  In pursuit of carbon neutrality, many countries have adopted renewable
portfolio standards to facilitate the integration of renewable energy. However,
increasing penetration of renewable energy resources will also pose higher
requirements on system flexibility. Allowing renewable themselves to
participate in the reserve market could be a viable solution. To this end, this
paper proposes an optimal dispatch model for joint energy-reserve procurement
that incorporates renewable portfolio standards and RES serve as reserve
providers. Potential generator outages and deviations in renewable and load
power are modelled through a given number of probability-weighted scenarios. In
particular, reserve resources are initially booked in the base case and then
activated in non-base scenarios through the re-dispatch process. Marginal
pricing is used to derive energy, reserve, and power deviation prices. Next, we
develop the associated settlement process and establish several market
properties. The proposed pricing scheme establishes equivalence between thermal
generators and renewable units by accounting for their uncertainties, including
thermal generator outages and renewable power deviations, and their
flexibility, namely reserve and re-dispatch. We have shown that for renewable
resources, supplying reserve according to the dispatch results compared to
generating as much as possible leads to better profits. Simulations validate
the effectiveness of the proposed method and properties established.
