As tides rise and fall twice a day, vast amounts of water swirl around the earth. This is a huge energy source that's currently largely untapped. An estimated 3000 gigawatts are available to be harvested globally, enough to power a third of the earth's homes. Yet compared to wind and solar, the technology needed to harness tidal power is still in its infancy. The power of the ocean’s tides is the last great untapped energy source on Earth. From sub-sea kites to floating platforms, teams of engineers are racing to perfect the technology to harness the vast flows of water.

Rehearsals briefly resume amid uncertainty over the band's future. Following a productive meeting with Harrison, the Beatles agree to abandon the idea of a live show and relocate to their Apple Corps studio to formally record the new album. Billy Preston, a musician the group met in Hamburg, joins in on the sessions on electric piano.

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.

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?