LED grow lights have become one of the most reliable ways to grow herbs and vegetable indoors. The increased interest in LED grow lighting means that this technology is advancing fast. Every year we see new and improved models, promising better yields, more savings and increased power.
But what makes a LED grow light powerful? Do more Watts equal more power? And how many Watts does your panel really need to have for a successful indoor grow? Read our article to find out!
What are Watts?
Named after the Scottish inventor James Watt, a “watt” is a unit of measure that quantifies the total rate of power used by an electrical circuit. When it comes to light bulbs, the Watt has been used to measure the amount of light emitted by the source. An 80W light bulb is brighter than a 36W one. But things are not so simple when it comes to grow lighting.
Brands will often try to sell you on LED grow lights based on the Watt count alone. Newbie buyers will easily fall for this trap, thinking that a 1000W behemoth will definitely be better than a 600W LED panel. But in reality, you may end up supplying your plants with less usable light than you expected.
Measuring a LED bulb
The main reason for that discrepancy is that LED bulbs are a much more sophisticated piece of equipment than floodlights and indoor lights. The quality of the circuits, diodes and semiconductor material of each chip play a decisive role in the final efficiency of a LED panel. The technical specifications are far too complex for an average consumer to understand, and this works in favour of many companies who rely on this to sell more units.
These days, LED bulbs mainly come in 3W, 5W and 10W models (albeit the latter are much more expensive and used mainly in industrial grows). It is important to realize though that these measurements are not set in stone: A 3W LED bulb can run potentially run at 4W, although its lifespan will be reduced dramatically. These numbers are only an estimate of the manufacturer and almost never reflect reality. However, you can be sure that a 5W will always offer better light penetration than a 3W, as it is built on a larger chip.
COB lights are a relatively new technology that packages many 3W or 5W LED chips on a board (from where it takes its name), creating a lighting panel. This architecture multiplies the efficacy of LED bulbs and offers greater light intensity and increased penetration rates.
Light efficiency on cheap LED panels
Many manufacturers use older technology to drive their LED panels and claim that they are better based on absolute numbers. However, when buying any type of light, you must always be aware that a considerable amount of the power generated will be lost to heat. In the best of cases, only 70-80% of the electricity is turned to usable light. In cheaper models, this “energy leak” is way more pronounced.
Also, bear in mind that the number advertised by the manufacturer always reflects the potential of a LED panel. Much like you would never run your car full speed all the time, it is unlikely that you will ever need to run your LED lights at 100% of their capacity (unless you want to burn them). In the best of cases, the true power output is about 60% of what is advertised. Serious LED grow light manufacturers will list their actual power draw on the spec, or at least provide you with the Volts and Amps numbers so you can calculate the actual wattage on your own. Use this handy tool to measure the true capacity of your next LED panel.
This is why you will see many dirt cheap 1200W LED grow lights being sold on Amazon by Chinese vendors. The actual light you will get from these fixtures is about 150W, at best. It might still be a decent choice if you want to grow a couple of lettuce plants, but you’re way better off buying a 200W panel from a more reputable source.
Is Watts a reliable measurement of light output?
Simply put, Watts is only a unit that measures energy. It doesn’t tell you much about the quality of light that a LED panel produces. Higher wattage often means that a LED panel produces more light, but that’s not saying much: the main role of a growing light is not to illuminate, but to emulate sunlight.
Many growers will tell you that the optimal number is 300-500W per square meter (meaning you have to use a 400-600W LED light), but that’s nothing more than an arbitrary number. Colour temperature, light wavelengths and light intensity are the measurements you should really be looking into if you need a quality grow light for your indoor garden.
Stay tuned for more articles on LED technology! Until then, don’t forget to check out our extensive LED grow panel catalogue. We have a wide selection of quality grow lights that will surely cater to your needs.