I'm looking for a way to make solar hot water, or CO2, very cheaply. Solar collecting via stallite dish model or trough style need some structure, and have to track the sun. After looking at this link on peswiki http://peswiki.com/index.php/Directory:Charles_Shults%27_Fresnel_Solar_Design and the companies listed on peswiki which use trough solar, often use natural gas or something to further heat the water, because steam or stirling engines are more efficient with a larger temperature difference. By this it seem like it's most economical to use a cheap/simple heat collector to bring the water up to a certain temperature, and then use a high heat concentrator like a lens, or mirror to bring it up the rest of the way. Now maybe a black hose metod is the way to go. Often when I see collectors like this they're under glass, I think this is to insulate the black hose, and cause a greenhouse effect. Just a black hose by itself may lose heat fast from the wind blowing around it, but with a glass cover the air will be held there, and act as an insulator. Right now I'm wondering about 2 black tarps that could melted together every inch or 2 to make the hose, and green house plastic should be pritty cheap to cover it with, with air inbetween ofcourse.
Go to your public library and check out some books on solar water heater designs(free).Ebay has a lot of good info for sale.Aluminum foil reflects 60%of sunlight.White paper reflects a lot of sunlight too.
All kinds of plastic throwaway bags(like potatoe chips) have reflective mylar in them.A green or dark colored garden hose full of water will pick up a lot of heat.Triffid
Check out this old codger.....his method actually makes good sense:
http://jc-solarhomes.com/MTD/MTD_solar_heating.htm
Also, if it's within your budget and you live in the northern U.S. check ebay for evacuated solar tubes. sometimes you can get them cheap and they make the best solution for the money when it comes to heating a northern lattitude home hot water supply, without a doubt.
Peace,
TS
I use this:
http://en.wikipedia.org/wiki/Space_blanket
also to isolate my rooms , and some more appications
GP
I suppose it all depends on how much sun you get and how cold it is.
The collection box is very successful.
4' x 8' plywood
2" x 4" 's around the edge to make a 4" depth.
paint the inside black
use a black hose
cover the whole thing in plexiglass or glass.
The water will be so hot it will burn you......
until the sun goes off the collector. Then the water temperature gets cold right away.
The price goes up from here. The above was really cheap, but you must use the water when the sun is on the collector.
If you want the water to stay hot, now, you need to devise a way to circulate the water to an insulated tank and get it to keep circulating and then shut off when the sun goes down.
There are lots of ways for the cost to go up.
But if you live in a sunny area and the temperatures stay no lower than freezing in the winter, you ought to be able to do it for cheap money.
--------
I had a friend in Boston who had a thing that size (4' x 8' x 4") that was an air collector which had an inexpensive fan at the top and which circulated the warm air from top of the collector into the room all the sunny days.
Another hole in the bottom leading into the room brought the room air back into the collector to reheat it.
Even in frigid winter days which were well below freezing, if the sun was on the collector the house would be toasty warm when she got home and the heater had been off all day, [when my heater was on all day just to keep the pipes from freezing.]
Solar is great.
enjoy your project.
jeanna
I have had good results with simply making use of SR after it enters one's already insulated home. Afterall, why reinvent the window if one doesn't have to....
Stand up a piece of sheet metal painted with stove paint inside a window and install a mylar covered plywood panel horizontally outside just beneath the window to increase the amount of reflected SR hitting the sheet metal. Stand the metal on a couple blocks to facilitate convection and voila. Also, if one has a storm door, then they have probably experience how hot even a shiny lacquered, light colored wood front door heats up appreciably even on cold days. Imagine making use of that surface area as well. Not purdy, but it's easy and practical.
Of course, a better solution would be to install vertical blinds and replace the slats in winter with black chrome slats with short focus fresnel sheets in front of each slat, then install a small tracking motor to the spindle rod blind adjuster so they track the sun across the sky!
Of course, evacuated solar tubes are very efficient and great for use even in the extreme northern U.S.
Peace,
TS
I have often felt that corrugated cardboard could be used to heat up air with if it was used in a solar hot air heater.Just paint it black and let air flow through the little holes in the cardboard.Triffid
Perhaps the cheapest way to convert solar radiation that I've ever heard! Given the insulative properties and small corrugated convection pathways, however, it is a comparatively inefficient choice......but it's way better than nothing at all.
TS
Actually, as long as it stays dry, cardboard is a really good option.
