For BioNova founder and CEO Nikoloz Gongliashvili, the difficult part of developing a biodigester was never producing biogas.

“The chemistry has been understood for a long time,” he says. The challenge was building a system that a farmer could operate every day in Georgian conditions without requiring an engineer on site.

That approach has taken BioNova through four smaller prototypes, repeated material and design changes, and conversations with more than 165 farmers. The company is now preparing its BN-108 system in Udabno, Kakheti, as it moves towards wider commercial deployment.

BioNova is targeting a segment Gongliashvili believes has been poorly served by conventional biogas technology: farms that produce substantial volumes of organic waste but are not large enough to justify the scale and cost of traditional industrial plants.

Its proposed business model is also unusual. BioNova says it intends to supply the hardware at production cost rather than earn a margin on the equipment. Farmers would retain the energy generated by the system, while BioNova expects to build recurring revenue through fertilizer and, eventually, carbon credits.

renewables.GE spoke with Gongliashvili about what the company learned from its prototypes, how the economics of farm-scale biogas could work, and what has to happen before BioNova can move from individual installations to wider deployment.

From prototypes to a farm-ready system

renewables.GE: BioNova has already tested four smaller prototypes, ranging from around 5 to 15 tons, and is now moving toward larger commercial-scale systems. What did you learn from the prototype stage, and what had to change before moving to the current generation of biodigesters?

Nikoloz Gongliashvili: The main thing we learned is that making biogas is not the hard part. That chemistry has been understood for a long time, and it has been working at industrial scale in Europe for decades.

The hard part is making something a farmer can actually use every day, in Georgian conditions, without an engineer standing next to him.

So we started by listening. We built four units, somewhere between 5 and 14 tonnes, and at the same time we spoke with more than 165 farmers. The ones who tested the prototypes told us what was wrong, both in the engineering and in the design, and we put those fixes into the next unit.

We never designed one finished product and then went looking for buyers. Every prototype had something in it that a farmer had asked for.

A lot of that work was choosing the right material, and that was mostly my co-founder and CTO, Nikoloz Chikhladze. For the shell alone we went through more than five options.

We looked at what the unit actually has to live through here: temperature, wind speed, snow load, how often it rains, and we ran a seismic analysis for the regions we install in. In Georgia the same digester can face heavy snow in winter, serious heat in summer, and an earthquake in the same decade. You cannot solve that on paper. You build it and you leave it outside for a year.

The second thing that changed is that the digester stopped being just a tank. Over those four prototypes it got a control system and automatic feeding and mixing. Today it has full functionality with an app connected to it, so the farmer can see what the system is doing and control it from his phone, and we can see it from here too.

The third thing is how it gets built. The early units were basically assembled on the farm, which is slow and depends on who is doing the work. Now the parts are made off site and put together at the farm in days instead of weeks. That is what we mean by modular. Fast to install, and the same every time.

What the BN-108 looks like in practice

renewables.GE: BioNova is currently developing the BN-108 biodigester in Udabno. Could you explain what a system of this size looks like in practice — how much organic waste it requires, what type of farm it is designed for, and what kinds of energy and fertilizer output it can provide?

Nikoloz Gongliashvili: It is a round tank of 108 cubic metres, about five and a half metres across and a bit over four metres tall. Next to it there is a gas holder, a generator and the control box.

We build the parts in advance, so on the farm itself it takes days to put together, not weeks.

It does not matter much what animals the farm keeps. Cattle, pigs, sheep, goats, buffalo — it all works. What matters is how much waste there is. You need at least 1.42 tonnes a day, so around 600 tonnes over a year. And you have to be able to collect it.

If the animals are in barns, fine. If they are out on a hillside all day, nobody is going to gather that manure, no matter how many animals you have.

That is exactly the kind of farm nobody was building for. Too big for a small household unit, too small for an industrial plant.

What the farmer gets from it is three things.

Electricity — at least 200 kilowatt-hours a day — which stays with the farmer and can cover things like milking, cooling, lighting and pumps.

Then fertilizer: roughly 80 tonnes of solid and 470 tonnes of liquid fertilizer a year. We collect that fertilizer and sell it, and the farmer gets his share.

And the third thing is the methane. Normally it sits in an open pit and escapes into the air. Here it is captured, and that is where the carbon credits come from.

Designing for smaller farms

renewables.GE: Conventional biodigesters are well-established technology, particularly in countries such as Germany, but are often designed for much larger agricultural operations. What has BioNova changed to make the technology more affordable, modular and practical for small and medium-sized farms?

Nikoloz Gongliashvili: The technology itself is nothing new, and we never pretend otherwise. Biogas is a natural process.

So we did not invent the chemistry. What we changed is who the system is built for.

A German plant is engineered for a farm with a thousand animals and a budget to match. You cannot shrink that design and expect it to work. Build a small version of an industrial plant and you get an expensive small plant, and the farmer still cannot afford it.

