When growers compare lighting quotations, the conversation usually starts with wattage. It is an easy number to compare, which is exactly why it persists — but what matters to the crop is not how much electricity the fixtures draw. It is how much useful light actually reaches the plants over the course of a day.
Start from the crop, not the catalogue
Different crops need different amounts of light, and the need changes with the seasons. A good lighting plan starts by asking how much light the crop should receive each day, how much the sun already provides through the roof, and how large the gap is in the darker months. The number of fixtures falls out of that calculation — not the other way round.
Even light means an even harvest
Average light level is only half the story. If some rows are noticeably darker than others, the whole compartment ends up harvested at the pace of its slowest corner. Good designs spread the light evenly across the growing area, and a supplier should be able to show you that calculation before you sign anything.
Cheaper things to try first
Before investing in fixtures, it is worth checking the basics. A dirty roof can block a surprising amount of daylight, and screens left closed on bright winter mornings shut out light that is free. Sometimes cleaning the glass and adjusting the screen settings recover more light than a modest lighting installation would have added.
What to ask a supplier
Ask any lighting supplier to show how much light their proposal delivers to the crop in each month of your season, and how evenly it is spread across the floor. A serious proposal always includes those figures.