Using “junk” for Solar Water Heating Systems
On June 07, 2009 in General Information
I saw this post on Instructables called Solar Thermal Water Heater For Less Than Five Dollars
Obviously it is going to cost more than $5 to be able to actually use this for something, but I had never thought of using the coil from the back of a refrigerator as the tubing inside a flat plate collector before. Don’t get me wrong, I find junk laying around all over the place and love to think up ways to use it, this is just one piece of junk I hadn’t considered for a flat plate solar hot water collector.
They claim pretty decent heating with their not so great setup, so with some small improvements it would probably work quite decently. To do any decent scale I would probably connect a few of the coils in a parallel arrangement with headers of a larger diameter than the coils themselves.
Well reading about all that got the wheels in my head rolling and I ended up at this post on PhysicsForum about using a car radiator as a heat exchanger in a solar water heater setup. This particular setup was for preheating biodiesel to cut down on electricity costs during production, but had some excellent points. Unfortunately they never followed up with any results.
So then I stumbled over to this site about a Solar Water Heater made from a car radiator. This is also in a flat plate setup. But of course they want you to spend money on some book rather than sharing information about it.
Well being put off by being asked to pay for access to information, I dug around some more and found this crazy long usenet forum post with lots of good info about solar water heaters, mostly related to using a car radiator as a solar collector.
From there I ended up at the Iowa Renewable Energy Association’s website where I found this little blurb about using a car radiator and a fan in a solar heating system:
“Storage of solar energy in water has been a proven method over many years. This water can be used as DHW, but also can be used to heat some or all of your house, garage, or workshop. To install enough solar panels and storage to heat an entire older home would be expensive, so most people try to do just some space heat. If your house is modern and very energy efficient, then solar could do a large part of your heating. An easy method is to install “kickspace heaters,” which can be as simple as a car radiator and a fan to distribute the heat from the water storage to one or two rooms.”
This info comes from their page on Solar Thermal but definitely check out the rest of the site as they have loads of good information.
Using recycled parts is great, especially in something like a solar water heater, and so stuff like this really makes me think. If anyone can think of any other relatively common objects/materials that can be repurposed for a solar heater (yeah we’ve all heard about the soda can heaters, and recycled pipe and fittings are awesome but hopefully most folks would think of that), leave a comment here on this post.
That’s all for now, just wanted to ramble about my thought process and the various places and things the internet can lead you to see and read about in a short period of time.
Camper and RV Solar Panels
On May 03, 2009 in Links, photovoltaics
I haven’t had much time with work and school to update the site lately, but I wanted to throw some links out here as I have been getting asked more and more about Recreactional Vehicle (RV) and Camper solar electric installations. Questions have ranged from DIY advice to where to purchase equipment. I try to stay away from the where to purchase equipment questions except for giving helpful advice about what to buy, rather than where you buy it.
These links have been added to the Electricity page of SolarDIY as well.
“How to Install an RV Solar Panel“ - Might be a little too step-by-step for some, but has some good points that will make you think about your install beforehand. One thing that I do not like is that they assume the panels will be fix mounted, and a few people have expressed interest in the ability to move around one or two panels to get optimum sun on the panels when in an area with tree cover, without having to move the RV.
RV Boondocking has a set of articles detailing the installation of their 780 watt roof mount setup as well as information on an RV solar tax credit, and their battery bank system.
RV Solar - article on RV Solar Electric Power. I like the way this one was written, and it has some excellent points.
Holy Solar has two articles about the Unisolar 64w thinfilm panel they installed. one and two
12voltsolarpanels.net has a good article about RV Solar Chargers as well
Thanks for stopping by, and if you have any questions about RV/camper solar setups or the links, feel free to leave a comment on this post. I will add more as time progresses, and will also try to free up more time to add content to the site.
High Rise Apartments With Solar Domestic Hot Water in Saranac Lake, New York
On November 19, 2008 in water heating
Lake Flower Apartments in Saranac Lake is a high rise apartment building (~9 stories tall) that provides housing to elderly people.
Here is a link to a little information about Lake Flower Apartments, although there doesn’t seem to be much out there on the internet about the place.
