"One of the most important and challenging undertakings in the IEA's history", asserts the foreword in the IEA's analysis of what needs to be done to achieve net zero by 2050.
Whereas previous IEA reports examined a number of scenarios, this one focuses on "the most technically feasible, cost-effective and socially acceptable" pathway. The report sets out some 400 milestones on the way to transforming the global economy dominated by fossil fuels into "one powered predominantly by renewable energy like solar and wind."
The IEA admits the task is formidable and "requires vast amounts of investment, innovation ... International cooperation and effort across many other areas".
The scale of the challenge for wind can be visualised by looking at the projections for electricity generation. In 2020, total wind generation worldwide was just under 1,600TWh. By 2030, it needs to increase fivefold — to 8,000TWh; the corresponding generating capacity is 3,101GW. That means, on average, 236GW will need to be built every year from 2020 to 2030.
If we assume a mix of onshore and offshore machines, with an average rating of 8MW, then almost 30,000 turbines a year will need to be built. The pace slackens slightly to 2040 and eases further to 2050, by which time world wind capacity would be 8,265GW.
Wind and solar PV together will account for 68% of electricity generation by 2050, with wind contributing slightly more, according to the IEA. Hydro will contribute 12% by 2050 and other renewables (bioenergy, concentrating solar power, wave and tidal energy) 9% in total.
Nuclear too expensive
The IEA envisages a modest expansion of nuclear generation, which roughly doubles between 2020 and 2050, to reach 5,500TWh per annum. The sluggish development may be attributed to its high capital and financing costs, with a weighted average cost of capital of 8% in the US and Europe and 7% in China and India. This compares with values of 3-4% for wind and PV. By 2050, nuclear is still more expensive than any of the renewables. It is cheapest in China, at $60/MWh.
Renewable costs continue to fall
The IEA study quotes generation costs in four regions (US, the European Union, China and India). By 2030, solar PV is expected to be the cheapest technology, everywhere. The lowest PV capital cost in 2050 — $220/kW — is expected in India, giving a generation cost of $15/MWh.
The chart below shows generation cost estimates for the US from 2020 to 2050. Onshore wind in 2020, at $35/MWh, is cheaper than elsewhere and is also cheapest in 2050 — at $30/MWh. Offshore wind starts from a high baseline in the United States but falls rapidly to $40/MWh by 2050. In the EU, however, offshore wind falls to $25/MWh by 2050, which is less than onshore wind. Although the capital costs of offshore wind are about 10% higher, this is more than offset by higher capacity factors offshore (59% compared with 31% onshore).
The generation costs of the renewables are mainly driven by the capital costs, which fall steadily in all regions. However, operation and maintenance (O&M) costs are also expected to fall, particularly in the European Union, where offshore O&M costs may reach $5/MWh by 2050.
Achieving net zero by 2050 is a tough challenge. Following the IEA scenario, worldwide wind generation needs to increase by a factor of 16 from the 2020 figure. The latest edition of the Annual Energy Outlook published by the US Energy Information Administration suggests that wind generation in the United States will increase by a factor of just 2.3 by 2050.
The IEA admits that "the pathway remains narrow and extremely challenging, but technically feasible, cost-effective and socially acceptable".
At a glance — this month's report conclusions
Net Zero by 2050. A Roadmap for the Global Energy Sector, International Energy Agency, Paris, May 2021 Sets out a pathway that would achieve net zero by 2050, assigning wind a substantial share; incudes cost projections up to 2050