Im a bit of a simpleton, but from the first post i read :
the LED with 120w (90w) produced 436 units of light.
the HPS with 250w produced 507 units of light.
my basic maths came up with :
LED : 120w (90w) : 436 light units : 3.63 light/w (4.84 light/w)
HPS : 250w : 507 light units : 2.028 light/w
which means the LED is waaay more light per watt of electricity. Assuming the purchase cost is zero (which we know its not) the LED does better with less and the globes last waaay longer too.
can anyone point out the flaw in my logic?
That's a good way to illustrate the difference, but to be fair to the HPS the number climbed to 700
when i closed the door to enable the important side reflection, and the HPS ballast draws 30W at least,
so it should be 90W vs. 280W and 436 vs. 700.
But the big question is what about the all the green yellow light coming from the HPS, that is making the meters high reading in the sensitivity spectrum chart,
can a plant use all that, I think my par meter is deeply unfair to LED.
NB. If the unit is making my electricity bill decrease by a 1/4 then the unit will have payed
for it self in a year. My modifications have maybe pushed that to 1.5 year ( the price for the added head sinks )
but the unit should last much longer after the mods.
When you pay 40 cents for a kilowatt hour, LED and alternatives in general looks very attractive, I think that's the hole
point of hitting ourself with an serious energy tax, it make alternatives as wind and solar compete on, some would say, an equal non polluting ground.