We started from the other end. We asked what a Georgian farm can realistically spend, and designed backwards from there.

That meant keeping the technology simple: no complicated parts, nothing that needs a specialist to repair. On top of that sits our own control and monitoring system and the app.

The other two changes are the materials and the assembly. We tested more than five materials for the shell and made the choice against our real conditions: heat, cold, snow load, wind, even seismic data for the regions where we install.

And we build the parts in advance, so on the farm the unit goes up in days rather than weeks.

The last part is not technical at all. We sell the system at what it costs us to build, and the electricity stays entirely with the farmer. We earn later, from the fertilizer and the carbon credits.

That is what makes it affordable. Not a cheaper machine, but a different way of getting paid for it.

When does a biodigester make economic sense?

renewables.GE: At what scale does the technology begin to make economic sense for a Georgian farm? Could a farm with around 40 cattle already be a viable customer?

Nikoloz Gongliashvili: The number that decides it is not how many animals a farm has. It is how much waste there is and whether it can actually be collected.

Our working figure is 1.42 tonnes a day. That is what the system is built around and where it performs best. But it is not a wall. If a farm has no other option, it can start at around one tonne a day and the digester will still process it, just with less output.

So there is no fixed number of cattle. A farm with forty head can work. So can thirty, depending on the animals, how they are kept and what else is available.

And manure is not the only thing that goes in.

Cattle manure on its own gives relatively little gas. It is stable and reliable, but it is not rich. The moment you mix in other material, the output rises sharply.

Food waste, dairy waste, spoiled silage, crop residue, waste from a slaughterhouse nearby — some of these produce several times more gas than manure does.

A farm with fewer animals but access to other organic waste can easily outperform a farm with more animals and nothing else.

Why the feedstock matters

renewables.GE: How strongly does the type of organic waste influence the performance of a biodigester?

Nikoloz Gongliashvili: It matters a lot. You can take two farms with exactly the same digester and get completely different results just because of what goes in.

The best output comes from food waste and field waste — crop residue, spoiled silage, vegetable waste, anything with fat or sugar in it.

Cattle manure is the opposite. It gives you much less gas because the cow has already taken most of the energy out of it before it ever reaches you. But it is the easiest thing in the world to work with. It is steady, it behaves the same way every day, and it is very hard to ruin the process with it.

Poultry waste is somewhere in the middle. Much more gas than cattle manure, but it is very high in nitrogen, and too much nitrogen turns into ammonia in the tank.

In practice, a mixture always beats one single material. The manure keeps everything stable; the food and field waste bring the energy.

And the one thing that matters more than the recipe is sticking to it. Whatever you decide to feed it, keep it roughly the same every day.

A business model built around recurring revenue

renewables.GE: How is BioNova designing its business model so that the technology remains affordable for farmers while also creating sustainable recurring revenue for the company?

Nikoloz Gongliashvili: The starting point is that we do not make money on the hardware.

We install the digester at production cost, with zero margin. That is a deliberate decision, not a discount.

If we put a margin on the machine, the price goes up, the payback period stretches and the farmer walks away.

What the farmer gets is everything the system produces in energy. The electricity and the gas are his, all of it. We take no share of that.

Our side of it is the fertilizer. Almost everything that goes into the digester comes back out as biofertilizer, and that is the part we keep the larger share of.

We collect it, handle the processing and sales, and once it is sold the farmer receives his share of the revenue.

Then there are the carbon credits. That is a bonus on top, and we retain those in full.

So the recurring revenue is the fertilizer and the carbon credits, not the hardware. That is the whole point of the model.

A company that sells equipment earns once, on the day of the sale, and then has to go and find the next customer. We earn every year that the system keeps running, from every farm we have ever installed.

And that alignment matters more than it sounds. Because we earn from what the system produces rather than from selling the box, we have every reason to make sure it keeps running well for years. If the farmer’s digester underperforms, we lose too.

What still has to happen before BioNova can scale

renewables.GE: BioNova is targeting 2027 for wider commercial sales. What technical, operational and commercial milestones still need to be reached?

Nikoloz Gongliashvili: One thing first, because the question makes it sound like we have not sold anything yet. We have.

Our first system went in a while back, though I would be honest about it — it was small, it was not proportional, it was really an improved prototype. It worked and we learned a lot, but it is not what we build now.

Udabno is the first proper one, and it starts up in a few months.

So 2027 is not our first sale. It is when we go from one at a time to many.

Technically we are in final testing and filing patents on several models. The system works. What we still need is a full year behind it, winter included, so that when we scale we are repeating something we have watched work, not something we hope will.

Then certification, in two parts. The fertilizer one starts very soon, with ATB Potsdam in Germany, and it is not a side project — the fertilizer is what lets us sell the hardware at cost, so until it is certified the model cannot scale.

The second is European certification for the system itself. Without it we are a local product. With it we can sell in Europe.

