Is PPE Important for Grow Light? Is Wattage Important for Plant?

PPE is important — but not so important as you thought. It depends on how you understand it.

From a user’s perspective, PPE is a number that indicates how energy-efficient a product is. But if you blindly chase high PPE values, you might overlook other, more important factors.

There are several ways to increase PPE:

• Using higher-efficiency LED chips

• Adding more red LEDs

• Boosting the PPF of the tested fixture

When it comes to LED chip specs, PPE varies across brands and models. We’ve spent a lot of time comparing PPE performance across different chips, and based on the test results, we chose the brands we use now:

For white light chips, we found that Samsung LEDs have the highest PPE at specific driving currents, while also maintaining great stability.

For red light chips, Osram performed the best. Even though its raw red output isn't the highest, it excels in lifespan. Osram’s lenses are highly integrated and don’t fall off easily, and the light decay is minimal.
Cree and Seoul chips also performed decently.

If you have DIY skills, you can build your own spectrum using well-regarded branded chips — achieving both high PPE and quality.

But still, higher PPE isn’t always better.

If you look at LED chip data sheets, you’ll see that red light has the highest PPE, while UV has the lowest. So here’s what can happen: A grow light may use an excessive amount of red light, reduce blue and UV, and reach a PPE above 4.0. This kind of light may perform extremely well in the flowering phase, but poorly in other growth stages.

So, when choosing a full-spectrum grow light, you should avoid focusing too much on PPE. Instead, ask: Is the spectrum effective?

One last thing — PPE can be increased by using higher current during testing. But high current doesn’t reflect normal usage, and this kind of testing is meaningless. Worse, it shortens the lifespan of the LED chip.