Unobtainium

Have you ever heard of unobtainium?

It's the magical energy mineral found on the planet Pandora in the movie Avatar. It's a fantasy in a science-fiction script, but environmentalists think they've found it here on earth in the form of wind and solar power. They think all the energy we need can be supplied by building enough wind and solar farms – and enough batteries.

The simple truth is that we can't. Nor should we want to – not if our goal is to be good stewards of the planet. To understand why, consider some simple physics realities that aren't being talked about.

All sources of energy have limits that can't be exceeded. The maximum rate at which the sun's photons can be converted to electrons is about 33%. Our best solar efficiency is currently 26%. For wind, the maximum capture is 60% - our best machines are at 45%.

So – we're pretty close to wind and solar limits. Despite PR claims about big gains coming, there just aren't any possible. And wind and solar work only when the wind blows and the sun shines, whereas we need energy all the time. The solution, we're told, is to use batteries but again, physics and chemistry make this very hard to do.

Consider the world's biggest battery factory: the one Tesla built in Nevada. It would take 500 years for that factory to make enough batteries to store just one day's worth of America's electricity needs. This helps explain why wind and solar still currently supply less than 3% of the world's energy, after 20 years and billions of dollars in subsidies.

Putting aside the economics, if your motive is to protect the environment you might want to rethink wind turbines, solar panels and batteries because they're built from non-renewable materials. Consider some sobering numbers:

A single electric-car battery weighs around half a ton. Fabricating one requires digging up, transporting and processing more than 250 tons of earth somewhere on the planet. Building a single 100 megawatt wind farm, which can – in theory – power 75,000 homes, requires some 30,000 tons of iron ore and 50,000 tons of concrete, as well as 900 tons of non-recyclable plastics for the huge blades. To get the same power from solar the amount of cement, steel and glass needed is 150% greater.

Then there are the other minerals needed, including elements known as rare-earth metals. With current plans, the world will need an incredible 200 to 2,000 percent increase in mining for elements such as cobalt, lithium and dysprosium, to name just a few. Where's all this stuff going to come from? Massive new mining operations: almost none of it in America, some of it imported from places hostile to America, and some in places we all want to protect.

Australia's Institute for a Sustainable Future cautions that a global gold rush for energy materials will take miners into remote wilderness areas that have maintained biodiversity because they haven't yet been disturbed. And who is doing the mining? Let's just say that they're not all going to be union workers with union protections.

Amnesty International paints a disturbing picture. The marketing of state-of-the-art technologies are a stark contrast to children carrying bags of rocks! And the mining itself requires massive amounts of conventional energy, as do the energy-intensive industrial processes needed to refine the materials and then build the wind, solar and battery hardware.

Then there's the waste. Wind turbines, solar panels and batteries have a relatively-short life: about 20 years. Conventional energy machines, like gas turbines and electricity generators, last twice as long. With current plans the International Renewable Energy Agency calculates that by 2050 the disposal of worn-out solar panels will constitute over double the tonnage of all of today's global plastic waste. Worn-out wind turbines and batteries will add millions of tons more waste. It will be an entirely new environmental challenge!

Before we launch history's biggest increase in mining, dig up millions of acres in pristine areas, encourage childhood labour and create epic waste problems we might want to reconsider our almost inexhaustible supply of hydrocarbons – the fuels that make our marvellous modern world possible. And technology is making them easier to acquire and cleaner to use every day.

The following comparisons are typical – and instructive:

It costs about the same to drill one oil well as it does to build one giant wind turbine. And while that turbine generates the energy equivalent of about one barrel of oil per hour (should there be sufficient wind) the oil rig produces ten barrels per hour. It costs less than 50 cents to store a barrel of oil or its equivalent in natural gas, but you need $200 worth of batteries to store the energy contained in one barrel of oil.

Next time someone tells you that wind, solar and batteries are the magical solution for all our energy needs, ask them if they have any idea of the cost to the environment.