Optimized utilization of groundwood lines with single layer grinding surfaces for pulp production and electrical grid stabilization

The climate change is forcing the power production from controllable fossil-based combustion to intermittent renewable resources like wind and solar power. The power production and consumption must be equal at all moments
to stabilize the power system. This has traditionally been achieved with controllable production but the new situation with intermittent production requires new solutions. One solution is demand response that means flexible consumption to achieve balance between production and consumption in the power system. This paper analyzes the techno-economical possibilities for groundwood lines with single layer grinding surfaces to both produce pulp and to participate in electrical grid stabilization. Thanks to the on/off nature of the batch processing and the fast-loading response in wood grinding the process is suitable also for more valuable reserve markets. Based on the measured loading response, reserve requirements and marketplace prices investments for
participation in Frequency containment reserve for normal operation (FCR-N) and Fast frequency reserve (FFR) have a payback time shorter than 10 months that is attractive for forest industry. After payback the annual earnings are significant.