Microgrids, a technology whose time has come

The traditional image of a power station is of a sprawling complex with a group of huge cooling towers shaped like sawn-off cones, belching noxious white steam as they loom over it. Thermal power plants fired by coal or gas use high-temperature steam to drive turbines, converting heat into electricity. The steam then has to be cooled with fresh water before being reheated and reused. The result is inefficient, as well as polluting, as a finite resource is consumed and carbon is released into the atmosphere. Nuclear power stations, which do not emit carbon, also use steam to drive turbines. Historically, hydroelectric power has been widely used as a renewable, and it currently has a share of about 16% of capacity worldwide. The growing climate emergency and its ever-more-visible results enhance the lure of alternative ways of generating electricity. These are also known as distributed generation assets:  they are renewable, sustainable and emission-free, and can be linked together as microgrid systems.

 

However, the share of renewables still has some way to go, with almost 80% of total energy produced expected to come from renewable sources by 2050. The United Nations’ Sustainable Development Goal is for almost half of generation to be met from renewables by 2030.  Wind and solar are now the cheapest means of electricity generation across two thirds of the world, according to Bloomberg New Energy Finance. The energy consulting arm of the data giant expects them to undercut coal and gas almost everywhere by 2030, such is the scale of the drop in price. The advantages of wind and solar generation also include size. Onshore wind farms and solar arrays are typically far smaller than the huge sites that house traditional power stations, meaning they can be located close to, or even on the site, where the power will be used. That avoids wastage, because the further electricity has to travel, the more of it is lost.