You are worried about air miles, but are willing to accept artificial light?
Do you just want to feel like you are being environmentally friendly, or do you actually want to be environmentally friendly?
I've been surprised at how many people only want to feel that way, but don't actually care about being environmentally friendly. (A good example of this is locavores.)
> of tuning the light to suit photosynthesis by using phosphors, I am surprised that has not been possible before.
It has been thought of before, people have been doing it for decades. This is just an incremental improvement.
LED lighting use more, even without doing the calculations I feel quite confidant in saying that it uses much more.
With a single trip 100m trip, the LEDs lose. With 10^7 100km trips, the LEDs win. The question is where the line is, and the answer is that it's going down all the time.
Hu? You are planning on shipping a single tomato 621 million miles? That's enough to ship it to Mars and then back.
Why in the world would you do that? Wouldn't it spoil?
You know you have to pay to power the LED, right? It's not just equipment cost? It takes less energy to grow a tomato in the sun, then fly it somewhere then it does it grow it indoors with artificial light.
And no, LED efficiency is not going up all that much anymore - there are physical limits to that.
If you only ever grew one tomato then you probably could buy a cheap plane ticket to deliver it, for less than the lights. So you'd be right, the LEDs would use more energy (cost to make, ship, and use) vs the delivery charges for the sun-grown (free energy) tomato from farther away - even if shipped expensively.
But if you grew millions of tomatoes from the same LEDs then you'd be wrong - now buying the grow lights is much more efficient than shipping in sun-grown tomatoes from even a few kilometers away.
How many tomatoes are you going to grow?
You keep focusing on buying the lights, but I'm not talking about that. I'm talking about running the lights.
In theory these lights change everything, why grow peas in Kenya, put them on a plane and send them 1/4 the way around the world when a greenhouse in the Home Counties will do nicely?
The cannabis angle is pretty good too. As things stand growing those plants takes a stupendous amount of energy with all the problems of ventilation, mould growth, noise from the ventilation and the need to 'not get caught'. With this technology those that can hold down a job can get growing their own without having to have the huge 'leccy bill or having to be friends with dealers.
I like the lateral thinking of tuning the light to suit photosynthesis by using phosphors, I am surprised that has not been possible before. One day this will seem so obvious yet it wasn't until this product came along.