| dc.description.abstract | Today is a time of ever-increasing renewable energy penetration in national power systems. Although this is paving the path to a cleaner and greener future, it comes with a price regarding electricity grid stability and the security of energy supply. Effectively, the largest renewable energy additions are in form of wind and solar power, who’s primary source of energy is well beyond Mankind’s control. They are prone to variability through the week, day and even hour: they consist of intermittent renewable energy plants.
To tackle this intermittency, energy storage is needed in order to balance the electricity grid without having to immediately turn to fossil fuels or nuclear power. The growing challenge in the world today is finding appropriate energy storage technologies to manage our increasing energy needs, with the concept of integrated power systems where energy production and energy storage are combined in a co-location context. Today, pumped hydro storage (PHS) makes up 96 % of all energy storage worldwide, and constitutes if not the sole only form of large-scale electricity storage. But it requires important topographical settings in order to be installed. However, many countries that hold strong shares of intermittent renewable energy in their energy mix exhibit relief-deprived topographies, such as the Netherlands, Northern Germany and Denmark.
This research looks into a novel concept which would expand large-scale energy storage possibilities: Underground Pumped Hydro Storage (UPHS). This technology adapts the conventional PHS scheme to areas of little to no-relief, by taking the plant into the subsurface, creating hydrological head through depth underground (instead of strict height in mountainous contexts). Going underground enables large hydrological heads to be used, and limits water-use and environmental degradation.
GIS-based modelling, combined with geological literary insight manage to assess countries of the European Union regarding their UPHS physical implementation potential. Results are found distinctly, first in terms of realisable surface potential along the lines of two scenarios (according to UPHS surface requirements & constraints), and secondly in terms of geological adequateness. Both delineate geographical extents where UPHS finds niches. These two streams of findings are finally combined to seek out geographical regions and zones that express both the surface and subsurface constraints.
The overall results give substantial UPHS potential in Europe, with UPHS plants being found to meet surface constraints over an area of 4124,55 km2 in the first scenario, and 43 656,62 km2 in the second less-stringent scenario, dispersed throughout 8 countries of the EU. Geological insight narrows-down these results to specific geographical regions where, on top of the surface constraints, the subsurface is most likely to hold adequate UPHS-able characteristics.
These final results distinguish Europe’s UPHS implementation potential, and correspond to zones in the geographical regions of: Zeeland in the Netherlands, the Southeast of the UK, the Northern tip of France, throughout the island of Ireland, and finally the South & central portions of Denmark. | |
