The latest issue of the U.S. Energy Information's (EIA) Electric Power Monthly (with data through March 31) reveals that renewable energy sources (i.e., biomass, geothermal, hydropower, solar—inc. small-scale PV, wind) accounted for 19.35 percent of net U.S. electrical generation during the first quarter of 2017. Of this, conventional hydropower accounted for 8.67 percent, followed by wind (7.10 percent), biomass (1.64 percent), solar (1.47 percent) and geothermal (0.47 percent). Combined, non-hydro renewables accounted for 10.68 percent of total generation.
Yet, just five years ago, in its 2012 Annual Energy Outlook, EIA forecast: "Generation from renewable sources grows by 77 percent in the reference case, raising its share of total generation from 10 percent in 2010 to 15 percent in 2035 ... The share of the total electricity generation accounted for by non-hydropower renewable generation increases from about 4 percent in 2010 to 9 percent in 2035."
If one assumes growth continuing at about the same annual rate as during the 25-year EIA forecast period (2010-2035), renewables would not be expected to reach 19.35 percent until roughly the year 2057—40 years from now.
EIA's 2012 report further forecast: "Wind [electrical generating] capacity increasing from 39 gigawatts (GW) in 2010 to 70 GW in 2035." A corresponding chart illustrates that projection and also shows solar reaching 24 GW of capacity in 2035.
In reality, according to the Federal Energy Regulatory Commission's latest Energy Infrastructure Update, with data for the first three months of 2017, wind generating capacity already totals 84.59 GW while utility-scale solar has reached 25.84 GW (and this does not include distributed small-scale systems such as rooftop solar). *
"Thus, not only has renewable energy's share of total domestic electrical generation nearly doubled in the past seven years, it has reached a level of output that EIA—just five years ago—did not anticipate happening for another four decades," Ken Bossong, executive director of the SUN DAY Campaign, noted.
"While one might conclude that EIA's methodology is seriously flawed, it is also safe to say that renewables—especially solar and wind—are vastly exceeding expectations and breaking records at an astonishing pace."'
This is clearly evidenced by comparing 2017 to 2016 year-to-date. During the first quarter of 2016, renewables provided 17.23 percent of total generation versus 19.35 percent in 2017. Actual generation by renewables is 9.70 percent greater than just a year ago. In particular, solar (i.e., solar thermal, utility-scale PV and distributed PV) has ballooned by 34.1 percent, wind has expanded by 11.4 percent, conventional hydropower has grown by 7.7 percent and geothermal has increased by 3.2 percent. Only biomass has declined year-on-year—by 1.6 percent.
* Note that generating capacity is not the same as actual generation. Electrical production per MW of available capacity (i.e., capacity factor) for renewables is often, but not always, lower than that for fossil fuels and nuclear power. The total installed operating generating capacity provided by utility-scale renewables in 2017 is now 19.5% of the nation's total for the first three months of 2017 (according to the latest U.S. FERC figures) whereas actual electrical generation from renewables for the same period is roughly 19.4 percent. However, both of these figures understate renewables' actual contribution because neither EIA nor FERC fully accounts for all electricity generated by smaller-scale, distributed renewable energy sources. FERC's data, for example, is limited to plants with nameplate capacity of 1 MW or greater and thereby fail to include distributed sources such as rooftop solar.