2025-08-18

Green revolution within tenement walls: from vacant space to a vertical farm – a comprehensive analysis of potential, costs, and risks

Introduction: A new life for vacant spaces – urban agriculture as an answer to the challenges of modern metropolises

Urban and social context

Modern Polish metropolises, despite dynamic growth, are struggling with a quiet yet progressive problem – a growing number of vacant properties. These are not just abandoned factories or warehouses on the outskirts, but also unused office spaces in city centers, and even entire apartments in historic tenement houses. This phenomenon, documented in numerous reports and urban analyses, represents a double loss. From an economic perspective, these are frozen assets that generate no value and burden owners with maintenance costs. From a social perspective, empty and neglected spaces contribute to the degradation of the urban fabric, lowering the sense of security and the aesthetics of the surroundings. City authorities, aware of the scale of the problem, are looking for innovative ways to adapt these properties, as exemplified by actions taken in Krakow, where renovations of vacant spaces and land purchases for greenery are planned.

Food system challenges

Parallel to urban challenges, cities face a fundamental question about their food security. Global trends are alarming. Projections indicate that by 2050, nearly 70% of the world’s population will live in urban agglomerations. The current model of supplying cities with food is based on long, complex, and high-emission supply chains. Food production accounts for about a quarter of global greenhouse gas emissions, and the transport of fruits and vegetables alone generates as much as 36% of the emissions associated with the transport of all food products. Moreover, traditional agriculture, dependent on increasingly unstable climatic conditions, is vulnerable to droughts, floods, and other extreme events, threatening supply continuity.⁴ This dependence on external producers and complex logistics makes urban food systems extremely sensitive to all kinds of crises – from geopolitical to climatic.

Main thesis

In response to these interconnected challenges, an innovative concept emerges that connects the seemingly distant worlds of real estate and agriculture: transforming urban vacant spaces into technologically advanced vertical farms. This is not a futuristic vision, but a real strategy already being implemented around the world, allowing for the production of fresh, healthy food in the very heart of the city – in former office buildings, abandoned warehouses, and even unused parking lots. Instead of threatening with emptiness, these spaces can turn into vibrant, vertical gardens providing the local community with lettuce, herbs, and vegetables.

This approach is also gaining popularity in Poland. The activities of startups such as Warsaw’s “Listny Cud”, which established its pilot farm in a post-industrial building in Mokotów, show that adapting existing infrastructure is not only possible but also economically justified.⁸ This report is a comprehensive analysis of the potential, costs, and risks associated with implementing such a project on a smaller scale – within a 100-meter apartment in a tenement house. This analysis shows that adapting vacant spaces into vertical farms is not only a solution to the food problem, but also a powerful tool for urban revitalization. It is the convergence of two key problems – property degradation and the instability of food supply chains – into a single, synergistic solution that transforms a problem into a strategic opportunity to build more resilient and self-sufficient cities.

Part I: Technology and vertical farming methods – how does a garden work in a confined space?

1.1. Foundations: Controlled Environment Agriculture (CEA)

The conceptual and technological foundation of every vertical farm is Controlled Environment Agriculture (CEA). This is an approach that treats plant cultivation not as a process dependent on the whims of nature, but as a precisely managed production process. Within CEA, all key factors affecting plant growth – such as light spectrum and intensity, air and nutrient solution temperature, humidity, carbon dioxide (CO2) concentration, and the composition and concentration of nutrients – are constantly monitored and optimized using advanced systems.

The goal is to create ideal, laboratory conditions for a specific plant species, which allows for the maximization of growth rate, yield size, and nutritional value. It is CEA technology that is the key to completely decoupling crops from external conditions: climate, seasons, diurnal cycle, or environmental pollution. Thanks to this, production can take place anywhere on Earth – from the center of a metropolis to a desert – and last continuously 365 days a year.

1.2. Soilless cultivation systems: the heart of the vertical farm

Vertical farms abandon traditional soil in favor of more efficient and controllable methods of delivering water and nutrients to plants. The three main technologies dominating this field are hydroponics, aeroponics, and aquaponics.

