Independent thesis Advanced level (professional degree), 20 credits / 30 HE credits
The growing share of installed wind power in the Swedish electricity system has
caused concerns whether the available regulating power will be sufficient. Several
studies have examined the need of regulating power using both statistical and
modelling approaches. However, there is a risk that some aspects of the short-term
regulation of hydropower might have been missed.
By using one of Vattenfall’s hydropower planning tools, the short-term operation of
The Lule River has been simulated with an increasing penetration of wind power. The
tool includes detailed models of reservoirs, generating units including efficiency curves
and start/stop costs. By introducing a day-by-day simulation with a seven-day window
price forecast, updated with a new wind forecast for each iteration, a 21-days
scenario has been simulated. Transmission limits are disregarded and the thermal
production is reduced with the average wind production.
To quantify and compare the regulation capacity, the regulation factor is introduced.
It reflects the ability to utilise high-price hours and considering that the need of
regulating power for the short-term perspective is reflected in the price it will also
reflect the regulation capacity.
It is shown that the regulating factor is correlated to the discharge factor,whichis the
relation between the maximum discharge to the average statistical discharge for a
plant. A high discharge factor provides the flexibility to utilise the fluctuations in price.
The discharge factor is adapted to the plants placement in the reach, accounting for
both reservoirs located upstream and downstream, especially for The Lule River
which has been designed to regulate for the fluctuations in the load. The flexibility
required by the rest of the Nordic rivers is quantified for future studies.
It is concluded that The Lule River is able to meet some of the fluctuations of wind
power production due to the overcapacity ininstalled power. The production can, at
the expense of decreased efficiency of the generating units, alter the production to
suit a more fluctuating price.It is important to emphasise that The Lule River alone
cannot balance a large penetration of wind power.
To fully take into account the effects of a large penetration of wind power the study
must be expanded to include more scenarios. The study should include different types
of hydrological prerequisites and the seasonal variations in power production as well
as additional rivers.
2014. , 46 p.
Flexible generation, forecast error, HOTSHOT, hydropower planning, intermittent renewable energy sources, profit optimisation, regulation factor, short-term regulation, short-term production planning, The Lule River
Flexibel kraft, förnyelsebara intermittenta energikällor, HOTSHOT, korttids reglering, korttids produktionsplanering, Lule älv, prognosfel, reglerfaktor, vattenkraftsplanering, vinstmaximering