I used it as insulation once when I was very poor and lived in an uninsulated barn. I stapled it onto the rafters. The heat rising from the heater in the tenant's apartment below mine kept that room toasty. The rest of the rooms with sheetrock walls and ceilings were frigid. (This was Concord, Massachusetts. oo ee baby reallllly cold!) Not that room.
So, keep it dry and go for it.
Also, in an earlier post about the hot air heater (I remember this thread is supposed to be about water!!!) I didn't go into the detail about the greenhouse effect happening inside the unit. This is the reason the unit heats up so well. You know, long rays IR not able to escape etc...
jeanna
QuoteActually, as long as it stays dry, cardboard is a really good option.
And cheap too! However, for nominal added cost, try comparing it to black metal, which will radiate heat effectively from both sides.
If one can afford sheet metal, the decision is a no brainer, really.
TS
I have built a 12kw heating spiral from black irrigation pipe, it is unglazed but to glaze it would be pointless because the plastic and fittings don´t like high temp. This design is best for high flow with modest temp rise, like 10c rise:
(https://overunityarchives.com/proxy.php?request=http%3A%2F%2Frimstar.org%2Frenewnrg%2Fsplyucca%2Fsplyucca_spiral1.jpg&hash=f1b1b2a658caebe3dabca1e258437f3a385b781b)
Steve Duffrense compiled a page about it on his Rimstar site:
http://rimstar.org/renewnrg/splyucca.htm
I mention how to make a good water heater capable of 60c at the bottom of that page. Just need to get hold of leakfree mat black car or truck radiators from scrapyard and build a glass fronted box over them. I read about this elsewhere online.
Yucca
@Yucca,
I'd be interested to see the efficiency increase in duplicating your setup with high temp stove paint on copper tubing.
Check out the MTD solar heating method link above, it is quite efficient and cheap.
Or buy a few evacuated solar tubes on Ebay. They are insanely efficient and reasonably priced!
TS
Quote from: TechStuf on October 21, 2008, 06:06:13 PM
@Yucca,
I'd be interested to see the efficiency increase in duplicating your setup with high temp stove paint on copper tubing.
Check out the MTD solar heating method link above, it is quite efficient and cheap.
Or buy a few evacuated solar tubes on Ebay. They are insanely efficient and reasonably priced!
TS
Hi TechStuff,
Yes that would be much more efficient especially if glazed plus you could run mains pressure. Only downside is that copper pipe is quite expensive.
I will check out those links.
Yucca.
Copper just dropped considerably so get it while the gettin's good.
Oops, too late.
lol.
Side note: Some of the most ingenious and cost effective solar setups I've ever seen are contained in the Backwoods Home anthologies. Great magazine.
TS
Could Thompston's water seal be used to water proof corrugated cardboard?Make sure it flows through the holes in the cardboard?
The same stuff you waterproof your deck with?Sorry I can't seem to spell it right.I know this thread was for solar heated water but I did point out my tip was for solar heated air.Also black plastic garbage bags could hold some water.i.e. be used in a hotwater system.aluminum paint could be used to reflect light.Triffid
I could not believe that last night night I found in one of my text books a design on how to build a solar hot water heater using cardboard as a frame
and newspapers as bedding.I was so excited.While its a student's experiment it could be scaled up to put on a house.Pay attention to this:
Materials;Shoe box painted black on the inside and filled with newspaper(crumpled up) painted black.rubber or plastic tubing,1-mm diameter and about 1 m in length.Plastic wrap. The rest of the materials listed were there to help the students do their experiments.But the point is that someone used CARDBOARD TO HEAT WATER WITH SOLAR POWER.Triffid
Source-"Physical Science" by Hurd,Mclaughlin,Bacher,&Silver
second edition cc.1991
Publisher-Prentice Hall
page 430
I confess,I smell a business here.Making solar hot water heaters out of mostly cardboard and using wooden box frames with glass windows to protect them from rain on a person's roof.I just couldn't see before last night.Triffid
As noted higher in the thread:
http://jc-solarhomes.com/MTD/MTD_solar_heating.htm
Already being done cheaply and effectively.
TS
Thanks,tech student,I think new ways of capturing the the sun's energy is always desired.We (the human race) are energy starving in the midst of plenty(solar power).Triffid
Yes, we are starving, and in various ways.....and there is a critical, sobering reason for this.
