PG&E leads in clean energy, greenhouse gas reductions and natural gas leak detection


(NAM clean energy fellowship sponsored by PG&E)

Pacific Gas and Electric Company (PG&E), one of the largest combined natural gas and electric utilities in the U.S., recently took members of the ethnic media on a day-long tour of its San Francisco headquarters, Vaca-Dixon Solar Power Plant, Vaca-Dixon Substation and Vacaville Grid Control Center, and presented why it is a national leader in clean energy, greenhouse gas reductions and natural gas leak detection.

Solar cell technology comes of age
It wasn’t even 10 years ago when clean energy was still too expensive and just too difficult to sustain. Solar cell technology has been around since the 1960s. But it wasn’t until well into the 2000s when solar panels were installed in houses and even then, only on affluent homes.

Though a solar panel array has hundreds of solar cells, each cell was only 15 percent efficient. Since the panels capture sunlight only in the day, the energy needed to be stored in batteries – these were expensive and did not last long. Some home-owners who wanted solar panels on their roofs were dismayed to find it would take several more years after installation before they could realize savings in their electric bills.

There were few practical solar energy experts and fewer reliable companies that could install solar panels cheaply. In the rush to fill the ranks of “boots on the roofs,” unemployed tech workers, sales agents and admins were trained in early crash course classes in photovoltaic systems, home energy efficiency rating, building performance analysis, OSHA standards and some carpentry math. The North American Board of Certified Energy Practitioners (NABCEP), the exam for certifying installers was still getting started and not everybody recognized it. Permits to operate solar panels varied from city to city and nobody was sure who should file it.

In the ensuing years, more light-sensitive particles were discovered and increased a panel’s efficiency up to eight percent more. Another material that can be chemically altered increased a panel’s efficiency about thrice as much. When Molten Salt Storage technology came along, solar plants began to operate at temperatures over 500 degrees Celsius. This breakthrough lowered costs to store solar energy and now utility companies like PG&E can practically store that energy rather than just meet power demand only at specific daylight hours. Suddenly moving shadows and migrating birds were no longer a big deal.

Then the move from silicon to thin film technology really brought down the cost of manufacturing solar cells. The raw material is recovered from seawater and it is also abundant and safe to use. The new material boosted a solar cell’s efficiency up to 15 percent. Because of these and other factors, solar costs have declined by 56 percent in the last six years.

Enter PG&E
As NABCEP became standard and life went on after Solyndra, the Permit to Operate eventually became accepted as the contractor’s responsibility. Solar Workforce Training standardized practitioner’s courses even as the Solar Foundation annually tracked careers in the solar industry. Currently, there are 38 percent more solar jobs in California – about 1/3 of these jobs in the U.S. are here. The State put out a database of licensed contractors and PG&E counseled would be solar-powered home-owners to work closely with qualified contractors rather than going up their roofs on their own. PG&E also raised consumer consciousness by referring home-owners to their bill and understanding net energy metering.

Around 2007, the State launched the California Solar Initiative (CSI) that provided cash rebates for homeowners to install solar energy systems. Now, consumers didn’t have to wait to realize savings in the electricity bills. Although it was put on hold, the Property Assessed Clean Energy (PACE) program that started in Berkeley, promised no money down for home upgrades, including solar, with no background check and attaching the loan to the property tax bill, the stage was set for affordable solar upgrade.

PG&E supported incentives for solar power installations with CSI (ending in 2013), the New Solar Homes Partnership (ending in 2014) and the Multifamily Affordable Solar Housing (ending soon). PG&E also supported CSI’s program for solar water heating and program for wind, fuel cell and other clean energy alternatives under the Self-Generation Incentive.

Small wonder that PG&E has installed more than 200,000 solar panels on rooftops – about 25 percent of nationwide installations. PG&E adds about 6,000 new solar customers each month – a growth of 41 percent since 2010. PG&E has interconnected more solar customers than any other utility in the U.S.

They have been named to the S&P Climate Disclosure Leadership Index five times. PG&E provides some of the nation’s cleanest energy, with a CO2 emission rate that is about 1/3 of the national average among utilities. Approximately 58 percent of PG&E’s electric supply are from non-greenhouse gas emitting facilities. Also, PG&E has 80,000 electric vehicles in service – more EVs plugging in than any utility in the U.S.

With clean energy comes great responsibility
Realizing that the pursuit of alternative energy and sustainable fuel sources could consequently result in toxic substances and dangerous situations, PG&E adds safety as part of its commitment to consumers.

In 2012, PG&E became the first utility company in the world to roll out a 1,000 times more sensitive leak detection equipment. Using Cavity Ring-Down Spectroscopy, the world’s most precise and robust methane-measuring technology, PG&E contracted Picarro’s truck-mounted Surveyors for natural gas leaks in their pipelines.

Picarro’s technology detects leaks down to one part per billion in ambient air while eliminating false pointers from biological sources of methane. It measures and maps methane plumes in the air as the truck drives through the area.

The tablet-equipped driver easily transmits the data to a PG&E collection central for speedy analysis. A far cry from the traditional walk-through survey with a less accurate hand-held device.

The Surveyor unit fits in the back of the truck. The top module is the “brains” of the system. Below it, the larger module contains the pumps, power inverter, filters and back-ups. A metal canister off to the side of the large module contains a known gas sample, which allows PG&E to confirm the unit is in calibration. With the known values, it takes only 10 minutes to process each sample. Two field samples ensure validity (sometimes, sewer gas and other things like pool heaters can create false positives for the highly sensitive device). Thirty minutes later, the process is complete and a questionable leak source is confirmed as PG&E gas or not. PG&E will also dispatch resources to all indications detected by the Picarro unit to determine if there is a leak within 36 hours.

PG&E started out with six Surveyor trucks, Currently, they have eight operating around their Northern California territory, fine-tuning the gas leak detection system to prevent another tragic pipeline explosion that occurred in San Bruno in 2010. (Harvey I. Barkin)