| dc.description.abstract | An enhanced hydropower planning framework is introduced in a revamped formulation of the long-term European power system expansion model EMPIRE, making it a hybrid model featuring a combination between the traditional operational EMPIRE and a load-duration curve approach. Dynamic reservoirs and evaluation of expected intermittent renewable production facilitate cross seasonal storage of water in a strategic stage between the existing investment periods and operational hours. Full year time series of renewable production, inflow and reservoir contents are assessed to cover the expected load, together with thermal subsidiaries in 8 so-called subsubperiods per period, or season. The strategic generation mix is found by utilizing a load-duration curve approach. Expected load and intermittent production in the strategic stage is represented by duration curves approximations, and the model is required to cover expected load in all subsubperiods by combining the expected renewable production with available regulated hydropower and thermal sources. The aggregated strategic hydropower generation over a period constrains seasonal operational production, effectively incorporating real world dynamics of regulated hydropower. Additionally, with full year time series for intermittent generation the model is expected to better intercept intermittent variability when making investment decisions. By weighting the costs between strategic and operational decisions the model effectively becomes a hybrid model. The work is motivated by the substantial position of hydropower in a power system, particularly with regards to the increasing penetration of intermittent renewable energy sources. With more wind and solar power, the task of continuously balancing supply and demand becomes ever more challenging, giving hydropower an increasingly important role.
It is shown that the revamped model improves hydropower utilization by promoting cross seasonal flow of water. Compared to the original EMPIRE investments are altered with a higher preference towards wind power, a result of improved recognition of intermittent fluctuations in the strategic stage. The introduction of oblique subsubperiods shows how altering the temporal segmentation can facilitate different effects as solar power investments are intensified with better peak approximations. Extensive investments in intermittent renewables take place throughout the modeling horizon for all instances. | en |