Blessings in Yeshua,
Mitch
try www.solarcooking.org for a whole lot of ideas on how to heat water with solar power.triffid
Would a one way mirror have a better greenhouse effect then normal green house glass?
No, such is used to cool buildings, not warm them. Unless your idea is to face the reflective face inward....which, due mostly to light/energy conversion characteristics of matter prevent such from proving more efficient than transparent materials.
Allowing as much light to enter the structure and convert such rays into heat has long proven more beneficial.
Of course, if your objective is increased green house effect, placing mirrors on the ground at the correct angle to multiply the amount of light entering the structure, should prove beneficial.
TS
for more ideas on solar heaters try www.solarcooking.org they have cookers from all over the world.Triffid
I don't know if this adds anything as I have not read through the entire thread. I am working on a solar preheater for my trailer propane water heater. Basically black hose in a well insulated box with at least two layers of plastic for the sun to shine through with air trapped tightly between. Also I am using black painted brick as the background for the hose to lay against as brick will retain some of the day-time heat transferring some of that to the hose at night. A well insulated storage tank for the hot solar heated water that goes between the solar heater and main water heater is an important addition. An old water heater can be used for this.
That said, low-tech solar hot water heating is a super underutilized green energy storehouse. Very sad; but glad you are making yours. :)
jt
I gave a fairly good idea on a solar project some time ago but no one cared to discuss it it is cheap ...
Look up the posts by me...
Or I can briefly explain the concept here ...
Magnifying glasses cheap ones at the proper distance aligned around a tube full of water metal tube copper is fine... A tube about 1 - 3 ft in diameter with a ton of cheap small magnifying glasses to concentrate the sun onto the tube at all hours of sunlight...
If done properly cheap and productive.
-infringer-
I think everybody's ideas on solar energy is important.I have seen solar collector designs that do not use foil but use a white surface with a black pot inside a clear plastic bag to keep the warmth in.Great for countries where foil cannot be had for the price. everybody keep posting.triffid
Infringer,your design is similar to one of my projects.I came up with a burning mirror design that could generate up to 10,000 degrees.I want to use it for solar powered rockets.If I could find a material (metal or ceramic)to soak up the heat we could probaby use seawater for fuel and let the rockets take off at sea level.triffid
Actually you can buy sheets of Fresnel lens at office supply places.
These sheets are about 30cm x 30cm in size and they can light a piece of wood on fire very quickly.
They sell them for book reading lenses, because you can place the sheet across the whole page.
These would be ideal for focusing the suns rays on any type of collector.
Here's a video of a large one at work.
http://uk.youtube.com/watch?v=DGtA8E5iw3k
They used to sell large ones you could place across your TV screen to turn a smaller screen into a larger one.
Check out the "light sharpener".....
http://www.cockeyed.com/incredible/solardish/dish01.shtml
I really stand behind fresnel technology:
http://img261.imageshack.us/img261/5919/bobbleheaddaddo6.jpg
TS
Solar powerd rockets, great idea. Solar powered turbines too. Someone on another forum has figured out that CO2 gas is the best to use, after looking at ammonia and hydrogen.
The biggest problem that I'm seeing is that reflective material, or lenses have to use tracking systems to work fully. Just laying out a "green house type" is very cheap but doesn't heat the air/water very much, and loses heat because of the larger area. I guess it's a matter of insulation. If one square meter of "greenhouse" is perfectly insulated then it will be as good as 1 square meter of lens focusing on a small spot. As long as Black absorbs different quanaties of light the same... more effort will have to be put into making it look dark inside the greenhouse, because the greenhouse has more area for the light to excape. (if you don't see light then the heat is not excapping, probably a high serfice area black matterial would work best, black plastic actaully does reflect light.)
here's something that utilizes the greenhouse and the reflective methods.
http://www.sunoven.com/
solar walls seem very worth while.
http://www.retscreen.net/ang/video.php
http://www.steorn.com/forum/search.php?PostBackAction=Search&Keywords=solar&Type=Topics&btnSubmit=Search
http://www.wsetech.com/waterheaters.php?gclid=CLTOhffu45cCFQ2LDQodA2PWCQ
http://www.wsetech.com/waterheatersWSE47.php
http://www.apricus.com/html/evacuated_tubes.htm
insulation by vaccum.
