Energy is unlimited

The following is mostly extracted from Dr Yuval Noah Harari’s splendid book Sapiens – A Brief History of Humankind which is full of fascinating facts and consequences, and well worth reading

We all know energy is vital for economic growth

But why do so many doomsayers, nowadays, keep alarming us by saying we’re running out of energy – fossil fuels are exhausted – oil wells are running dry

In the past, whenever this seemed imminent, humankind discovered new energy sources so that the sum total just kept growing

Our first energy source was plants which we plus oxen/ cart horses, say, ate and our bodies converted into muscle power

Then the Industrial Revolution arrived, fuelled by fossil fuels and steam then internal combustion engines to drive water pumps, locomotives and motorised vehicles

Then, more recently, atomic, nuclear, wind and tidal power were employed on an industrial scale

But shining over them all throughout has been solar energy

The amount of energy stored in all the fossil fuel on earth is negligible compared to the amount that the sun dispenses every day, free of charge

Only a tiny percentage of the sun’s energy reaches us, yet it amounts to some 4,000,000 exajoules of energy each year:

• One joule = a unit or energy, about the amount you use to lift a small apple one metre straight up
• One exajoule = One billion billion joules

All the world’s plants then capture only about 3,000 of those solar exajoules through the process of photosynthesis

And all human activities and industries put together consume about 500 exajoules annually, equivalent to the amount of energy Earth receives from the sun in just 90 minutes

And that’s only solar energy

In addition, we have hardly tapped the full potential of other enormous sources such as nuclear and gravitational energy, the latter most evident in the power of the ocean tides caused by the moon’s pull on the Earth

Energy supply is thus not a problem for humankind – nor is it ever likely to be

So, whilst energy demand will most likely continue to grow, even exponentially, to meet future human needs, our only problem will be knowing how to harness and convert the supply

We’ll just need to create more new pumps