SoCalGas’s Minter on Renewable Natural Gas as a Foundational Fuel

In our previous interviews, you have made a strong case that natural gas is not a transitional fuel, but a foundational fuel. With 2018 on the horizon, is your viewpoint unchanged?

George Minter: When we talk today about achieving clean and renewable energy, we only talk about electricity. But natural gas, like electricity, can come from many renewable sources. Natural gas will continue to be at the foundation of our energy economy for many years to come. But as we move to 2050, I think natural gas as we know it—fossil gas—will increasingly be displaced by renewable natural gas from biological resources.

At the end of the day, the question is where we should direct our dollars to achieve the most emissions reductions while maintaining a reliable energy supply in the most cost-effective way. As a good example of that, the California Air Resources Board’s (CARB) emission inventory tells us that electrification should be focused in light-duty vehicles, and natural gas should be deployed in the heavy-duty sector.

Light-duty vehicles are responsible for 70 percent of the greenhouse gas emissions in transportation. In this case, electrification makes sense; there is no natural gas technology that can deliver the emissions reductions that electrification can for the light-duty sector. But for the heavy-duty vehicles, there is.

In terms of air quality, 90 percent of smog-forming emissions in California come from the transportation sector, with the single largest source being heavy-duty trucks. Clearly, that’s where we need to focus. We have the technology to achieve near-zero-emissions with clean, renewable fuels, and we need to deploy it today.

Given current public policy regarding renewable energy, elaborate on the nexus between natural gas and electricity. 

It’s important to realize how natural gas backstops renewable energy. Even though we’re building solar and wind systems, 60 percent of the electricity generated in California comes from natural gas.

The gas generation sector has changed. California used to rely on baseload gas plants for power. Now, INCREASINGLYourIncreasingly, our b baseload power is becoming renewables—solar and wind—and gas will be a peaking technology. It fills in the gaps. We need that peaking technology in place in order to facilitate more baseload renewables.

The concerns about natural gas are that it’s a combustible fuel and that it produces emissions. So, the challenge is to achieve renewable gas, zero-emission gas technology. We can do that in a variety of ways. 

What exactly is “renewable” natural gas?

Renewable natural gas is gas that comes from a biological or organic source, like plants—which trap carbon in the sense that they breathe in carbon dioxide—or like the decay of waste produced from agriculture and animals.

In California, 85-90 percent of methane emissions come from the waste stream—wastewater treatment, sewage, landfills, organic waste, dairies, agriculture, woodland waste, etc. The state has committed to capturing 40 percent of that methane by the year 2030. But once we capture it, what are we going to do with it? Well, we can put it into the utility pipelines and deliver it as renewable energy.

The methane capture law also requires SoCalGas and other utilities to develop at least five pilot projects each at dairies. We’re working with a lot of players in the dairy business in the San Joaquin Valley, and by the beginning of next year, we’ll have set up a group of dairies with a methane-capture and delivery systems.

In order to develop the renewable gas market, though, we need to establish some rules and regulations. When the state was trying to develop renewable electricity, utilities were required to buy power from solar and wind in order to ensure that there would be a market for it. Those long-term contracts enabled long-term financing for capital projects. We need to do something similar now and require gas purchasers to buy renewable gas. We also need to build pipelines to renewable gas sources—just like we built new transmission lines to solar and wind facilities.

Increasingly, storage is becoming a focus for both the CEC and utilities. SoCalGas reportedly is piloting demonstratation projects with both UC Irvine and the National Renewable Energy Laboratory (NREL). What are the technical challenges that these demonstration projects seek to overcome?

Right now, California is facing the challenge of a renewable supply that is overbuilt relative to the demand, which leads to congestion problems. In the middle of the day, we have all this excess solar power, and we need to do something with it—otherwise it will fry the grid.

One suggestion is to sell our surplus energy to the next state over—Arizona or Nevada. But they’re generating solar, too. They don’t need extra power; in fact, they have the same problem we do.

