Why do we have mains?

      There’s an old story about the width of railway lines. The dimension was taken because it fitted the axles that were already used on carts. The axles on carts were set to allow for the arms that connected the wheels to a horse.

      But the spacing of the arms was defined by the gap needed to fit two horses. So the spacing on of railway lines is defined by the entirely irrelevant measure of an average horse’s rear.

      This all changed with the car.  Wheel spacing on cars can be whatever makes sense for the vehicle- there’s no need to follow convention when the technology has grown out of tradition methods.

      It’s the same in off-grid energy. For many years, governments have been working on ways to connect rural communities to the grid, but to what end? 1.3 billion people worldwide, mainly those in hard-to-reach rural communities, still live without electricity - how long would we have to wait to connect them all in the conventional grid way?

      Horse-and-cart methods just won’t work on a scale like this- we need to abandon the idea that Africa will become electrified in the same way as densely populated Western countries, and wake up to the possibility of new technology as a way forward. Africa is ready to jump over the industrial revolution and step straight into the information age by using the latest solar technology to solve the problem of rural electrification.

      There’s a fundamental difference in the kinds of power we’re talking about. Solar creates low voltage “DC”. Mains electricity is high voltage AC so it can be converted readily and travel long distances. However, distributed power does not need to travel long distances and many devices such as modern LCD TVs struggle to work with mains, needing to have an external transformer to reduce it to low voltage DC.

      When you think of electricity, the idea of making a coffee of having a shower comes to mind. But users where electricity is scarce would be horrified by such a wasteful idea. Electricity is a valuable resource and used in small quantities for high value activities such as lighting, phone charging and entertainment. Almost all of these solid-state devices run from DC voltages very efficiently, so lets break the convention and define the DC house.

      The DC house has no high voltage- it’s efficient and works well, with DC power running DC devices. With no high voltage, there’s no electrocution risk- you’re not going to manage to kill yourself with 12 volts, no matter how much water you pour over it. No electrocution risk means it’s easier to install it and know it’s going to remain safe- a matter of importance when the nearest technician is half a day’s bus ride into town. More importantly, it can be installed in minutes, without the need for massive electrification programs that can take years to deliver, if at all.

      With this new power, families can enjoy the evenings together, children can complete their homework and life is no longer tied to the speed of rotation of the earth.

      As a result, we have a new way of delivering home electricity that does not rely on a quirk of history. It can be delivered by businesses as well as governments who realise that the course of rural electrification doesn’t have to rely on the metaphorical horse’s backside of grid connection.

Pippa Bransfield-Garth

In-house blogger, Azuri