Full spectrum solar cell?

[jtr1962]

I came across this article (http://www.spacehike.com/berkeleysolar.html) when researching white LED efficiency. By a stroke of luck, some scientists studying the properties of indium nitride as a light emitter found that it had properties that could make it an effective light to electricity converter. Current solar cells have efficiencies of at most 25%. This material promises efficiencies to 70%. The implications of this are staggering, especially given the fact that the costs of these solar cells are potentially much cheaper than anything thus far. It may very well become feasible for every building to generate most or all of it's electrical requirements from solar cells on its roof, or for a car that makes most of the power it requires while sitting in a sun-baked parking lot. Besides the unexpected use of this material as a solar cell, it also shows great promise in an improved white LED, the light of the 21st century. Current commercial white LEDs are about as efficient as light bulbs(15-20 lumens/watt). LEDs just coming out of the lab and into production are around 30 to 40 lumens/watt. Once white LED efficiency exceeds that of the best fluorescents(about 80 lumens/watt) and the costs per lumen come down it will make economic sense to use white LEDs as a general lighting source. Maximum theoretical efficiency for white LEDs can be as high as 330 lumens/watt. (http://www.rpi.edu/~schubert/Reprints/1999%20Guo%20et%20al%20(IEDM)%20Photon%20recycling %20semiconductor%20light%20emitting%20diode.pdf)

[Tea]

Indeed, that could be great news!

[CougTek]

Very interesting JTR. Someday, I plan to fill a part of the electricity needs of my house with a solar panel. Now it isn't a very attractive option on the economical side. You need a huge, expensive panel, that cannot even answer the entire demand of a typical house.

[fool]

When someone starts making these (http://news.bbc.co.uk/1/hi/sci/tech/354646.stm) with indium nitride, I'll be a very happy bunny.
The company (http://www.solarcentury.co.uk/) that guy runs does some really interesting stuff. (http://www.solarcentury.co.uk/content.jsp?sectno=1&subno=1&pageno=1)

[Howell]

I stumbled into some stuff recently:

The Database of State Incentives for Renewable Energy (DSIRE) is a comprehensive source of information on state, local, utility, and selected federal incentives that promote renewable energy. To access information, use the menu to the left or click on the maps below.
http://www.dsireusa.org/

Announced in June 1997, Million Solar Roofs (MSRI) is an initiative to install solar energy systems on one million U.S. buildings by 2010. The initiative includes two types of solar technology: solar electric systems (or photovoltaics) that produce electricity from sunlight and solar thermal systems that produce heat for domestic hot water, space heating, or heating swimming pools.
http://www.millionsolarroofs.com/index.html

The last time I did the calcultions for covering the barn the payback period was too long. With these improved cells plus the federal and state incentives I recently found, I'm gonna have to take another look.

[SteveC]

When someone starts making these (http://news.bbc.co.uk/1/hi/sci/tech/354646.stm) with indium nitride, I'll be a very happy bunny.

"On a typical day, my roof creates enough power for me to make 350 cups of tea, watch 70 episodes of Coronation Street, or make 800 slices of toast."

Only in the UK is power measured in cups of tea. :)

[SteveC]

The last time I did the calcultions for covering the barn the payback period was too long. With these improved cells plus the federal and state incentives I recently found, I'm gonna have to take another look.

There's a cost calculator here (http://www.srpnet.com/power/solar/home/cost.asp), which you may be interested in.

[blakerwry]

Has anybody considered a partially sub terranian house?

It makes sense to me to have say half of your house underground, or even most of it. The earth is at a constant 53F? It just seems so much more economical to have the Earth help insulate your home and keep its temperature regulated.

I would do this if it were available in the region i lived in.

[Tea]

Huh? Everybody measures power in cups of tea. :wink:

Underground houses are great, Blake. Whether the problem be heat or cold, they offer enormous efficiency gains. The main problem is ensuring proper drainage, which is one reason why they tend to remain uncommon. In the opal mining towns of outback Australia, where it practically never rains and gets hot as very few other places do (think Death Valley and you'll get the idea), they are common as ... er ... mud.

[blakerwry]

i think there are a few subterranian office spaces available within a 10 minute drive fom my home...