What is very cool about the building, is that they installed a 48 collector solar domestic hot water system in March of 1987. Why they did this is anyone’s guess, but it was certainly a great idea.
The history of the system is a little fuzzy but essentially it was used to an unknown capacity from 1987 (when installed) until sometime in the late 90’s/early 2000’s. In 2006 the system was drained and refilled, and some maintenance was performed by another contracting company. This included replacing some insulation as well as rerouting some piping and installing a propane fired on demand water heater as a backup to the solar system.
The solar array on the roof preheats cold water before being sent to the tankless propane fired water heater which will heat it up the rest of the way if needed. From here it goes to a series of three 100gallon storage tanks and then is distributed amongst the apartments in the building as needed.
The building houses 78 residents and with staff, about 90 people total. Between the solar hot water system and the propane tankless water heater, 100% of hot water demands are met.
The solar hot water collector array consists of 48 collectors in groups of 3-7 collectors each. Each group of collectors is connected in series, and the separate groups are then connected in parallel.
I was lucky enough to get a tour of the building and the setup by the maintenance guys, which was coordinated through one of my college professors.
Here are some pictures of the setup for your viewing pleasure.
Click on the thumbnails to make them larger.
First is a picture of the building itself from the gas station across the lake. You can see the collectors on the roof, and they are really not that unattractive or intrusive.
The collectors are mounted on the roof in what seems to be the best setup for space maximization
The mounts are rather straight forward, and the condensation you see here in the panels is normal.
The panels were mounted on trusses that went the span of the roof and attached on the ends
I believe these are 4′x8′ panels but did not actually measure them
Collectors in each group are connected together like so:
There are vents in each collector to let moisture from condensation out as they heat up:
And each foot for the mounting has rubber underneath. This is to keep the two dissimilar metals (steel and aluminum) from causing corrosion.
Air vents on each group of collector were closed. The maintenance people said they were advised to do this for some reason or another, and it hadn’t caused any problems yet.
The view was simply amazing.
As suggested by many, the pipes connecting collectors are insulated, and the insulation is covered in an aluminum sheathing to prevent UV degradation
Most groups of collectors had a thermometer installed in the outlet. This one was reading 90 degrees fahrenheit.
As you can see though this was a rather complicated setup. Much more so than most of us will ever have to endure when setting this up on a residence.
Here is a picture of the SRCC rating label on the collectors. Good stuff, I had no idea SRCC ratings were around in the late ’80s. If you want more information on SRCC ratings, check out solar-rating.org
Some of the insulation was degrading. This is an insulated Tee fitting with some kind of plastic around the insulation
Some of the insulation in the panels was degrading too. There was also some corrosion. I still don’t think this is bad for 21 years of service
Here is the only “shady” part of the install (no pun intended). This is an old barrel they put up here to collect any glycol in case of a pressure related blow out.
Here is the Resol differential controller and the Rinnai tankless propane water heater controller (the brains of the operation)
And a large storage tank
And here is the Rinnai tankless propane water heater
A close up of the Rinnai connections:
If you have any questions about the system, feel free to leave a comment here and I will get back to you. We will be doing some data logging to actually figure out how effective this system is.
I also have some diagrams of the system I will scan and upload in a few days.
DIY Photovoltaic Solar Panel Mount
On September 14, 2008 in photovoltaics
I have been getting more questions about the satellite dish mount that I used to mount my solar panel with, so here are some pictures that will hopefully give some more insight.
The original post can be found here: DIY Solar Panel Mount
This is a mount that I removed from a Dish Network satellite dish.
The elevation and skew are marked on the mount in degrees, making it easy to mount your panel at the correct angle. Here is a link to some great info about the Optimum Orientation of Solar Panels
Here is the mount, with the markings for skew visible:
The solar panel will mount to the part of the satellite dish mount with the skew markings on it. I used two bolts, one on each side.
The elevation markings can be seen here. With the mount oriented as it is in the picture, the solar panel would be face down on the table.
Looking down at the mount, you will see this:
The circular part slips over a piece of pipe which can be mounted to your house or set in the ground. Unfortunately I do not have measurements on the mount with me, but will update with them later.