Another idea is battery storage. But the amount of excess energy we’re talking about is vast, and well beyond the capacity of battery storage today. We are starting to see advancements to the point that, at the scale of a home, deployment of battery storage make sense. The problem with batteries, however, is not only capacity, but also drainage: the stored energy is lost over time.

The EU nations have already dealt with this challenge. Germany had built a lot of wind power in the North Sea, and of course, the wind continued to blow and produce energy at night. They had excess energy that couldn’t be absorbed on the grid.  One solution had them actually paying Sweden to take it off their grid! The federal government realized that this didn’t make sense and instead decided to redirect that money and make a capital investment in an electrolysis facility.

In electrolysis, or power-to-gas, you run electricity through water and end up with hydrogen and oxygen. Transforming the electricity into molecules means that you can store forever with no drainage. Or, you can put the hydrogen into the gas pipeline, where it will blend with the natural gas.

There are now about 30 commercial electrolyzer projects in Europe. SoCalGas believes this could be applicable in California, and we have developed the United States’ first electrolyzer at UC Irvine. UCI is a good place to study how all this works together because the campus has a microgrid that uses rooftop solar, as well as a self-contained gas pipeline. So far, we see tremendous potential to store excess renewable electricity in the gas grid and then redeploy it as renewable gas for either power or heat.

Our project at NREL is another power-to-gas facility, but it goes a step further with methanation. Hydrogen can be blended into the grid as is, but a lot of people would prefer to turn it into methane because methane is a more stable hydrocarbon. But the truly exciting and unique thing about this project is not the methanation itself—it’s how we’re doing it.

Typically, to methanate hydrogen, you need carbon dioxide. But at NREL, we’re using a biogenic process: There is a microbe that eats hydrogen and carbon dioxide—and produces methane as the end product! That’s a game-changer. It could simplify and reduce the costs of creating renewable methane from renewable hydrogen.

What infrastructure investments would California need to make in order achieve Germany’s success and actualize grid-scale storage?

The beauty of power-to-gas is that it can utilize the energy delivery system that we already use today. We would simply be delivering a renewable methane instead of a fossil methane.

In the short term, power-to-gas facilities would be best located at a substation experiencing congestion problems. The power and gas lines are already there, so when congestion problems begin, you could switch right over into electrolysis.

The infrastructure need is: adjacency to gas pipelines, adjacency to a substation, and a supply of water. And in terms of water conservation, our work at Riverside and NREL tells us that storing enough electricity to run your house would only require about 1 percent of your household water usage.

Our long-term vision for power-to-gas is as grid-scale, economy-wide energy storage—similar to how EU nations are using it—with massive amounts of energy being stored in central facilities.

How does power-to-gas or electrolysis technology fit into California’s energy future, given that Governor Brown recently signed a bill directing utilities to plan for storage?

At the PUC proceedings implementing the governor’s storage mandate, the Gas Company has argued that gas ought to be considered a storage medium. Everybody agreed conceptually, but unfortunately, the legislation was very specific in requiring an “electrical” storage medium. Therefore, power-to-gas doesn’t meet the requirements.

It makes sense to drive battery technology for small-scale uses—vehicles, homes, maybe even microgrids in institutional settings, like a university campus or even an apartment building. But from a broad, economy-wide perspective, we’re going to need something that can handle both massive volumes and long-term storage far better than batteries.

This issue also includes an interview with the CEO of Proterra, the electric bus company. Address their ability to challenge the existing domination of diesel and natural gas in that sector of transportation market. 

They’re presenting the view that an electric vehicle is inherently superior. That’s an attractive view, but at the end of the day, it all comes down to the emissions profile on a full-scale basis.

Polls have found that 80 percent of voters assume that electric vehicles are automatically clean and renewable. But the reality is that driving a Tesla in Chicago—which is coal-fired—is way dirtier than driving a standard gasoline compact car anywhere.

When we analyze diesel, gasoline, or natural gas, we do a full-cycle analysis. That includes the emissions associated with producing the gas and transporting the gas as well as the emissions from the tailpipe. When we look at electricity, we need to do full-cycle emissions analysis as well. What are the emissions associated with generating the electricity? What about emissions from producing the battery—mining for lithium? And what about battery disposal?

