Todd Woody, The New York Times

Regulators have a message for companies seeking to build solar power plants in the California desert: Don't use much water, take good care of endangered species and make sure you have signed a deal with a utility before you submit an application to regulators.

Those are some of the rules laid down this week by a state task force charged with developing guidelines to protect fragile desert ecosystems while accelerating the rollout of dozens of megawatt solar farms and other renewable energy plants in California.

The "Interim Guidance for Desert Renewable Energy Project Development" is a draft report and subject to revision, but it offers some insight into regulators' thinking.

Given that there are already a dozen large-scale solar power plants undergoing licensing in California, with another two dozen projects moving into the queue, it is a bit like assembling a car while driving at 100 miles an hour.

Most of the guidelines laid down by the task force - which includes representatives from the California Energy Commission, the California Department of Fish and Game, the United States Bureau of Land Management and the U.S. Fish and Wildlife Service - reflect existing state and federal policy.

But the main idea is to head off conflicts over water and wildlife that have bogged down some big solar projects.

The report's authors say in no uncertain terms that solar developers should not even think of using drinking-quality ground water or surface water to cool their power plants. They are also encouraged to embrace dry cooling, which uses relatively little water.

Those facilities planning to tap reclaimed water from a local municipality are instructed to have an agreement in hand before submitting a license application.

The regulators also want a renewable energy developer to have signed a power purchase agreement with a utility before filing a license application with the California Energy Commission.

There are at least two big solar projects in the midst of a years-long licensing process that have yet to announce a buyer for their electricity.