I think all the ideas presented here are good ones.We as a nation need to get hellbent on using more solar power.Its out there anyway.Even moonlight can be collected.Maybe no heat from moonlight since ir travels in straight lines and moonlight is reflected light.So maybe we can get electricity from moonlight if nothing else.Triffid
there is a how to on the internet for a cheap solar collector, use the perferated plastic sheets basically from the side they have long hollow tubes but from the front its a solid sheet of plastic, this combined with some pvc pipe and special glue can make a excellent hot water heater of 30-40% there are many ways to get this plastic. often it is used for the "vote this senetor" signs on the side of the road. it doesnt have a fantastic life span as it does get brittle after some years so keep it in a area that if it leaks there will be no water damage.
I think vaccum insulated windows will be a big heat saver. If it's cold where you are just feel under your windows, and compiar that to the walls
http://www.goodcleantech.com/2008/03/heatsaving_vacuum_insulated_wi.php
http://greenbuildingelements.com/2008/03/17/super-insulating-vacuum-glass/
Polycarbonate just over a $1 per sq foot?
http://www.builditsolar.com/Experimental/PEXCollector/PEXCollector.htm
I have been told that" harbor freight "(a store here in dallas and else where) has a point and click IR thermometer that you aim at a surface and get the temperature of it .And "Harbor Freight " has them for about 10 dollars,Looks like a keychain almost.Could be very useful in solar power experimenting. I used to use a bigger one when I was a kiln operator for Acme Brick.Triffid
A very good report http://www.solar-thermal.com/index.html
esolar's site is worth reading too.
Solar thermal is going to be cheaper then coal, and I have done calculations that show as low as $500 per KW average output. Coal is $1500-$1300 per KW output. $2000 per kw is a conservative estimate I did for solar thermal. The report doesn't know that there's a few types of turbines that are 80% efficient. The solar companies don't seem to realize that it's more suitable to use multiple kinds of collectors and step them up. Like trough and then pipe it to a tower or lenz. Most overunity devices would cost at least $500 per kW output anyways.
Moonlight will be an expensive to undertake but... Who knows maybe the common ir sensor in your cable box may hold the key.
As far as solar heaters I have gave my idea several times a couple differnt places and I have yet to have see it disproven for the sake of not repeating myself just look for me and look at solar discussions.
Using mirrors or reflective materials to aim up to 100x the sunlight through
a fresnel lens might be possible .Afterall most of the heat would pass through the lens not harming it.I think.Triffid
Mirror tint the inside of the glass pane protecting the solar panel so that light reflected off the panel reflects back onto the solar panel.
Heat is trapped in the 'cell'. Now, run your solar water heating through the same said solar cell, and gain heat to water.
Next, trap water for conventional hot water use through an exchanger.
Behind the exchanger, post exchanged, and the ambient air, place a sterling engine, and generate motion for electricity.
Combine and store energy for use.
Not super cheap, be it's taking step toward utilizing waste heat and sunlight.
Using the right kind of glass to trap high energy light is important.
Nature invented solar farming way before man.The giant clam"tridacna"
grows" lenses" on the outside of its mantle to concentrate the sun's rays on the swarms of microsopic algae that live in its tissues and the clam eats more algae as a result.So far I have never heard anywhere of man trying to grow bigger plants by reflecting more light upon them.Maybe we should try solar farming too?It took a clam to lead the way.We should be ashamed?Don't we have more brains than a clam?
Triffid
Quote from: triffid on January 18, 2009, 03:42:11 PM
Nature invented solar farming way before man.The giant clam"tridacna"
grows" lenses" on the outside of its mantle to concentrate the sun's rays on the swarms of microsopic algae that live in its tissues and the clam eats more algae as a result.So far I have never heard anywhere of man trying to grow bigger plants by reflecting more light upon them.Maybe we should try solar farming too?It took a clam to lead the way.We should be ashamed?Don't we have more brains than a clam?
Triffid
Gigantism is caused by higher ambient pressures or genetic abnormalities. Do a search on high pressure farming.
Also, your thoughts on clams reminds me of Diatoms whose silica shells help focus light on their chloroplasts.
Done some searches on high pressure farming, didn't find anything.
focusing on a solar cell with a lens doesn't only lower the cost by replacing much of the cell material, but also makes the cell work at 37-40% efficiency, whereas unfocused light cells work at 12-15% efficiency. Like high temperature gradients makes steam turbines and stirlings etc, work more efficient.
reflective material is much cheaper then lenses.
