Horticultural Lighting Design

Cerise365+GreenHouseDesigner™ is lighting design software specifically for greenhouses, polytunnels, and vertical farms. This software is based on SunTracker’s architectural and roadway lighting design software, which has a current user base of an estimated 20,000 professional lighting designers worldwide.

SunTracker has developed Cerise365+GreenHouseDesigner™ to automatically model greenhouse and polytunnel structures and materials using only a few basic parameters, such as building dimensions, roof style and glazing materials (Fig. 2), perfect for those not familiar with using proprietary computer-aided drafting (CAD) programs.

Horticultural lighting design for vertical farms is straightforward, and can be modelled well, using existing architectural lighting design software. Horticultural lighting design for greenhouses and polytunnels, on the other hand, is almost impossible. The challenges include predicting daylight availability, which is influenced by geographic location, time-of-year, and weather conditions1; in addition to the structure of the greenhouse or polytunnel, its orientation, and covering materials.

Different crops require different amounts of daylight during their growing season, measured in units of Daily Light Integral (DLI). Predictions of daylight availability, shown in Figure 1, are calculated using geographic location, time of year, and weather conditions[1].

The amount of daylight available inside a greenhouse is confounded by additional variables, such as the greenhouse structure, covering materials, and orientation. Potentially, the DLI inside greenhouses may be less than half that of the outdoor DLI.

For horticulturalists, this information is critical.

Cerise365+GreenHouseDesigner™ software also addresses the distribution of daylight in polytunnels, where agricultural films covering the crops both absorb and diffuse the incident daylight. Again, the polytunnel structure, covering materials, and orientation, as well as the geographic location and its weather conditions, determine the DLI available to the crops.

When the monthly DLI within a greenhouse or polytunnel is insufficient for a given crop, supplemental electric lighting is required for plant photosynthesis and growth. This has traditionally consisted of high-pressure sodium (HPS) lamps, but these are being supplanted by light-emitting diode (LED) modules. One reason for this is that LED lighting can be dimmed; thereby providing the minimum amount of required supplemental lighting. Electrical energy for lighting typically accounts for 30 percent of greenhouse operating costs, and dimming can reduce these costs by 60 percent (Watson et al.  2018).

Cerise365+GreenHouseDesigner™ software accurately models the optical performance of commercial horticultural lighting fixtures (or “luminaires”), including photon intensity distribution, dimming, and spectral power distribution. These software features are essential for horticultural lighting design, and are not found in any existing architectural lighting design programs.

Cerise365+GreenHouseDesigner™ is offered as a software-as-a-service (SaaS) product, where the software resides on SunTracker’s servers and clients access the program through any Web browser, laptop, or smartphone.

This includes direct access to the product data of participating manufacturers of horticultural light fixtures and greenhouse manufacturers.

Using Cerise365+GreenHouseDesigner™, horticulturalists, greenhouse manufacturers, and horticultural luminaire manufacturers will be able to calculate:

Daylight distribution; Daily Light Integrals; project electrical energy costs; automated shade and energy curtain deployment schedules.

Commercial greenhouse building construction costs range from $100 to $300 USD per square meter, and supplemental electric lighting costs between $150 and $350 USD per square meter. Therefore, the advantages of being able to predict the performance of multimillion-dollar construction projects during the design phase is substantial.

There are currently some 500,000 hectares of greenhouses and 5,130,000 hectares of polytunnels and similar horticultural structures worldwide. There is a clear need for horticultural lighting design software.

Cerise365+GreenHouseDesigner™  will address this need.

Literature Cited

Ponce, P., et al. 2015. Greenhouse Design and Control. Leiden, The Netherlands: CRC Press.

Watson, R.T., Boudreau, MC. & van Iersel, M.W. Energy Inform (2018) 1: 1. https://doi.org/10.1007/s42162-018-0005-7


Fig. 2

DLI Calculator

What is the DLI Calculator?

This web app has been designed to help you determine daily light integral (DLI) values throughout the year for any location on Earth. It uses worldwide weather station data and algorithms[1] to deliver the most accurate DLI values for your location.

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SunTracker’s Senior Scientist, Ian Ashdown’s

Blog Website: AllThingsLighting.org