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.
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.
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.
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.
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.
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!
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.
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.