In Kansas City most houses have basements, which is a good thing. A finished basement is a nice addition to any house.

The house I'm living in has a walk out basement that stays very comfortable even without proper heating/cooling. The problem is that it's not finished and all our junk is stored down there... I live 2 stories up from the basement and my room is uncomfortably hot in the summer (it's over 80F in here at the moment on this nice spring day of 73F)

When I move out into an apartment I would prefer one that is below ground level. Most apartment complexes in the area have 1 apartment below ground level on the entry side of the building and the apartment has a walk out patio/porch area.

[Howell]

Has anybody considered a partially sub terranian house?

Yes, I've considered building my house that way. Into the side of a hill is what I had in mind. But as it is a way off, I've not thoroughly considered the drainage problem, as T hints at, or the method of piping sunlight to the underground area. Unnatual lighting just doesn't cut it for long.

[Howell]

There's a cost calculator here (http://www.srpnet.com/power/solar/home/cost.asp), which you may be interested in.

I was using this one (http://www.bigfrogmountain.com/calculators.cfm) which is from a company based locally.

[Howell]

Has anybody considered a partially sub terranian house?

Yes, I've considered building my house that way. Into the side of a hill is what I had in mind. But as it is a way off, I've not thoroughly considered the drainage problem, as T hints at, or the method of piping sunlight to the underground area. Unnatual lighting just doesn't cut it for long.

Let me continue with, I know several people who take advantage of thermal piping. Water is either pre-heated or pre-cooled by passing through pipes on the roof or pipes buried in the ground (geothermal).

[mubs]

Howell wrote:
the method of piping sunlight to the underground area. Unnatual lighting just doesn't cut it for long.
Check out Solatube. (http://www.solatube.com/home.htm) I've known about them for a while, and always wondered why people that built homes never used these. I too love natural light and will use them if/when I build a home. Problem is that out here in CA, it breaks your back just to buy a tract home, and to build your own, you have to be a certified millionaire.

[Howell]

Pretty neat mubs. Also neat is that you managed to get the box around my quote to dissapear.

[mubs]

Well,

Silly, dumb ole me, I've been trying to figure out how you guys don't get the "Quote" title when you quote somebody! If you'll tell me that, I'll tell you how I made the box disapper. Trade? :D

[Buck]

Well,

Silly, dumb ole me, I've been trying to figure out how you guys don't get the "Quote" title when you quote somebody! If you'll tell me that, I'll tell you how I made the box disapper. Trade? :D

Mubs, you'll need to use the BBCode tag [quote]. For example, you would write [quote="mubs"]. To complete the tag, use an end-quote tag.

[Buck]

An end-quote BBCode tag looks like [/quote]. Of course, you can always go here (http://www.storageforum.net/forum/faq.php?mode=bbcode) for more information.

[Howell]

mubs wrote


Silly, dumb ole me, I've been trying to figure out how you guys don't get the "Quote" title when you quote somebody! If you'll tell me that, I'll tell you how I made the box disapper. Trade? :D

Here's a secret, quote a message and read the syntax. You could probably start a thread for testing without hearing snickers.

[mubs]

Mubs, you'll need to use the BBCode quote tag. To complete the tag, use an end-quote tag.
Thanks, Buck. As always, you're a real gentleman.



Here's a secret, quote a message and read the syntax. You could probably start a thread for testing without hearing snickers.
Howell, buddy, I'm an old dog and over the years my troubleshooting skills have dimmed a bit from fatigue and from becoming a little ornery.
One thing I know for sure is that one can't know everything. It's more important to know how/where to get info. I'm not ashamed to ask (I do ask for directions if I get lost).

[Howell]

Here's a secret, quote a message and read the syntax. You could probably start a thread for testing without hearing snickers.
Howell, buddy, I'm an old dog and over the years my troubleshooting skills have dimmed a bit from fatigue and from becoming a little ornery.
One thing I know for sure is that one can't know everything. It's more important to know how/where to get info. I'm not ashamed to ask (I do ask for directions if I get lost).[/quote]

Oh my. I wasn't trying to be rude. I was giving you my secret. That was the offer right?

If you'll tell me that, I'll tell you how I made the box disapper. Trade?
You can use that to figure out all kinds of things. That's how I figured yours out.

