The more light there is in a greenhouse, the better the crop grows. In other words, the less light a greenhouse structure blocks, the less artificial lighting is needed and the more environmentally friendly the greenhouse. TNO develops models for calculating how much light a structure blocks. This enables greenhouse builders to design structures that will significantly reduce energy costs for growers.

Light transmission - the amount of light a greenhouse structure lets in – is an important criterion in greenhouse design. High light transmission means that the grower can achieve greater yields with the same amount of energy. Designers and builders, as well as growers, prefer to have precise calculations as early as possible, in the design phase. Greenhouses with sufficient light transmission can apply for a Green Label Greenhouse (GLK) certificate, and if successful they will also be eligible for an attractive grant. The certification is in line with the objectives of the Dutch greenhouse-horticulture sector as a whole, which is aiming to become more sustainable.

Simple calculations...

TNO has developed the IDT method, software that calculates light transmission in a straightforward way. Builders enter details of the structural profiles in the database, and the programme calculates the light-blocking factor. This information can be used when applying for GLK certification.

In addition to the IDT method, TNO has also developed more complex models that, in combination with existing ray tracing software, can process new situations. Ray tracing involves following the path of a large number of individual light rays, such as refracted or reflected rays. This makes it possible to calculate, for example, how a non-standard screening installation affects the light level. Another example is a tool that calculates light transmission and, at the same time, the electricity yield of PV panels on a greenhouse roof. Designers and builders who are developing a product, and want to know how the design affects light transmission, can make use of TNO's models. To contact TNO, simply call or send an e-mail.