In the past, many civilisations worshipped the Sun. For the ancient Egyptians it was Ra, creator of humanity. Ancient Indians called the Sun Surya, the all-seeing god who expels darkness and disease.¹ The AztecsThe most powerful Central American civilisation in 1492, when Europeans first made sustained contact with the Americans. Their civilisation was destroyed by the Spanish, who enslaved what was left of their people. cut out the hearts of their prisoners to appease the Sun and keep it rising in the mornings.

Future archaeologists might come to the conclusion that 21st-Century humanity also worshipped the Sun. They might find bottles of suncream warning of the dire effects of sun exposure. They might find mental health books waxing lyrical about the positive effects of sunlight.

And they might find rows and rows of vast black panels all directed at our local star.

Last year, manufacturers passed an important milestone when they worked out how to make solar panel cells that can convert more than 30% of the sunlight they receive into electricity.²

Now the world is seeing a solar panel boom. In the EUEuropean Union. An economic and political union of 27 countries. alone the solar sector is growing by 40% a year.³

In CaliforniaA large state on the west coast of the USA. It is the country's most populous state, with more than 37 million people. First settled by Native Americans as much as 13,000 years ago, the area was subsequently conquered by Spain, then was absorbed into Mexico, which was forced to hand it over to the USA in 1848., since early March, solar panels have produced more electricity than the entire state actually needs.⁴

Why does this matter? In many ways, the history of humanity is a history of our relationship with energy. We were able to evolve such big brains because we harnessed the power of fire. Fire allowed us to cook our food, so we could get more calories from it - more energy - and power our growing grey matter.⁵

For most of our history, we were bound by an equilibrium between two forms of energy: food and fuel. Our only source of fuel was wood, so if we wanted more of it we had to grow more trees, but that meant less land for food which, in some cases, led to famine.

Then in the 18th Century we discovered coal. Coal is a much more efficient fuel than wood and it does not take up much land to mine. It could be acquired very cheaply. It meant we could produce more food and more fuel. This, historians say, is what fuelled the Industrial RevolutionA period of sudden, rapid industrialisation that transforms a country from an agricultural to an industrial economy..

But it was too good to be true. We now know burning coal actually imposes a new limit on us: climate breakdown. The more non-renewable fossil fuels we burn - coal, oil and gas - the more carbon dioxide we release into the atmosphere and the less viable life on Earth becomes.

Renewable energy means we can enjoy many of the benefits of industrialisation, but without the destructive impacts of fossil fuels.

And it is good for our health. The air pollution caused by burning coal, oil and gas, as well as worsening the climate crisis, also contributes to lung and heart diseases.⁶

In contrast, once they have been manufactured, solar panels and wind turbines do not cause any pollution.

That is why so many people now believe that cheap renewable energy is the key to a flourishing and prosperous future for the human race.

Is cheap energy the solution to everything?

Yes: Cheap energy brought us the Industrial Revolution. Now, in clean form, it will bring us a new revolution in our everyday lives. It will make us richer, healthier, and happier.

No: Replacing fossil fuels with clean energy will only persuade us we can maintain our wasteful lifestyles regardless of the environmental damage they cause. To safeguard our future we must consume less, not more.

Or... Cheap energy can improve our lives, but to get its full benefits we need not only to produce lots of it, but also to electrify the entire economy. This will be expensive and take a lot of time.

Aztecs - The most powerful Central American civilisation in 1492, when Europeans first made sustained contact with the Americans. Their civilisation was destroyed by the Spanish, who enslaved what was left of their people.

EU - European Union. An economic and political union of 27 countries.

California - A large state on the west coast of the USA. It is the country's most populous state, with more than 37 million people. First settled by Native Americans as much as 13,000 years ago, the area was subsequently conquered by Spain, then was absorbed into Mexico, which was forced to hand it over to the USA in 1848.

Industrial Revolution - A period of sudden, rapid industrialisation that transforms a country from an agricultural to an industrial economy.