Massachusetts approves offshore wind PPA between Cape Wind, NSTAR

Massachusetts state regulators on Nov. 26 approved a 15-year power purchase agreement (PPA) under which NSTAR Electric will buy 129 MW, or about 27.5%, of the power output from Cape Wind Associates’ proposed Cape Wind offshore wind project.

That amount is about equal to 1.9% of NSTAR Electric’s distribution load in 2013, according to the state Department of Public Utilities’ (DPU) order.

NSTAR merged with Northeast Utilities (NYSE:NU) earlier this year.

The Massachusetts Supreme Judicial Court in December 2011 upheld the DPU’s approval of Cape Wind’s PPA with National Grid plc subsidiary National Grid USA for 50% of the project’s power, Cape Wind said.

According to the Nov. 26 order, under the PPA, the facility must meet certain milestones to trigger NSTAR Electric’s purchase obligations, including beginning construction by Dec. 31, 2013, and meeting a deadline for commercial operation of all phases by Dec. 31, 2015.

All milestones are subject to certain extensions: Cape Wind may extend the commercial operation date for one year with no additional security and it may further extend that date for two six-month periods by posting additional security of $645,000 for each six-month period.

Under the PPA, Cape Wind will sell and deliver to NSTAR Electric three products associated with the facility’s output: energy, capacity and renewable energy certificates (RECs).

Project’s transmission plans

In a previous interview with TransmissionHub, Mark Rodgers, communications director with Cape Wind, explained the project’s transmission plans.

“In our case, when we started out, it was obvious that we didn’t have to build? that kind of [transmission] system in place here,” he said. “So it would be, just as it is typically for a land-based wind developer, our responsibility to provide transmission” to interconnect to the grid.

According to Cape Wind’s final environmental impact report, an electrical service platform (ESP) will have to be installed and maintained within the approximate center of the wind turbine generator (WTG) array. The ESP will serve as the common interconnection point for all of the WTGs within the array and each WTG will interconnect with the ESP through a 33-kV submarine cable system, the report added.

From the centrally located ESP within the wind park, the wind-generated energy from each of the WTGs will be transformed to 115-kV. Two 115-kV AC submarine transmission circuits will bring the electric energy from the ESP to the mainland, a distance of about 12.5 miles. Those submarine transmission lines will make landfall at the proposed location at the end of New Hampshire Avenue in the town of Yarmouth, Mass.

From this landfall, the report added, an upland 115-kV transmission line will be installed in an underground conduit system within existing roadways for about four miles until it intersects with NSTAR’s existing transmission line right-of-way (ROW) at Willow Street in Yarmouth. From that point, the upland transmission line will go west and then south in an underground conduit system about 1.9 miles along the existing NSTAR Electric ROW to the Barnstable switching station.

The report also said the interconnection with the existing NSTAR Electric transmission system will allow renewable energy from the WTGs to be distributed to consumers connected to the New England transmission grid.

The proposed electrical interconnect facility on the proposed route will be two 115-kV solid dielectric submarine transmission lines and two 115-kV solid dielectric upland transmission lines. The submarine transmission lines, the report added, will be jet plowed below the seabed and the upland transmission lines will be encased in an underground concrete transmission ductbank system.

Costs associated with the project’s transmission aspect are all Cape Wind’s, Rodgers said.

Details of the PPA

The PPA establishes a base price equal to $187 per MWh for energy delivered in calendar year 2013.

The bundled price is the base price, as adjusted for size, tax credits and financing. The order also noted that the bundled price will be adjusted downward if, at that price, the costs to build and operate the facility are such that Cape Wind’s internal rate of return would exceed 10.75%. Also, the bundled price is subject to an annual escalation factor.

The DPU said the contract price may be adjusted based on changes to the facility’s size. The 2013 base price will be adjusted upward if Cape Wind reduces its nameplate capacity below 468 MW. Specifically, the base price will increase by about 8 cents per MWh for each megawatt reduction in nameplate capacity below 468 MW, but the 2013 size-adjusted base price cannot exceed $193 per MWh.

Among other things, the DPU said the PPA includes a mechanism to lower the price of the contract to reflect lower debt financing costs for the facility. The tax credit-adjusted price will be adjusted downward if Cape Wind obtains debt financing at an interest rate lower than 7.5% per year. If realized, the reduced financing costs will flow to NSTAR Electric’s ratepayers in an amount equal to 75% of Cape Wind’s reduced annual payment obligation – on an after-tax basis – for each year of the contract term for the company’s entitlement portion, assuming a 35% tax rate.

The DPU said: “[W]e conclude that the attributes of the Cape Wind facility, when considered in the aggregate, remain unique among Section 83-eligible resources and will provide benefits to NSTAR Electric ratepayers that far exceed those that could be provided by other potential Section 83 contracts. The critical unique attributes of the Cape Wind facility relate to its size, capacity factor, location on the regional transmission system, and stage of development.”

On the remainder of the project’s output, Rodgers told TransmissionHub on Nov. 26: “We are moving forward financing the project on the basis of the PPAs we have, 77.5% translates to 101 wind turbines. When we sell additional power we will seek additional financing for that.”

Cape Wind President Jim Gordon said, “With this decision, Massachusetts electric consumers have secured an abundant, inexhaustible and clean energy resource that provides price stability and avoids all of the external costs of fossil fuels.”

Cape Wind is owned by Energy Management.

About Corina Rivera-Linares 3286 Articles
Corina Rivera-Linares was TransmissionHub’s chief editor until August 2021, as well as part of the team that established TransmissionHub in 2011. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial from 2005 to 2011. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines.