Vertical Farming

Vertical Firm 2.0

Designing an Economically Feasible Vertical Farm

Executive Summary

This report proposes a vertical farm design concept based on objectives to demonstrate optimization in advanced controlled environment cultivation, energy- and waste stream improvements, system automation as well as modular system applications. The Vertical Farm 2.0 (VF 2.0) report is the result of a Concurrent Engineering (CE) workshop held at the German Aerospace Center (DLR) in Bremen in conjunction with the Association for Vertical Farming (AVF). This workshop brought together experts from throughout the world to lend their experience and knowledge in a collaborative manner. The baseline scenario developed for VF 2.0 involves modular levels specialized for either leafy greens production or vine crop production. The final synopsis discussed is a facility which consists of five modules in total; two of those modules are dedicated to leafy greens and two modules to vine crop production. The ground floor is a dedicated processing level which deals with harvested products and transport of goods out of the facility (see Figure 1).

The structure has a modular design so that more production modules can be added vertically without changing the design and support features. The leafy greens module aims to house crops like lettuce, basil, and kale while the vine plant module is for crops which require trellising such as tomato, pepper or cucumber. Initial design parameters for each of the modules are based on lettuce and tomato respectively. An airlock separates access to the production (growth) and decontamination areas thus the production areas are proposed as clean room zones. The production system area is at optimal climatic conditions for the plants. The overall building footprint is 75 m by 35 m which equate to a total area of 2.625 m2.

The administrative/operation core area in each module measures 10,25 m by 35 m, separated into two 3 meter floors. The base is designed to support heavier loads such as vertical transport systems, nutrient delivery system tanks and air management equipment amongst others. The production

areas will support only the weight of the nursery racks, cultivation racks and the crop itself. Each production area is 63,5 m by 35 m giving a total floor area of 2.222,5 m2. The floor to floor height in the production areas is 6 m.

The cultivation zone, within the production area of the leafy greens module, contains five growing racks each 50 m by 5 m by 5 m. Each of the 5 m high growing stands are divided along their length into four growing levels each one meter in height and is equipped with a conveyer belt system, where the plant cultivation gutters will travel. Irrigation pipes and drippers allow for the nutrient solution to flow in on one side of the channel and a run off drain on the other end of the gutter to collect the water run-off. Irrigation is suspended above the ends of the gutters to allow for mobility of the gutters. On the top of each growth level compartment are Light Emitting Diode (LED). The maximum distance between the plants and the LED panels is 0,25 m. The total growing area within the production zone of the leafy greens module totals 5.000 m2.

The lettuce cultivar selected as a crop model for this study is the Salanova® salad from Rijk Zwaan. Salanova® has an average 48-day seed to harvest life cycle. A total of 8.076 heads (each 200 grams) will be harvested every day resulting in a total marketable weight of 1.615,2 kg/day.

Within the production area, the cultivation zone of the vine crop cultivation module measures 50 m by 34 m and contains a conventional indoor high wire system. The system comprises 18 cultivation rows with trellising wires reaching up to a maximum height of 5 m. The distribution of the LED lights includes intra-canopy lighting on two levels and one level of top lights. The maximum distance between the plants and the top LED lights is 1 meter.

The selected tomato cultivar to perform the scenario calculations was the Lyterno® and the Brioso® from Rijk Zwaan. The total growing area is 1.700 m2. There are 4.250 plants in the cultivation zone, and the total harvested weight is 63,5 kg/m2 per year and 50,8 kg/m2 per year respectively.

Shown below, Table 1, is the calculated total power consumption for each of the subsystems. The plant lighting system and the air management system make up close to 98% of the energy demand.

Table 2 shows condensed yearly cost analyses for the baseline scenario VF 2.0. Total investments in the building and equipment amounted to 36.697.003 €. A margin of 10% was utilized to reflect a certain level of risk due to unforeseen costs, the unpredictability of the implementation of new technology, and volatilities in cost estimates. The investment costs for the construction and subsystem components will be amortized over a period of 30 years, with no residual value at an interest rate of 3%.

Yearly cost distribution is shown in Figure 2. Energy costs are the highest followed by initial investment costs. The total variable cost are 4.745.946 € per year.

VF 2.0 determined economic feasibility by finding the break-even point, or, price per kg (€/kg) that the total yearly produce would need to achieve to cover the estimated annual production costs. For VF 2.0 to break even it would have to sell its head of lettuce for 5,81 €/kg and tomatoes for 9,94 €/kg.

These values represent a starting point and need to be reviewed and discussed in further studies. Reducing energy costs is the primary goal of decreasing production costs. To this end, the illumination system, the air management and thermal systems [Chapters 7 and 8 respectively] will come under the most scrutiny.

In recent years there has been a significant improvement in the efficiency of LED lighting systems. Over the years to come, the energy demand and the thermal properties of the

lights will improve further lowering the production costs and render them more thermally efficient. Thermal regulation (climate) cost within the building can also be reduced by tailoring the thermal management system to the specific life cycle of the distinct cultivars as they transpire less during their growth phases.

As the vertical farming industry matures, more efficient solutions will become available to growers, from efficient illumination systems to climate management system and with improved business plans, these factors will drive down the cost of production in the future.

1 Introduction

With 2016 set to become the hottest year ever recorded by NASA, coupled with the dramatic rise in world population and the urbanization of that population many are questioning the world’s food security. Consistently producing fresh produce for people in new mega-cities is a growing problem which has led to the advent of many new agricultural technologies and approaches. Vertical Farming is positioned to offer a solution for this problem. Vertically stacking growing space with artificial lights allows optimizing the available land space thus producing more crops on a smaller area with highly efficient system.

Development programs for long-term human space flight by the EDEN team at the DLR in Bremen, Germany have led to technologies for earthbound Vertical Farms. This information will help to reduce the costs and ultimately make new vertical farms a sustainable, economically feasible and environmentally friendly way to produce significant amounts of food for people in the major cities.

With this in mind, the DLR and the AVF teamed up to bring together experts in the Vertical Farming industry to design the optimized Vertical Farm and publish these plans to raise awareness and help promote this new industry. In November 2015 the DLR in Bremen hosted the Vertical Farm 2.0 Concurrent Engineering workshop. During this workshop various objectives and design guidelines and goals were set. See Tables 1-1 and 1-2.

Mission Objectives The design objectives for the VF 2.0 are listed in Table 1-1.

Study Objectives

The objectives for the workshop are listed in Table 1-2 with their respective numbers.

Study Domains

Because the domains for the VF 2.0 workshop differ from the typical satellite design studies conducted within the CE Facility, different areas where assigned. The areas and their location in the CE facility are in Figure 1-1.