Algorithmic investment screening for wide-area transmission network expansion planning

In concert with increasing co-ordination of energy markets, transmission planning for location-constrained generation is forcing a shift from regional to wide-area transmission network planning. Planning for locationconstrained generators, notably wind and solar resources, is complicated by uncertainty in policies driving their growth. To design transmission systems robust to uncertain future expansion of location-constrained generators, planners must incorporate stochastic generation into models. The size of the transmission expansion problem makes this computationally
intractable. This paper presents a screening model to reduce the number of transmission investments which must be considered. The screening model combines sampled generation expansion scenarios with a two-stage relaxed planning model to identify corridors of interest. A St.Clair curve-based filter translates corridors to investment variables. In a 240 bus model of WECC, this method reduced the number of corridors of interest 98% from 19,503 to 303 and reduces the number of investment variables 99% from 58,503 to 432.