At this time of year it is hard to imagine, but last winter it was dark in Canada. Dark, and expensive: electricity prices, particularly in Ontario, were exceptionally high, a situation that could easily return in the coming winters. Dimming the lights or even switching them off may then seem like an option. “The moment you start dimming or switching off, you also need to adjust other settings,” advises Led’s Consult crop consultant Piet Hein van Baar, advising growers to have a plan for future price spikes. “Electricity will only become more expensive.”

Switch off the lights
Piet Hein visits his Ontario clients each month and connects with Canada almost every day. “Usual winter prices are around 3 to 4 cents per kilowatt hour. Last winter, these rose to 17 and even 40 cents per kilowatt hour. Those are differences that make you take notice,” he recalls. For some growers, this was reason enough to switch off the lights. That may seem like a strategically logical decision. “But if you do that with a fully productive crop, you are effectively killing the plants. And if you have to clean out by the end of February because the plants have failed or lost significant yield over the following months, the calculation looks different. Then you have to ask yourself how far you should go to avoid those few hours of high prices, or whether you simply have to accept it and continue.”

© Led’s Consult

Dimming
Over the past few years, more and more growers have switched to dimmable LED lighting, and dimming appears to be a safer option. “But only to a safe level.” At the same time, other measures are required. “The light-to-temperature ratio has to remain in balance, so if you have less light, you also need to work with a lower temperature.”

The next step is that the plants transpire less. “That means you also need to adjust your irrigation.” Instead of irrigating at fixed intervals and working with a maximum time between irrigation shots, growers should set their strategy based on the evaporation of the plants. “By working with a strategy based on the drydown of the slab, the frequency of the irrigation adjusts itself when the evaporation goes down because of less light and lower temperatures. But keep in mind that when you give less water, you might have to increase your nutrition levels in the irrigation water. If you do not take these kinds of measures, you take a big risk to run into problems.”

More horticultural software programmes are becoming available in which lighting can be controlled based on electricity prices, with dimming taking place above a predefined price level. Other tools, such as ProJoules, allow growers to adjust their cultivation plan when they can only provide 12 hours of lighting instead of 18.

Insight is important, Piet Hein emphasises. “We do not know whether prices will be this high again this winter or fluctuate as much, but as a grower you need to take it into account and decide which actions you will take to get your crop through the winter in a reasonable way. Will it be enough to only adjust your temperature/ irrigation strategy or do you also need to adjust your pruning strategy to get your plants back into shape?”

Another expensive winter?
The high prices last winter had several causes: ageing infrastructure, nuclear facilities undergoing maintenance, the phase-out of coal, gas, lack of investment in the North American grid and new regulations in the energy market, among others and increased demand for eletriafication and data centers. The result was power rates that were particularly high during the day, while the night offered more opportunities for affordable lighting.

Piet Hein expects that these situations are not an exception but rather an indication of what may come, given that the pressure on the regional electricity network is only increasing. “Most of the sector has switched to LED lighting, but greenhouse horticulture in Ontario continues to expand. Time will tell to what extent this directly affects electricity prices. But regardless, energy is to become more expensive.”

Is contracting your electricity prices a better option? “Most growers expect that prices will not be as high as the levels at which they can currently fix contracts”, Piet Hein says. He also does not expect CHP systems to become more popular in the short term, as feeding electricity back into the grid is not possible due to current grid regulations. “There are discussions about moving in that direction and creating more stability on the electricity grid, but nothing concrete has been decided.”

So dealing with high prices it is. A situation that might put pressure on the regions winter production. “There will certainly be growers who decide not to use supplemental lighting above a certain electricity price, or will adjust their planting dates to avoid high prices of power” Yet, Piet Hein wants to emphasize that when lights are turned off or dimmed, it is important to carefully weigh whether the immediate savings are worth the loss in production in the future. Talk to your accountant, talk to your fellow growers, to your consultant, and take all inputs in consideration. By taking the right measures, you can prepare yourself and with the right strategy you must be able to stay in control”

For more information:
Led’s Consult
Piet Hein van Baar
+31 613 608 455 (Nederland)
+18254494429 (Canada)
[email protected]