Interest in powering datacenters at least partially using on-site renewable sources, e.g. solar or wind, has been growing. In fact, researchers have studied distributed services comprising networks of such \"Green\" datacenters, and load distribution approaches that \"Follow the renewables\" to maximize their use. However, prior works have not considered where to site such a network for efficient production of renewable energy, while minimizing both datacenter and renewable plant building costs. Moreover, researchers have not built real load management systems for follow-the-renewables services. Thus, in this paper, the authors propose a framework, optimization problem, and solution approach for siting and provisioning green datacenters for a follow-the-renewables HPC cloud service.