Sempra Energy, the parent company of both San Diego Gas & Electric and SoCalGas (serving Riverside County), is in the planning stages for a massive new $600 million natural gas pipeline running roughly from Miramar north to Rainbow, on the San Diego/Riverside county line.
The 36-inch line, dubbed Line 3602, would partially replace the aging Line 1600, a 16-inch pipe that entered service in 1949, delivering gas to the region from Riverside. Due to safety concerns following a 2010 explosion in San Bruno, state regulators want the utility to either conduct pressure testing on Line 1600 or reduce the pressure at which gas flows through it.
Sempra prefers the latter option, keeping the existing line at a downgraded rate of service while installing the new one along a slightly different route. Another large pipe, Line 3010, already exists – it runs from Rainbow south along a more coastal route to Tecolote.
Environmentalists have come out in opposition of the plan, saying that decreasing demand for natural gas as the state moves toward renewable energy to meet tough pollution control targets means the new pipeline, several times larger than the old, is unnecessary.
"This will be a stranded asset from day one, and consumers will be paying for it through 2063," says Matt Vespa, legal counsel for the Sierra Club.
"The primary argument is that this is a sort of backup in case the existing large pipeline, Line 3010 was to somehow go out of service. But it's a very costly insurance policy, given that historically Line 3010 has only gone out for one day in 1985.
"SDG&E would have us spend $600 million on this pipeline that would just be there in case the existing line were to have an outage."
In testimony before the California Public Utilities Commission, Catherine Yap of the Southern California Generation Coalition suggests that any temporary shortages in gas supply could be resolved through a pipeline flowing north from Otay Mesa.
"The Applicants acknowledge that they have relied upon deliveries of gas at Otay Mesa in the past when shortfalls have arisen between customer demands and deliveries across Lines 3010 and 1600," Yap noted in a partially-redacted copy of testimony provided to the Reader.
The shortages Sempra fears are based on projections for "one-in-ten-year cold days," though pipeline opponents say even the projections are flawed, failing to account for advancements not only in solar deployment but in energy storage capabilities for use when renewables aren't generating power.
"The question becomes, as we continue to de-carbonize very rapidly, do we really need an expanded fossil fuel infrastructure?" Vespa continues. "Because this line is much bigger than the old one, and if you look at their demand projections by the time this pipeline would enter service the existing line would have enough capacity to meet the Commission's established standards.
"I feel like this is actually a success story about renewables and green energy, in that gas reliance is headed down to the point that we don't have to make these types of investments any more."
While development talks have been ongoing for more than a year, approval is still far from certain for Line 3602.
"There was another proposal called the North-South Pipeline last year that was a northern segment that would connect to this pipeline going through Riverside, but the PUC rejected it, finding that we don't need it, and they didn't even move forward with CEQA review," Vespa continued. "Sempra is pushing this one more aggressively, though, having learned some lessons in that last denial.
"Of course, the state is going to keep moving toward de-carbonizing heating, moving toward electric to service needs like that, which is just going to further reduce the demand for gas. We won't realize the financial benefits of de-carbonizing if we're making these investments in fossil fuel infrastructure that will ultimately go unused – it really makes no sense."