Why Gary adds a set of list commands before and after the text of his posts is a mystery? :wink:

You can also mouse click on the buttons near the top of the input page to get the tags you need if you don't know the exact syntax.

Try a banana for that orneryness. It works for Tea.

[mubs]

No, no, I didn't imply that you were rude! I did figure out how to quote, create web links, etc, but this one trick I didn't have the patience to. Till Buck told me how.....

[Buck]

Thanks, Buck. As always, you're a real gentleman.

You are welcome mubs, and thanks for the compliment.

[jtr1962]

Has anybody considered a partially sub terranian house?

It makes sense to me to have say half of your house underground, or even most of it. The earth is at a constant 53F? It just seems so much more economical to have the Earth help insulate your home and keep its temperature regulated.

I would do this if it were available in the region i lived in.

This is definitely the way to go in my opinion. The only problem is it's really only useful for single family home situations. In a city like New York it is possible in theory to put a 50-story apartment building underground but the costs would be enormous compared to the energy savings. In fact, the energy required to dig the hole would likely be more than the energy saved heating/cooling over the life of the building. Still, it doesn't mean we can't try to make tall buildings more environmentally friendly, starting with more efficient lighting, better insulation, and putting solar panels on the sides of the building to satisfy most or all of the power requirements.

Assuming this new type of solar panel is as cheap and efficient as the initial data suggest, it may very well revolutionize our society. The power grid will be largely replaced by onsite solar electrical generation. In many cases the surplus power will be sold to the electrical company, so people can supplement their income by setting up large arrays of solar panels. It may be feasible to eventually start retiring power plants, starting first with the fossil fuel ones. Large arrays of solar panels can be set up in parking lots to supplement the solar panels built into electric cars, making the range issue of these cars a moot point(not that the 60 to 100 mile range of current models is that big of a handicap for the 99% of trips that are less than this distance anyway), and offering virtually free "refueling". About the only thing that can't be powered directly via solar panels will be large airplanes, but perhaps some scheme where solar-generated electricity is sent to the plane via microwaves will be feasible. In any case, this has the potential to be an invention that may make oil next to worthless within a few years after it is mass produced, so let's all hope this doesn't turn out to be another promising idea that never sees the light of day. Given that many times more power falls on the Earth's surface than we humans need it makes little sense not to take advantage of it once the means are economically available. The beauty of solar power is that once the system is purchased the energy is essentially "free" other than occasional maintainance/repair of the solar grid.

The prospect of being able to make a home electrically self-sufficient for a few thousand dollars or less is too attractive a propostion to pass up. Probably the biggest costs will be the batteries to store surplus power for night hours, and the inverters to convert the DC to 120 VAC or 240 VAC. Perhaps as solar power catches on we will see more and more DC appliances so that the inefficiencies inherent in the DC/AC conversion process can be avoided. Electronics can run right off the solar grid with only cheap voltage regulators rather than the cumbersome transformers required to run off AC. Once thermoelectric modules, which run off DC, are made more efficient they can satisfy home cooling needs. DC brushless motors can be used in any appliances which require them, etc. Perhaps appliances of the future will be able to run off 120 VAC/240 VAC or 12 VDC/24 VDC via a simple switch selector. It certainly wouldn't be that hard to convert many current appliances, including PCs, to do just that. Also, we'll need to standardize on a DC voltage once this idea catches on, and also an outlet type. Perhaps a higher voltage, like 120 VDC, instead of 12 or 24 or 48, will make more sense in order to keep wiring losses low(higher voltage has less amps for the same power and line losses are proportional to amps²). Just throwing out some ideas here. :excl:

[Tea]

Zubterainian house in New York? My word yes. Just the thing. Much zafer.

[Howell]

Wouldn't 50 stories below ground in NYC be below the water table?

[Tea]

Duh. I didn't think of that. They don't have water here in Australia. Not so as you would notice, anyway.

[jtr1962]

Wouldn't 50 stories below ground in NYC be below the water table?

Most of the WTC foundation is below the water table(since it's on former landfill the water table begins only a few feet down). It's nothing that a little engineering genius can't solve if it makes economic sense to do so. Apparently it doesn't, or we would already have buildings fifty stories underground.