2016 The Authors. Published by Elsevier Inc. on behalf of International Energy Initiative. This is an open access
article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Except where otherwise noted, this item's license is described as 2016 The Authors. Published by Elsevier Inc. on behalf of International Energy Initiative. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).