In light of the recent Guardian story that Portugal generated all its electricity with renewables for four days, I thought I’d re-examine how well Portugal is doing overall. While it’s significant that Portugal ran four days with only renewable energy—and the lights stayed on—it’s more important to know how much of their annual consumption comes from renewables.
Annual generation tells us more about total emissions of greenhouse gases than a snapshot of less than one week. Moreover, it’s not as startling as most might think that a nation generated 100% of its electricity with renewables. It was not so long ago when this was quite common. Norway generated 100% of its electricity with hydro up to 2008. And Iceland currently generates 100% of its electricity with hydro and geothermal.
Because the US Energy Information Administration (EIA) is asleep at the switch—again—there’s no data on Portugal since 2012. Consequently, I’ve interpreted charts on the web site of APREN (Associação Portuguesa de Energias Renováveis).
From APREN’s chart it looks like Portugal is generating about 16.5 TWh per year from new renewables. In wet years, Portugal generates some 15 TWh from large hydro alone. In 1988 for example, hydro provided 58% of Portugal’s 21 TWh of generation.
Unfortunately, Portugal’s consumption has doubled since 1988 to more than 50 TWh per year. And hydro’s contribution is highly variable, dropping to a low of 5 TWh in the drought year of 1992.
Since my last report on Portugal in 2013, new renewables have continued to increase their share of generation. As you would expect, this is squeezing fossil-fired generation.
In good years, such as 2015, Portugal’s renewable generation is made up of mostly hydro–both large and small dams–wind, and biomass.
Significantly, solar PV makes up only a few percent of Portugal’s electricity generation.
APREN’s chart on total production suggests that in 2015 large hydro generated somewhat more than 10 TWh, possibly as much as 13 TWh.
Together, large hydro and new renewables are contributing some 30 TWh per year to Portugal’s demand of somewhat more than 50 TWh, supplying 55% of total electricity consumption in 2015.