Beyond carbon: power for the 21st century

Most people who read my blog would no doubt agree with me that the world needs to phase out the burning of coal, oil and gas as quickly as we can. ‘Let’s do it already,’ say a lot of people. Most people probably also think they know which technologies should replace hydrocarbons. Here I’m going to take a closer look at that second question.

A large coal-fired power plant can generate around 5,000MW of electricity, and the world’s total electricity requirement is presently around 6,000,000MW, equivalent to a thousand of these coal-burning monsters. How can we replace them?

I guess that most people will say renewables: hydro, wind and solar.

Hydro-electric
The largest renewable energy plant in the world is the Three Gorges dam in China. This massive hydroelectric plant generates 22,500MW of power, equivalent to more than 4 large coal-fired plants. It’s huge! How big, exactly? The area of land flooded by the creation of the dam is more than 1,000 square kilometres. The construction of the dam displaced 1.3 million people. It’s fair to say that its construction was controversial, not least on environmental grounds. You could really only build it in a country where the citizens have no say and the government can do whatever it wants. I don’t see it happening in Europe or America. Besides, there just aren’t many sites suitable for large-scale hydro.

Onshore wind
One of the largest onshore wind farms is the Los Vientos wind farm in Texas. The first phase of this farm to be completed generates 200MW of electricity and takes up 30,000 acres of farmland. To generate all of the world’s electricity from facilities like this, we would need to cover around 900 million acres of land with wind farms. That’s around one third of the total land area of the United States. Or 8 times the total area of Sweden, if you prefer. Something tells me that might prove to be a problem.

Offshore wind
The world’s largest offshore wind farm is currently at Walney in the UK. It’s a group of wind farms with a total generating capacity of 659MW, and covers an area of 73 square kilometres. We’d need almost 10,000 of these to generate the world’s power, covering a sea area of 660,000 square kilometres. That’s a quarter of the Mediterranean Sea – a lot less than the amount of land needed for onshore wind, and perhaps not completely impossible to imagine.

Solar PV
What about solar power? China claims the largest solar PV plant in the world at Golmud. It generates 138MW peak power from two parks covering a total area of 640 acres. Scaling that up, you can see that to supply the world’s electricity needs, we’d need almost 50,000 of these giant parks, covering a total land surface of 28 million acres. Now that’s big, but seems more realistic than wind.

However…
Of course, the ratings of wind and solar power plants are their peak outputs. When the wind doesn’t blow (or blows too hard), wind farms can’t generate power. As for solar, even during the sunny summer months, the Golmud solar plant runs at far less than its nominal generating capacity. That means that the amount of land use I quoted above is a serious underestimate of what would actually be required.

Also bear in mind that once we’ve replaced our gas-guzzling cars and planes with electric vehicles, and swapped out all the gas-burning heating in homes and offices, we’re going to need to generate substantially more electricity than we do now. Probably twice as much. Does that mean that we need to build a wind farm the size of an entire continent? I hope not.

Do you doubt my numbers? A European Union report published this year estimates that if Europe were to obtain all of its energy from onshore wind, 15% of all land would need to be converted to wind farms. Arable farmland makes up less than 10% of land in Europe. So even if we entirely stopped growing food, we still couldn’t generate all our power from wind!

Nuclear
There is another option on our list – nuclear. A single nuclear plant can match the largest coal-fired plants for output and availability, and with zero direct CO2 emissions. ‘Let’s do it already,’ say I.

You might want to tell me that nuclear is a far more dangerous option than renewables, but in fact you’d be completely wrong. While coal, oil and gas have claimed more deaths than any other kind of energy source – by orders of magnitude – renewables kill twenty times as many people as nuclear, and that includes the Chernobyl and Fukushima accidents.

When the Shimantam dam in China failed in 1975, 171,000 people died. Even the number of workers killed each year installing and maintaining wind turbines and solar panels far exceeds the number of fatalities from nuclear power generation.

My solution
I advocate a mixed approach to power generation to tackle climate change. For me, nuclear has to be a key component of that mix. Probably a large component. Without it, it will take far longer for the world to reach carbon neutrality. And you can see from the numbers I’ve presented here that renewables come at a very significant cost in terms of land use. Let’s not create another problem for future generations to solve.