Hydroponics

Hydroponics is the most popular and often most cost-effective method used in vertical farming.¹⁶ It involves growing plants in a system where their roots are immersed in or regularly sprayed with an aqueous solution of precisely balanced nutrients, the so-called nutrient solution.¹⁰ Since no soil is used that could mechanically stabilize the plant, its function is taken over by an inert, sterile substrate such as perlite, expanded clay, mineral wool, or coconut fiber. Its task is solely to provide support for the root system and maintain adequate moisture and aeration.¹⁰ Water with nutrients circulates in a closed loop, which drastically reduces its consumption and allows for precise dosing of fertilizers directly to the root zone.¹⁰

Aeroponics

Aeroponics is a more technologically advanced and efficient variety of soilless cultivation. In this system, plant roots are not immersed in water or placed in a substrate, but hang freely in the air in enclosed chambers.⁴ At regular, short intervals, they are sprayed by high-pressure nozzles that create a nourishing mist. Microscopic droplets of water with dissolved mineral salts settle on the roots, providing them with constant access to both nutrients and oxygen. This method allows for even greater savings of water and fertilizers compared to hydroponics, and also often results in faster plant growth rates.¹⁹ Its main disadvantage, however, is the higher initial cost and greater technical complexity of the system, which is more sensitive to power outages or nozzle clogging.¹⁷

Aquaponics

Aquaponics is a unique combination of aquatic animal farming (usually fish) with plant cultivation, creating an almost fully self-sufficient, closed ecosystem.¹⁰ This cycle works on the principle of natural symbiosis. Fish, fed in breeding tanks, produce waste rich in ammonia, which in higher concentrations is toxic to them. Water from these tanks is pumped into the cultivation system, where two groups of beneficial nitrifying bacteria convert ammonia first into nitrites and then into nitrates. Nitrates provide an excellent, natural fertilizer for plants, which absorb them through their roots while simultaneously cleaning and filtering the water. Clean, oxygenated water then returns to the fish tank, closing the cycle.²² This system eliminates the need for synthetic fertilizers and minimizes water losses, but requires careful balancing of both components – fish farming and plant cultivation.

1.3. Key Technological Components

The success of a vertical farm is directly proportional to the advancement and reliability of its technology. This is not a traditional field, but rather an advanced plant factory fully dependent on an integrated technological system. The failure of a single key component, such as a pump in a hydroponic system, can destroy an entire crop within a few hours, which constitutes a fundamental difference in the risk profile compared to traditional agriculture, which is characterized by much greater inertia.¹⁸ Investing in a vertical farm is therefore not only an investment in equipment, but above all in knowledge, reliability, and security systems.

Structures and Modules

The heart of every vertical farm is a system that maximizes growing space within a limited horizontal area. This is achieved through the use of multi-tier racks, vertical growing towers (columns), or wall-mounted panels.⁵ A key feature of these systems is their modularity, which allows for easy installation, flexible adaptation to almost any space, and the possibility of future expansion and scaling of production.¹⁴

LED Lighting

In enclosed spaces without access to sunlight, artificial lighting 100% takes over its role in the photosynthesis process.¹³ Modern vertical farms use almost exclusively energy-efficient LED lamps for this purpose.⁴ Their advantage over older technologies (e.g., HPS lamps) lies not only in lower energy consumption, but above all in the ability to precisely control the spectrum of emitted light. Different light wavelengths affect different physiological processes in the plant. For example, blue light stimulates vegetative growth (leaf and stem development), while red light is crucial for the flowering and fruiting process.²⁶ Thanks to the ability to tailor the “light recipe” to a specific species and its stage of development, growth can be significantly accelerated and yields increased.

Automation and Control

A modern vertical farm is largely automated. A central computer system, connected to a network of sensors, constantly monitors all environmental parameters and adjusts them in real time.⁴ These systems automatically control irrigation cycles, precisely dose nutrients into the nutrient solution, maintain the set temperature and air humidity, and even enrich the atmosphere with CO2 to intensify photosynthesis.¹² This level of automation not only minimizes the risk of human error and reduces ongoing labor costs, but also allows for the creation of detailed “growing algorithms” for each plant, which guarantees the repeatability and predictability of harvests.¹⁰

Part II: Multifaceted Benefits – Why Invest in Urban Farms?

Investing in vertical agriculture, although capital-intensive, brings a number of benefits spread across environmental, economic, and social dimensions. These advantages make this technology perceived as a key element in building sustainable and resilient food systems in cities.

