Is renewable natural gas the silver bullet for a greener future or a complex puzzle yet to be solved? While many industrial and natural gas companies have looked to RNG as a potential solution to decarbonize their operations, the fuel source is not without some issues.
Paul examines how RNG is made, used and contributes to decarbonization goals. But he also looks at how and why some of those claims may not fully stand up under scrutiny.
Is renewable natural gas the silver bullet for a greener future or a complex puzzle yet to be solved? While many industrial and natural gas companies have looked to RNG as a potential solution to decarbonize their operations, the fuel source is not without some issues.
Paul examines how RNG is made, used and contributes to decarbonization goals. But he also looks at how and why some of those claims may not fully stand up under scrutiny.
This is 8 Minutes a podcast helping you understand the energy and climate challenge. In just a few minutes, I'm your host, paul Schuster. Let's talk about decarbonizing natural gas. Nothing makes up about one third of our US energy mix, so solutions that can decarbonize this fuel are super important. One such potential solution Renewable natural gas. Sound too good to be true? Well, it may be.
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Today, I'm going to unpack what renewable natural gas is, how it's made, what it's used for, and then we'll spend some time talking about whether this is truly a decarbonization magic bullet for the natural gas industry or a solution that may need some further work to refine. Wait a minute. It's how long it takes to suns race it, or the amount of time the sun's shown yesterday. Okay, not really, but these winter months are just dark, long and brutal. Let's get it on. We burn a lot of natural gas in the US. The Energy Information Administration estimates that 36% of our nationwide energy use is through burning methane and, frankly, that's been a good thing, as the usage of natural gas has displaced other, dirtier fossil fuels, such as coal, over the past couple of decades. But now it's gas's turn to decarbonize, and there's a lot of questions around how best to address this energy source.
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One of the more prevalent solutions being proposed is in the production of renewable natural gas, or RNG Sounds appealing, right, renewable and natural in the description. Whereas traditional natural gas comes from geologic formations, rng is a biogas. It's captured from other sources, such as landfills or biodigesters at farms or wastewater facilities. It could be the methane being captured from livestock or organic waste operations. That renewable gas is gathered up and processed so they can be used as a fuel source and then burned in much the same fashion as traditional natural gas, because it is methane, same as traditional gas. Oh, it has some advantages because it's been processed to get to this point. For instance, rng has fewer particulates and volatile organic compounds. In fact, the purity of RNG can reach 96 to 98% methane, while normal natural gas may be a bit lower, but it's still methane, which is important for our existing infrastructure. As companies that are already burning natural gas can now burn RNG with relatively little adjustment to their processes or systems, end users can claim decarbonization goals while not having to overly disrupt their existing operations. But if RNG is just methane in a different package, what makes it a viable decarbonization solution?
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The theory here is twofold. Which kind of work with each other. First, rng is the methane captured from biological material like plants and trees. These are resources that captured carbon in the first place. So the idea is that you're not introducing new carbon into the atmosphere, just carbon that had already been captured, so the process is carbon neutral.
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The second argument for RNG being a sustainable solution is that the methane coming from livestock and landfills Well, that's methane that's being released into the atmosphere anyway. If we can capture that and use it in place of traditional natural gas sources. That's kind of like taking an entire methane stream completely off the table. Whereas before we had two streams of methane, one to burn and one that was going straight into the atmosphere, now we just have the single stream of burning methane. But this is why it gets tricky and why the evolving considerations for RNG are so complex. Let's take that last point about using captured biogas, processing it and using it as an alternative fuel source for traditional natural gas. From a very valid perspective, we're capturing methane, which is a far more potent greenhouse gas than carbon dioxide is, and we're displacing a traditional natural gas source. So this is a more climate-friendly solution, but it's not zero carbon.
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We can't just look at the narrow focus of just the methane capture and claim success. The entirety of the carbon cycle here needs to be considered, because the RNG that we're burning still emits carbon dioxide into the air. Want to do some math with me? Think of the original scenario where a herd of cows emit methane into the air and a farm purchases natural gas from their utility to burn in their water heaters. The cows may emit one part methane and the water heaters may emit two parts CO2. Now the farm installs a capture system for that methane, processes it up to RNG standards and burns that instead of the gas from the utility. The methane that the cows were emitting is now gone, but the farms still drop in two parts of CO2 into the air. It's just now coming from the biogas. Now that doesn't mean that capturing the methane and reusing it is a bad idea. We're still removing the potent methane and that's good. It's just that we have to be honest about the full impact.
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Or consider the first argument for the renewable nature of biogas, in that biogas from organic material was captured via photosynthesis in the first place and what we're really discussing is kind of a circularity of capture, burn and capture again, looked out in a vacuum. That circularity suggests that certain biogas can be considered carbon neutral, but while the carbon that's been captured by the plants in the first place could have taken place years or, if not decades ago, the burning of the biogas today puts that carbon out immediately. There's a time component that needs to be considered here, and if you're familiar with the concept of the time value of money, then think of this as the time value of carbon. Carbon captured today is more valuable than carbon captured in the future. The last concern RNG is expensive. It's about 50% more expensive than traditional natural gas, and there are fewer than 200 RNG projects operating in the US, which means that even if you want to pay for that type of premium for RNG, it may be really tough to get your hands on the biogas in the first place.
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And it's these concerns on whether RNG is truly a clean, renewable energy resource that has divided the industry. On the one hand, capturing free methane is a good thing for the environment, but RNG doesn't truly meet the standards for full decarbonization, which is why certain states and other entities are starting to pull back from strategies that relied upon RNG as a net zero resource. For instance, at the end of last year, massachusetts Department of Public Utilities issued a notice that they would no longer recognize RNG nor hydrogen as viable solutions for decarbonizing the state's gas distribution network. Instead, the DPU will require utilities to develop plans to fully electrify residential heating load through heat pumps and the use of renewable energy, rather than reposition gas networks for RNG. Other states such as New York and California are considering similar restrictions, and this debate has ramifications at the federal level as well.
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If we're to get the price of RNG down, we would need to invest billions and billions of dollars into new RNG projects in order to scale up the technology and infrastructure. But if RNG isn't going to fully bring us to the end goal of a net zero economy, well, is that type of investment really worth it? Or should we take the path of Massachusetts and simply invest behind full electrification in the first place? But then what do you do about the methane in agriculture that wouldn't then have had the end market end goal? Rng is a tricky subject, but it's a topic that needs to be looked at across the entirety of the carbon life cycle and not easily dismissed as clean energy. I'm Paul Schuster and this has been your 8 Minutes.