Operationally, logistics and supply are sorted. Now it is about speed. Today it takes about 45 days from order to installation and we want 20 or 25.

Demand is not the problem. We have talked to more than 165 farmers and several have asked us to send them an invoice.

So what stands between us and scale is not the technology and not demand. It is a year of proven operation, the certifications, halving that delivery time, and the money to build at that pace.

“A farmer does not trust a brochure”

renewables.GE: For many farmers, a biodigester will be unfamiliar technology. What does it take to build trust, and how important will the first successful installations be?

Nikoloz Gongliashvili: A farmer does not trust a brochure. He trusts what he can walk up to and see working, and he trusts what his neighbour tells him.

That is not scepticism, that is sense.

Before we had anything worth showing, we spoke to more than 165 farmers, and what they told us went straight into the design.

Talking only gets you so far, though. That is why we decided to put the first systems in for free.

The BN-108 is going into Udabno, in Kakheti, at the Georgian Farmers’ Association site, where anyone can come and see it running and see the real numbers. In 2027 we are doing the same in Khobi and elsewhere in western Georgia.

Those first installations are worth more than any marketing we could buy.

One working system that a farmer’s neighbour has seen with his own eyes beats a hundred presentations.

And it has to work, because the opposite is just as true — one public failure would set us back years.

Building hardware in Georgia

renewables.GE: BioNova has received grant funding and participated in international programmes and competitions. What has that experience taught you about building a hardware-based climate-tech startup in Georgia?

Nikoloz Gongliashvili: The first thing hardware teaches you is that being wrong costs real money.

In software you make a mistake and fix it that afternoon. Here a mistake is thousands of dollars of material that is already cut, welded and sitting in a yard.

For a young company still testing and developing, that is hard, because testing is exactly where you are supposed to get things wrong.

We learned the material lesson the expensive way. Early on we started prototyping with cheap, poor-quality material and the results were bad.

A cheap material that fails is not cheap. It is the most expensive thing you can buy.

The harder lesson was not technical. For most of this there was a lot of negativity around us. People said it would not work, that we were taking far too long, and they compared us with software startups where you build a prototype in a week on a laptop.

Those conversations were not pleasant, but they made us stronger.

Hardware is just slower. You cannot rush a winter.

We also had help from outside. Georgia’s Innovation and Technology Agency has been involved in our work, and we have been through several accelerators and worked with partners including Junior Achievement, DENA, ITU SEED and the Georgian Farmers’ Association.

We have raised more than $180,000 without giving up any equity. Eighty-nine per cent of it went straight into hardware, with the rest going into research, development, engineering and design.

The type of financing you need changes completely when you go from prototype to commercial scale.

Grants are right at the start. But a grant builds one unit, not fifty.

For us, the next stage requires serious working capital. Not to survive, but because the whole thing runs on paying first.

From farm equipment to energy infrastructure

renewables.GE: Looking three to five years ahead, what would success for BioNova look like — both in Georgia and internationally — and what role could small-scale biogas realistically play in Georgia’s renewable-energy sector?

Nikoloz Gongliashvili: In Georgia, success in three to five years means at least 500 digesters installed.

Not 500 pilots — 500 farms where biogas is simply normal equipment, like a milking machine or a tractor, bought because it obviously pays for itself.

It also means going up in size, not only in number. Farm-scale units are where we start, but we are planning to build several proper plants — stations producing around 25,000 kilowatt-hours of electricity a day each.

That is the point where this stops being an agricultural product and becomes energy infrastructure.

Internationally, it means we are out of Georgia. Turkey, Central Asia and Eastern Europe are markets we will very likely enter as well.

I will say the ambitious part out loud, because we mean it. We want to become Georgia’s first unicorn.

As for what this does to Georgia’s energy sector, start with what 500 farm systems produce. Each gives at least 200 kilowatt-hours a day, so 500 of them is around 100 megawatt-hours every day, generated in the regions where the farms are rather than carried there from somewhere else.

The reason that matters is the kind of energy it is.

When people in Georgia talk about renewables they mean solar panels and wind turbines, and that is the whole conversation. The problem is that both only work when the weather cooperates. The sun sets, the wind drops, and you get nothing.

A digester produces steadily, day and night, in winter, whatever the weather is doing. It is the only renewable source that runs around the clock, which makes it the one that can sit underneath the others rather than compete with them.

And it gives you more than one thing. A solar panel gives you electricity and nothing else. A digester gives you electricity, gas, hundreds of tonnes of fertilizer a year, and it captures methane that would otherwise go straight into the air.

So I do not think small-scale biogas replaces solar or wind here.

I think it becomes the part of the mix nobody is counting yet.

Source note: Interview with Nikoloz Gongliashvili, founder and CEO of BioNova. Responses were provided in writing following an earlier conversation with renewables.GE. Answers have been lightly edited for length and readability without changing their meaning.