Tracking the emissions of megacities (in real time)

Do you know how many greenhouse gas emissions your city is generating right this very minute? Mike Woelk, CEO of Picarro, talks about the startup's emissions tracking technology and its plans for the London Olympics.

In Mike Woelk's view, greenhouse gas emissions measurements released by cities, countries and companies have a fatal flaw: They don't measure anything.

"Right now, there's not a city in the world that continuously measures their emissions," says Woelk, CEO of Santa Clara, Calif.-based Picarro. "By measurement, I don't mean tabulations to calculate emissions based on various inputs. That kind of self reporting is a management tool. It's not a measurement."

These "measurements" typically involve compilations of information and stats, such as electricity and fuel use, and tend to take a backwards view. In other words, the information is old and not very accurate.

Picarro has developed technology that could change how cities, companies and countries track and report greenhouse gas emissions. Picarro has created an extremely sensitive cavity ring-down spectroscopy (CRDS) instrument capable of measuring greenhouse gas emissions, such as carbon dioxide, carbon monoxide and methane, in real time.

The company also has developed gas analyzers that can detect natural gas leaks along pipelines and trace the geographical origin of food and beverage products to improve safety.

The CRDS devices have been used for some time by atmospheric scientists at research institutes and organizations, including National Oceanic and Atmospheric Administration. Now Picarro is trying to move beyond the academic world and into the industrial and commercial sectors as well as cities.

London calling

Picarro announced this week it secured $7 million from investors, funds that will help the company expand within the commercial and industrial emissions sector. And Picarro was selected earlier this month by EADS Astrium to provide its instruments to measure GHG emissions in London during the 2012 Olympic Games.

Woelk has high hopes for megacities and the London project should be a good test piece for what's possible. Picarro also is in the planning stages of installing instruments around Los Angeles as part of a megacities project with JPL, Caltech and NOAA.

Cities are responsible for 70 to 80 percent of the world's emissions and yet there's no real-time accurate measurement taking place, Woelk told me in a recent interview.

And what "calculations" are being done are often wildly inaccurate. Picarro's city carbon project during the World Economic Forum Annual Meeting in Davos, Switzerland revealed a wide discrepancy -- of about 35 percent -- between its emissions assumption and actual emission measurement.

Plus, megacities can be very powerful, competitive, aggressive and fearless institutions that can help usher in change, Woelk said.

"There's a level of progressive action in these megacities that doesn't really occur at the national level," Woelk said.

About four instruments were installed more than a month ago around the perimeter of London. The devices will measure the increase and decrease -- or net carbon flux -- occurring in the city in real time.

How it works

A laser that shines a beam of light into a cell, which the company calls a cavity, about the size of a cigar. That laser bounces around in a constant circle. A light is turned on in the cavity and the energy of the laser builds up, Woelk explained.

The light is then turned off. The speed at which that laser energy or light decays is directly proportional to the number of molecules of CO2 or methane in the cavity because those molecules absorb or suck up light. The more molecules you have in that cavity, the faster it goes dark.

Picarro's device is able to measure that direct absorption in the cavity. To get an accurate measurement of the entire city, the instrument takes into account how the wind moves the carbon molecules around. By measuring the wind as well as the concentration of molecules at high precision and high frequency, the company is able to measure the transport of molecules from somewhere else in the city to the analyzer.

"If you can monitor what's happening in my city versus the city where you live, that's actionable information," Woelk said.  "It makes cities far more intelligent and smarter if they're actually able to measure in real time what is being pushed into the atmosphere."

Photo: Flickr user Harshil Shah, CC 2.0


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