23 responses to “Beyond carbon: power for the 21st century

  1. Great post. Finally, people are looking at the solutions. And the solutions that are being proposed come with a whole bunch of problems, some with worse environmental impact than the problem. It’s sad that climate change topic has become a tool to divide society for political gain and the idiotic laws proposed on this issue serve the same purpose. Just wanted to share a video that changed my view on solar and wind. They are NOT the solution. We do need to invest in safe nuclear power.

  2. An interesting post. My own preference for renewable sources is solar photovoltaic cells. I wrote a post about this earlier this year

    https://explainingscience.org/2019/03/09/solar-energy/

    It is interesting to consider that the Earth receives more energy from the Sun in a hour than the whole of humanity consumes in a year.
    In fact we would only need cover 0.11% of the surface area of the Earth with solar panels to supply all the Earth’s current energy needs. Assuming a current global energy consumption of 160,000 TWh.

    Of course the problem with the solar energy is that the countries with the highest potential for solar electricity generation aren’t those with the greatest energy consumption.

    If we apply the same calculation to the UK the figure would be about 5,2% of the UKs surface area would need to be covered with solar panels, to generate the UK’s energy needs (Roughly 2 TWh)

    • Thanks, Steve. Even 5.2% of the UK’s land is a lot. It would make a serious dent in our ability to grow food. And of course you are aware of the many problems associated with energy storage. UK energy demand increases significantly in winter, whereas solar PV produces much less during these months. I know that you are a scientist. Why not use nuclear to fill the gap?

      • Agreed, a densely populated country like the UK with a high energy consumption per capita would find it very difficult to generate most of its energy from solar panels and in reality covering 5.2% of the UK’s land area with solar panels is impractical. If you look at the picture on a world scale that is not the case of course, many countries, particularly near the equator have the potential to generate many times their own energy needs by solar panels.
        The other point to make is that, over the past decades solar PVs have become cheaper and more reliable and their efficiency has improved (now about 22% for the best panels on the market) this trend is likely to continue in the near future. Domestic solar PVs should now have a lifetime of at least 30 years.
        As you can probable guess, I am a keen advocate of solar and think more could be done to promote the use of solar even in a cloudy country like the UK, e.g. making it standard (e.g. via Building regulation) that all new buildings have solar panels on their roofs and to provide incentives for solar panels to be put on the roofs of existing buildings. But to answer your question yes I agree with you nuclear power should be part of the mix.
        Steve

        • Well I think we’re in agreement. I would also like to see a rapid increase in solar PV. As you say, incorporating them in new builds greatly reduces the cost of installation.

  3. I also think that deforestation, probably, contributes to the global warming as much as burning fossil fuels, if not more. Few people talk about that. The focus is on fossil fuels.

    Another aspect is that there are no electric ships, airplanes, tractors, combine harvesters, and very few trucks. If we simply ban fossil fuels, the civilization as we know it will seize to exist, to the point that it will be impossible to grow food or deliver it to the store. If we want to drive those by electricity, it will require a lot of batteries. And battery production, I’ve heard, requires a lot of energy. Battery recycling also requires a lot of energy. So, when all is said and done, an electric car battery, probably, cause more GHG emissions than a gas car would have over its lifetime.

    • You’re right on deforestation, which occurs primarily in South America. In Europe we are actually increasing the forested area! As for electric vehicles, their GHG emissions are definitely a lot less than current transport technology.

  4. I actually do think nuclear power is dangerous. A disaster at one plant can have catastrophic consequences for centuries.

    But it doesn’t matter. We have a world of 7.7 billion people to service, and our power needs are relentless. As long as we’re supplying those needs with coal, we’re already poisoning the environment. And any solution is going to be dangerous in some manner.

    That said, I do think we need to approach nuclear with clear eyes, and realize that we’re harnessing demons who will turn on us in an instant. That means utility companies can’t be left to their own devices. Frankly it’s not clear to me that even individual governments can. There needs to be a framework to ensure that nuclear plants are built with the safest technologies available, and rigorous enforcement of regulations to ensure they’re competently run.

    Nuclear power is a deal with the devil, but as you describe, it’s not like we have lots of options.

