The energy that did go into making the kit would have been wasted had the kit not been made anyway
Under which assumptions are you saying that “the energy to make the device would have been wasted in any case?”
Yes, if you don’t make the Zero device, you will waste some hundreds of mW of optical power, but you (the world) will save much more energy because you actually are not going to make that device! (In particular you won’t need the solar panels for it).
Therefore it’s totally untrue that the energy required to manufacture Zero would have been wasted in any case! Because if you decide to buy some conventional mains-powered LED lamps, you will still consume (considering the whole device life time) much less energy than that required to manufacture Zero, in particular, its solar panels.
You might argue: “yes, but in this way you won’t light up THAT particular pretty lights”. Of course, but you can still buy similar mains-powered LED lamps!
And the main aims of that project are not those “pretty lights” but:
1) To make an eco-sustainable device, which saves energy (not just yours. He is talking about world’s energy consumption due to Christmas lights. Hence you use that device to light your tree, you must include the energy that the manufacturer spent to produce it).
2) To reduce lighting costs.
And the campaign says: (I’m quoting word-by-word what the author wrote in the project page)
1) “Illuminate Without Consuming Energy”.
2) “Humanity has the opportunity to make sustainable development [...] .”
3) “Energy equivalent to 6 bilions euro! That is what the planet consumes just on Christmas lights in December.”
4) “Hence no electricity consumption”.
Well let’s reply to those claims:
1) No, you ARE consuming energy! Because if 1000 guys buy that device, the factory WILL have to build those 1000. And because the typical energy payback of a silicon solar cell (under optimal SUNLIGHT exposure) is SOME YEARS, it follows that who knows how many Christmases you will need to get back the energy that was invested in making your “Zero”. Considering also that the device might stop working well before you arrive at the energy payback time.
2) Yes, the humanity has the opportunity to make sustainable development. By NOT buying that Zero (see 1), and, possibly, using mains-powered LED lamps instead of incandescent ones, which are still widespread.
3) The reported number has no sense at all, for the following reasons:
a) They are considering also public Christmas illumination (which is on almost only during night time! Therefore solar panels can’t be used, at least without some accumulators).
b) They are also considering the still present incandescent lights, which could be much more easily replaced by LED lamps, instead of thinking of recycling the light...
4) Yes, technically no electricity (in your bill) consumption. However there will be still energy consumption, if you take into account the manufacturer (and this plays against eco-sustainability). This energy is not likely to be compensated by the “zero energy” illumination.
Beside, a side effect of that gadget is that you need to keep on that 100-W desk lamp to light up less than 1W Christmas tree! (for instance I typically do not turn on a desk light if I don’t use, while I always keep on my Christmas lights in Christmas time). So is this power saving?
Other things that really stink:
1) There is no real picture at all, showing the device working. No video, no nothing. Just rendering. (I guess Kickstarter rejected its application, as they typically require a picture of a working prototype...).
2) The solar panels seem too small. Can they provide enough power? Let’s do the some ballpark calculations. Assuming a VERY GENEROUS 5% incandescent lamp efficiency, assuming a VERY GENEROUS 30% cell efficiency (as if the cells were better than top-quality monocrystalline silicon under 1-Sun constant exposure. And 30% is very close to the theoretical maximum for a single junction silicon cell), and assuming 100-W desktop lamp (indeed, what we need here is the optical power – i.e. efficiency*consumption – so you might also use a much more energy efficient lamp, with smaller power. Still it must emit light also on the sides, limiting the choices), you’ll get 1.5 W MAXIMUM (if the cells were arranged so that they gather all the incoming light. That is, the desk lamp is ) electric power. Still, you will not be able to get 100% of the light, but let’s say (see latter part of this post) a very generous 70%, i.e. 1W. Assume also a 100% DC-DC converter efficiency, so 1W might seem adequate for 48 LEDs (maybe they are arranged so that only 24 or 12 are on at the same time).
Still, as you could evaluate from the project image (that one which shows the Zero installed in the yellow desk lamp), you are getting only something like 25% of the light (and here I’m over calculating. As you can see I tried to draw some lines with similar length to estimate what is the coverage). Therefore, you haven’t 1W, but only 250mW. That is too close to the minimum, there is no margin (and too much generosity in my assumptions)! 250mW are barely enough to light up 12 20mW LEDs... And who uses a 100-W (or 10-W equivalent filament-led lamp, which has a similar 1200 lumen output?) in a desk lamp?!?
In conclusion: this project is definitely similar to the infamous Batteriser, and it is worthy to stay in this thread: they both promise a lot, which, under wrong assumptions (100% efficiency of the batteriser, and the fact that battery powered devices stop working at 1.3 V), could be achieved, at least in principle. However, in the real life they are likely to give you only a very limited gain (much less than that advertized) or even possibly they can worsen the problem.
As a last remark, I have now performed some measurements using a desk lamp and an integration sphere (see pictures below. The setup is not optimized for this lamp, so you must only take the results only as a ballpark starting point). I have to admit that you were partially right about the amount of light that can be reflected by the lampshade, even if I used much larger “fake” solar cells (those blue cardboards), and a much smaller desk lamp. With this configuration, in fact, you lose only 55 lumens out of the 199 that came out of that 60-W lamp (that lamp, alone, mounted on an Edison 27 socket, yielded about 640 lm – a bit lower than I expected, but I think because it was quite aged). Therefore the lampshade blocks a generous 69% of light (and that is the light that you can use for “Zero”. Still not enough, I’m afraid).
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