News and commentary about ecodesign, geothermal heatstorage, PAH seasonal storage, urban farming, rainwater harvesting, grey water recycling, natural ventilation, passive summer cooling, energy autonomy, off grid solar comfort, as well as refined prototypes i am currently building.
Onshore Wind Is The Cheapest Electricity Generation Option In Europe | CleanTechnica
These estimates are for Europe, but Neto suggested the cost
difference is even greater in the US, where recent contracts have been
struck between $20/MWh and $40/MWh. That’s despite the so-called shale
gas boom, which brought down costs of gas-fired generation for a short
period, but still cannot compete with wind.
“It is clear, more and more, that our product (wind energy) is good,
not just because it is green, but because it is cheaper,” Neto told the
analysts. (You can see the presentation here). He
said wind energy is also cheaper than gas in key emerging markets such
as Brazil, South Africa, Mexico, and major Asian markets.
Neto admits that the short-term outlook in Europe remains challenging because there remains a misperception.
He might have been referring to the likes of former Queensland
Treasurer Keith De Lacy, who in the front page lead for The Australian
today said renewables had “no place in a modern society.” And he might
have been referring to people like Institute of Public Affairs’ Alan
Moran, who insists that that wind energy is “three times” the cost of
coal.
Neto says “the less educated” typically refer to the spot price, but
this only reflects market dynamics and the level of supply and demand,
not the cost of the technology. New build coal is also “three times the
market price.”
iframe width 480 height 270 src //www.youtube.com/embed/PST3HysmSPk frameborder 0 allowfullscreen> /iframe>
As more and more contaminated water gets dumped into the ocean, listen to this well qualified woman talk about the currents and the health effects, very informative!
Public Lab: Mobius NDVI
In my quest to get good NDVI images from an Infragram-modified Mobius ActionCam, I previously found white balance settings that produced photos with color histograms like the ones for good Infragrams taken by Infragram-modified Powershots. I used the program mSetup on Windows
to install the white balance settings on the Mobius via USB (Mac and
Android solutions are also on that page). Yesterday I took a series of
test photos to see if those white balance settings produced useful
photos. I took photos of the test scene in the topmost image with these five
cameras. The four PowerShots have internal filters and the Mobius has
no internal IR filter but has a holder for filters in front of the lens.
All cameras have plates for easy attachment to a Manfroto tripod.
.
The dual camera system with an unmodified A495 and a pure near-infrared
A495 generally produce the best DIY NDVI images I have seen. So that
result is presented below as the benchmark. Ned's Fiji plugin was used
to align the two photos and compute NRG and NDVI values for each pixel
after stretching both histograms (parameter=2). This stretch parameter,
and the same color table, were used on all of the NDVI images below, and
no other adjustments were made on any of the photos or NDVI images.
. Photos from an unmodified A495 (top left), a pure NIR A495 with
Wratten 87 filter (top right), and a false color infrared image (NRG)
and Normalized Difference Vegetation Index image (NDVI) derived from
those two photos. Green plants are well differentiated from non-plants
in the NDVI image. This is a high resolution image, right click to
enlarge in new tab.
.
The Infragram-modified PowerShot A2200 with Wratten 25A filter produced
an NDVI image that differentiated plant and non-plant about as well as
the dual camera system. This camera was white balanced on red origami
paper in full sun, and was used in the calibration of the white balance settings for the Mobius.
. Super-red Infragram photo from a Canon A2200 and the NDVI image derived from that single photo.
.
The Infragram-modified PowerShot A2200 with glass BG3 filter also
produced an NDVI image very similar to the one from the dual camera
system. This camera was white balanced on blue origami paper under blue
sky in the shade, and was used in the calibration of the white balance settings for the Mobius. The BG3 filter is similar to the Rosco 2007 filter.
. Infrablue Infragram photo from a Canon A2200 and the NDVI image derived from that single photo.
.
The Mobius camera with Wratten 25A filter produced an NDVI image that
differentiated plant and non-plant about as well as the Powershot
Infragram cameras. The white balance setting for the Mobius was the one determined empirically by comparison with histograms of the PowerShot Infragrams. This setting is: red 310, green 500, blue 700.
. Infrablue photo from the Mobius ActionCam with Wratten 25a filter
and the NDVI image derived from that single photo. The Mobius has a a
much wider lens than the PowerShots, so these images are cropped for
comparison.
.