The natural gas internal combustion engine that Cummings Westport developed for transit and heavy-duty trucking is 90 percent lower in emissions than the current standard for heavy-duty transportation engines. UC Riverside’s Emissions Testing Lab suggests that its nitrogen dioxide (NOx) emissions are virtually zero. It’s not only cleaner than the emissions profile of California’s average grid mix, but it’s even cleaner than the ambient air in a polluted airshed like the South Coast. The air going in is dirtier than the air going out!  In all, it’s a lower-emission choice than an electric vehicle—even using fossil gas.

In Southern California, most transit agencies have already moved from diesel to natural gas and are now moving to renewable natural gas. At the end of 2016, 60 percent of the gas used in transportation here was renewable. It will rise to 90 percent by the end of 2017. To reiterate: California’s electricity is supposed to be 50 percent renewable by 2030. In its main transportation application, gas is going to be 90 percent renewable this year.

Renewable gas is replacing fossil gas in the transportation sector for one reason alone: The Low Carbon Fuel Standard Program has made renewable gas cost-competitive with fossil gas. That is driving the development of a renewable gas market. We want that to happen. Our interest in moving natural gas into heavy-duty transportation is that the low-carbon fuel standard creates demand for renewable natural gas development. It’s a market pull. 

The Los Angeles County Metro Board of Directors recently directed staff to develop a plan to achieve zero emissions by 2035. What is the adoptiong of that goal likely to mean for the furute composition of the Metro fleet, in terms of gas versus electric?

On the day the Board passed that directive, they also approved the purchase of about 400 low-NOx natural gas engines—those that are 90 percent cleaner than today’s engines. Metro’s fleet is already 100 percent natural gas, and by year’s end, will be 90 percent renewable natural gas.

Every year, Metro will also start cycling in electric buses. But at the moment, electric buses can’t do the full duty cycle of a Metro bus. The renewable natural gas buses will likely be driven for the next 15 years.

We can achieve a 90 percent reduction in emissions—today. And we need that reduction today; we can’t wait 10 or 15 years for zero-emission electric. 

Lastly, by all accounts, your credentials as a progressive go back decades. Yet you're facing, as a representative of SoCalGas, an audience in California which is currently negative on natural gas as foundational fuel. How personally challenging, given your history, your credentials, and your environmental values, for you to address their strongly expressed views?

In the climate debate, the progressive voice argues for science and facts against the conservative voice, which argues faith and belief. But within the environment and energy field, it’s very different. The left and progressive voice is very faith-based—operating on a belief system that electricity is automatically the best and cleanest choice—whereas the facts tell a different story about emissions. It’s ironic: When we’re arguing about the problem of climate change, facts are the only thing that matter. Yet when we’re arguing about the solutions to climate change, facts apparently don’t matter.

I have a long history in politics. I got started in energy in 1978, working on a package of bills—sponsored by a young Jerry Brown—that created the SolarCal commission. I took this package to the Alameda County Central Labor Committee, and they signed on. That was very gratifying to me, because it was the first time the labor community really got on board with an environmental initiative.

It’s still gratifying today to see the labor community embrace green jobs and the green economy. But the green economy isn’t defined by only one sector, and it shouldn’t be defined only by the intellectual environmental movement. It needs to be defined by a broader constituency that experiences the problems of climate change and clean air firsthand.

Polling research says that folks in port communities overwhelmingly support the deployment of clean natural gas trucks right now. Yet there are some who argue that we need to wait for zero-emission vehicles, and oppose renewable natural gas in the meantime.

I see these activists as the challenge, because they’re moving forward on belief systems. But fortunately, regulatory agencies—the ones who actually have to account for emissions reductions—are starting to look at the facts. The South Coast and San Joaquin Air Districts, as well as the ARB, have all adopted clean air plans focused on the deployment of low-NOx trucks. Why? Because that technology exists, and no other technology does that can achieve those reductions. I believe that at the end of the day, the facts and the science will win out.