The author mixes Gigawatts and "generation" in the same piece without explanation. This is a deadly confusing mix to the unwary. Gigawatts is power. Generation is in kWh or in this case TWh. He should have stuck with generation. That was the point of the story. When he inserts GW he needs to clarify that the capacity factor of wind is less than that of hydro. Now it wouldn't surprise me that EIA screwed up the press release. I take all info from the EIA with a grain of salt.
Paul, I was re-reading that quote and just noticed that (been under the weather), so thanks for pointing it out. I should have seen it and emphasized the difference in the original post. Here's what the EIA report itself says (Pages 15-16), which does make the distinction:
Electricity Generation. EIA expects total U.S. electricity generation across all sectors to average
11.3 gigawatthours per day (GWh/d) in 2019, which would be 1.9% less than generation last
year. From 1980 through 2005, U.S. electricity generation grew by an average of 2.3% per year.
During the past decade, power generation has grown relatively little, fluctuating at an annual
average of about 11.2 GWh/d since 2010 with year-to-year changes related to weather. EIA
forecasts U.S. electricity generation will grow by 0.3% between 2019 and 2020.
Renewables Generation and Capacity. Renewable generation provided 17% of total electricity
generation in 2018, and EIA expects the share of generation from renewable sources to increase
in 2019 to 18% and to 20% in 2020. Within the renewables category, hydropower was 7% of
total generation in 2018 and EIA forecasts that it will be about that share in 2019 and in 2020.
The share of total generation for renewables other than hydropower, which was 10% in 2018, is
forecast to rise to 11% in 2019 and to 13% in 2020.
EIA forecasts almost 5 gigawatts (GW) of utility-scale solar photovoltaic (PV) capacity will be
added in 2019 and 6 GW will be added in 2020. Also, EIA expects nearly 9 GW of small-scale
solar PV capacity to be installed during 2019–20, mostly in the residential sector.
Domestic PV markets are still adjusting from several factors. Tariffs on PV modules imported
into the United States started at 30% in January 2018 and are expected to decline 5 percentage
points annually as they phase out over four years and expire completely after 2021. In addition,
revised PV installation targets in China produced a near-term surplus of PV modules that the
international market is still rebalancing. The Internal Revenue Service published a safe harbor
provision for PV installations to qualify for a 30% investment tax credit, which allows for a four
year construction period upon project initiation (considered to be the start of physical
construction or the expenditure of 5% of project value).
EIA expects wind capacity to increase from 96 GW at the end of 2018 to 107 GW at the end of
2019 and to 114 GW by the end of 2020. Because wind capacity is often added at the end of the
calendar year, increases in generation frequently lag increases in capacity for the year they
occur and are reflected in the generation for the next year.
The build out of new wind capacity through 2020 is strongly affected by the phase out of the
federal Production Tax Credit (PTC) for wind, which began with projects under construction
starting after 2016. Such projects take several years to complete, and the last tranche of
projects eligible for the full $25 per megawatthour tax credit will start to enter service in
significant numbers in 2019. Activity will taper off in later years as projects started in 2016
approach the limit of their safe harbor provisions and as the construction pipeline begins to
shrink, reflecting reduced PTC pay offs for projects beginning construction in 2017 and later.