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.

Since the original series went on the air in 1966, the Star Trek franchise has had a history of ups and downs in the toy business - from AMT's faithful scale model kit of the USS Enterprise to Remco's obscure tie-in merchandise, to Mego's best–selling action figure line. Following Mego's bankruptcy in 1983 and a string of flops by Ertl and Galoob, Playmates Toys picked up the toy license in the late 1980s and sparked a resurgence in the franchise's toy sales.
From the mid-2000s onwards, companies such as Art Asylum and McFarlane Toys continue to keep the Star Trek toy franchise alive.

Space colonization is no longer the fodder of science fiction, it is becoming a reality. Examine the efforts underway to establish a human colony on Mars, including how they plan to grow food, recycle wastewater and introduce greenhouse gases to revive the red planet and make it more habitable for humans. Cutting-edge computer graphics are used to bring the universe down to earth to show what life would be like on Mars, and to imagine what kind of life forms might evolve in alien atmospheres.

When Japan’s military expansion in the Pacific reaches its fever pitch, Roosevelt is forced to act. By cutting off oil supplies, he hopes to force Japan to back down. But far from sedating their imperial expansions, he pushes them to take one of the greatest gambles in military history – taking their entire striking fleet 4000 miles across the Ocean to attack the American Pacific fleet in Pearl Harbor. It’s a huge gamble, and if it goes wrong, it will spell suicide for Japan.

Jeremy's restaurant opens in a matter of days, but it's all on the QT. Jeremy does not want the council to find out until just before it opens. Which is why Jeremy and Kaleb are laying pipes for water and electrics across a field in the dead of night. Pepper the heifer is still very much alive and is enjoying the company of Break Heart Maestro a lot.
Two days until Restaurant Opening Day, Jeremy informs the council and it's game on: Alan and his team of builders work at full throttle, Pip and her team of chefs do too, and the blend of excitement and panic is affecting everyone. The day itself arrives. Will the Diddly Squat Farm Restaurant sink or swim? Or will the council shut it down before the first steak hits the grill?

The results of the TB test are in... but just as important is the fact that numerous calves are scheduled to be born in the next couple of weeks. The first few happen very quickly in the dead of night before Jeremy's woken up, but soon he and Kaleb are dealing with some very challenging situations. Jeremy also meets local farmers to discuss a farmers' co-operative to supply the restaurant - much-needed by some who are really struggling - because the clock is counting down to Decision Day, when the Council will hold a public meeting to decide the fate of Jeremy's restaurant.
After weeks of waiting, the day of judgement for Clarkson's restaurant is at last here. He and Charlie set off to put their case to the powers that be. Is it a Yes? Or is it a No?