  Most renewable energy sources (RES) do not provide any inertial response.
Their integration in a power grid implies a highly reduced level of system
inertia, which leads to a deteriorated frequency performance. Then, the
requirement for frequency response is significantly increased in order to
maintain frequency security. Alternatively, enhanced provision of inertia from
auxiliary sources may alleviate this problem. However, the benefits of inertia
provision are not yet fully understood.
  In this paper, an inertia-dependent Stochastic Unit Commitment (SUC) tool is
applied to quantify the economic value of inertia. The results demonstrate that
enhanced provision of inertia would lead to significant economic savings,
although these savings vary under different system conditions. These results
should be brought to the attention of both market operators and investors, in
order to inform the design of an ancillary-services market for inertia and the
investment in auxiliary provision of inertia.
