Wind Power and Power System Balancing
A power system load and generation must be equal or within the allowed deviation for security reasons. Power systems operate either at 50Hz or 60Hz frequency.
The violation of the balance between power consumption/load and production/generation in a power system will alter the frequency and threaten the stability of the power system (Basit et al. 2012).
European Transmission System Operators must maintain a real-time balance between generated and consumed electrical energy (Mott MacDonald 2013). Balancing responsibility for a power producer is to match the output of forecasted electricity in real-time (The European Wind Energy Association 2015).
Wind power generation is variable and production forecasts are not reliable, and the additional reserve capacity needs to meet possible net load changes (Sader 1993). There are two types of reserve services: spinning reserve and supplementary reserve. The spinning reserve of a power plant is the difference between the available power generation capacity and actual power output, and reserve power plants in a power system are supplementary reserves (Basit et al. 2012). Thermal and hydropower plants can serve as additional reserve capacity for wind power variations.
Wind power generators also can be used to provide capacity for a power system balancing. Wind power generators can ramp down/downward when they produce electricity and ramp up/upward when they operate below their potential.
The variable cost of wind power generation is low (Henriot 2015), and it is costly to operate wind turbine generators below their potential output. For economic reasons, wind power is better suited to provide downward balancing (Hirth & Ziegenhagen 2015).
Basit, A., Hansen, A. D., Margaris, I. & Hansen, J.C., 2012. A Review of Grid Requirements for Wind Farm in Denmark and China. In China wind power 2012.
Henriot, A., 2015. Economic curtailment of intermittent renewable energy sources. Energy Economics, 49, pp.370–379.
Hirth, L. & Ziegenhagen, I., 2015. Balancing power and variable renewables: Three links. Renewable and Sustainable Energy Reviews, 50, pp.1035–1051.
Mott MacDonald, 2013. Impact Assessment on European Electricity Balancing Market.
Sader, L., 1993. Reserve Margin Planning in a Wind-Hydro-Thermal Power System. IEEE Transactions on Power Systems, 8(2), pp.564–571.
The European Wind Energy Association, 2015. Balancing responsibility and costs of wind power plants., 2015.