Slashdot Mirror
Solar Panels Reach $1 a Watt
ZosX writes "An article over at Popular Mechanics announces that, for the first time, solar cells have been manufactured for the much sought-after figure of $1/Watt. They also talk about a new study of the cost of the particular raw materials used in different manufacturing processes. The conclusion is that the company that just achieved the $1/W milestone, using cadmium telluride technology, may not prove to be the long-term winner capable of meeting demand when it rises into the terawatt range."
This is something we are told about just about any mineral resource, and usually once it gets short, we manage to find a new resource, obviously this cant happen forever, but running out mightnt be an issue for a while. Also it means this technology isnt going to be cost effective for long using the current materials.
This sounds like the classic solar is not a renewable energy source tale because of the non-renewable materials in solar cells. You do realize that once the cells are built, that they continue to work until damaged or otherwise decommissioned, and that the nonrenewables are not consumed in the process? Also, there are alternative materials to use, and alternative places to mine what there is.
It is dangerous to be right when the government is wrong.
Mod parent up - the mining industry typically just isn't wandering around prospecting for new ore veins unless they a) don't have enough reserves to meet projected demand or b) the price is high enough to justify opening new mines. When the price gets high enough or the reserves get low enough, they go looking and they usually find something. Most of these alarmist "we're out of element X" projections are based on proved reserve numbers, which are just what the mining companies know about *right now* and can extract.
It won't last forever, but there's a lot of ground out there to be dug up yet. I can't promise it'll be as economical to extract as current reserves and prices may fluctuate accordingly, but there *IS MORE OUT THERE*.
I hate to break it to you, but nearly everything is toxic at some level. The ugly truth is that we're not going to get to a green utopia without some exotic materials that'll probably kill you if you look at them funny. Coal and oil are very safe, non-toxic materials - as is any reasonable concentration of CO2 - but the reality is that they're not green overall. The "green-ness" of a material is in its overall impact, not in its intrinsic properties. We can engineer around the fact that handling them is toxic - it's just a process and plant design question.
We aren't going to build a completely renewable energy infrastucture out of rainbows and ponies. It's going to take some very strange stuff, much of it not good for you. We just have to manage it well.
The point of these installations isn't to keep going without the grid - it's to generate your power either greener or cheaper depending on what angle you're coming from.
But grid-tie won't help at all when the grid goes down.
It also won't help if your phone is disconnected or your house catches fire - what's your point?
The question was whether it makes economic sense, not if it's better than the power grid.
sic transit gloria mundi
None of the elements being discussed are rare earth elements (which are indeed all metals). Cadmium and tellurium are not, and neither are copper, indium, gallium or selenium. This is too bad actually, since despite their name none of the rare earths, except of course for promethium, is very rare.
Tellurium is fairly common for an element of its atomic weight in the Universe. On Earth it is quite rare, but instead of 1/10,000 as common as gold as you would have it, tellurium has about one fourth the abundance of gold in the Earth's crust. See this abundance table.
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
There is a lot going on in Thermal Solar right now as it has the greatest potential to meet base load power needs when coupled with molten salt storage.
My ism, it's full of beliefs.
For 5V, for example, use a 7805
The 7805 isn't a switch-mode power supply, it's a simple series regulator. The voltage that appears across it x the current through it equals its power dissipation, i.e. the power it is merely wasting as heat in order to drop the voltage to 5V. That can be quite considerable - if it's handling 1A and dropping from 12V, it's wasting 12-5 X 1 = 7W, while delivering only 5 X 1 = 5W to the load. That's only 41% efficient. You don't want that sort of figure when your power source is solar.
A true SMPS will do much better, but unfortunately is more complicated than one three-legged IC and a few caps.