    • Mike, I’m surprised to hear you using such colourful language to describe a technology that we have been using for seventy years. Every technology carries risks, and every industry comes with a death toll. If you look at the actual numbers for nuclear, you’ll see that it’s one of the safest industries ever. The data does not back up the use of phrases like “catastrophic consequences” or “deal with the devil”. I would urge you to look at the data. Pick the worst nuclear accident ever (Chernobyl) and look at realistic estimates of the number of fatalities (4000). Compare this with the number of people who die from car accidents (thousands every single day of every single year). Over the 70-year lifespan of nuclear power, for every 1 person killed by nuclear power, 10,000 died from car accidents.

      • Steve,
        From what I know about Chernobyl, Fukushima, and a number of other accidents, we’ve been pretty lucky until now. Taking that luck as a given, it seems to me, is a pretty risky stance.

        Again, I’m not arguing that we should conclude from that that we shouldn’t use nuclear power. I really don’t think we have much choice. All I’m saying is that we shouldn’t treat it as everything’s fine and there’s nothing to worry about.

        Incidentally, I think the same is true for oil drilling and transportation. We’ve had accidents that caused widespread ecological and economic devastation (examples are off the coast of Alaska and in the Gulf of Mexico). We’re not about to get off of oil anytime soon, but we should be clear eyed about the dangers involved.

        • Mike, I hear what you’re saying, but I don’t think luck is really a factor here. We have been using nuclear power for 70 years now. In that period there have been just two incidents causing loss of life:
          SL-1 (3 killed)
          Chernobyl (44 killed)
          SL-1 was an experimental military reactor. Chernobyl – well, you know the large number of factors that contributed to that. There has never been a fatality from civil nuclear power accidents in the US, Europe, China or Japan. There are currently 450 nuclear reactors in 30 countries. The latest generation are designed with many passive safety features. They don’t rely on luck. Far from being dangerous, I believe the data clearly shows that the nuclear industry is one of the safest industries ever.

    • I’ve heard (don’t recall the source) that there are much fewer deaths and accidents on nuclear plants than there are on coal or hydro plants. Yes, safety measures are necessary. Enforcement of these safety measures are necessary. The same is true for any sort of power source. Batteries explode and cause spectacular fires, you know. I think that the fear of nuclear energy is completely irrational. For some irrational reason, people fear radiation more than inhaling smoke from the burning coal which, actually, may be more harmful. It’s just perceived as “safer” simply because it’s better understood. If done properly, nuclear power is a far better, more reliable, more scalable, and environmentally friendly power source in the long run than other sources.

      • Nuclear plants are subject to extremely stringent safety requirements. No doubt that makes them a lot safer than other plants.

        There is definitely an irrational element of fear of radioactivity, perhaps because it is invisible, perhaps because of its association with nuclear weapons.

        Once we begin deploying renewable energy on a larger scale, the advantages of nuclear may become more obvious to the general population. For now it is too easy for people to just say no. Difficult choices will have to be made in the next two decades.

  5. Too bad nuclear has such a negative connotation.

    • You’re right, Jim. I am hoping that by writing about it, I can make a small contribution to changing people’s minds. We’ve already convinced the next generation to take on climate change. Now we need to give them the means to do it.

  6. I have become less and less of a fan of nuclear power over the years. It offers a lot of advantages, I don’t deny that. But you mention not wanting to create another problem for future generations, and I worry that the need to keep all our nuclear waste stored securely will become a huge burden for future generations.

    • James, I actually spent 10 years working for the nuclear industry as a physicist in the field of radioactive waste disposal. It is of course an important issue, which is why I chose to work in that area, but we have managed for 70 years already. The key point to remember with radioactive waste is that the most dangerous waste has a short half-life, and that the long-lived waste has low activity. I believe that we should be investing heavily in breeder reactors, which generate more fuel than they consume, thereby reducing waste and extendending the amount of fuel available by a factor of 100.

      • In that case I defer to your superior knowledge and experience! I remain concerned about nuclear power, but what you’ve said has alleviated my concerns, somewhat. I’d never heard before that the more dangerous waste has a short half-life. That is kind of a relief!

        • Don’t take my word for it, that’s always a bad idea. Think about it logically: high-level radioactivity occurs because an isotope is decaying very rapidly. This inevitably means it has a short half-life. Campaigners against nuclear power will often state that radioactive waste is highly dangerous, and that it lasts for millions of years. This is highly misleading, since the isotopes that last for millions of years are necessarily those like U-238 with low levels of activity. You would have to ingest large quantities of U-238 before it posed a health risk.

        • Yes, that does make sense to me.

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