Compared to the struggles of traditional agriculture in the past, entering into automated and environmentally controlled agriculture has a definite level of helpfulness for the stable production of set amounts of food crops. However, at the same time, entering into the use of automated facilities places increasing demands on power resources. Therefore finding ways to maintain a balance between the two is a big problem.

Talking about this brings us to the issue of energy resource technologies used in automated agriculture. As they replace the functions of nature, with costly agricultural facilities, how can farmers make a profit? Nobody is interested in business models that have no use. From the standpoint of the electrical power problem, we first encounter the basic element of environmentally controlled and automated agriculture – the impact of electrical power created by artificial lighting and cooling systems.

Figure I: Currently for agricultural environmental control the biggest problem is choosing a source of artificial lighting.

According to an LEDinside report, in recent years the number of sunny days in some parts of the northern hemisphere is smaller than in the past. Taking Taiwan as an example, the amount of sunny days is at a sixty-one year low. In a similar fashion, the same thing is happening in the United States, Europe, Japan, and Mainland China. As a result, there are more subsidies and attention being paid to plant cultivation factores and plant lighting in order to make up for insufficient lighting and meet the increasing demands for light in the plant lighting market. This is especially the case in Japan following the 311 earthquake of 2011.

Currently the biggest problem for agricultural environmental control is choosing a source of artificial lighting. The environmental control systems at most contemporary green houses or plant factories use artificial lighting. Traditional lighting sources, such as fluorescent lamps or high-pressure sodium lamps have low luminous efficiency, consume large amounts of electricity, and create heavy cost burdens. They also create large amounts of excess thermal energy, which has an adverse effect on the plants. Consequently, setting up air conditioning that can handle heat created by the lighting has become a key solution.

Therefore, the majority of environmental control for agriculture relies upon air conditioning. However heating requirements are not as high as air conditioner requirements. Professional analyses suggest that because there is a suitable temperature range for growing plants, as long as good “microclimates” can be created near the plants with the capacity of fixed temperature management and which only use cold wind or water, appropriate control devices can be installed to maintain target temperatures.

Figure II: Light sources are a plant cultivation factory's biggest electricity expense.

An even bigger problem is reducing temperatures in the summer. Because of non-soil cultivation in agriculture systems, keeping the cultivation solutions at a constant temperature is a major issue. However, it is easy for higher summer temperatures to cause excessive cultivation solution temperatures, which affect growing environments. If air conditioners are used, the air conditioning load will lead to higher production costs; therefore, the energy problem is very serious. Most basic environmental control facilities for agriculture include light, temperature, and humidity controls, and the biggest difference between fields are the carbon dioxide controls, which facilitate resource conservation.

Improving Energy Use Efficiency Through Technological Integration

Solving these problems includes saving energy and creating resources, and entrepreneurs must consider these two important issues. For instance, the aforementioned demand for the manufacturing of carbon monoxide can be matched up with other resources, and through cross-sector cooperation the resources can be used together to reach targets.

For example, the process of mushroom cultivation produces high-concentrations of carbon dioxide. These farms can be matched with environmentally controlled agriculture for the free use of this carbon dioxide. Furthermore, after smoke emissions from power plants undergo desulfuration, the carbon dioxide can be collected in cylinders and then be provided to environmentally controlled agriculture companies.

Due to the perspective of the carbon reduction effect, production capacities of environmentally controlled agriculture can be used to calculate the amount of fixed carbon. This will be the future direction for rescuing industry with agriculture.

On the other hand, resource conservation planning can be used to usher in inexpensive cooling methods, such as evaporative cooling. This is especially helpful for the problem of cooling cultivation solutions. Furthermore, cooling around the plants, supporting localized cooling liquids, or performing intermittent cooling at night, or adjusting the temperature to match the outside temperature are all solutions for integrating systems with the requirements of the industry.

Of course implementing solutions from the lighting problem is one way that could be considered a direct solution. Because of the progress of plant lighting in the Japanese market, their technical lead, and their active development, in the year 2020, the global market value of their LED lighting is expected to reach 300 billion yen. Moreover, the overall output value of plant cultivation will amount to three trillion yen, which is a growth strength that should not be underestimated.

Figure III: Different plants require different growing environments There is not a consistent standard that can be applied to all..

In 2001, the central Japanese government and local governments begin to counsel local cooperating agriculture industries to develop plant cultivation facilities and use LED lighting to supplement the inadequate sunlight. They also advised them to influence the farmland yields through plant cultivation factories and hydroponic growing methods to make up for shortages. From Hokkaido and northeastern prefectures, such as Aomori, Iwate, Miyagi, Yamagata, and Fukushima, to the Kanto Region, with its even more industries, there are plant cultivation factories with a range of plants from vegetables, and flowers, to cash crops.

LED Manufacturers in Mainland China are also actively engaged in the development of plant lighting. However, the application times for plant cultivation factories in Mainland China are short, and in traditional markets, plant lighting has yet to gain a firm foothold. However, LED plant lighting has made a strong showing in the market, and in the future it will greatly enhance the Mainland Chinese market so that it is prepared to meet the conditions for overseas exports.

However, although local Mainland Chinese LED companies want to develop plant lighting, there is still a threshold to be overcome. Currently the two types on monochromatic lights in wide use are red (630-660nm) and blue (460-470nm). In addition, there are different lighting requirements for every kind of plant. Many companies lack the ability to adjust the wavelength of light response according to the plant. They also do not know the specific wavelengths needed for different plants. Therefore, in the current state of affairs, the use of just these two types of monochromatic lights is a technical problem for Mainland Chinese companies.

As a result, LED plant lighting manufacturers, plant cultivation factories, and plant researchers must closely work together and match up lighting arrangements in accordance with the special characteristics of each plant in order to promote photosynthesis in plants. In addition, they must attempt to produce a large spectral range of light sources or combine multiple light sources and smart controls in order to simultaneously satisfy the requirements for different types of plants.

Every type of plant has different lighting needs, and a number of companies lack the ability to adjust the light length in accordance with those different needs.

In addition to European and Japanese companies’ having matured in their abilities for LED plant lighting technology, Taiwanese companies are also progressively trailing behind. The lighting requirements for plant lighting include high luminous efficiency and plans for maintaining appropriate distances from light sources in response to the system plans that have been developed for plant lighting LED applications.

Energy and food problems are definitely two major environmental issues in recent years. A number of companies are discussing ways to take care of both problems and achieve optimal effects. Automated agricultural systems, such as environmentally controlled agriculture and plant cultivation factories are both “developing” technologies. Systems integration for future development will facilitate means of solving these problems.

(TR/ Phil Sweeney)