Coal, oil and batteries all store energy. If you had said just a decade ago that we would be looking at a future where the most important source of power could be the third one I doubt many people would have believed you.

Not so long ago ‘renewable energy’ was a phrase whispered by the few, ridiculed by the many and certainly held at bay by the giant energy suppliers.

Now it’s at the forefront of the promotion of pretty much any product or service that is fuelled by a finite and polluting resource no longer seen as acceptable by us all.

Power to the people.

It seems that, certainly in the western world, we have reached a tipping point where the importance of renewable and sustainable sources of energy has moved from being a hippy dream to a part of mainstream, day-to-day life.

The industrial revolution was powered by coal but the post-war boom and the explosive growth that followed was fuelled by oil. ‘Black gold’ was an endless resource. Sometimes it had to be pumped from the ground but often enough the oil companies simply dug a well in the right place and the stuff gushed out to meet us. By pipeline and tanker the oil flowed around the world and a stream of money followed it.

It was hard to imagine it ever coming to an end, but then some people started to realise that one day, it would. At the same time, oil began to get a stain on its reputation. Pollution and, later on, global warming and climate change became hot topics. We had a stick and a carrot to drive us all to find a better way; the promise of clean energy and the threat of the oil running out.

Rechargeable.

The sheer scale of change is perhaps easiest to see in the car industry. Transport represents over 60% of the world’s crude oil consumption and petrol-heads must be the world’s biggest fans.

Now, the once sexy petrochemicals used to propel beautiful sports cars around the streets of Monaco might soon be consigned to the history books. Look at how quietly (pun intended) Formula E has worked its way into the mainstream of motorsport. Look at the number of electric and hybrid cars on the road, from Tesla’s new Cybertruck to the Nissan Leaf. It’s a trend that will only increase. Once you’ve burnt a litre of petrol, its gone but once you’ve drained your battery, you simply recharge it.

Positives and negatives.

Thanks to AC/DC transformers, it is easy to send electricity from where it is made to where it needs to be used but oil still has one big advantage. Oil stores energy but electricity is hard to store. Batteries are the pinch point of this clean revolution.

That hippy I mentioned earlier was probably using truck batteries or even submarine batteries to store his wind and solar power but that simply isn’t commercially viable or practical. Lithium-ion batteries have got us so far but there are issues of production, disposal and durability that limit them. We must look for something better.

Fuel cell technology – making electricity from hydrogen and oxygen – offers great possibilities but there is still a long way to go. At the moment it would be like trying to use a steam engine to propel an aeroplane.

The sun and the wind.

Electricity is only clean and renewable when it is produced by sustainable sources of power. Wind power is the UK’s strongest source of renewable energy and now makes up 20% of our electricity. Solar panels contribute 6%. There are electricity providers who offer tariffs that are 100% renewable and they will include hydroelectricity – just 2% of UK power generation.

Of course, there are other ways to be green that are closer to home.

Domestic wind turbines are fairly rare but a lot of houses – including mine – have solar panels, either for heating or generating electricity. Even closer to home, how is our industry dealing with the issue, and the opportunity?

Warm leisure

In 1976 I helped my father to build our first swimming pool and, as a sign of things to come, that pool had a DIY solar heating system made from black alkathene pipe rolled up like a giant liquorice coil located on the roof of the plant room.

Solar powered heating has been used in our industry for years alongside traditional fossil fuelled heaters but now the heat pump has really come of age; whisper quiet, high performance, connected and coming to a pool or hot tub near you.

Heat pumps save on energy because a heat pump only uses electricity for power rather than for generating heat. They offer a remarkably high efficiency rate and will heat a pool or spa all year around, even in this country.

Over the years, I have seen our industry become far more responsible when it comes to green issues, not just with energy, but water and chemical use as well.

It’s a trend that, fortunately for all of us, shows no sign of fading.