With frequency and intensity of extreme weather events, especially hurricanes, is increasing rapidly as a consequence of climate change, power cuts in many parts of the world become more and more apparent.
Utility grids are under enormous pressure to deal with such emergency situations way more often, while at the same time they should be providing cleaner, and yet not more expensive electricity.
Although these problems have been addressed, a general solution that could be applied everywhere, has not been found, resulting in lights going off more regularly than we all hope. This is why lately we have been able to observe an increasing interest in microgrids– small power networks, providing electricity from small-scale renewable sources like household solar panels or fuel cells, which can operate on a local scale, independent from the national grid.
According to experts, microgrids have now become a movement. The original idea comes from the concept of district energy, which was implemented many years ago, and it was essentially a specific design of neighborhoods, where buildings were constructed close to each other in order to share the sources of heat. The modern version, or microgrids, are somewhat an update to this, with a main advantage being the multiple sources of electricity, which reduce the risk of power loss during storms or at times of energy crisis.
In more detail, the main power sources that could be used in microgrids are four- district energy, used as a heating source, microturbines, usually found in utility power plants, solar, one of the most desired and much cheaper than before renewable energy source these days, and fuel cells, which convert chemical energy to electricity only minus the emissions.
Now, how do microgrids operate? Currently, they are only used as a complimentary to the power grid energy source. They are connected via the so called point of common coupling, where voltage levels and general maintenance occurs. In case of a disaster or a system failure, a circuit breaker separates the two, and allows the microgrid to provide power to the local communities.
The Department of Energy has already allocated $7 million for microgrid designs, and some states, such as Connecticut, are already in the process of building microgrids as local alternative sources of power in case of emergencies. No wonder these are seen as one of the green technologies that could completely transform the energy world
Image (c) Peter & Maria Hoey