Next-generation access networks must provide bandwidths in the range of 50-100 Mb/s per residential customer. Today, most broadband services are provided through copper-based VDSL or fiber-based GPON/EPON solutions. Candidates for next-generation broadband access networks include several variants of WDM-PONs. The total cost of ownership of these solutions is determined mainly by operational expenditures, where the cost of energy is one of the major contributors. We show that a combination of WDM-PON with active L2 switching can minimize the total cost of ownership while at the same time offering the highest scalability for future bandwidth demands.