If solar farming(reflecting 2x-3x the amount of normal light upon a plant) could increase world food supplies 2 or 3 times what it is today.Is this not a major breakthough?Afterall the ir component could be removed from sunlight to avoid overheating of the plant.Giant clams have been around how long?(millions of years?) So its worked for them.Why not put the same idea to work for us?This is not my idea,Nature is already doing it .But I am totally shocked that in the 30 plus years me since me being a science major in both biology and chemistry since college I have never run across someone somewhere who was reflecting more sunlight upon food crops to grow more food.Maybe now world hunger can be a thing of the past?Triffid
Quote from: triffid on January 20, 2009, 12:37:14 PM
If solar farming(reflecting 2x-3x the amount of normal light upon a plant) could increase world food supplies 2 or 3 times what it is today.Is this not a major breakthough?Afterall the ir component could be removed from sunlight to avoid overheating of the plant.Giant clams have been around how long?(millions of years?) So its worked for them.Why not put the same idea to work for us?This is not my idea,Nature is already doing it .But I am totally shocked that in the 30 plus years me since me being a science major in both biology and chemistry since college I have never run across someone somewhere who was reflecting more sunlight upon food crops to grow more food.Maybe now world hunger can be a thing of the past?Triffid
Plants can get sunburned from too much light. Reading about greenhouse glazing I find that they don't want too much infrared light because it will cause too much heat. They do use reflecting to help plants grow.
http://cgi.ebay.com/4'-x-25'-Mylar-Sunleaves-Reflective-film--Hydroponics_W0QQitemZ360118074480QQcmdZViewItemQQimsxZ20081221?IMSfp=TL081221118007r10526
How much light and heat it can take will depend on the kind of plant.
One of the benefits of using more than 1x sunlight might be that not too many crop eating insects could handle the excess sunlight too.Something would have to evolve almost to handle the excess sunlight.I agree that we would want to use reflected light as much as we can to remove the IR part of sunlight real cheap.Moonlight is a beautiful example of reflected sunlight(no heat in it).I like the idea too that someone here expressed about diatoms.Maybe those silica shells evolved to focus the sunlight too.triffid
I like it too that someone somewhere is using reflected light upon plants.I had never seen an article about it before not.Now I don't feel so ashamed.For the past three days I've felt the giant clams were one up on us.Triffid
Us humans anyway.triffid
Now I hear that ther's a jellyfish out there that's figured out a way to beat death.So it's immortal(turritopsis nutricula).What's next from mother nature?Triffid
Quote from: triffid on February 04, 2009, 06:23:10 PM
Now I hear that ther's a jellyfish out there that's figured out a way to beat death.So it's immortal(turritopsis nutricula).What's next from mother nature?Triffid
Aliens
I don't fear aliens so much as I do the thought that we humans may have the most advanced brains in our galaxy.It would mean that there's nobody smarter than us.If we are alone then its up to us to fill up our galaxy.Triffid
Here is a great breakthrough for this thread.A super cheap design for a solar cooker plus no need to track the sun. http://www.youtube.com/watch?v=nC6-MMRHJdw&feature=related triffid
more ideas on the above cooker. http://www.youtube.com/watch?v=X24sj-EsmMQ&feature=related triffid
another video on the solar tyre cooker.Pay attention too the cooking pots!!! http://www.youtube.com/watch?v=bRMc-9-sR2s&feature=related triffid
solar grilling grilling .pay attention to how he protects his eyes. http://www.youtube.com/watch?v=yMeYO93XTsE&feature=related triffid
some ideas on solar cooker construction. http://www.youtube.com/watch?v=C_yhZsGPj0o&feature=related triffid
test
Bottle cutting with solar power.Also forced air heating with bottles. http://www.youtube.com/watch?v=oP40BDFF1cQ triffid
How to make silver mirrors with silver nitrate. http://www.youtube.com/watch?v=hUX_cpFWNso&feature=related triffid
How to make silver nitrate. http://www.youtube.com/watch?v=d6hPgGV_qAg&annotation_id=annotation_30199&feature=iv triffid
high temperature splitting of water. http://www1.eere.energy.gov/hydrogenandfuelcells/production/water_splitting.html triffid
This video shows how to use plastic bottles for solar heat storage. http://www.youtube.com/watch?v=UpeDnTMFgdg&feature=related triffid
Not sure if anyone has seen this before, but I bet it's been shelved by now. http://www.bbc.co.uk/news/science-environment-12051167 (http://www.bbc.co.uk/news/science-environment-12051167)