2.1. Environmental Benefits: Sustainable Production in the Heart of the City

Water Conservation

One of the most striking advantages of vertical farms is the drastic reduction in water consumption. Traditional agriculture is one of the most water-intensive sectors of the economy, accounting for about 70% of global freshwater use.¹² In field crops, a huge portion of it is lost as a result of evaporation, surface runoff, and deep percolation into the soil. Systems used in vertical agriculture, such as hydroponics or aeroponics, operate in a closed loop. Water that is not taken up by plants is recovered, filtered, and reintroduced into the system. Even water transpired by plants can be condensed and recovered by air conditioning systems.²⁸ As a result, vertical farms can use up to 70-95% less water than conventional growing methods to produce the same amount of biomass.⁴

Elimination of Pesticides

Growing in an enclosed, controlled, and often sterile environment almost completely eliminates the risk of pests, weeds, and soil-borne diseases.²³ Thanks to this, production can take place without the use of any chemical plant protection products – pesticides, herbicides, or fungicides.⁴ This means not only a healthier and cleaner end product for the consumer, but also no negative environmental impact associated with the contamination of soil and groundwater by agricultural chemicals.

Carbon Footprint Reduction

The location of vertical farms directly in cities, in close proximity to consumers, radically shortens the supply chain. Instead of transporting vegetables and herbs hundreds or even thousands of kilometers from distant agricultural regions, they can be delivered to the local market within a few hours of harvest. This reduction in so-called “food miles” leads to a significant decrease in emissions of carbon dioxide and other pollutants associated with road, sea, and air transport.¹⁰

Spatial Efficiency

The vertical arrangement of crops allows for the multiplication of yields from every square meter of area. It is estimated that vertical farming can be several dozen, and in some cases even several hundred times more spatially efficient than traditional agriculture.¹⁰ According to some analyses, a single vertical farm located on a one-hectare plot can produce the same amount of food as 10 to 100 hectares of conventional field crops.¹⁵ This extraordinary efficiency allows for food production without the need for further deforestation and the conversion of valuable natural ecosystems into agricultural land.³²

2.2. Economic and Operational Benefits: Predictability and Efficiency

Year-Round Production

Complete independence from external conditions means that production on a vertical farm can run continuously all year round, 24 hours a day, 7 days a week.⁴ This eliminates the problem of seasonality, ensuring a constant supply of fresh produce on the market regardless of the time of year. For the producer, this means stable and predictable revenue, and for the consumer – access to their favorite vegetables and herbs 365 days a year.¹⁵

Higher Productivity

Optimal growth conditions, precise fertilization, and perfectly matched lighting make the growing cycles on vertical farms much shorter than in nature. For example, the growing time for lettuce can be shortened from 30-45 days in the field to just 15-20 days in a vertical system.³⁴ Shorter cycles, combined with higher plant density and the possibility of continuous harvesting, translate into unprecedentedly high annual yields.¹⁰

Real Estate Revitalization

The ability to adapt existing, often degraded and unused buildings gives them a new, productive, and profitable function.¹⁴ Utilizing old warehouses, abandoned office buildings, or post-industrial halls is often cheaper and faster than building new infrastructure from scratch.⁸ In this way, vertical farming becomes a tool for urban revitalization, breathing new life into forgotten spaces.

2.3. Social Benefits: Health, Safety, and Local Development

Food Security

A distributed network of urban vertical farms enhances local sovereignty and food security. In the event of a crisis that could disrupt traditional supply chains (e.g., a pandemic, natural disaster, armed conflict), cities with their own food production sources are significantly more resilient and self-sufficient.¹²

Better Product Quality

Products from vertical farms can be harvested when they reach optimal ripeness, flavor, and nutritional value, rather than at a stage meant to withstand long-distance transport. Delivering them to the consumer within hours of harvest guarantees maximum freshness and quality that imported produce simply cannot match.¹⁴

New Jobs

Growth in the vertical farming sector generates new, specialized jobs in cities. It calls not just for crop handlers, but also for technologists, engineers, biologists, and automation specialists to design, build, and oversee farm operations.¹⁴

A fundamental shift introduced by vertical farming is the paradigm change in food production risk. Traditional farming is a constant battle against unpredictable natural factors—drought, flood, hail, or pest invasions.⁴ Thanks to CEA technology, a vertical farm eliminates these variables, offering near-laboratory predictability and crop repeatability.¹⁵ There is no need here to insure crops against natural disasters.¹⁴ However, this certainty comes at the price of complete reliance on steady, high operational expenses, primarily electricity.⁴ In this way, risk shifts from uncontrollable weather to economic and technological factors which are theoretically controllable, yet generate constant, high costs. Success in this field no longer depends on the rain, but on the price of a kilowatt-hour and the reliability of the power grid. This demands a completely new set of competencies from the “urban farmer”—they become an advanced factory manager rather than a traditional grower.

