Clean tech costs have fallen 41–94% over the past 7 years. Wind and solar accounted for two-thirds of new energy installations in the US in 2015.
A new report from the US Department of Energy paints a bright picture for our prospects to cut carbon pollution and prevent the most dangerous levels of climate change. The report looked at recent changes in costs and deployment of five key clean energy technologies: wind, residential solar, utility-scale solar, batteries, and LED bulbs. For each technology, costs fell between 41% and 94% from 2008 to 2015.
a wind turbine installed today on average has 108% longer blades and is 48% taller than one installed in 1999. The longer blades allow each turbine to capture more energy, and taller towers allow access to the stronger and more consistent wind speeds that occur at higher altitudes in many parts of the country. Combined, these innovations allow each turbine to produce more electricity, reducing both the number of turbines needed to produce a given amount of electricity and the land area needed for their installation.
For example in 2015 the Department of the Navy procured 210 MW of a utility-scale PV project to support fourteen Navy installations in California.