A limited number of hydro schemes can currently deliver electricity cheaper, but hydro — with limited extra resources — does not feature in their assessment of costs out to 2022.
By that date, wind is still cheaper than solar — but only just. The respective average costs of energy are projected as $45/MWh and $48/MWh.
Irena’s assessment of current costs are shown in the chart below.
The global weighted-average cost of electricity for onshore wind is $56/MWh, with offshore wind at $127/MWh. Solar PV comes in at $85/MWh, bioenergy at $62/MWh and geothermal at $72/MWh. The figure for hydro is $47/MWh and concentrating solar power (CSP) is still somewhat more expensive at $185/MWh. Irena estimates that the fossil-fuel price range is currently $50-170/MWh.
Both the solar technologies (PV and CSP) have come down in price rapidly over the past ten years and Irena expects CSP to undercut offshore wind by 2022.
The overall averages mask considerable variations in costs and performance.
Installed costs of onshore wind vary from $1,170/kW in China to $2,237/kW elsewhere in Asia; the global average is around $1,500/kW.
There have been significant reductions in cost since 2010, averaging around 35%. During the same period, capacity factors increased, and the levelised costs of generation now range from $50/MWh in China, South America and North America to around $110/MWh in some Asian countries.
Another factor that has helped to bring down generation costs has been the reduction in operation and maintenance (O&M) costs.
Irena suggests these average $20-30/MWh for onshore wind farms, but a more recent paper from the US-based Lawrence Berkeley National Laboratory (LBNL) suggests they now average around $11/MWh, based on a survey among wind industry professionals.
The apparent discrepancy may be due to the fact that the LBNL data was drawn from North America, where large wind farms enable economies of scale and more efficient practices. Irena suggests offshore O&M costs range up to $50/MWh.
The wide variations result from the many aspects that make up O&M costs, some of which, such as property taxes, vary with location.
The costs of unscheduled repairs also influence data from individual wind farms.
The LBNL report includes a detailed summary indicating the scope of O&M costs (see table), which shows that turbine maintenance accounts for around half of the total costs.
The LBNL report suggest that O&M costs — across Europe and the US — came down by around 15% during the period 2008-16 and are expected to fall further.
At a glance — This month’s report conclusions
Renewable Power Generation Costs in 2018, International Renewable Energy Agency, 2019 Detailed assessments of worlwide cost trends of renewable-energy technologies finds onshore wind cheapest now and to 2022.
Benchmarking Wind Power Operating Costs in the United States: Results from a Survey of Wind Industry Experts, Wiser, Bolinger, and Lantz, Lawrence Berkeley National Laboratory, 2019 Comprehensive review of onshore wind O&M costs in the US