07 Apr '17 13:51>
https://phys.org/news/2017-04-crystalline-material-silicon-efficiency-solar.html#nRlv
Big news if it works out.
Big news if it works out.
Originally posted by humyWe will will be producing all our power from renewables long before then, so it won't change much at all.
I cannot wait until 99% energy efficient cheap solar cells are made and out of only cheap materials with only common readily available chemical elements such as carbon, silicon etc.
That will change everything.
Originally posted by humyFrom what I've read 68% efficiency is a hard limit. The sunlight reaching solar cells is a blackbody spectrum which has some consequences. First any radiation with a frequency less than that corresponding to the band gap energy won't excite electron hole pairs. Photons with an energy greater than the band gap produce super energetic electrons whose energy can't be harnessed, the excess energy is lost as heat. So one can get 1.1eV per photon from silicon. What the material advanced by the group sonhouse's OP referenced has done is find a material that can harness more of the energy from the super energetic charge carriers. This still leaves photons whose wavelength is less than the bandgap, as well as losses from electron hole recombination.
I cannot wait until 99% energy efficient cheap solar cells are made and out of only cheap materials with only common readily available chemical elements such as carbon, silicon etc.
That will change everything.
Originally posted by twhiteheadIf you double the efficiency, for homes it means half the physical size for the same power. That alone has to lower the cost per watt since there is less installation time and cost.
The reality is that except for particular situations where space is at a premium, efficiency is not important. What is important is price per Watt. The goal of high efficiency has mostly had to do with the fact that higher efficiency can mean lower cost per Watt. If the price is low enough, doubling the area covered really doesn't matter in most situation ...[text shortened]... is more about mass than area. Lighter materials might be easier to find than higher efficiency.
Originally posted by sonhouseIt only lowers the cost if doubling the efficiency is achieved with similar costing materials.
If you double the efficiency, for homes it means half the physical size for the same power. That alone has to lower the cost per watt since there is less installation time and cost.
Originally posted by twhiteheadTrue but some of us can't get solar no matter how much we want it. Financial situation for us right now is dire. May lose home, much less getting solar. A lot of people in the US are in that boat right now. I would have to get a grant of some kind to contemplate solar.
It only lowers the cost if doubling the efficiency is achieved with similar costing materials.
Halving the manufacturing costs can be just as effective - and for the higher efficiencies will be much easier to achieve. More importantly, there is a hard limit on efficiency. There isn't one on manufacturing costs.
[b]Part of the renewable equation is hom ...[text shortened]... diate drop in your electricity bill - its a no brainer. That leaves simple resistance to change.
Originally posted by sonhouseHave you tried contacting solar city? If I am not mistaken, they, or other companies like them, can install solar for you, at no cost whatsoever, and your monthly electricity bill will go down. If that is the case it will help your financial situation not harm it.
True but some of us can't get solar no matter how much we want it. Financial situation for us right now is dire. May lose home, much less getting solar. A lot of people in the US are in that boat right now. I would have to get a grant of some kind to contemplate solar.
Originally posted by twhiteheadOn roofs you can't arbitrarily double the collecting area. Most solar installs I see cover 90% of the roof now, at least on the sun side. I only see a few installs with say 20% coverage. I imagine those would be done by the homeowners who could not afford full roof coverage.
Have you tried contacting solar city? If I am not mistaken, they, or other companies like them, can install solar for you, at no cost whatsoever, and your monthly electricity bill will go down. If that is the case it will help your financial situation not harm it.
[b]But doubling the efficiency will put more power into the grid whether it is roof top ...[text shortened]... area is easier to achieve. Quadrupling the area is possible, quadrupling the efficiency is not.
Originally posted by sonhouseMaybe so. I don't see many solar installs here in SA. The fact is that the vast majority of roofs are empty.
On roofs you can't arbitrarily double the collecting area. Most solar installs I see cover 90% of the roof now, at least on the sun side. I only see a few installs with say 20% coverage. I imagine those would be done by the homeowners who could not afford full roof coverage.
Originally posted by sonhouseHouses of the future will have bigger roofs and need less heating so the
On roofs you can't arbitrarily double the collecting area. Most solar installs I see cover 90% of the roof now, at least on the sun side. I only see a few installs with say 20% coverage. I imagine those would be done by the homeowners who could not afford full roof coverage.
Originally posted by twhiteheadThat would be one goal, rooftop units powering civilization. Of course that is a pipe dream.
Maybe so. I don't see many solar installs here in SA. The fact is that the vast majority of roofs are empty.
So, given that most installs you see are at 90%, why would they want to double that? Surely they have 90% because that is what they thought they would need. Or are you suggesting that individual home owners should be the primary source of power for industry?
Originally posted by sonhouseThere are two main reasons why power back to the grid is unpopular. There is the question of who pays for the grid and there is the question of profits.
Power companies don't really like that for several reasons, one, they have to pay for the electricity generated so they screw the homeowner and only pay 1/3 or so of what they would pay a fill in power company for the same energy and they also bitch about safety issues where if a power line goes out and a dude has to come out to fix it there would be power ...[text shortened]... so built the extra switches. And pay the people what they pay another company for fill in power.
Originally posted by twhiteheadSeems we would still need the grid because of industrial use of electricity goes way beyond that of homes, megawatts and more. I used to work at Firestone tire and rubber in LA and one of my machines was the 'Banbury 27', a system that ground rubber and other stuff in a huge mixer, with a 1500 horsepower electric motor that ran at 200 RPM, big as a house. It was geared down to 16 RPM to run the actual mixer that took in 500 pounds of rubber and oils an stains in a given recipe and ground them all up and such then feeding the output to a continuous production line. That motor had a megawatt power meter on it that pegged when it started up and then settled in to a couple of megawatts. You need grid for that kind of usage. If you have a production plant using say 50 megawatts you would be hard pressed to get that with solar. say 1000 watts hits the ground per square meter so 1 megawatt needs 1000 square meters times whatever efficiency percentage so 20, 5000 square meters times 3 for 24/7 and now it's 15,000 square meters just for one megawatt and then times 50 to get that 50 megawatt number and you are talking 750,000 square meters of collection space at 20%. 60% = 250,000 square meters and even that is a half kilometer by half kilometer space.
There are two main reasons why power back to the grid is unpopular. There is the question of who pays for the grid and there is the question of profits.
Currently, the grid is payed for out of the power companies income and they and the local governments share the profits. It is perfectly reasonable for them to pay the home owner less for power onto the ...[text shortened]... ot we should keep the grid at all. It has many advantages, but they might not be worth the cost.