The False Economic Promises of Offshore Wind

Of all commercial renewable generation technologies, offshore wind is the costliest, far more so than solar photovoltaics and onshore wind. The newest incarnation of offshore wind--floating turbines that can be sited in deep water--are more expensive still. Although offshore wind is supposed to benefit from more prevalent ocean breezes, it remains, like land- based wind and solar power, an intermittent source of electricity. Hence, as offshore wind comprises a larger share of total electricity capacity, it requires ever more backup generation or storage to compensate. Offshore wind's high cost and intermittency raise a simple question: Why have renewable energy advocates and policymakers in many Atlantic Coast states, as well as those on the West Coast, placed such emphasis on this technology? One justification, like all forms of renewable energy, is that offshore wind will reduce U.S. greenhouse gas emissions. Whether that is true remains an open, empirical question. Offshore wind's high costs, which require substantial--and increasing--taxpayer and ratepayer subsidies, will raise electricity rates and reduce electricity consumption. Even offshore wind manufacturers such as German- based Siemens Energy admits this. By itself, reduced electricity consumption may reduce greenhouse gas emissions slightly, as will offshore wind replacing lower- cost natural- gas- fired generation. However, any such reductions will be so small as to have no measurable effect on climate.