The institutions that policymakers turn to for data and projections on important energy trends aren’t doing a very good job when it comes to renewables, almost invariably selling things like solar and wind short when it comes to growing deployments and lowering costs.

So say Eric Gimon and Sonia Aggarwal, from America’s Power Plan, a group that has come up with a set of recommendations for transforming the U.S. electrical system.

The pair looked at the recent performances of the Energy Information Administration, National Renewable Energy Laboratory and the Western Electricity Coordinating Council.They found consistent lag in these institutions in understanding where renewable energy markets had moved and overly conservative projections about future trends in cost and deployment. And that can have real consequences, they said.

By using two- or three-year-old numbers for solar and other disruptive technologies, policymakers are driving blind, underestimating the deployment rate for new technologies and overestimating their costs. With one foot in the past and one foot in the future, policymakers can’t fully take advantage of important new technologies available today. — Driving Blind: The Worst Examples of Outdated Data Skewing Renewable Energy Projections, published on Greentech Media

With all this in mind, Gimon and Aggarwal recommend the policymakers push hard for the most current data, test a wider range of cost assumptions (less conservative ones, presumably) and “build continuous improvement into policies and/or use an iterative approach.”