[Maxious]

> AWS and Sustainable Energy http://aws.amazon.com/about-aws/sustainable-energy/

> Many AWS customers have workloads with latency requirements that require they be hosted near their customers. [...] we locate AWS datacenters in places that allow companies to get the latencies they require.

> Both the Oregon and GovCloud Regions use 100% carbon-free power. AWS customers who want to operate in a Region that uses 100% carbon-free power can select one of these two Regions. We will continue to work hard on our own, and alongside our power providers all over the world, to offer our services in an environmentally friendly way in all of our Regions.

So if latency is important to you, there's an AWS Region for that. If carbon-free power is important to you (and maybe heroku could pass this through?), there's an AWS Region for that.