Part III: Threats and Challenges – Risk Analysis of a Vertical Farm Project

Despite its enormous potential, vertical farming carries a series of serious challenges and risks that pose a significant barrier to its widespread adoption. These are primarily financial, technological, and market barriers that require careful analysis before making an investment decision.

3.1. Financial Barriers: High Entry and Maintenance Costs

High Capital Expenditures (CAPEX)

The most serious obstacle to the development of vertical farms is the very high initial capital expenditure. Building or adapting spaces, as well as purchasing and installing advanced technology—hydroponic systems, LED lighting, precision air conditioning (HVAC), automation—require substantial financial outlays.⁴ These costs can range from tens of thousands of zlotys for small experimental setups to many millions for commercial-scale farms.⁴ For many potential investors, especially under Polish conditions, these costs are often prohibitive, and the return on investment, while potentially fast, carries risk.³⁷

High Operating Expenses (OPEX)

Even after incurring high initial costs, running a vertical farm involves significant, fixed operational expenses. The absolutely dominant item in the budget is electricity consumption.⁴ Specialized LED lamps must operate for 12-18 hours a day, and air conditioning and ventilation systems run continuously to maintain optimal conditions. In countries with relatively high energy prices, such as Poland, this cost can pose a key challenge to the profitability of the entire venture and serves as the main operational risk factor.⁴

In this context, vertical farms embody a certain paradox of sustainability. On one hand, they are promoted as an ultra-ecological solution due to radical water savings and the elimination of pesticides. On the other hand, their huge demand for electricity—which in many countries, including Poland, still largely comes from burning fossil fuels—undermines their “green” image. High power consumption from a coal-based grid translates into significant carbon dioxide emissions. This means that a vertical farm may solve certain ecological problems (water usage, pesticide pollution) while simultaneously worsening others (greenhouse gas emissions). A key condition for this technology to achieve true sustainability is therefore its strict integration with renewable energy sources (RES), such as rooftop photovoltaic panels or the use of heat pumps.⁸

3.2. Technical and Operational Challenges

Required Specialized Knowledge

Effective management of a vertical farm requires interdisciplinary, specialized knowledge. The operator must possess competencies in plant physiology, chemistry (preparing nutrient solutions), engineering (system operation), and IT (managing control software).⁴ This is not simple gardening, but a complex biotechnological process. A lack of proper qualifications can lead to costly mistakes and crop loss.

Technological Dependency

Total reliance of production on technology reliability poses a major risk. A failure of a key component—a power outage, a broken water pump in the hydroponic system, a failed fan, or a software glitch—can lead to a catastrophic and irreversible loss of the entire crop within just a few hours.¹⁸ This requires investing in backup power systems (UPS, generators), redundancy of key equipment, and constant monitoring, which further drives up costs.

Limited Crop Variety

Currently, vertical farming technology is economically viable mainly for a limited group of plants. These are primarily species characterized by a short growth cycle, small size, and high market value, such as various types of lettuce, herbs (basil, mint), microgreens, and certain fruits like strawberries.⁴ Cultivating staple yet heavier and more space-demanding root crops (potatoes, carrots) or grains remains unprofitable and is the domain of traditional agriculture.

3.3. Market and Regulatory Challenges

Price Competition

Due to high investment and operational costs, products from vertical farms are usually more expensive than their mass-produced field counterparts, especially imports.⁴ This creates a significant market barrier, particularly in price-sensitive segments. Commercial success depends on the ability to convince consumers that the higher price is justified by better quality, freshness, the absence of pesticides, and the local origin of the product.

Legal and Construction Issues

Adapting a residential apartment in a tenement building for production activities, even ones as clean as a vertical farm, can face serious legal and administrative barriers. This process will certainly require changing the intended use of the premises, which involves a complicated official procedure and the necessity of obtaining permits. Installing advanced technological systems may require the consent of the housing cooperative or community, as well as meeting rigorous fire, construction, and sanitary standards. An additional major problem can be the insufficient electrical connection capacity in older buildings, and upgrading it can be costly or technically impossible.

Social Acceptance

Although ecological awareness is growing, the concept of food grown “in a factory”, without soil and sun, may still arouse skepticism among some consumers. Educational efforts that highlight the advantages of this production method and build trust in a brand based on transparency, quality, and sustainable development are key to market success.

