A computer-implemented method for determining an optimal award schedule for satisfaction of energy efficiency and energy supply requirements for a portfolio of one or more buildings. A first auction is conducted so as to receive over a computer network, from one or more prospective efficiency suppliers, a plurality of first bids for the provision of energy efficiency, each such first bid specifying an amount of energy saved and a cost. A computer is used to determine a schedule of remaining portfolio energy supply requirements that would remain after the provision of energy efficiency from at least a plurality of the first bids. A second auction is then run so as to receive over the computer network, from one or more prospective energy suppliers, one or more second bids for a plurality of the remaining portfolio energy supply requirements, each such second bid specifying a cost. A computer is then used to determine the lowest cost combination of a first bid and a second bid that satisfies the portfolio energy requirement.