The Mobius camera with Rosco 2007 filter produced an NDVI image that
was quite meaningless. The white balance setting for the Mobius was the
one determined empirically by comparison with histograms
of the PowerShot Infragrams. This setting is: red 690, green 500, blue
240. The NDVI image sort of differentiates between plant and non-plant,
but NDVI values are consistently higher for non-plants than for plants,
which seems to be a serious flaw. I don't yet understand what's
happening here, but the process of determining white balance settings
that worked for the red filter gave very different results for the blue
filter.
. Infrablue photo from the Mobius ActionCam with Rosco 2007 filter and
the NDVI image derived from that single photo. The Mobius has a a much
wider lens than the PowerShots, so these images are cropped for
comparison.
.
I tried several combinations of white balance settings and also tried
a Wratten 47B filter (not shown), but did not find a combination that
produced useful NDVI images. I also have not come up with a hypothesis
to explain the failure of a blue filter to produce usable NDVI
information when a red filter works very well.
. NDVI images with different white balance settings in the Rosco 2007
Mobius ActionCam. NDVI values for non-plants are generally higher than
for plants. The lower right image has this pattern somewhat reversed and
is the best version I have produced.
.
It might be possible to find settings that produce somewhat better
results with a blue filter. But a red filter seems to work well, and
there are other important reasons to use a red filter instead of blue. So the next task is to find a red filter that is less expensive than antique Kodak Wratten 25A gelatin (Rosco Fire, please).
.
Critics of lithium-ion batteries (and there
are many) have plenty of arguements in their corner. These batteries run
hot – hot enough to cause the occasional fire.
They take a long time to recharge. They are expensive and have a
limited life cycle. When they are used up, they become potentially
hazardous waste. Is this really what the world wants to depend on for
its transportation needs?
The folks at Japan Power Plus don’t think so.
They have just announced the all new Ryden battery, which is made
primarily from cotton. Yes, you read that right, the fabric of our lives
has become a battery. Ryden in Japanese translates into “god of
lightning.” For the new battery, cotton fibers are modified to create a
new form of carbon fiber unlike any ever seen before, according to Chris
Craney, JPP’s chief marketing officer. The modified cotton forms the
anode and cathode of the Ryden battery an organic fluid is used as an
electrolyte.
Why is this a big deal?
Several reasons. The Ryden battery recharges
20X faster than its lithium based cousins. It lasts through many
thousands of discharge cycles. It does not run at high temperatures, so
no cooling system is required. All its components are organic and
recyclable. Most importantly of all though, it should be cheaper than
lithium-ion batteries once full-scale production begins.
And when will that be? Well, the
basic research dates back to the 1970′s, and JPP has been working on the
project for more than 6 years. So the Ryden battery won’t be on the
shelves at your local auto parts store anytime soon. But if the folks at
JPP are right, their cotton battery could do for electric vehicles what
gasoline did for the auto industry.
If you missed out on Apple or Microsoft, this
might be a good time to pick up a few shares of JPP, before everyone
else finds out.
My
interest is in using the glass evacuated tubes not as a component of a
commercial collector, but as an insulated collector for a DIY parabolic
trough concentrating collector. With the addition of a rotatable
tracking parabolic trough behind a single evacuated tube, it is possible
to increase the heat capture significantly, up to 8-15x safely. In this
manner, it would be possible to do things that are not possible with a
flat plate or an evacuated tube system - making steam for example. In a recent demonstration I showed that temperatures of over 630°F are possible on an experimental DIY basis. Please see Wikipedia
for a backgrounder on evacuated tube solar collectors or Google
"evacuated tube solar" or "solar vacuum tubes". Much has been written
about this method of solar heating that seems to be popular elsewhere
than North America.
(click any picture to enlarge)
Searching
the web reveals numerous manufacturers and truly, there are many.
Evacuated tube collectors are widely produced in large volumes, mostly
in China and India. Here are some that I found which give some specific
information on tube specs and various details about the tubes.
These are not my recommendations, just suggested links for further information:
First, a video from Apricus showing manufacture of evacuated tubes in their Chinese plant:
Links to other manufacturers websites:
Haining Jixang Solar Energy Co. Ltd.
Haining, Zhejiang. Schroll down the page for the specs. Note the
diameters and lengths OD 47mm and 58mm, lengths of 1500 and 1800mm - you
will be seeing these again. Select "heat pipe" on the left menu and you
will see the specs for the heat pipe. Note Transfer power:≥150W. Check
out the wide variety of their systems.
