INDUSTRIAL SYMBIOSIS

The Data Center industry is one of the most energy-intensive and accounts for 1-2% of the world's total demand for electricity. The electricity used to power a center's IT equipment is usually discharged into the environment as air at a temperature of about 30–45 °C.

The largest potential benefit of the energy recovery investigated is found in vegetable farms. Here lies the possibility of industrial symbiosis.

Industrial symbiosis means that two different industries achieve economic and environmental benefits by organizing themselves around the exchange of resources, such as material flow or energy.

GREENHOUSE OPTIMISATION

The question of how to utilize excess data center heat has proven to be one of the major barriers to recovering it from servers in the first place. Low-temperature levels have long been argued not to be suitable for actual integration into existing heating demand or heating grids.

Waste heat from data centers should be transported to other energy systems so that it can be used. This energy system may be a greenhouse, swimming pool, nearby buildings, district heating, etc. Waste heat from data centers has a rather low temperature for district heating and needs to be heated up to around 85 °C.

For this purpose, a heat-pump system is used to raise the temperature level, which is a process requiring some extra electricity to be used.

Furthermore, the waste energy for nearby buildings and swimming pools, particularly in winter, is not very attractive, since they have to be raised to a higher temperature in order to be really useful.

In fact, greenhouses are one of the few applications where waste heat from data centers can be used directly without any further manipulation.

Greenhouses and data centers can be easily combined in order to increase the overall efficiency of the system. For this purpose, warm air can be directly extracted into a greenhouse system. Excess fresh air can then be used in order to adjust the temperature and relative humidity.

TOWARDS SELF-SUFFICIENCY

Studies have highlighted the possibility of increasing a country’s degree of self-sufficiency in the food supply, by using a Data Center as a heating source for greenhouse production.

A study focused on northern Sweden calculated the hourly exhaust air output from a 1 MW DC for one year and the corresponding heating demand for two different greenhouse sizes, 2000 m2 and 10.000 m2, and two different production scenarios.

Partial-year production without grow lights and full-year production with grow lights. As of today, 91% of all vegetables consumed in northern Sweden are imported. Energy consumption in Swedish greenhouses was 627 GWh in 2011 and 41% came from oil and natural gas.

The study showed that 5.5–30.5% of the electrical input to a 1 MW DC could be recovered. The 2000 m2 greenhouse could operate almost entirely, 89.7–97.9%, on excess heat, while only 50.0–61.5% of the 10.000 m2 greenhouse heating demand could be met for full- and partial-year production, respectively.

The 10.000 m2 greenhouse with full-year production was the most prominent case and would cost-effectively yield 7.6% of northern Sweden’s vegetable self-sufficiency.

In a typical datacenter, 5kW per rack is standard. For reference, 5kW is around 20 solar panels with a clear sky. In terms of computing power, a typical server with websites will use around 200-300 watts.

A whole data center of 9 racks adds to around 180kW in total, which is enough to heat 20.000m2 of greenhouses in the summer and 5.000m2 in the winter. 1m2 will grow about 50 kg of tomatoes in a year. Just nine server racks can grow hundreds of tonnes of tomatoes per year.

In the case of the Netherlands, energy use is responsible for about 75% of the environmental impact of tomatoes grown under glass, with carbon footprints ranging from about 0.78-2.0kg CO2 per kilogram of tomatoes. In other words, the emissions weigh as much as the food itself.

ORGANIC DATA CENTERS

The organic data center (ODC) concept constitutes an efficient solution to employ the heat produced in typical data centers and high-performance computing (HPC) facilities. Since it connects the growing industries of data and computing with a sector covering a very basic need, i.e. the food industry, a number of positive synergies can be identified regarding sustainability.

In particular, by analyzing the United Nations (UN) Sustainable Development Goals (SDGs), one can identify positive impacts of ODCs on at least 5 of the 17 goals.

Firstly, the implementation of ODCs would positively impact SDG 2 on zero hunger, due to the efficient use of the heat from the data center for more efficiently producing food.

