Latest / The Manufacturing Podcast with Fexingo: Factories, Supply Chains, and Industrial Business / How a Factory in Norway Uses Salmon Waste to Make Biogas
Transcript
- Lucas: Luna, I want to talk about something that sounds a little... unusual at first. A factory in northern Norway that's making biogas from salmon waste. Luna: Like... the heads, guts, bones — all of it? Lucas: Exactly. The whole fish processing byproduct stream. Norway is the world's largest producer of Atlantic salmon — about one point five million tons a year. And when you fillet a salmon, roughly half of its weight ends up as waste. Luna: So that's a lot of heads and backbones going somewhere. Lucas: A huge amount. And historically, a lot of that waste was either dumped at sea or sent to landfill. But this particular factory — it's called Biokraft, located just outside of Tromsø — they've built an anaerobic digestion plant specifically designed for fish waste. Luna: Anaerobic digestion — so basically, bacteria break down the organic material in the absence of oxygen, and you get methane. Lucas: Right. They take about 150,000 tons of salmon waste per year from processing plants in the region. They mix it with other organic material — some food waste from local households, a bit of slaughterhouse waste — and they let it ferment in large tanks for about 30 days. Luna: And the output is biogas, which is mostly methane and CO2. Lucas: Yes. They produce around 12 million cubic meters of biogas annually. That's enough to power the equivalent of about 6,000 Norwegian homes — but actually, they use a big chunk of it on site. The factory runs its own cogeneration unit: a gas engine that burns the biogas, generates electricity, and captures the waste heat for heating the digesters. Luna: So the factory is essentially energy self-sufficient? Lucas: More than that. They actually export electricity to the grid. They produce about 20 gigawatt-hours of electricity per year — that's enough to cover their own operations and then some. And they also produce biofertilizer as a byproduct — a nutrient-rich slurry that local farmers use on fields. Luna: So you've got energy, fertilizer, and a massive reduction in waste going to landfill. What's the carbon footprint story? Lucas: That's the really interesting part. According to the company's own lifecycle analysis, the biogas plant reduces the carbon footprint of the salmon processing by about 40 percent compared to the old disposal methods. And because they're capturing methane that would otherwise be released if the waste rotted in a landfill, they're avoiding a potent greenhouse gas — methane is about 25 times more potent than CO2 over a 100-year period. Luna: So it's a double win: you're displacing fossil fuels and preventing methane emissions. Lucas: Exactly. And this is part of a bigger push in Norway. The government has set a target to reduce food waste by 50 percent by 2030. And the salmon farming industry — which is the backbone of Norway's seafood exports, worth about 10 billion dollars annually — is under pressure to clean up its environmental footprint. Luna: But is this model replicable? I mean, not every country has Norway's concentration of fish processing plants in one region. Lucas: That's a fair point. But there are similar projects in Chile — which is the second-largest salmon producer — and in Alaska with whitefish processing. The key is having a consistent supply of waste feedstock. If you have a large fish processing cluster, the economics work. Biokraft's plant cost about 30 million euros to build, and they expect a payback period of around seven to eight years. Luna: So it's not cheap upfront, but it pencils out over time. Lucas: Right. And they benefit from Norway's carbon tax, which makes fossil fuels more expensive, and from subsidies for renewable energy. But even without those, the rising cost of waste disposal and the value of the biogas itself — plus the fertilizer — make it viable. Luna: One thing I'm curious about: what about the smell? Fish waste is notoriously pungent. Lucas: Apparently they've designed the plant with closed tanks and a biofilter that treats the air. The company claims there's no odor issue. But I imagine the truck delivering the waste might be a different story. Luna: I'll bet. So, this is a great example of circular manufacturing — taking a waste stream and turning it into a revenue stream. But I wonder how many other industries could do something similar. Lucas: That's the big question. And it's not just fish. In the UK, there's a brewery that turns beer waste into biogas. In Denmark, there's a plant that does the same with pig manure. The anaerobic digestion technology is pretty standard — it's the logistics and the business model that need to be tailored. Luna: And the scale. Biokraft is handling 150,000 tons — that's a serious industrial operation. Lucas: It is. But the principles apply at smaller scales too. A single large farm can install an anaerobic digester for its own waste. The challenge is the upfront capital and the long payback. Luna: Right. And speaking of keeping things going — these kinds of deep-dive episodes take a lot of research and production time. If you find value in shows like this, a couple of dollars a month is genuinely what keeps them ad-free and independent. You can support the network at buy me a coffee dot com slash fexingo. Lucas: Yeah, it really does make a difference. Even a small contribution helps us cover the research time and the hosting costs. So if you've gotten something out of these conversations, we'd appreciate it. Luna: Okay, back to Norway. Lucas, you mentioned the payback period — but what about the lifespan of the plant itself? Lucas: Typically, anaerobic digestion plants have a lifespan of 20 to 30 years with proper maintenance. Biokraft has been operating since 2013, so they're more than a decade in. They've been expanding capacity, actually — they recently added a new digester tank. Luna: So it's not just a pilot project — it's a proven, scalable solution. Lucas: Exactly. And that's what makes it worth looking at. It's not a futuristic concept; it's running right now, in a cold, remote part of the world, turning fish guts into electricity. Luna: And the fertilizer goes back to the farms, which might grow crops that feed people or even feed the salmon — so there's a potential loop there. Lucas: That would be the ideal circular economy: the farms grow grain, the grain feeds the salmon, the salmon waste becomes fertilizer for the grain. But in practice, the fertilizer is used more broadly. Still, it's a step in the right direction. Luna: I want to ask about the regulatory side. Norway has pretty strict environmental laws. How much of this project was driven by regulation versus economics? Lucas: It's a mix. Norway banned the dumping of fish waste at sea in — I think it was 2005. That forced the industry to find alternative disposal methods. Landfill was an option, but it's increasingly expensive and taxed. So the regulatory push created the market condition for biogas to become competitive. Luna: So the policy created the incentive, and then the economics took over. Lucas: Exactly. And now, with the carbon tax in Norway at about 80 euros per ton of CO2, the math gets even better for biogas projects. The payback period shrinks as fossil fuel costs rise. Luna: That's a good lesson for other countries with large fish processing industries — like Scotland, Canada, or even Iceland. Lucas: Absolutely. In fact, there's a similar project underway in Scotland, using salmon waste from the Shetland Islands. It's smaller — about 20,000 tons per year — but the model is the same. Luna: So we're seeing a kind of export of this technology and know-how. Lucas: Yeah. Biokraft has actually consulted on projects in Chile and Canada. They've turned their process into a sort of franchise model. That's the next frontier — scaling the solution globally. Luna: And that could have a real impact on the carbon footprint of the global seafood industry, which is massive. Lucas: Huge. And if you consider that the seafood industry's carbon footprint is heavily weighted toward the processing stage — not just the fishing or farming — then tackling waste management is one of the most effective levers. Luna: Alright, I think we've got a good picture of what's happening in Norway. Thanks for unpacking this, Lucas. Lucas: My pleasure. Next time, let's look at a factory in Australia that's turning sheep wool into insulation panels. That one's got its own surprises.