The meteoric rise of renewable energy has consequences for our electricity supply. While coal and gas fired power stations can generate electricity whenever you need it, renewables are intermittent by nature. So we need a backup plan for when the wind stops or the sun goes down.
All over the world, engineers and scientists are racing to solve one key problem; how to safely and efficiently store electricity at a huge scale but at a low cost. The quest is producing some truly remarkable ideas and this episode details three of them.

Ewan McGregor and Charley Boorman, after more than a decade since their last motorbike adventure around the world, will cover 13,000 miles over 100 days through 13 countries. Starting from the city of Ushuaia at the tip of South America, Ewan and Charley travel through the glorious and underexposed landscapes of South and Central America to Los Angeles in the United States in their most challenging expedition to date. In their journey they will use cutting-edge technology on the backs of their prototype electric Harley-Davidsons in order to contribute to the sustainability of the planet.
In the first episode, Ewan McGregor reunites with his best friend Charley Boorman to evaluate what's important in their lives, following a life-threatening accident of Charley.

Electricity is not just something that creates heat and light, it connects the world through networks and broadcasting. After centuries of man's experiments with electricity, the final episode tells the story of how a new age of real understanding dawned - how we discovered electric fields and electromagnetic waves. Today we can hardly imagine life without electricity - it defines our era. As our understanding of it has increased so has our reliance upon it, and today we are on the brink of a new breakthrough, because if we can understand the secret of electrical superconductivity, we could once again transform the world.

A humpback whale mother and calf embark on an epic journey from tropical coral paradises to storm ravaged polar seas. Newly discovered coral reefs in Indonesia reveal head-butting pygmy seahorses, flashing 'electric' clams and bands of sea kraits, 30-strong, which hunt in packs. Elsewhere plagues of sea urchins fell forests of giant kelp. Huge bull fur seals attack king penguins, who despite their weight disadvantage, put up a spirited defence.

We face one of the greatest challenges in the history of humanity, to eliminate the fuels that have driven progress and technology for over a century, while our thirst for energy only grows. The sun is the biggest source of energy in the solar system. It's like a nuclear reactor in the sky, and it provides endless power. If we can harvest just fractions of this, it can power all our consumption. Innovators are searching for new ways to capture more of the sun’s power, and make it available through the night, everywhere.

Episode 3 continues to show the obstacles faced with charging electric bikes in remote places, but Ewan McGregor and Charley Boorman start to learn and evolve their process. The risk of cold temperatures is high but they bravely do it anyway. The duo is having a hard time of it out there but, thankfully, the scenery is absolutely stunning. Heading through Patagonia, Ewan and Charley stay at an eco-lodge in one of the world’s remotest areas with people that live off the grid.