How would you describe the challenge facing the world?
The Industrial Revolution and all that followed has been fuelled by our ability to find, extract and use abundant sources of fossil energy with increasing ingenuity.
For an increasingly larger fraction of humanity, our homes are lit at night, warmed in winter and cooled in summer.
We ride in vehicles that have the power of hundreds of horses and in planes with horsepower in the tens of thousands.
But there is a catch. The cost of keeping the equivalent of billions of horses working for humanity has a modern-day equivalent of keeping the stables clean.
Our modern-day waste products are the sulphur and nitrogen oxides, particulate matter, mercury and other pollutants that are emitted when we use fossil fuels.
In addition, the atmospheric concentration of greenhouse gases (GHGs) such as carbon dioxide (CO2), methane and nitrous oxide has risen sharply in the last 65 years.
The average global land and ocean surface temperature has risen by around 1.1° Celsius since 1880.
More worryingly, 80% of that temperature rise has been in just the last 38 years.
So, the world needs to clean up its stable urgently if it is to stay healthy. But what about the 1.1 billion people with no access to electricity? How can they be helped?
For people in the developing world, improved access to energy would help raise their standards of living.
And, just as cell phones leap-frogged past landline use in the developing world, new technologies can give people in those countries access to energy.
Small local solar power grids in isolated rural areas in developing countries can be used to charge cell phones, to pump and purify water, and charge LED lanterns to read at night without poisoning the air in their homes with kerosene lamps.
Even when backed by batteries, solar power is a cheaper and cleaner alternative to diesel-fuelled power generators.
I’m optimistic that they can bring energy to a lot of rural areas which would not have been connected to countries’ national grid systems for a long time.
What about generating cleaner electricity in the developed world, in Europe for example?
The price of solar has fallen dramatically around the world, but I don’t see much potential in northern Europe.
Most of the future growth in renewable energy will be in wind power. But when there’s no wind you need to be able to call on other sources of energy.
You need back-up, or on-demand, energy sources that you can control, energy storage and electricity transmission links that are hundreds or even thousands of kilometres long to reach better wind power sites.
For on-demand electricity you only have two choices – fossil fuels or nuclear. Virtually all technologies have learning curves whereby the more you produce the better you get at it and the cheaper it gets.
Nuclear is one of the very few technologies to have inverse cost curves; the more plants we have built the more expensive it has become, largely because of rising concerns about safety and public fears.
I don’t think nuclear plants are going to play a major long-term role in many countries until we relearn how to build them on time and on budget.
Gas is the least polluting of the fossil fuels. Hopefully, within 10-15 years we will have piloted technologies that can capture and compress CO2 at a cost of around $35/tonne of CO2. The question is what do we do with the CO2 after capture?