Releasing Climate-Sensitive Critical Infrastructure Power Reserves to Improve Grid Resilience

Reserve power systems are widely used to provide power to critical infrastructure systems in the event of power outages. The reserve power system may be subject to regulation, typically focussing on operational time, but the energy required for ensuring the supply of reserve power may be highly variable. The energy required may be strongly influenced by prevailing weather conditions and seasonality, for example, heating and cooling requirements have strong temperature sensitivities. Reserve infrastructure can therefore offer potential benefits and services back to the wider electricity system when not in use, supporting a transition to low-carbon technologies such as wind and solar power.

Drawing on the Great Britain (GB) telecommunications systems as an example, we present a methodology and case studies demonstrating that historic meteorological reanalyses can be used to evaluate the capacity of reserve required to maintain the regulated target of 5-days operations. Across three case-study regions with diverse weather-sensitivities, it is shown that infrastructure with cooling-driven electricity demand leads to a peak in the energy consumption during the summer, thus determining both the overall capacity of the reserve required and the availability of 'surplus' capacity (with the surplus appearing during other periods of the year when demand is lower).

Both the total capacity and surplus are further shown to depend strongly on risk preference, with lower risk tolerance leading to substantial cost increase (in terms of capacity required) but also enhanced opportunities for the use of surplus capacity. It is also shown that meteorological forecast information enables greater volumes of surplus capacity to be accessed for a given reserve capacity and risk tolerance.

The availability of surplus capacity is compared to a measure of supply-stress (so-called demand-net-wind) on the wider GB energy network. For infrastructure with cooling-driven demand (typical of most UK telecommunication assets), it is shown that surplus availability peaks during periods of supply-stress, offering greatest potential benefit to the national electricity grid.