Part IV: Case Study – 100m² Vertical Garden in a Tenement Building: Financial and Operational Analysis

To translate theoretical considerations into practical realities, this section provides a detailed financial and operational analysis for a hypothetical project converting a 100-square-meter apartment in a tenement building into a small commercial vertical farm.

4.1. Project Assumptions

Location: Commercial or residential space of 100 m² in a tenement-type building, requiring adaptation.
Cultivation Area: It is realistically assumed that about 60% of the total area will be effectively utilized for multi-level cultivation systems. The remaining 40% will be allocated to necessary technical infrastructure: the nutrient preparation zone, storage, control systems, communication pathways, and packaging zone. Therefore, the effective cultivation area is 60 m².³⁹
Technology: A hydroponic system was chosen as the solution offering the best compromise between investment cost, efficiency, and ease of operation at this project scale.¹⁶
Crops: Production focused on high-market-value assortments with a short growth cycle, such as microgreens (e.g., radish, peas, sunflower), specialized varieties of lettuce, and popular herbs (e.g., basil, cilantro, mint).⁸

4.2. Estimated Investment Costs (CAPEX)

The table below presents a detailed, estimated investment budget for the described project. The goal is to provide a transparent, quantitative picture of the entry barrier, which is a key decision-making factor for a potential investor. This table demystifies the general statement about “high costs” by breaking them down into specific, quantifiable items extrapolated from data for larger commercial projects.

Table 1: Investment Budget for the 100m² Vertical Farm Project (60m² cultivation)

Category	Specification / Rationale	Estimated Cost (PLN)
Space adaptation and preparatory work	Construction work (waterproofing, wall finishing), modernization and reinforcement of the electrical system to handle high loads, installation of efficient mechanical ventilation.	50,000 – 80,000
Hydroponic system	Multi-level growing racks, NFT gutters or Ebb & Flow trays, piping system, circulation pumps, water and nutrient tanks, filtration systems (reverse osmosis).	120,000 – 180,000
Professional LED lighting	Specialized LED panels with adjustable spectrum and high PAR efficiency, adapted for multi-tier cultivation. This is the most expensive single component of the system.	150,000 – 250,000
Air conditioning and ventilation (HVAC)	Precise temperature and humidity control system, dehumidifiers, circulation fans, carbon filters for odor elimination.	80,000 – 120,000
Automation and control systems	Central controller, sensors (pH, EC, temperature, humidity, CO2), automatic fertilizer dosing systems (peristaltic dispensers).	40,000 – 60,000
Other equipment	CO2 atmospheric enrichment system (cylinders, controller), harvesting and packaging equipment, washers, scales, basic laboratory equipment (meters).	20,000 – 40,000
TOTAL (CAPEX)	Total estimated project launch cost	460,000 – 730,000

4.3. Estimated Monthly Maintenance Costs (OPEX)

This section directly answers the key question about the ongoing maintenance costs of the farm. The table below presents a simulation of monthly operating expenses, highlighting the dominant role of electricity costs, which is the most important conclusion from the risk analysis.

Table 2: Simulation of Monthly Operating Costs for a 100m² Farm (60m² cultivation)

Category	Calculations / Rationale	Estimated Monthly Cost (PLN)
Electricity	Estimated lighting power demand: 300 W/m². Total power: 60 m² * 300 W/m² = 18 kW. Operating time: 16h/day. Consumption (lighting): 18 kW * 16h * 30 days = 8,640 kWh. Additional ~20% for HVAC, pumps, fans: ~1,728 kWh. Total: ~10,368 kWh/month. Price: ~1.20 PLN/kWh.	12,000 – 15,000
Water and sewage	Consumption reduced by >90% compared to traditional crops, but still present (water bound in biomass, evaporation, system rinsing). Estimated at 3-5 m³ monthly.	100 – 200
Fertilizers and nutrients	Cost of professional, multi-component hydroponic concentrates, pH regulators. Depending on crop intensity and plant type.⁴⁰	800 – 1,500
Consumables	Seeds or seedlings, starting media (e.g., rockwool), system disinfection agents, packaging.	500 – 1,000
Labor	Cost of employing one part-time employee for ongoing maintenance, harvesting, and packaging, or the owner’s equivalent working time.⁴²	2,500 – 4,000
Rent and administrative fees	Cost of premises rental (if not owned), housing cooperative fee, property tax. Value heavily dependent on location in the city.	3,000 – 6,000
TOTAL (OPEX)	Total estimated monthly maintenance costs	18,900 – 28,700

4.4. Financial Summary and “Cost Brackets”

Case study analysis leads to clear conclusions regarding the financial scale of the undertaking. Transforming a 100-meter apartment in a tenement house into a functional vertical farm is a project of a professional investment nature, rather than hobby gardening.

