As an LED manufacturer we have been following the Massachusetts laws closely since they were released and while I applaud them for trying to make a positive impact it was done with poor information provided to the legislators who made the rules. I my opinion it would have made more sense to come up with a total number of watts allowed for a facility based on canopy. As it stands, a facility can buy incredibly efficient lights but buy inefficient cooling, dehumidifiers, etc. which would only offset the savings of the LEDs.
The specific section of the law pertaining to this thread is as follows:
The Lighting Power Densities (LPD) for cultivation space must not exceed an average
of 36 watts per gross square foot of active and growing space canopy, but for Tier 1 and
Tier 2 a requirement of 50 watts per gross square foot of active canopy or growing unless
otherwise determined in guidelines issued by the Commission.
We interpret this to mean you can use less in veg and more in flower, as long as you keep your total average at or below the requirement for your Tier. For example, if you were a Tier 1 grower with 10,000 square feet of canopy with 7,500 Flower and 2,500 veg you would be allowed a total of 360,000 watts for your lights. In reality you would likely run something like 40 watts per square foot in flower and 25 watts in veg with even lower levels in early stage plants.
A couple months back a test was set up with our lights over a 6X6 area simulating this very scenario. We usually like to see tests with higher light as we recommend in production environments but this test is all about how well our lights can do when you have a wattage limitation. We are definitely learning a good amount from the test and look forward to the results. Our goal is to till hit at least 75 grams per square foot, which would equate to 6 pounds of high quality flower off of the 6x6 space while running this low wattage.
Regardless of how our test turns out, this law is only the beginning of the future. California has a rule to test for mercury. How long until all the growers out there realize that one blown HPS bulb will mean the entire crop in that flower room is now garbage. And once they realize the possibility of losing hundreds of thousands of dollars to a single bulb failure, LEDs will look a lot less expensive as an insurance policy.
In case you are curios to see the test mentioned above, the picture below is at about week 6.