PTC Mechanism

The Production Tax Credit pays wind farms roughly $28 per MWh of electricity they actually generate. Unlike the ITC, which rewards building a project, the PTC rewards producing power. This distinction shapes which technologies prefer which credit and why.

The PTC provides a per-kWh tax credit for the first 10 years of a qualifying facility's operation. Wind has historically been the dominant PTC claimant because wind's economics favor production incentives: capital costs are moderate, capacity factors are high (35-50%), and the credit compounds over billions of kilowatt-hours. Solar, with higher capital costs relative to output, historically preferred the ITC. The Inflation Reduction Act (2022) made both credits available to both technologies, letting developers choose whichever is more valuable.

Compare the credits. A 200 MW wind farm costs $300M and produces about 700,000 MWh/year at 40% capacity factor. ITC value: $300M x 30% = $90M upfront. PTC value: 700,000 MWh x $28/MWh x 10 years = $196M over a decade. The PTC is worth more than double for this project.

Why would any wind developer ever choose the ITC?

Financing structure. The PTC's value depends on future production, which carries risk (low wind years, curtailment). The ITC is certain at construction completion. A developer with high financing costs or risk aversion might prefer the smaller but guaranteed ITC. Offshore wind projects, with very high capital costs, sometimes find the ITC more valuable despite wind's traditional PTC preference. The IRA's technology-neutral approach lets each project optimize for its specific economics.

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