| dc.description.abstract | Since COP21 there is international agreement on the problems caused by anthropogenic greenhouse gas emissions. These emissions originate for a substantial part from electricity production from fossil fuels. Most countries already invest in a transition towards renewable electricity production from solar and wind resources. The challenge is concerned with the intermittent nature of these renewables. Energy storage and demand response are both regarded as possible solutions to this challenge. However, a flat country like the Netherlands seems to be at a disadvantage with its unsuitable geography for the worldwide most common energy storage system; pumped hydro storage (PHS). The solution was proposed in a PHS that has an underground lower reservoir connected to a surface reservoir, thereby requiring no geographically elevation to be present.
This research investigated the possible benefits that can be achieved with underground pumped hydro storage (UPHS) in the Dutch power system. Literature research provided the results for possible benefits that UPHS could provide to a power system in general. Additionally, a model of the Dutch power system was developed using PLEXOS modeling software. The UPHS was compared to both battery energy storage (BES and BESXL) and demand response (DR), using scenarios. The model was run with each scenario for the model years 2017, 2020, 2025, 2030 and 2035. These future years had increased renewable capacity and shrinking thermal power generator capacity for each subsequent model year. The results from the model runs provided the basis for comparing the performance of UPHS, BES and DR in the Dutch power system.
Both literature research and model runs indicated that several benefits can be expected from implementing UPHS in the Dutch power system. The most important benefits are: The substantial reduction in unserved demand when thermal generator capacity cannot meet demand (observed in the 2035 model year). Less flexibility burden on thermal power generators, which results in less costs and less renewable curtailment. And the possibility store renewable production surpluses, thereby helping reduce the amount of CO2 emissions from the power system.
The model results showed that the UPHS outperformed DR on all aspects, except the average electricity price which was lower in the DR scenario. The performance difference with the battery storage scenarios (BES and BESXL) is limited, as both energy storage technologies are similarly used in the power system. Further comparison showed that the benefits of UPHS compared to the BES are: Its dedicated application as grid energy storage, its longer lifetime and the possibility to implement it at a large scale. UPHS does not have to compete with other applications for key components. Battery based grid storage on the other hand will have to compete for Li-ion cells with the increasing electrification in the automotive industry. The substantial difference in lifetime of the storage systems also result in a favorable case for the UPHS system compared to BES. In the long run UPHS may even compete with gas turbines as peak load generator, because both have a similar COE (costs of electricity) in the 2035 model year. | |
