Vertical farms


As Spanish architect Javier Ponce reveals his plans for a vertical farm in Tai Po, Samuel Lai looks at how growing crops in towers could feed the Hong Kong of the future

The Hanging Gardens of Babylon have plants above the ground and are cultivated in the air, with the roots of the trees above the earth." These are the words of Greek historian Philo of Byzantium, who was describing the only one of the Ancient World's Seven Wonders that may have been purely mythical. But that myth could become a reality in Hong Kong in the not-too-distant future, if one forward-thinking Spanish architect sees his plans for vertical farming towers in Tai Po district come to fruition.

Javier Ponce hit the Hong Kong headlines a few weeks ago when he revealed his award-winning Dynamic Vertical Networks – or Dyv-nets – farming solution could be installed in Tai Po, thus aiding the problem which could soon face the SAR: with seemingly little space for farming, how can our heavily import-dependent city feed a growing population, especially when the UN warns of looming worldwide food shortages? The architect has detailed plans which see the erection of 187.5m-high farming 'towers' where food is grown on rotating floor-plates which give the crops as much sunlight as possible for growth. The proposals – which were submitted to the government a couple of weeks ago to a fairly warm reception – have sparked debate and already garnered support from those who are looking for farming solutions in a city where large scale agriculture has become increasingly impossible.

'Vertical farming' is seen by some experts as the most logical way forward in urban areas. And Hong Kong, with its existing ethos on building upwards and lack of available space, seems like a logical place for Ponce to get this project (high) off the ground. It's estimated that our city will have an extra 1.4 million mouths to feed between now and 2041, so Dyv-nets and other examples of vertical farming could, in theory, help sustain this rise in the population. "More agricultural land can be created by building upwards," says Ponce. "We foresee a paradigm shift to vertical agriculture structures which provide food, save land and, at the same time, act as a biodiversity magnet."

While Ponce's futuristic-looking towers are, for the moment, 'very conceptual', there are other pioneers in Hong Kong who are already putting their ideas of vertical farming into practice. "The most obvious advantage of vertical farming is that you can do more with a given amount of land," says Benson Ko, representative director of Urban Farms, one of the few commercial vertical hydroponics farms already in place in Hong Kong. In his indoor farm, in an industrial building near Yau Tong, crops are grown on multi-storied trays which are stacked in layers. Using this method, Ko has created a 30,000sq ft cultivation zone out of a 10,000sq ft floor area. "In conventional farming, if you have one hectare of land, that's all the farming area you are going to get. With vertical farming, you can increase the arable area by multiple times," says Ko.

The greens cultivated in these vertical farms are said to taste much fresher because they, on average, take less than a day to reach retail shelves or restaurants. In contrast, much of the food we eat now travels up to 10 days over 2,400 km to get to us. "Think of all the carbon emissions and transportation costs when vegetables travel by airplane to get all the way from foreign countries to Hong Kong," says Steve Cheung, executive chef of IPC Foodlab, a farm-to-table restaurant in Fanling that advocates eating locally grown produce. The restaurant on the ground floor gets its food directly from the crops vertically farmed on the higher levels. "Our customers taste their food literally minutes after harvest," says Cheung.

Crops grown using vertical farming techniques are near 100 percent pesticide free and are not exposed to air pollution and heavy metal contamination, as opposed to conventional crops. In fact, they are so clean, say experts, you don't even need to wash the vegetables before tucking in. This is because vertical farming doesn't require soil, where pests and germs abound. Instead, hydroponics, where plants absorb nutrients directly from a mineral solution, are used. Vegetables grow in an enclosed, clean indoor environment with a meticulously computer-monitored system. Farmers have total control over the temperature, humidity, carbon dioxide concentration, nutrient supply and lighting. "This means we can produce crops all year-round without any geographical and climatic constraints," says Kenneth Law, marketing manager of the Vegetable Marketing Organisation, a government-contracted group that established a research and development centre in Cheung Sha Wan in December which grows crops using hydroponic and vertical farming technology. "This makes agriculture immune from typhoons, drought and other unpredictable weather conditions," says Law.

