Things to look for in a light deprivation system
Most advanced, hybrid cannabis greenhouses use automated light deprivation systems to precisely control the day length. Some cannabis growers – mainly residential growers or three-season greenhouses — use hand-operated systems. In this case, the curtains are pulled open/closed twice a day. That comes with the obvious drawback that someone must be there to operate them — a less reliable strategy overall. As the industry evolves toward larger hybrid cannabis greenhouses with precise environmental control, automation will continue to be the norm for commercial greenhouses.
Automated systems employ motors and controls to manage the system. Controls use a timer, but can also be integrated with a main controller to operate the system based on temperature or other variables. Smart controllers monitor many variables, operating a system accordingly. For example, say it is a cloudy afternoon in the winter. A control system monitors indoor light levels, and will turn on the supplementary lights accordingly. Based on the time of day, it could also close the greenhouse light deprivation system based on set parameters. If it is morning, you may set the curtains to still be open so the plants can take advantage of the diffuse natural light from outside.
Black-out systems can also be operated based on indoor temperature and seasonal conditions. In this way, the grower has a huge amount of control over the indoor environment and light levels. While automation does add significant cost, the return of many crops in a year allows for a very high ROI and quick payback. For example, in a recent Ceres’ commercial cannabis greenhouse, the light deprivation system added roughly $60,000 to the budget. However, it also enabled the grower to achieve 4-5 harvests each year, each of which generated more income than the original cost of the system. In the end, the investment in a light deprivation system was small compared to the added production it allows.
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