters, making ice for air conditioning units, 3D printing-based manufacturing, neural networks, and the most exciting possible application of all, water desalination. Others think energy generated in optimal conditions could be used to made synthetic fuel or hydrogen.
  • I save the most exciting one to last - ultra high voltage direct current. In 2019, China built a long-distance high voltage direct current line covering 3,300 kilometres. It only saw a modest loss of power. Imagine the implications of such technology. Energy generated in North Africa could be transmitted into Europe. The energy could even be generated from different time zones, so a region could be receiving energy generated from solar when it is dark, but light in the area when the energy is generated.

Put all of the above, and intermittency can be overcome — and that is why I believe we can drastically reduce the carbon footprint from energy generation and become better-off, in the long run.

Article originally published on share.com

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