Capital Expenditures (CAPEX): You must prepare for a one-time expense ranging from 460,000 to 730,000 PLN. The final amount will depend on the standard of the selected equipment, the scope of adaptation work, and negotiations with suppliers.
Monthly Operating Expenses (OPEX): Crucial for profitability assessment are fixed operating costs, which can be estimated at from 19,000 to 29,000 PLN per month. It should be emphasized that over half of this amount constitutes the cost of electricity, making the project’s profitability extremely sensitive to electricity price fluctuations. The given brackets include rent for the premises; if you own the property, operating costs would be correspondingly lower.

Conclusion: prospects and recommendations – is a tenement farm the future of Polish cities?

The conducted analysis clearly shows the dual nature of vertical farming as a solution for urban vacancies. On the one hand, this technology offers unprecedented ecological, production, and social potential. The possibility of growing fresh, healthy food all year round, with minimal water consumption and without pesticides, in the very heart of the city, is a remarkably appealing vision. On the other hand, realizing this vision encounters powerful financial, technological, and regulatory barriers. High investment and operating costs, dominated by the price of energy, as well as the requirement for highly specialized knowledge, make a vertical farm an enterprise with a high entry threshold and significant risk.schl

Recommendations for Investors

Potential investors considering a project on the scale described in the case study must approach it with full awareness that this is a technologically advanced production enterprise, not an expanded form of gardening. Success depends on several key factors:

Solid Business Plan: It is essential to conduct a detailed local market analysis, identify niches (e.g., restaurants, health food stores, resident subscriptions), and develop a pricing strategy that justifies the higher premium product price.
Securing Financing: High CAPEX requires a stable source of financing that will cover not only equipment purchase but also adaptation costs and provide a financial buffer for the first months of operation.
Energy Cost Optimization: Access to cheap electricity is a precondition for profitability. Priority should be given to locations with the possibility of installing renewable energy sources (e.g., rooftop photovoltaics on a tenement house) or considering long-term green energy supply contracts.
Acquiring Knowledge: Investing in training, hiring qualified staff, or cooperating with companies offering comprehensive implementations and technical support is absolutely crucial.

Recommendations for cities and communities

In order for the potential of vertical farms to be fully utilized as a tool for revitalization and building resilience, active support from local governments and public institutions is necessary. Following examples such as Kraków ², cities can:

Create a Friendly Regulatory Environment: Simplify and speed up procedures related to changing the use of vacant properties for urban agriculture purposes, offering legal and architectural advisory.
Offer Financial Support: Create subsidy programs, grants, or low-interest loans for startups and cooperatives wanting to invest in urban farms.
Promote and Educate: Organize information campaigns on the benefits of local food production, building awareness and demand among residents.

In summary, a vertical farm in a tenement house is not yet a mass solution, but it constitutes a fascinating direction of development for the future of Polish cities. Although this technology will certainly not fully replace traditional agriculture, it is its key and complementary addition in dense urban fabric.¹¹ As technology progresses, costs drop, and renewable energy prices rise, vertical gardens may cease to be a technological curiosity and become an integrated, common element of a sustainable, healthy, and self-sufficient city of the future.

Extended Analysis: Vertical Farm Powered by a Thorium Reactor

The idea of using a dedicated nuclear energy source, such as a thorium reactor, to power a vertical farm is conceptually very coherent. These farms have one main operational challenge – enormous and constant demand for electrical energy. Nuclear reactors, in turn, provide stable, almost emission-free energy 24/7, regardless of weather conditions.

What is a Thorium Reactor and why does it fit the concept?

A thorium reactor is a type of nuclear reactor that uses thorium as fuel instead of uranium. This technology, especially in the form of Molten Salt Reactors (MSR) or Small Modular Reactors (SMR), is perceived as the future of nuclear energy for several reasons:

Intrinsic safety: Many MSR designs are “inherently safe,” meaning that in the event of a failure, the reactor shuts down automatically without the need for human intervention.
Less waste: They produce significantly less long-lived radioactive waste compared to traditional reactors.
Huge efficiency: Thorium is much more abundant in the Earth’s crust than uranium and can be utilized more effectively.
Scalability: The SMR concept assumes the construction of small, factory-produced reactors that can be delivered and installed near the point of demand (e.g., a city, an industrial zone).

