‘Generic light recipe per crop is bullshit’


Many growers believe that the light output of a fixture is indicative of the efficiency of a grow lighting installation. Hortilux sees this differently: a grow light solution should contribute to the goal the grower wants to achieve―increased production or a better tasting product, for example. This goal is therefore the focal point of the grow light solution which Hortilux develops in consultation with the grower. “A general light recipe for a crop does not exist”.

How many micromoles does grow light deliver, relatively to the energy consumed? That is, for many growers, still the definition of efficient illumination. “Although Hortilux fixtures belong in the top segment when it comes to efficiency, it is not always the light output of a fixture which is indicative of the efficiency of the grow light installation”, says Paul van der Valk, account manager Western-Europe at Hortilux. “Many factors play a role. For example, think about the irradiation of sunlight, the energy cost, the cultivation phase, the greenhouse construction, the electrical installation, the efficiency of the plant, etc. The most important consideration, is that the grow lighting installation helps to achieve the goal of the grower. One grower wants to grow flavourful tomatoes, while the other one wants to harvest as many kilos as possible. And yet another wants to consume as little energy as possible, because the CHP is almost at maximum capacity. In the final case, it might be an option to invest in LED. The costs are higher, but investing in another transformer will be even more expensive. In short: the ideal grow light solution differs per company per situation. A generic light recipe per crop is bullshit. Don’t relate efficiency to a product but to a goal!”

Around the table

Hortilux always handles with this believe when a company asks for a grow lighting installation. “We often receive quote enquiries for specific fixtures”, says Arno Wartewig, Director Business Development at Hortilux. “We will not simply send a quote to the customer, but will first sit around the table. Does the customer need the specific fixture, does this fit with their grow strategy and their company situation? We need this information to make a light plan and to develop the optimal grow light solution. We try to clearly define the goal, meaning we sit down with the grower several times to discuss all the factors which can be of importance within the company. This approach requires a lot of time from our side as well as from the customer. The conversations are intense.”

Van der Valk indicates that this way of working is new to many growers. “They are too focused on the light output per fixture. A culture shift is necessary; but that goes step by step. However, a grow lighting installation, partly because of LED, is becoming more capital-intensive, which makes the growers put more thought into the efficient use of their grow light.”

For a grow lighting installation to contribute toward achieving the goal, an integrated approach is necessary according to Hortilux. “As a supplier you can’t focus on solely LED or HPS fixtures”, says Wartewig. “HPS fixtures deliver heat radiation, LED hardly. This will be desirable for one grower, but not for another. And this even differs per cultivation phase. Hortilux is the only manufacturer that develops, produces and supplies, both LED and HPS fixtures (or even a Hybrid grow light solution, if desired) incl. the electrical installation. Integrated thinking instead of product thinking; that’s where the future lies!”

Monitor efficiency

When a grower selects an efficient grow light solution for his situation, it is important to maintain the efficiency at a certain level. HortiSense is the ideal tool for this. The digital platform by Hortilux, is designed to increase the efficiency, company reliability, and goal-orientation in relation to the usage of grow light. Different grow light processes are monitored via sensors. Besides this, HortiSense monitors the current, which is partly responsible for the quality of your grow lighting installation. HortiSense also shows the lifetime of your lamps, measures and monitors the temperature in the transformer stations and in the panels. When a deviation is detected, the grower receives a notification. “All this helps to optimize the return per m2”, says André Flinterman, account manager the Netherlands and Belgium at Hortilux. “And this can help a lot, as the investment in energy for HPS fixtures is so much higher than the costs for the lamp itself.”

Use efficiently

Paul van de Valk adds that HortiSense not only helps to use the grow lighting installation efficiently, but also helps the grower with an optimal grow lighting strategy. “HortiSense collects data: sun radiation, plant efficiency, realized sum of light, light extinction in the crop, assimilation production, the amount of fresh weight produced per mol of light, etc. All the data, which accumulates along the way, will help the grower to optimize the grow lighting strategy. This is a continuous process. We, as Hortilux, support this as well. For example by distilling the average data of customers, by speaking to the growers when deviations are detected. You can invest in an efficient grow light solution, but it is also cause to use it as effectively as possible.”

Richard ter Laak

“Together with Hortilux we came to the ideal solution”

This spring the new Daylight greenhouse of Ter Laak Orchids in Wateringen went into use. In this new innovative greenhouse, which is developed to save energy and to create an optimal grow climate, Hortilux has installed a Hybrid grow lighting system. The ideal and most efficient light plan was made in consultation between both companies. The goal of Richard and Eduard ter Laak was to realize optimal plant quality. “When we came to Hortilux we had a clear vision of what we wanted”, says Richard ter Laak. “We have run trials with LED and phalaenopsis for years. This has taught us that a combination of HPS and LED is the best solutions for this crop. However, the precise light recipe differs per cultivation phase.”

Ter Laak discussed in multiple meetings with the specialists from Hortilux, the optimum grow light solution for each specific cultivation phase. “Hortilux advised us to choose HPS in the first cultivation phase, because we needed the heat. In the finishing and cooling area, LED was the best fit; in these phases we had a heat surplus. This resulted in a Hybrid installation consisting of the HSE NXT II 1000W fixtures with HORTILED Top fixtures; currently the most efficient LED fixture on the market. The knowledge and involvement of Hortilux was very valuable in this process; together we came to the ideal picture! We looked at so much more than the light output of a fixture; all facets that play a role have been discussed.”

The warehouse, where the orchids are packed, required special attention. “You want to keep the plants in good condition, you do not want heat, but you need daylight. In the end we decided to use the LED full spectrum luminaire.”

Richard ter Laak shares the opinion of Hortilux that light output is not indicative of the efficiency of the grow lighting installation. “So many more factors play a role in this. There are many phalaenopsis growers that use more grow light than others. This depends on the cultivation strategy and what the grower wants to achieve. Some growers also have to deal with certain restrictions, for example in the field of electricity. You need to take into account the capacity of your CHP. For this reason you can’t copy a light plan.”

Ter Laak calls Hortilux ‘the ideal partner to custom fit an efficient and integral grow light solution’. “Hortilux has a lot of knowledge and gives an independent opinion because it supplies HPS as well as LED fixtures. This really helps the grower.”