Using Lightning as a Source of Renewable Energy

As the entire planet looks for new renewable sources of energy to reduce carbon emissions, and to prepare for the day when traditional fossil fuels become too expensive, we must consider every single available option. With that in mind I propose lightening. It's common, relatively, naturally produced, and harnesses large amounts of electrical energy.

Each year about one and-a-half billion lightning flashes occur in the atmosphere, with roughly 25 percent striking the ground. Each lightning bolt that actually hits the earth averages about one billion joules of energy, more than enough to power a 60 watt light bulb for six months. On the surface this seems a decent amount of energy, surely you can see why I suggest lightning as an energy source.

Unfortunately, as we look a bit closer a few flaws start to appear in my plan.

Let's look at the figures first. The average American household consumes 41 billion joules of energy each year, which means it would take 41 lightning bolts to power a house. There are 114 million households in the US, which means that the US requires 4.72 quintillion joules to power all its houses. This number is pretty meaningless to most but it basically signifies that the energy in all the lightning bolts on Earth in a year could only power eight percent of US homes. This number falls even further to just 0.6 percent if we assume that the US could only capture the lighting that actually strikes American soil, about 30 million strikes a year.

So the figures have left me a little deflated, now to continue with the analysis of my apparently ridiculous idea and look at the physics of capturing lightning. The greatest challenge is that the one billion joules of energy in the lightning bolt is released in mere fractions of a second in the form of heat, sound and electrical energy. In order to convert this energy into useful electricity and store it would require a giant capacitor capable of charging up instantly and then slowly and steadily releasing the energy when it's needed. Such devices are incredibly difficult and expensive to create and worst of all very inefficient.

The long and short of it after this brief and basic analysis of lightning as a source of energy is that it is not feasible. The physics of capturing and storing the energy are too complex to be worth the effort, and the actual energy levels involved are not really as large as one might think at first.

By. Joao Peixe of Oilprice.com