Monthly Archives: October 2014

Can Nuclear Power help save the Rain Forests?

This is my latest look at what life might be like in 2050. It looks at the use of nuclear power, a topic that I have hesitated to cover because it causes so much division among those who are concerned to protect the planet. However it is an important option for 2050, which is likely to be required unless our energy use falls significantly. I apologise for the sketch, I am taking lessons but progress is slow!

A nuclear station near a rain forest
A nuclear station near a rain forest

A power station comes into view on a tropical coast in 2050. It is one of many nuclear stations of various types and sizes that have been built  over the past 30 years.

There has been a big expansion in nuclear power because the amount of energy required by people on the planet is so large. The poorer countries in the world have all become richer and have energy requirements of their own. Transport is electric, as is all heating, so that electricity demand has soared.

There are of course major renewable installations as well. Large blocks of the Sahara desert, the Australian desert, and the North American deserts are covered in solar panels and solar concentrators for power generation. There are many floating wind turbines at sea. There have been huge strides in cutting energy use, many of which I have covered previously, such as the trend to live in cities and to use community transport rather than individual cars. However, despite these changes, the growing wealth and population of the planet mean that energy demand remains high and that nuclear power is required to meet it.

Back in 2014 there was a strong aversion to nuclear power. Many people were terrified of it. There had been an accident in Japan that contaminated a stretch of land and caused it to be evacuated. That in turn led to decisions by Germany and France to shut perfectly sound nuclear stations. The somewhat idealistic intent was to replace the nuclear stations with renewables but this proved physically impossible. The outcome was therefore an increased burning of coal and the burning of  more and more bio-fuels.

Back then bio-fuel was seen as  a useful way to generate electricity and power cars. It was obtainable from woodlands or from crop wastes so there was little impact on overall food markets. However as it began to be used more these sources reached capacity and bio crops began to be grown on agricultural land – land that was already under pressure from the growing demand for food. To meet the combined demand for food and bio-fuel more and more wild spaces were taken into agricultural use. Some of that land was rain forest. Eventually the demand for bio-fuel was brought under control by building large solar plants in the desert and by building more nuclear plants.

How much land could be saved by nuclear plants? A large plant like this produces the same output as 2/3 of Wales would produce if it was entirely devoted to growing bio-fuel. Rain forest areas can be more productive because they are hotter and wetter, so the area saved is rather smaller, but it is still around a quarter of Wales, three times the area of Greater London or 50 times the area of Manhattan for each large nuclear plant. For an explanation look below, underneath the poll.

Why can’t this happen now? Firstly because many green organisations fiercely oppose nuclear power. More and more people are questioning their position, but as yet there is little sign that they are changing.

Secondly nuclear power ideally needs some intense development. Most of the current investment in nuclear development is devoted to waste reprocessing and to the long term aim of making a nuclear fusion plant. We need Research and Development focused on developing plants that have lower costs, are inherently robust against natural disasters, and are quick to build. .

Explanatory Note

Suppose we compare this typical nuclear station against a bio-fuelled power station of the same output. What area of land would it take to supply the bio-fuelled station?

Assuming that we grow the best crops, process them well and burn them in the best power station, the output we might expect in Europe or North America is around 0.2 Watts for each square metre that is devoted to growing crops, on average around the year. This figure is taken from Ref. 1, which contains a full explanation. It may look small but crops grow quite slowly and the plant material needs to be converted to electricity, a process that is at best around 50% efficient.

Now how much power can the reactor produce? Let us assume that it is similar in size to the reactors planned at Hinkley Point in the UK. The two reactors on that site can produce, on average after allowing for shutdowns, nearly 3000 Megawatts.

Taking the figure of 0.2 Watts/square metre, the output from the nuclear plant therefore equates to the bio-fuel grown on 14,400 square kilometres of land, which is 5,560 square miles. That is an area nine times greater than Greater London, 24 times greater than Singapore, and 165 times greater than Manhattan. It is a square block of land 120 km (74 miles) across. It is equivalent to 2/3rds of Wales saved by this one nuclear station alone. Quite a lot!

What happens if we grow our crops in a hot, wet place? We can get more plant material out, perhaps three times more. That means that this station is worth around three Greater London’s worth of rain forest.


Will Robot Bikes bring home the bacon?

The robot bikes arrive!
The robot bikes arrive!

This post looks at the rather crazy sounding idea of robot bikes, with no rider. They are however technically feasible given the rate of advance in computing and would have many convenience, cost, and environmental advantages. As usual I’ve tried to liven the technical stuff up with a story.

Chloe has thrown a surprise barbecue. Some friends just called to say that they were in the area and since it is a nice day she suggested a barbecue. She lives in the country, twenty minutes from the nearest butcher. She called the butcher an hour ago and they promised to deliver.

The robot bike has just arrived. She unloads the meat while her partner fires up the barbecue. A second bike arrives with the bread, salad and drinks.

These bikes have no rider and navigate the narrow country lanes at safe speeds. They do not need to go fast because they carry no driver charging time by the hour. They can cope with potholes and if they need to stop they simply put their feet on the ground. They are electrically powered, and because they are so light (the heaviest thing on a bike is normally the rider), they use little energy to get up hills. Their energy consumption is around one tenth of that used by an electric car, which is itself much more energy efficient than a diesel. They are the lowest cost way to deliver goods.

In 2050 they are common. They have transformed some parts of the world, notably Africa, by their ability to deliver drugs, food, and equipment across rough roads using only locally generated solar power to recharge their batteries. There are many cities around the world where the roads are simply too small and crowded for cars and vans, and where these robot bikes  are much easier to accommodate.

Why can’t this happen now? Obviously self-driving cars are becoming available. Robot bikes are a further technical challenge but they can be built. A Chinese company is starting their development and some US companies are looking at them for military applications.