In particular, Target 2.4 (on sustainable food production systems) would benefit from the synergy in energy use from ODCs, in terms of resilience of food production but also regarding robustness towards changing climatic conditions.

Another positive impact will be on SDG 7, related to affordable and clean energy, due to the fact that the heat used for the greenhouse is directly extracted from the data center as part of its operation and, therefore, it comes at no additional cost. Additionally, HPC-enabled solutions may lead to the more efficient operation of energy systems, which also supports the mentioned positive impact.

ODCs are expected to also have a positive impact on the sustainability of industry and cities, represented by SDGs 9 (on the industry, innovation, and infrastructure) and 11 (on sustainable cities and communities), respectively. The more efficient use of energy from data centers would contribute towards the achievement of Target 9.4, which aims at upgrading industries to more efficiently use the available resources.

Data centers are expected to play a progressively more prominent role in a wider range of industries, a fact that would make this particular target especially relevant. On the other hand, ODCs will probably become relevant to Target 11. b, on the implementation of policies towards resource efficiency and climate change.

This also applies to SDG 13 on climate change, where a resource-efficient solution such as ODCs may have a positive impact on all its targets. Target 13.1, aimed at strengthening resilience to the problems associated with climate, is probably the most relevant in the context of ODC usage and implementation.

The symbiosis of a data center and a greenhouse will constitute an excellent solution in terms of efficient energy use, given the fact that the current industrial requirements point towards the wider use of HPC resources.

EU TAXONOMY

The EU taxonomy is a complex system to classify which parts of the economy may be marketed as sustainable investments. Rules for most sectors came into effect this year, affecting the data center industry as well.

The EU's goal is to eliminate its net emissions by 2050; the rules also aim to stamp out greenwashing, where organizations exaggerate their environmental credentials, among so-called eco-friendly investment products.

The rules classify three types of green investments:

• First, those that substantially contribute to green goals, for example, wind power farms.

• Second, those that enable other green activities, for example, facilities that can store renewable electricity or hydrogen.

• Third, transitional activities that cannot be made fully sustainable, but which have emissions below the industry average and do not lock in polluting assets or crowd out greener alternatives.

VERTICAL FARMS AND GREENHOUSES

In standard vertical farms, plants grow indoors, inside a controlled environment. The lack of free natural sunlight within the floors of such modern farms, however, has led to the application of artificial light as a common strategy to enhance food production.

Besides that, the use of artificial lights allows for complete control over the plant’s life cycle, as no variables enter the equation and the results are standardized. This way, maximum productivity can be achieved.

Managing the photoperiod or day length can improve the production and productivity of plants with photoperiodic flowering responses.

Promoting flowering is most useful for those food crops which are grown for their flowers or fruits. In contrast to flowering and fruiting food crops, flowering should be inhibited for those crops sold for their foliage to improve productivity.

Controlling the day length in indoor production facilities where there is no ambient sunlight is easy. In comparison to indoor production facilities, managing the photoperiod in the greenhouse is a bit more challenging. Natural light is always followed by variables, such as the weather and the building’s orientation.

On the one hand, the integration of sunlight into a greenhouse vertical farm alone, would not achieve the standardized quality produce of the controlled environment.

On the other hand, by eliminating the need for artificial lighting most of the day, the energy demand, and therefore the carbon emissions, will be greatly reduced, thus making this option a more sustainable one.

Artificial lighting also produces heat. In greenhouses, additional heat is usually wanted. Indoor vertical farms heat up quickly, and as closed systems where opening a window is not an option, any extra heat from LEDs must be balanced with air conditioning or creatively repurposed, like district cooling, for example.

To achieve both the maximum profitability of a controlled-environment vertical farm and the sustainability of a greenhouse, a combination of these is not enough.

The integration of AI technology is crucial; by calculating the effect of each day’s sunlight and calibrating the amount of artificial lighting needed, as well as ventilation demands, a greenhouse vertical farm can incorporate the best of both worlds.

