Remember the days when batteries in mobile phones and other device ran flat every day? A major irritation to be sure, but for critical implanted devices like pacemakers, failing battery power was nothing short of life-threatening.

That’s what prompted the idea that under-skin solar power-packs could drive such medical devices. Researchers in Switzerland proved the theory after extensive testing, showing that even in low-sunlight areas, and regardless of the season. these power cells could generate around 12 microwatts – double the requirement for a pacemaker.

From there it was an easy step to scale up the efficiency of the devices, as has been happening with solar generation everywhere, and the company SkinPower was launched. It offers simple surgical implants of under-the-skin powerpacs, able to charge most of our mobile toys and medical gizmos – and in particular new-generation implanted communication devices.

Even though batteries across the board have radically improved in efficiency, the idea of becoming a walking power plant clearly appeals to a new generation of tech-enthused people, and SkinPower has become the new must-have.

In fact, solar overall has become the world’s No. 1 power source, backed by hugely efficient battery storage. The critical difference is that solar is a technology, not a resource, and is thus effectively limitless.

The tipping point was reached last year when, pretty much anywhere in the world, the cost of installing and running rooftop solar plus battery storage, whether residential, commercial or industrial, was shown to be cheaper than the cost of producing and transmitting energy, no matter the source – coal, natural gas or nuclear.

And now the age of true human power – and free – is upon us!