People used to think I was mad. Some still do.
The problem with renewable energy is that
if we can't store it on the days when the sun doesn't shine and the wind doesn't blow,
we won't be able to use it.
I'm just a quiet man in the background coming up with ideas.
I don't have any qualifications or anything.
I've actually never passed an exam, so I'm completely self-taught.
And, yeah.
I really started looking at things in the 1960s.
And probably I was about 12 years old.
I looked at the world and I realised
it wasn't sustainable by using fossil fuels.
I did look at lots of alternatives,
but I'd always had the idea of using liquid air as energy,
as an energy carrier really, it's not an energy source.
It's like batteries store energy.
You can store it in various other means.
And I chose liquid nitrogen because not many people were working on that.
The liquid nitrogen engine works on the same principle as a steam engine.
You boil the liquid nitrogen same as you boil water into steam.
That creates the pressure which acts on the piston or the turbine,
and that creates your mechanical energy.
Problem with liquid air has always been
that it creates a very high pressure,
and when you expand it from the high pressure,
that creates cooling, that makes the gas shrink,
and that makes it very inefficient.
My invention overcomes that.
This is a representation of the Dearman Engine.
You can see, we've got the heat exchange fluid on top of the piston.
As the piston approaches the top, it goes over the top
and then draws some fluid in,
and then we add in the liquid nitrogen.
I'm just using air here, just to show how it works.
By adding a heat exchange fluid on top of the piston
and the gas and liquid nitrogen injected into the fluid,
and it maintains the temperature as it's expanded.
It is a very simple solution,
and it does seem obvious once you've seen it,
but it's like most inventions, it's having that sort of light bulb moment.
The lawnmower engine was OK,
but I needed something a bit more impressive.
to publicise that liquid nitrogen could power a car.
So I modified a car engine and ran it up and down the street.
It was 50 years in the making
to actually finally get behind the wheel of a car powered by liquid nitrogen.
You know it's going to work,
but you need to actually do it to prove it.
I have had it doing over 30 miles an hour.
We're not all driving around in liquid nitrogen cars at the moment,
because liquid nitrogen is a low energy density fuel,
so it will never perform like a petrol car.
Well, obviously my neighbours see me riding up and down in this car.
Most of them are just very interested.
Some probably thought I was a madman,
but you having an invention,
that's only a small part of it.
You need to then bring it to the wider world, show them that it works,
and then find a practical use for it.
So we're using liquid nitrogen to store energy.
On the days when we have surplus energy,
we use that to compress the air and liquefy it,
and then when we need the energy,
we expand the liquified air to drive a turbine and produce power.
The advantage over using batteries
are that it doesn't use any scarce materials
and it doesn't wear out.
Batteries may only last 10 to 20 years.
This system will keep going for at least 50 years.
Batteries are about 90% efficient.
Liquid air can actually approach that if you
use waste heat and waste cold from other industrial processes.
Well, particularly with global warming,
as temperatures rise, there's much bigger need for refrigeration.
More and more food will be wasted unless we can find a clean and efficient way of preserving it.
We're using the Dearman Engine on a truck refrigeration system.
The engine itself powers the control systems and the evaporation of the liquid nitrogen,
which produces the cold,
is used to refrigerate the truck.
The Dearman Engine replaces the diesel engine,
which are very polluting at the moment.
This has the potential to help reduce pollution
in a really sustainable way.
It is a big deal. Yeah, yeah. Um, yeah,
how to put that into words though, yeah.
With global warming,
if you can power a car with liquid nitrogen,
you can use the cold to create air conditioning
and the power to drive the car.
And that's what I'm working on at the moment.
It might not work, so
I don't want to say too much about it.
I know it will, but...
Tried lots of inventions, but they usually fail
because until you look into it,
you don't know, do you, what the future holds.
People used to think I was mad,
and it's very difficult to get people to take notice
of somebody who's working on their own in their shed.
You know, you're a lone inventor.
You haven't got the resources that big institutions have got,
with thousands of people working on things.
Well, most people think well if it was any good, the idea,
it will already have been done. That's quite common.
There's so many problems in the world,
the more minds that we can put to it,
the more people that can work on them,
even if it's only on their own in their shed,
you can make a difference.