Superior technology and competitive pricing are the tools natural gas deployed to bump coal off the leading position for power generation in the US. Well, turnabout is fair play. Now renewable energy is applying the same workbox to put the screws on natural gas. It’s not just happening in the power generation space. A new renewable hydrogen project in California could also shake natural gas loose from its grip on energy for building systems, including cooking, laundry, heating, and cooling.
Renewable Hydrogen Is Nudging Fossil Gas Aside
Somewhat ironically, the main source for hydrogen currently is natural gas. Renewable alternatives are beginning to emerge, though. One pathway is to use biogas instead of fossil gas. Another is to “split” hydrogen from water using an electrical current powered with wind, solar, or other renewables.
Water splitting, aka power-to-gas, is beginning to take hold globally and that’s the basis for the new California project. The work pairs Southern California Gas Co. (aka SoCalGas) and German power-to-gas specialist Electrochaea in something called biomethanation.
That’s fancyspeak for a complex process that starts with generating renewable energy — in this case, solar power — and using it to split hydrogen gas from water.
The next step is where things get tricky. The hydrogen is doped with carbon dioxide and sent to a bioreactor stocked with water-dwelling microorganisms. They produce methane by digesting the tasty gas combo.
The new system has already had a trial run in Europe, where it demonstrated an efficiency rate of 50%-60%. The aim now is to bump up its performance to achieve commercial viability while taking into account the intermittent nature of solar power.
The Renewable Hydrogen Bottom Line
Don’t hold your breath for that renewable methane, though. The SoCal-Electrochaea project is still in the form of a bioreactor located at the Energy Department’s National Renewable Energy Laboratory in Golden, Colorado. They are looking at a two-year period to assess the system’s bottom line performance. That will involve more elements than simply selling the gas to end users.
The prospects look pretty good. Methane is the primary ingredient of fossil gas, and the end result of the whole process is “pipeline quality” gas. That means Electrochaea’s renewable methane can get into a building without requiring a whole new distribution and storage infrastructure.
Now add the value of an existing maintenance and repair workforce complete with transferable tools, training, and supplies. That’s a cost-saving factor that could come into play for some markets.
Renewable hydrogen is becoming viable as a large scale, long duration storage medium for excess renewable energy, so the new system will add value on the energy storage side as well. For example, power-to-gas systems can store excess wind energy at night for use during the day.
Power-to-gas is also edging into energy storage on a regional level. Planners in the Netherlands, for example, are looking at a scenario in which power-to-gas will enable them to build more offshore wind farms, beyond the needs of their own grid.
If you caught that thing about adding carbon dioxide to the renewable hydrogen, carbon capture is another value-added element. Just about any source could work, though for purposes of scale the demo project has ethanol plants and anaerobic digesters in its sights, particularly in California.
The falling cost of wind and solar will also continue to force the cost of the system down on the water-splitting end.
Now You’re Cooking With (Renewable Hydrogen) Gas
The path to market-ready renewable hydrogen has been a long one. The SoCalGas project actually has roots in a 2003 Energy Department initiative, aimed at deploying microscopic algae to produce hydrogen from water.
One branch of the research, conducted by the lab of Laurens Mets at the University of Chicago, eventually digressed into microbial methane production before finding its way to Electrochaea. Mets licensed the technology to the firm and stayed on as its technical adviser.
If and when the demo project achieves its aims, it will add another weapon to the arsenal of biogas alternatives that are already peppering the US energy landscape.
Fossil natural gas is already getting stung in the power generation sector by low cost wind and solar, and a new surge of activity in the building electrification field is nipping away at its market.
Another factor that should worry fossil gas stakeholders is the Energy Department’s ongoing support for concentrating solar power as a low carbon substitute for conventional baseload power plants.
Costs are dropping in that area, too. In one particularly interesting twist, the Energy Department is looking at concentrating solar systems that add value with renewable hydrogen, by pairing them with power-to-gas.
Meanwhile, CleanTechnica is reaching out to Electrochaea for more insights on the demo project, so stay tuned for more on that.
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Photo (cropped): NREL bioreactor (“Nancy Dowe initially grew a small batch of the microorganisms” by Dennis Schroeder, NREL 47789).
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