Photovoltaic (PV) module costs have declined rapidly over forty years but the reasons remain elusive. Here we advance a conceptual framework and quantitative method for quantifying the causes of cost changes in a technology, and apply it to PV modules. Our method begins with a cost model that...

Biofuels have been evaluated based on their greenhouse gas emissions, costs, and potential scale of production. Here we propose that feedstock supply risks should be added to the list of key metrics for evaluating the performance and scalability potential of transportation biofuels. Biofuels...

If global photovoltaics (PV) deployment grows rapidly, the required input materials need to be supplied at an increasing rate. In this paper, we quantify the effect of PV deployment levels on the scale of metals production. For example, we find that if cadmium telluride {copper indium gallium...