Cost of Building a Thorium Reactor

This is the biggest challenge. It must be emphasized that thorium reactor technology is still in the research and development stage and is not widely available commercially. Currently, you cannot “buy off the shelf” a small thorium reactor. Costs are therefore estimated and based on pilot projects and forecasts.

Estimated cost: Analyses regarding Small Modular Reactors (SMR) in general (not just thorium ones) indicate costs ranging from 1 to 3 billion dollars per reactor with a capacity of 50 to 300 MWe (megawatts electric).
Scale comparison: A vertical farm with an area of 1000 m² might need about 0.5-1 MW of power. This means that even the smallest designed SMR would have a capacity 50-100 times greater than needed for one large farm.

Conclusion: Building a nuclear reactor, even a small one, exclusively for the needs of a single vertical farm is absolutely economically unviable. The cost of the reactor would exceed the cost of the farm thousands of times.

What Would a Realistic Scenario Look Like Then?

The scenario becomes realistic when we think on the scale of a city or a large district. An SMR-type thorium reactor would not power a single farm, but would constitute the heart of a local energy system that serves:

Several or a dozen vertical farms.
Residential estates.
Industrial plants and data centers.
Urban infrastructure (lighting, public transport).

In this model, the vertical farm becomes one of many consumers, but an ideal consumer – with a steady, predictable, and high power draw, which helps stabilize the entire grid.

Impact on the Costs of Building and Running the Farm

Let’s assume such a reactor already exists and the farm can buy energy from it at production cost rather than market prices.

1. Costs of Building the Farm (CAPEX):

Unchanged: The cost of installing hydroponic systems, LED lighting, automation, racks, air conditioning, and building adaptation remains the same. Estimated at from 1.5 to 4 million PLN for an advanced 100 m² farm.

2. Costs of Running the Farm (OPEX):

A revolutionary change: This is where the fundamental difference lies. The cost of electricity is the largest component of operating expenses.
- Grid-powered model: At a price of 1 PLN/kWh, the annual energy cost for a 100 m² farm (approx. 240,000 kWh) is 240,000 PLN.
- Thorium reactor-powered model: The operational cost of generating energy in a nuclear reactor (fuel, maintenance, upkeep) is very low. It is estimated at a few groszy per kWh. Assuming an optimistic e.g., 0.10 PLN/kWh, the annual energy cost drops to 24,000 PLN.

This means a more than 10-fold reduction in the largest operating expense!

Cost Comparison Table (Estimate for a 100 m² farm)

Cost Category	Grid-Powered Model (annual)	Thorium Reactor-Powered Model (annual)	Difference
Electricity	~ 240,000 PLN	~ 24,000 PLN	– 216,000 PLN
Staff	~ 120,000 PLN	~ 120,000 PLN	Unchanged
Water and nutrients	~ 20,000 PLN	~ 20,000 PLN	Unchanged
Consumables	~ 10,000 PLN	~ 10,000 PLN	Unchanged
Total OPEX (estimated)	~ 390,000 PLN	~ 174,000 PLN	Savings ~55%

Summary and Conclusions

Technological Synergy: Combining stable, zero-emission energy from a thorium reactor with the constant demand of a vertical farm is technologically ideal.
Economic Barrier: The cost of building a thorium reactor is astronomical and currently disqualifies its use for a single agricultural project. The technology is not yet commercially mature.
Realistic Vision: The only realistic model is a systemic approach, where an SMR reactor powers an entire district or industrial zone, and vertical farms are among the key clients benefiting from ultra-cheap and stable energy.
Shift in Profitability: Access to such cheap energy would drastically lower farm operating costs, allowing for food production at prices competitive with traditional agriculture. This would solve the biggest problem vertical farms face today.

Incorportaing thorium reactors into the plan is a vision of the future that could revolutionize the concept of food and energy self-sufficiency for cities. For now, this remains in the realm of concepts for coming decades, but it shows a fascinating direction of development

FAQ – Green revolution within tenement walls: from vacant space to vertical farm – a comprehensive analysis of potential, costs, and risks

What are the most important takeaways from this article? Focusing on customer needs and adapting to changing technologies is the foundation of success.