Haining Qiruite Photoelectric Co. Ltd. (Qirui)
Haining, Zhejiang. A bit hard to understand in the English, but the
same sizes can be seen about half way down the page. Do they make a 70mm
dia? The length looks like a mistake.
Jiaxing Jinyi Solar Energy Technology Co., Ltd. (Jinyi)
Jiaxing City, Zhejiang. Produce standard (JVN series) evacuated tubes
with IDs of 37mm, 47mm, 58mm, lengths 500mm 800mm 1500mm 1800mm 1900mm
2000mm 2100mm. Have advanced (JVT series) three coating tubes.
Zhejiang Qianjiangcho Luminous Energy Co.
Haining, Zhejiang. Seem to be redoing their web page, seems less
complete than when I last visited and got specific sizes and lengths.
Have three different types of coating systems available in their "vacuum
tubes". ID's 37mm, 47mm, 58mm all +/- 0.7mm, corresponding ODs 47mm,
58mm, 70mm, standard lengths 1200, 1500, 1700-1800 and 2000mm all
+/-5mm.
Patrick Ward of Fossil Freedom, Denver, CO? sells recycled US Government surplus evacuated tubes 45.75"/ 1160mm long.
If you like the idea of an evacuated tube which is open at both ends with expansion bellows fitted: Dezhou Mingnuo New Energy Co., Ltd., Dezhou City, China offers a 4000mm receiver tube of this type.UPDATE: The link no longer works. I have written to the company to get info."Sun Island" Haining Chaoda Solar Collector Tubes, Ltd
is another manufacturer. These do not have bellows, or an absorptive
coating. Open both end tubes are rare and you would have to import a
case lot. The open at one end tubes are much more commonly available, at
least in North America. I searched "open both ends solar evacuated
tube" to find these.
The
(open one end) tubes that I have measure ID 43.5mm OD 58mm and 71
inches (1803mm) including the pinch off but not including the heat pipe.
This seems to be a size common to at least three of the manufacturers
listed above, so we could assume this size might be also available from
others? I cannot find a specific international specification for the
tubes alone. If anyone knows this spec, please let me know.
For
me, the length of 1800mm (5.9') is a convenient size for my standard
parabolic reflector with a 4 foot length. About a foot of evacuated tube
sticks out both ends of the concentrator which helps to suspend it in
place at the focus. Fluid and electrical connections are made to the
internal absorber at the open end. The diameter is critical for the max
size of absorber I can insert into the evacuated tube. 43-47mm seems to
be a fairly standard size.
I
can only give pictures of the construction of the evacuated tubes that I
have at hand but others I have seen, although different in some of the
details, are similar. Here I am removing the "guts" of the tube by
pulling on the bulb of the heat pipe. With this particular tube, the
innards pulled out readily. With others, the heat pipe (the copper tube
assembly in the center) comes out of the aluminum absorber leaving it
behind in the evacuated tube. With those, I had to pick away at the
fiber glass "bung" until I could grab the absorber with pliers and pull
it out.
Here
is an end view of the aluminum absorber. The heat pipe is held in the
center of the evacuated tube, supported down it's entire length by this
formed sheet aluminum part with also improves heat coupling from the
inside wall of the evacuated tube to the heat pipe.
In
this view, I have shown the bulb end of the heat pipe. The heat pipe
dia is 0.317" / 8.04mm. The bulb dia is 0.943" / 23.97mm and has a
length of approximately 3.905" / 100mm. The fiberglass bung can also be
seen.
Here
is the other end of the heat pipe, the aluminum absorber support and
the evacuated tube. The evacuated tube has a shiny metallic "getter" on
the inside which will be familiar to readers old enough to have worked
with electronic vacuum tubes. The getter is a metallic coating which
removes impurities in the vacuum after the tube has been sealed. It is
also a diagnostic for the quality of the vacuum since it will turn to a
powdery white appearance as it is depleted. If the vacuum is good the
getter will be bright and shiny like this one.
The
bung which seals the top of the evacuated tube is a powdery brittle
compressed bit of what looks to be fiberglass? Hopefully it is not
asbestos? It basically flakes apart when you remove it so is not
reusable. Winding fiberglass pipe wrap into a cylinder was found to be a
useful replacement for the bung and also able to accommodate an inlet
and an outlet tube as was done for the test of an insulated concentrator. So
where do you get yourself some evacuated tubes for your own
experiments? I don't think that you will yet find these at your local
home center unless you are in the southwest USA or Mexico.