Here is the part where the solar panel mounts:
The whole thing will then rotate about the pipe collar by loosening the elevation bolt.
Another view here:
The side opposite the elevation markings:
This is how the mount would look when mounted on a vertical pipe.
Here you can see that the elevation of the mount is currently set to an angle of slightly less than 40 degrees. (this is after removing a satellite dish from the mount.. actual angle will depend on your location)
Hopefully this information is helpful to anyone looking to use one of these satellite dish mounts to hold solar panels.
Solar Cells — Made In a Pizza Oven
On August 26, 2008 in Solar News
From smh.com.au (The Sydney Morning Herald)
FOR her 10th birthday, Nicole Kuepper received an inspirational present from her parents - her first solar-energy kit.
It sparked a fascination with solar technology that last night led to Ms Kuepper, 23, winning two Australian Museum Eureka Prizes for her scientific research.
She has developed a simple, cheap way of producing solar cells in a pizza oven that could eventually bring power and light to the 2 billion people in the world who lack electricity.
Ms Kuepper is a PhD student and lecturer in the school of photovoltaic and renewable energy engineering at the University of NSW.
“I love working with passionate people who want to help address climate change and poverty by thinking and experimenting outside the square,” she said.
Today’s photovoltaic cells that convert sunlight to electricity are expensive and need sophisticated, “clean” manufacturing plants.
Ms Kuepper realised a new approach would be needed if affordable cells were to be made on site in poorer countries: “What started off as a brainstorming session has resulted in the iJET cell concept that uses low-cost and low-temperature processes, such as ink-jet printing and pizza ovens, to manufacture solar cells.”
While it could take five years to commercialise the patented technology, providing renewable energy to homes in some of the least developed countries would enable people to “read at night, keep informed about the world through radio and television and refrigerate life-saving vaccines”. And it would also help reduce greenhouse gas emissions.
Ms Kuepper said that the solar cells should be of high enough quality to be used anywhere in the world, including Australia.
An advocate of green technology, she gives talks about solar energy to the public, has held miniature solar car races to teach indigenous children about renewable energy, and was a delegate at the 2020 Youth Summit in Canberra in April.
Ms Kuepper was awarded the British Council Eureka Prize for Young Leaders in Environmental Issues and Climate Change and a $10,000 study tour to Britain.
She also won the People’s Choice Award, in which almost 16,000 members of the public voted for their favourite scientist out of six finalists. Twenty Eureka Prizes worth $200,000 were awarded last night at a ceremony at Royal Randwick Racecourse.
Other winners included Professor Robert Clark, of the University of NSW, for quantum computer research, Professor Stephen Simpson of the University of Sydney, for studies of locusts and human obesity, and Professor Matthew England and his University of NSW team for discoveries linking ocean temperature and rainfall.
I can’t wait to see what they have figured out. This could be a major break through.
Necessity is the mother of invention, I suppose..
And with invention, comes innovation. Once this process has been released to the public, others will be able to expand on it to either make it more efficient, or to spur them to create other cheap efficient means of manufacturing solar cells.
Three cheers and six beers for Ms. Nicole Kuepper
New Material to Generate Electricity From Heat - Twice the Efficiency of Other Materials
On July 29, 2008 in General Information
From Renewable Energy World:
Material May Help Autos Turn Heat into Electricity
by Pam Frost Gorder, OSUOhio, United States [RenewableEnergyWorld.com]Researchers have invented a new material that could potentially make cars more efficient, by converting heat wasted through engine exhaust into electricity. The researchers say that the material has twice the efficiency of anything currently on the market.
“We’d been working for 10 years to engineer this kind of behavior using different kinds of nanostructured materials, but with limited success. Then I saw this paper, and I knew we could do the same thing we’d been trying to do with nanostructures, but with this bulk semiconductor instead.”
– Joseph Heremans, Ohio Eminent Scholar in Nanotechnology, Ohio State University.
The same technology could work in power generators and heat pumps, said project leader Joseph Heremans, Ohio Eminent Scholar in Nanotechnology at Ohio State University.
The materials are known as thermoelectric materials, and they rate the materials’ efficiency based on how much heat they can convert into electricity at a given temperature.
