  Data centers owned and operated by large companies have a high power
consumption and this is expected to increase in the future. However, the
ability to shift computing loads geographically and in time can provide
flexibility to the power grid. We introduce the concept of virtual links to
capture space-time load flexibility provided by geographically-distributed data
centers in market clearing procedures. We show that the virtual link
abstraction fits well into existing market clearing frameworks and can help
analyze and establish market design properties. This is demonstrated using
illustrative case studies.
