[BETA] Fortnightly

Rooftop Risks

Dear Editor: Thanks for your enlightening editorial about the problems of feed-in tariffs for photovoltaic (PV) installations and the distortions they are causing in cost responsibilities among electric utility customers. (“Facing Facts ,” Frontlines, June 2012) . While these issues are an immediate and growing concern, an entirely different set of problems will emerge over the next decade as the share of renewables in total generation approaches the high levels being dictated by most regulatory authorities. These concerns will center on the risks of massive storm damage over large geographic areas to PV rooftop installations.

With the steady drift of the nation’s population towards the sunbelt, much of the renewables will logically be PV, encouraged by the high feed-in premiums highlighted in your article. Since the sunbelt is prone to major storms—including tornadoes and especially hurricanes along the Gulf Coast—restoration of service after widespread damage to a significant portion of the power supply will create a host of unique problems, to which little thought is being given. These include:

• Coordination of installation repairs;

• Responsibility for insuring roof top installations;

• Financing of restoration until insurance settlements are available; and

• Cost responsibility among customers for supply backup.

These questions give rise to the even more fundamental one of who should own individual facilities and who should determine their rate of installation in a given geographic area. Logic suggests that because the local utility is held responsible for reliability by both the public and regulators, it should have the final word as to how, when, and where dispersed PV generation is installed once it accounts for, say, 10 percent of a system’s capacity.

–Jack L. Schenck Kingwood, Texas

The Editor Responds: I was thinking along the same lines, in terms of a reliability threshold. To exceed a certain market penetration, PV will have to bear its own burden. Whether 10 percent is a reasonable threshold bears further analysis. And that threshold likely will change over time, particularly as smart grid technologies—notably advanced distribution management, demand response, and electric vehicle smart charging—play increasingly important roles in reliably and efficiently integrating variable resources like PV.

Re: storm damage … Manufacturers and installers say that, correctly installed, their systems are designed to survive storms practically as well as the roofs on which they’re mounted. But building codes and standards should help minimize the risks. Broward County, Fla., for example, proposed hurricane safety design load standards as part of its building codes for rooftop PV installations. We’ll cover this issue as it develops.– MTB

Getting Serious about Shutdowns

“Planning a Fossil Teardown ” by Baker, McCreary, and Ford in the April 2012 issue of  Public Utilities Fortnightly  addresses the organization of projects for the decommissioning and remediation (removal) of coal- and oil-fired generating stations; suggests that now is the time to “get serious” about removal projects, in view of decisions currently being made to close many such stations in response to environmental regulations; and demonstrates that such projects are complex. However, accounting and regulatory requirements dictate that owners get serious well