URBAN A&O'S WHERE AND HOW

Data Center, Vertical Farm, and Greenhouse; we have merged these types of infrastructures into a never-before-seen building design. The architecture is complex as it combines elements of intricate parametric design, controlled-environment farming techniques, and net-zero principles; we also focus on the social aspect and impact of such a building.

Urban A&O believes that the future is the 30-60 MW Distributed Edge Net-Zero Data Centers. Distributed Edge Data Centers are smaller facilities located close to the populations they serve that deliver cloud computing resources and cached content to end users.

To showcase our hybrid data center concept, Finland was selected as a case study, due to its cold climate and its drive for innovation and sustainability.

The site is located in the Töölö district, about 2.3 kilometers (1.4 mi) from the center of the Finnish capital, Helsinki. The plot is an empty parking lot next to the Helsinki Olympic Stadium, the largest stadium in the country, nowadays mainly used for hosting sports events and big concerts.

Adjacent sites include the Finnish National Opera and Ballet Concert Hall, the Helsinki Winter Garden - a historic greenhouse of the 19th century, an extended sports hall complex, a high school, cultural venues, restaurants, a city park, and a lake. Directly next to the plot is a tram stop; the site is accessible by both pedestrian walkways as well as main vehicle roads.

The hybrid building has been conceived as a distinct landmark. The proposal emphasizes the buildings’ simultaneous autonomy and interconnection both functionally and sustainably. The project proposes to completely enwrap a linear data center with greenhouse functions and vertical farms.

A parametric Voronoi structure covers the facility, with alternating panels of autoclaved aerated concrete, green walls, and polycarbonate glass; membranes are placed as needed to provide cover and isolate the interior environment from the cold, Finnish air.

Essentially, the concept takes the shape of an encompassing, naturalistic path between trees, views of indoor vertical farms, and openings to the technological interior, which guides the visitor through all the functions of this hybrid building. The visitor experiences the individual ambiance of each section of the building, alongside non-recursive geometrical and lighting design.

A pedestrian connection is formed between the urban ground floor and the rooftop public square. This is presented as a unified exterior path that interconnects the indoor greenhouse environment with the outdoor natural and urban landscape of Helsinki along with the adjacent cultural functions.

The building’s plan is an effortless transition from urban to natural landscapes and when reaching the top, the urban deck forms a visual connection with the surroundings by revealing views of all the encompassing elements.

The unique layout that bonds the parametric structure, the transparent interior, and the continuous ramp create an urban entrance for the hybrid building, strengthening the connection between the visitors and the interior by drawing them through the urban environment into the main lobby.

The landscape of the design incorporates both man-made and natural elements. The engineered Voronoi form on top divides the roof with sequentially membrane covers.

On top, there is the urban deck, an exterior plaza always open to the public which acts at the same time as a secondary public square.

On the other part, there is the greenhouse enclosed environment, which features a warm climate all year round. Besides viewing fruit trees, growing pods, and platforms, the visitor can rest at the greenhouse cafe. This experience will be one of a kind, signature to the city of Helsinki.

A number of synergies can also be found between other energy-saving and sustainable systems.

The building inside can be divided into two separate functions: the data center part and the biological products processing one. The latter will house, besides the greenhouse/vertical farm operations, methane digester systems and a wastewater treatment plant on-site.

That way, the Hybrid becomes even more sustainable by creating its own energy supply and clean water for irrigation. The open roof garden will help retain rainwater and reduce the amount of water directed to the sewer and the overall consumption as well.

With the application of immersion cooling, we can save space and maximize the waste heat captured. This way, we can properly heat the whole greenhouse, as well as redistribute the heat to the district, or implement other systems that require heat, such as a methane digester and a wastewater treatment plant on-site.

The landscape surrounding the Hybrid follows a similar parametric branching of Voronoi geometries, where two interconnecting levels are created. On top, pathways are leading to the Hybrid and the adjacent cultural facilities, and between them are planted areas and resting spots. The previous parking lot, which took up almost all the space, was transported to the underground level.

At the same time, a sunken public plaza is being created under the pathways. There, we will have the farmers’ market, selling garden-fresh produce, freshly picked from the Hybrid’s greenhouse and vertical farms.