Compromise terms for an offshore wind farm no longer require a separate onshore backup generating plant in Sussex County, a Delmarva Power official said Monday.

But two power plant operators say they would be happy to build a new power plant in southern Delaware if the state wants one.

Under the original proposal, NRG Energy and Conectiv Energy Services Inc. offered to build natural-gas-fired plants to supply Delmarva when production lagged from Bluewater Wind LLC's proposed 300-megawatt wind farm east of Rehoboth Beach.

The Public Service Commission ordered Delmarva to seek offers for up to 300 megawatts of backup power in 2007, citing concerns that Bluewater would be unable to meet its full advertised output during parts of the year. But the fact that Delmarva would be buying less power would mean it would have less to replace during periods of reduced wind.

On Monday, Delmarva Power Region President Gary Stockbridge said the company doesn't need the reserve under a new agreement calling for a 200-megawatt cap on mandatory purchases from Bluewater.

"From our perspective, we hope that they're kind of decoupled," Stockbridge said. "We could manage this in our portfolio, without any backup."

Bluewater and some offshore wind supporters had made similar arguments last year as concern about the cost of the project mounted. David Small, deputy secretary of Delaware's Department of Natural Resources and Environmental Control, also said Monday that state regulators would have to look closely at the potential for increased pollution emissions from any new fossil-fuel plant.

"As a layperson, it's my hope that building a new backup plant won't be necessary," said Pat Gearity, a Sussex County resident and active supporter of Bluewater's plan.

NRG and Conectiv officials, however, say they are willing to build a backup power plant if the state Public Service Commission decides one is needed.

Lori Neuman, a spokeswoman for NRG Energy, said the company still hopes to develop a new 300-megawatt generator at the Indian River Power plant near Millsboro.

"We're looking forward to working with the agencies on a plan to back up that wind farm," Neuman said.

Conectiv spokeswoman M.Q. Riding said her company also remains prepared to work with the Public Service Commission on a new plant. Conectiv offered to build a roughly 200-megawatt plant in western Sussex County to support Bluewater.

"There's still an opportunity for us to site a gas plant as a backup," Riding said.