The decline reflects possible delays in construction activity due to supply chain disruptions, lockdown measures and social distancing guidelines, as well as emerging financing challenges. The IEA expects the quantity of latest renewable energy rolling out this yr to fall by a 3rd to its lowest annual growth charge since 1996.
However, the majority of these delayed projects are expected to come online in 2021 and lead to a rebound in capacity additions, IEA believes.
Given 2019's exceptional renewable energy growth, Europe looks set to have one of the steepest drops in capacity additions, losing a third.
Renewables are the only fuel source with a forecasted demand increase in 2020.
The renewables, unlike fossil fuels and nuclear energy, have showcased their resilience during the pandemic and the economic slowdown, and are expected to rebound in 2021, reaching the same level of growth as in 2019, according to the IEA forecast.
For solar, which accounts for more than half of the renewable expansion globally in 2020 and 2021, additions are expected to decline from 110GW in 2019 to just over 90GW in 2020. Large-scale solar PV projects are expected to rebound in 2021, but overall installations are unlikely to surpass 2019 levels.
"The resilience of renewable electricity to the impacts of the Covid-19 crisis is good news but cannotbe taken for granted", said Dr Fatih Birol, the IEA executive director, in a statement accompanying the report.
"This is because of a significantly slower recovery of distributed solar PV as households and small businesses review investment plans", the agency added.
"Even before the Covid-19 pandemic struck, the world needed to significantly accelerate the deployment of renewables to have a chance of meeting its energy and climate goals". But the impact of the Covid-19 crisis is likely to be limited for offshore wind, as such projects have longer construction periods, it explained.
Birol said the resilience of the renewables industry can not be taken for granted, and warned governments against reining in clean energy spending to weather the looming economic crisis wrought by the coronavirus.
The IEA report said it was essential that governments provide policy predictability, which they could do through ambitious targets and objectives, reduce administrative barriers to renewables, and put renewables at the centre of stimulus packages.
"The continued decline in renewable energy costs alone will not be enough to shelter the industry from the current crisis".
While sectors supplying electricity - solar, wind and hydropower - would be largely resilient in the crisis, it said, the market for biofuels used mainly in transport would be "radically" altered as global travel is frozen and oil prices plummet.