You
could begin by writing to the companies listed above and any others you
find and asking them about dealer/installers in your area. Look at your
local sources for solar domestic water heating. You might be interested
in a complete system, but for the purposes of a DIY project, we only
really need a source for a few tubes, initially at least.
The
tubes are relatively inexpensive. A solar dealer installer will
typically offer this information readily if you ask what happens if a
tube breaks (what if my kid throws a baseball through one? or a hail
storm breaks some?), replacements will be required. The installer should
keep a supply of spare evacuated tubes for this possibility and he/she
will probably tell you something like "don't worry the tubes are only $X
dollars each". I have heard $10-25. Find out what sizes the dealer
carries in stock and have a look if you can at the heat pipe
construction and coupling to the glass tube. Find out if they use a
non-freezing fluid or water with some chemicals. Use the information you
get from the dealer or several to determine the price you are willing
to pay in your area and the most convenient supplier and then ask to buy
a few tubes. You will get raised eyebrows perhaps, but you should get
your tubes at a reasonable price. We don't really need the heat pipe
unless you want to use it that way.
The tubes are certainly
breakable and long and thin so getting them locally is a plus unless you
want to buy a box lot as I did and deal with shipping costs.
georgesworkshop: diy solar parabolic trough gen2 intro Gen2 design goals: Simpler hand or machine made ribs
In the original version, there were three different types of ribs - now
one rib does all three jobs. The new rib is simpler and lighter.
Thirteen can be made from a 2x4' (30x60 cm) sheet of material, only
seven of the original could be made from a sheet this size. The ends of
the rib are simplified to suit angle profile side channels which should
be available anywhere.
I show the methods I use to make small
quantities by hand using patterns. I provide .dwg files for CNC laser or
water cutting for larger quantity production.
(click any pic to enlarge)
Simpler side channels
I show how to use a standard angle profile in a very strong and precise
joint that can be made by hand or machine. Different materials can be
used, to suit what is locally available. The resulting reflector
assembly is robust yet light weight and completely grips the reflective
sheet along the long edge and supports it accurately from below. Better balance, more efficient
Each reflector assembly is balanced before installation. Balancing
ensures that minimal force and therefore energy is required to position
the array. In this way, different material can be used and the assembly
adjusted just once for any resulting balance shift. I think I should be
able to swing up to 25 reflectors with the existing motor drive with
this new method.
Insulated, high temperature collector option I show how to suspend a standard glass evacuated tube
at the focus and use it as a large thermos bottle to surround the
collector. Higher temperatures and or winter use are thus made possible
with this design. A ball bearing support and a much
stiffer reflector frame will make high altitude use possible (near
vertical mounting). You can use this either insulated or not. Flexible size I will show you how to make several different sizes of collector. All are based on the same parts. You can make this in your garage You need some basic woodworking tools. I have improved some of the methods. It will take less time to make. Please show your support by buying my books. My work is supported by book sales. Perhaps you've noticed that I haven't monetized these pages (no ads)?
The index at the top of this page takes you to articles on this blog about gen2.
Thanks as always for your feedback and Thank You for your interest.
George Plhak
Lion's Head, Ontario
Canada
World’s Largest Solar Array Set to Crank Out 290 Megawatts of Sunshine Power - Scientific American
The plant comprises more than five million solar panels that span the
equivalent of two Central Parks in the desert between Yuma and Phoenix.
It generates 290 megawatts of power—enough electricity to fuel 230,000
homes in neighboring California at peak capacity. The Agua Caliente
Solar Project represents a significant advance in the technology
compared with just four years ago, when the largest solar facility in
the U.S. generated only 20 megawatts. “Solar has completely arrived as a
competitive energy resource,” says Peter Davidson, executive director
of the Loan Programs Office at the U.S. Department of Energy (DoE).
The project, which cost a total of $1.8 billion to construct, received a
million-dollar loan from the Loan Programs Office. Under its “SunShot”
initiative (so-named in the spirit of president John F. Kennedy’s “moon
shot” program), the DoE provides guaranteed loans to unproved ventures
in solar power in the hopes of promoting innovation and making the
technology more cost-effective.* Although Agua Caliente (owned by U.S.
energy giant NRG Energy and partner MidAmerican Solar) is now the
largest photovoltaic solar facility in the world, it probably will not
hold that distinction for long. Other massive solar panel facilities,
such as Antelope Valley Solar Ranch One in California’s Mojave Desert,
are rapidly springing up across the Southwest. “This series of large
plants that are being built really mark the transition from the
technology being something experimental to real energy on the grid,”
agrees Robert Margolis, a senior analyst at the National Renewable
Energy Laboratory (NREL). Solar power currently accounts for 1 percent
of U.S. energy production, but it is the fastest-growing sector of the
energy landscape. Margolis says that Agua Caliente proves that investing
in solar power on a large scale is an effective way to make it more
viable in the current market.
