What are ‘hybrid grids’, a brief primer
This blog is the start of a series where I want to explain to you the widely used and often misunderstood term ‘hybrid grids’, what do people actually mean when talking about it? I will introduce the four key aspects that are associated with hybrid grids and elaborate on its implications.
First of all it is important to realize that increased digitalization, the use of information technology and power electronics are key enablers for the transformational change the electric power system encounters. Due to technological and societal developments we can observe an acceleration of the changes in the interconnected electricity systems that are the largest man made technical constructs on earth. Experts unanimously agree that the importance of electricity as ‘the fuel of choice’ will increase by 60% over the next 35 years and it will be greener, more affordable and more accessible than ever.
In the drawing schematically the power system is presented, from the regional wide area high voltage connecting grid on top through distribution via medium and low voltage delivery to our homes, offices or factories where the electricity is used.
The four key aspects or technology ingredients that shape the electricity system of the future and are commonly associated with hybrid grids are:
- Mix of generation; by what technological means is the grid accommodating for the ways electricity is produced? This generation can be conventional (will probably be around for some time) but increasingly comes from variable renewables like wind and solar in all sizes, ranging from big offshore wind farms, large solar fields down to rooftop solar panels.
- Mix of transmission and distribution; by what technological means is the electricity transported to the point where it is used? Here we can think of overhead lines and underground cables but also local generation with micro turbines with or without storage, mobile sources like batteries from electric vehicles and even wireless for low energy and/or short distances.
- Mix of delivery; in what technological ‘form’ or characterization is the electricity to be delivered during intermediate stages or ultimately to the point of use? Is it direct current, alternating current (frequencies 16.7, 50, 60 and 400 cycles/second are presently widely used), high frequency or even micro waves.
- Mix of control; how is a safe, stable and reliable electricity system operation at all levels guaranteed? The protection and control is governed by the increasing digitalization; combining prediction of electricity generation and load, sensoring/monitoring at global/regional and local level together with an optimal combination of slow (mechanical) and fast (power electronic) actuators.
By definition a hybrid grid is characterized with those four key aspects.
A hybrid grid accommodates for changing mixes of generation, transmission and distribution, delivery form and control technologies.
In summary, due to technological and societal developments the electric power system as we know it today changes into a flexible (future proof) reliable sustainable and affordable hybrid grid that encompasses the four key aspects, and it is our challenge to manage this transformation.
Stay tuned, in my next blog I will elaborate on the 4 key aspects of hybrid grids and its implications.