A recent report from Deloitte provides a good perspective on the prospects for wind and solar electricity.
Costs of wind and solar are now competitive with coal and gas. “Power purchase agreement (PPA) prices for wind and solar power are also competitive with other resources. The weighted average US price for the first half of 2021 from auction and PPAs for solar PV is US$31/MWh, while for onshore wind it is US$37/MWh. This compares to a weighted average wholesale electricity price of about US$34/MWh across US markets during the same period.” It now costs less to build new solar and wind plants than to continue operating existing coal-fired plants. Wind and solar costs are projected to fall by half by 2030.