A farmer from the Vegetable Marleting Organisation harvesting crops

Under vertical farming, our city could grow certain exotic crops which were impossible to cultivate in Hong Kong before. "Because we can adjust almost every variable in agriculture, we can simulate the growing environment of any foreign country," says Ko. IPC Foodlab grows Brazilian mushrooms, while Urban Farms cultivates ice plant crystal leaves and oyster leaves – all of which could never grow in Hong Kong's hot and humid climate.

It all sounds like a great plan, in theory. So why haven't huge collections of vertical farms already sprouted up across the city? "Vertical farming is just very expensive – at least for now," says Professor Jim Chi-yung, chairman of the geography department at Hong Kong University. "There are concerns over the practicality and cost-effectiveness of such a complicated farming system." Prof Jim says these farms have different crop varieties and production scales so the costs can vary. Law's research and development centre, for instance, cost $6.5million to start up. To produce a mere 30kg of crops a day, the centre's annual operations rack up $3m. So, with such high costs, vertical farming can only – at the moment – hope to fill a small niche of the local food market. In other words, they can grow high-end food products for those who can afford to pay hefty prices for them. Law's centre grows crops for restaurants in Ocean Park and The Peninsula Hotel. "We are competing with prime salad greens imported from foreign countries," says Ko of Urban Farms.

So, even if Ponce's project gets off the ground soon, those who hope vertical farming could significantly swell Hong Kong's fresh food stores must wait a while yet to see if costs can come down due to technological advances. Meanwhile, however, Prof Jim suggests that we look into other slightly more down-to-earth methods to reduce Hong Kong's dependence on food imports. One way is to simply tap into the unused farmland in our SAR. "Currently, 70 percent of the agricultural land in Hong Kong is abandoned," cites Prof Jim, "much of which has been converted into car parks or open area container yards. People often say there's no land for farming in Hong Kong – but just remember: in the 80s, Hong Kong produced 30 percent of all the vegetables consumed in the city. Now that figure has dropped to 2.3 percent. Due to repeated problems with food products from the Mainland, there is a certainly a huge demand for locally grown agricultural produce."

Another way for the city to grow more food locally is to make use of the available space on rooftops. This is something Prof Jim has worked on for years. Ko is equally enthusiastic. Says Ko: "On the rooftop of Yau Tong MTR station or Festival Walk, there are open flat areas of more than 100,000sq ft. Just imagine if we set up greenhouses in similar areas across the city's rooftops. That's another type of vertical farming, isn't it?"

Vertical farming around the world

Texas, USA
Caliber Biotherapeutics, a biotechnology company, has built a 'pink plant factory' for growing crops in. The plants, stacked up to 15m-high, are lit entirely by a mix of red and blue LEDs. Under these specific wavelengths, the plants absorb the majority of light they need for photosynthesis. Experts are conducting experiments to see how using LEDs affect the farm's energy consumption and the crops' growth rate.


Sky Greens is the world's first commercial vertical farm. Since October, the 3.65-hectare facility has been supplying half a tonne of veggies every day to Singaporean markets. The farm's crops are around 10 to 40 percent more expensive than imported equivalents, but costumers flock to purchase its products. The farm is hoping to increase production by four times in the near future with a $162million expansion plan.


Chicago, USA
The mega-sized FarmedHere, which opened in March, is the largest vertical farm in the US. It expects to produce a whopping 300,000 pounds of fresh greens by the end of the year. The farm is converted from a warehouse, signifying another direction of vertical farming: instead of having skyscrapers-turned-farms located in urban centres, an alternative is to have vertical farms in industrial areas where rents are cheaper.


Local Garden, established by Alterrus, is a 6,000sq ft vertical greenhouse on the rooftop of a parking garage in downtown Vancouver. Fresh vegetables in stacked, suspended trays are circulated by a moving conveyor system to ensure every plant receives maximum exposure to light (both natural and artificial).



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