  We compare two competing methodologies of market zones identification under
the criterion of social welfare maximization: (i) consensus clustering of
Locational Marginal Prices over different wind scenarios and (ii) congestion
contribution identification with congested lines identified across variable
wind generation outputs. We test the division of market into zones based on
each of the two methodologies using a welfare criterion, i.e., comparing the
cost of supplying energy on uniform market (including readjustments made on a
balancing market to overcome the congestion) with cost on k-zone market. A
division which maximizes the welfare is considered as the optimum.