Previously, the most efficient material used commercially in thermoelectric power generators was an alloy called sodium-doped lead telluride, which had a rating of 0.71. The new material, thallium-doped lead telluride, has a rating of 1.5 — more than twice that of the previous leader.
What’s more important to Heremans is that the new material is most effective between 450 and 950° Fahrenheit — a typical temperature range for power systems such as automobile engines.
Some experts argue that only about 25 percent of the energy produced by a typical gasoline engine is used to move a car or power its accessories, and nearly 60 percent is lost through waste heat — much of which escapes in engine exhaust. A thermoelectric (TE) device can capture some of that waste heat, Heremans said. It would also make a practical addition to an automobile, because it has no moving parts to wear out or break down.
“The material does all the work. It produces electrical power just like conventional heat engines — steam engines, gas or diesel engines — that are coupled to electrical generators, but it uses electrons as the working fluids instead of water or gases, and makes electricity directly.”
“Thermoelectrics are also very small,” he added. “I like to say that TE converters compare to other heat engines like the transistor compares to the vacuum tube.”
The engineers took a unique strategy to design this new material.
To maximize the amount of electricity produced by a TE material, engineers would normally try to limit the amount of heat that can pass through it without being captured and converted to electricity. So the typical strategy for making a good thermoelectric material is to lower its thermal conductivity.
In Heremans’ lab, he used to work to lower the thermal conductivity by building nanometer-sized structures such as nanowires into materials. A nanometer is one billionth of a meter.
Those nanostructured materials are not very stable, are very difficult to make in large quantities and are difficult to connect with conventional electronic circuits and external heat sources.
For this new material, he and his colleagues took a different strategy: they left out the fancy nanostructures, and instead focused on how to convert the maximum amount of heat that was trapped in the material naturally. To do this, they took advantage of some new ideas in quantum mechanics.
Heremans pointed to a 2006 paper published by other researchers in the journal Physical Review Letters, which suggested that elements such as thallium and tellurium could interact on a quantum-mechanical level to create a resonance between the thallium electrons and those in the host lead telluride thermoelectric material, depending on the bonds between the atoms.
“It comes down to a peculiar behavior of an electron in a thallium atom when it has tellurium neighbors,” he said. “We’d been working for 10 years to engineer this kind of behavior using different kinds of nanostructured materials, but with limited success. Then I saw this paper, and I knew we could do the same thing we’d been trying to do with nanostructures, but with this bulk semiconductor instead.”
Heremans designed the new material with Vladimir Jovovic, who did this work for his doctoral thesis in the Department of Mechanical Engineering at Ohio State. Researchers at Osaka University — Ken Kurosaki, Anek Charoenphakdee, and Shinsuke Yamanaka — created samples of the material for testing. Then researchers at the California Institute of Technology — G. Jeffrey Snyder, Eric S. Toberer, and Ali Saramat — tested the material at high temperatures. Heremans and Jovovic tested it at low temperatures and provided experimental proof that the physical mechanism they postulated was indeed at work.
The team found that near 450° Fahrenheit, the material converted heat to electricity with an efficiency rating of about 0.75 — close to that of sodium-doped telluride. But as the temperature rose, so did the efficiency of the new material. It peaked at 950° Fahrenheit, with a rating of 1.5.
Heremans’ team is continuing to work on this patent-pending technology.
“We hope to go much further. I think it should be quite possible to apply other lessons learned from thermoelectric nanotechnology to boost the rating by another factor of two — that’s what we’re shooting for now,” he said.
This research was funded by the BSST Corporation; the State of Ohio Department of Development’s Center for Photovoltaic Innovation and Commercialization at Ohio State University; the Beckman Institute; the Swedish Bengt Lundqvist Minne Foundation; and NASA’s Jet Propulsion Laboratory.
Pam Frost Gorder is an assistant director of research communications at Ohio State University.
Couple this with some heat from the sun, a wood stove, a propane stove, a clothes dryer, or just about anything else that loses a lot of efficiency through heat output, and things would become a lot more interesting. I’m kind of miffed about the working temperature though, wish it was a bit lower.
