According to LED grow light manufacturers their lights put off 90% less heat than HPS lights. This is one of the biggest selling points of LED lights. Anyone who has grown indoors in certain parts of the country during certain seasons knows that heat can be a major issue for a garden. Perhaps if you are an indoor grower in Alaska heat is not a concern, but I know that in my garage it gets very warm from the end of the spring through the summer. In the peak of the summer there’s simply no way to have a garden in my garage because it’s too hot, lights or no lights. That’s a big reason why I have been giving strong consideration to LED lights. They could give me a longer season, and cut back on AC requirements, which can be a huge energy hog and leads me to my next point.
Fluorescent bulbs also require thee same components, although the ballasts are smaller and usually integrated into the fixtures or bulbs. Luckily, there are kits available that include everything you need.
One of the deciding factors in choosing between LED grow lights and HID lights is that LEDs typically cost far more than an equivalent HID system.
LED grow lights use far less energy to generate the same amount of usable light as an HPS or an MH bulb. This drastically reduces operating costs and means that they turn out to be more affordable in the long run.
LED Grow lights produce very little heat, which for many is an advantage. However, those growing with LED’s in colder indoor areas may need to supplement the extra heat an HID light such as an HPS or MH would produce.
HID bulbs emit an enormous amount of heat, which will have to be dealt with. Cooling equipment is not cheap and neither is running it.
The question of LED vs HPS and which is “better” has been around since the LED grow light hit the market. While LED grow lights have certainly come a tremendous way since, can they compete, watt for watt, with the HPS grow light? And where do other types of HID grow lights come into play?
Both LED grow lights and HPS grow lights are equally capable of producing great yields, and both have advantages over the other. If initial cost is not an issue, the answer to which one is better really comes down to other main factors contributing to your grow such as the growing method you plan to practice as well as the ambient conditions and size of the grow area.
There’s a reason for this.
The question of LED vs HPS and which is “better” has been around since the LED grow light hit the market. While LED grow lights have certainly come a tremendous way since, can they compete, watt for…
Let’s break down the different kinds of lighting and how they are best applied in indoor greenhouses. We also talk about the different times that different spectrums may be used, and the different ways this can affect yield.
Aside from the upfront cost of purchasing lights, growers must also consider the cost of electricity. The question of LED vs HPS lights can also be affected by what continent you are living on. In Europe, electricity is more expensive than in the US. This tends to lead to gardeners in the US growing under 1000W bulbs, whereas their European counterparts lean towards 600W or even 400W bulbs.
LEDs are probably the best contenders in terms of spectrum at this stage, with newer full-spectrum models offering up to 11 bands of light wavelengths most needed by plants. For example, the US-made Platinum P450 274W LED grow light (which is listed as equivalent to a 600W HPS) offers 11 bands ranging from ultraviolet to infrared.
Mmol/s is increasingly seen as superior across the board for horticultural lights, as it is a measure of light usable by plants. Lm/W is a measure of what is visible to the human eye. Thus, it is advisable to get to know how to calculate PAR output measurement. A guide on the concept of PAR can be found here.
Theoretically, LEP’s luminous efficacy should exceed a HPS source by 15-20%, as no power is wasted on heating electrodes. In practice, light source efficacy of LEP (also known as “HEP” (high-efficiency plasma) or even simply “plasma”) grow lights range from 80 – 100 lm/W.
Although improvements have been made in HPS lighting technology, they are still generally considered poorer in their replication of daylight than other modern lighting systems. Without the addition of xenon or mercury, sodium vapour gives off an intensely reddish-yellow light.
- LED (light-emitting diode) lights are semiconductors, which allow electrical energy to pass with little resistance in one direction and overwhelming resistance in the other, across a “p-n junction”.
LEPs are often sold as full-spectrum and the closest approximation to daylight of any indoor light, but the spectrum is limited by the composition of the gases inside the chamber. Early LEP technology took decades to get off the ground for the precise reason that their colour rendering was so poor, with little coverage of the red areas of the spectrum.
Now, fine-tuning of variables such as the gases used, the coatings (such as metal halide salts) and even the pressure of the chamber can create far more precise replications of daylight. They also have the advantage of emitting some light in the UV spectrum. But the jury is still out on whether they are truly superior to “full-spectrum” LED systems.
Starting an indoor greenhouse? You’ll need all the tips and tricks for choosing lighting. Let’s discuss the best lighting for yield and cost.