Your first reaction might well be that this seems both an obvious (why hasn’t anybody done this before?) and a somewhat dangerous idea. With the ever-increasing search for renewable energy sources, over the last thirty years or so there have been various attempts to investigate the possibilities – unsurprisingly, when you appreciate that just one bolt of lightning can offer the equivalent of 5 billion joules of energy. In reality, this is only a minuscule of the power needed to energise just one typical home for a year.
Here in the UK, lightning strikes occur on average about 11 days or so each year (less in Scotland and Wales). So, how would you know where to harvest your lightning? Even if you could predict where electrical storms are most likely to hit, this is still a fairly random proposition. It’s also true that much of a lightning bolt’s energy is expended in heating the surrounding air – leaving only a limited proportion of it to gather, store and then put to good use.
A key problem, capturing the ever-changing energy would be nigh on impossible; for example, the actual placement of ground based rods is often reckoned to be too problematic. It’s also true that there are practical difficulties in the conversion of an instant high-voltage lightning strike into the lower voltage, that is then able to be stored for slow release.
It has been suggested, if never fully proven, that Benjamin Franklin famously – if a little foolishly – used a kite to try and attract atmospheric charges. If the experiment did take place and he had succeeded, it’s likely that we might never have heard much more of his brilliance. To harvest such charged energy is thought to be technically doable but the practicalities of requiring huge constructions to do so forms another major barrier.
More recently, a laser-induced plasma channel was trialled. It was used to form an ionised gas column as a conduit to direct lightening to a ground station, to then be harvested. Currently, this idea is being more often used as a safety measure, directing lightning away from rather than towards a location.
With the most famous harvesting of lightening yet to be achieved being to power a time machine (Back To The Future) or to give life to a monster (Frankenstein), let’s hope more effective and practical advances can be made. A final thought to show just how difficult this idea would be: we don’t know for sure whether any lightning bolt is going to carry a positive or negative charge, which means that capacitors and rectifiers would also be needed to equalise the currents. Therefore, even if it were possible, it’s difficult to see how it would be cost-effective!
In the meantime, if you have any questions about lightning or electrical defence systems, Lighting Strike is always happy to help. Please call 01158 752 686 with all your enquiries.