Bruce Oksol at The Million Dollar Way provides an updated scorecard on what he is seeing as the cost to construct a variety of electricity generating plants.
January 31, 2016: update on new energy plant costs in the US:
- Off-shore wind: $7.5 million /MW (intermittent; requires fossil fuel back-up)
- Solar: $3 million / MW (intermittent; requires fossil fuel back-up)
- On-Shore Wind: $2.5 million / MW (intermittent; requires fossil fuel back-up)
- Natural gas: $865,000 / MW
Notice that off-shore wind, on-shore wind, and solar all require backup power for the times the wind isn’t blowing or the sun isn’t shining.
Same article mentions two projects in Rhode Island. Combined cycle gas plant costing $700M will have rated output of 900mW. Deepwater Wind project with off-shore slice-and-dice turbines costing $225M will have theoretical output capacity of 30mW. Here is the comparison:
- $0.78M / mW – gas plant
- $7.50M / mW – off-shore wind, with actual output guessed at 40% to 60% of rated capacity, also requiring backup from fossil fuel plant
That would be 9.6 times as expensive. Not including the transmission line to get the electricity to shore. Not discounted for the fractional actual output.
Those actuals support the general numbers mentioned above.