Research institute and university The Swiss Federal Institute of Technology Lausanne (EPFL), is leading work to assess the impact of XFLEX HYDRO’s demonstrations on hydro plant operations and maintenance. Dr. Elena Vagnoni, scientist and lecturer at EPFL and XFLEX HYDRO Scientific Coordinator sets out the key parameters to be used.
To help evaluate XFLEX HYDRO’s technologies the ancillary services matrix, as described in the Flexibility, technologies and scenarios for hydropower report, will show the gains of the HPPs in supporting the provision of ancillary services. As well as these essential services to support power system balancing, XFLEX HYDRO activities also aim to strengthen the plants flexibility in terms of dynamic response services, optimised maintenance and improved availability.
For this, several key performance indicators (KPIs) have been defined to quantify the HPPs flexibility, focusing on the enhancement of operations and maintenance. This is being presented in a KPIs matrix, which is currently under development. The KPIs matrix will present the key parameters that will be evaluated to assess the benefits of each technological solution implemented in the demonstration projects. The identified KPIs are:
- Digitalisation: the measures adopted in the HPP for e-monitoring, advanced control systems and predictive maintenance will be evaluated to assign a digitalisation index linked to improved performance.
- Extended operating range (%): significant improvements in terms of operating range extension (off-design conditions) are foreseen.
- Fast start and stop (s): the time of the transient operations is expected to be noticeably reduced.
- Fast turbine turbine-pump / pump-turbine transitions (s): the time of the transient operations from pump (-100% load) to turbine mode (100% load) and vice versa is expected to be noticeably reduced.
- Fast ramp-up and ramp down (%/s): the rate for varying the power output in respect to the nominal condition is expected to rise.
- Optimised maintenance interval (h): the hours of operation between maintenance intervals are foreseen to increase, which will also denote a reduction of the outage time.
- Loading factor (h/d): the average number of hours of operation in a day are computed to evaluate the improved usage of the HPP.
- Extended availability (%): the percentage of availability of the HPP in a year, including planned maintenance, is estimated to highlight the increased readiness and availability of the HPP while decreasing unplanned maintenance, shortfall in the operations and unnecessary stops of the hydroelectric units.
- Increased weighted efficiency (%): the global efficiency of the HPP will be estimated by considering not only the efficiency of the hydroelectric unit, but also the power consumption of the auxiliary equipment, duly weighted. It is expected the overall efficiency of the HPP will rise.
The KPIs will allow quantitative assessment of the HPPs improvements thanks to the XFLEX HYDRO innovation activities; as well as tracking of the implementation of the technologies during the demonstration phase of the project. Once completed, the KPIs matrix is expected to highlight the potential of each technology demonstrated in the project, and their potential for integration across the hydropower fleet.
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This article was featured in the December 2020 issue of International Water Power & Dam Construction Magazine.