The energy contained in just one hour of sunlight could power the world
for a year, if only it could be harnessed. Traditional solar panels made
from silicon—the gold standard of semiconducting material—are
expensive, however, particularly in comparison with cheap but dirty coal
and natural gas. Agua Caliente, which is operated and maintained for
NRG by Tempe, Ariz.–based First Solar, uses newer, thin-film panels that that absorb the same amount of sunlight with a fraction of the material, boosting the array’s efficiency.
The Arduberry is a shield for the Raspberry Pi that connects Arduino Shields. You
can think of it almost as an Arduino, built for the Raspberry Pi. The
Arduberry connects to the Raspberry Pi with the standard 26 pin header.
The shield has an Arduino UNO-compatible microcontroller on it, as well
as standard pins for an Arduino shield.
The Arduberry requires virtually no hardware setup: slip it
onto the Raspberry Pi and go. It ships ready to work. The Arduberry
comes fully assembled, and you won't need to make any changes to the
hardware (no pinning, no batteries, no nothing!).
The Arduberry microcontroller can be programmed to run on it's own and access Arduino shields.
Shields that use digital communications can be accessed directly by
the Raspberry Pi, while shields that use digital or analog pins can be
controlled by the Arduino. The Arduino chip on the Arduberry can
communicate directly with the Raspberry Pi with no extra setup required.
The Arduberry from above.
The Arduberry from below.
How Does it Work?
You can program the Arduberry directly on the Raspberry Pi. With
the latest version of Arduino, you can directly copy most of your
Arduino sketches over to the Raspberry Pi with no modifications.
Program your Arduberry right on the Raspberry Pi.
While most shields can work directly with the Raspberry Pi, some
sketches, like those that use analog signals, will need slight
modification to the sketch to be able to relay information on to the
Raspberry Pi. We will create a tutorial that walks you through how to
adapt those sketches.
Our design uses an extended header, which is left open for
expansion and testing. The Arduberry has a special chip for translating
voltages between the Raspberry Pi and the Atmega 328 chip, protecting
your hardware.
The Arduberry's microcontroller is most similar to the Arduino UNO
with an Atmega 328 and Arduino UNO bootloader installed. The device has
a shield footprint almost identical to the Arduino UNO. We used a DIP
(pin rather than SMT) device for flexibility and to make the
microcontroller easy to replace.
The Arduberry Pinout.
The device is powered through the Raspberry Pi. For projects
needing a little more power, you can connect an auxiliary power supply,
or power the Arduberry through a USB micro adapter.
All rewards include the cost of shipping via USPS. An additional
cost is added to each level for international shipping. All of our
backers, no matter what the level they back at, will receive recognition
and thanks on the Arduberry's Wall of Thanks.
The Arduberry Board.
The Arduberry Board
The main show here. Fully assembled and programmed board for
adapting your Arduino shields to your Raspberry Pi. At the most basic
level, this is all you need to get your Arduino shields working with the
Raspberry Pi.
The Arduberry Image.
A 4GB SD Card with the latest build of the Raspbian Operating
System, the Arduino programming language, and Arduino examples
installed.
Power Supply.
5V, 1A power USB jack for powering your Raspberry Pi and Arduberry.
This is a North American power adapter with an input voltage of 100 -
240 V.
Inventors Kit.
The inventors kit is meant to get you started in developing your
own shields and electronics for the Raspberry Pi. It includes an Arduino Protoshield Kit from Sparkfun,
a breadboard, and the following electronics for getting
started: 74HC595 Shift Register, 2N2222 Transistors, 1N4148 Diodes, DC
Motor with Gear, Small Servo, SPDT 5V Relay, TMP36 Temp Sensor, Flex
sensor, Softpot, Jumper Wires, Photocell, Tri-color LED, Red and Yellow
LEDs, 10K Trimpot, Piezo Buzzer, Big Buttons, 330 and 10K Resistors.
Who are you?
We are Dexter Industries
and our team makes educational robotic stuff. We were founded by John
Cole, an engineer who had never touched a soldering iron before 2009,
but had a burning desire to make robots. When we saw the Raspberry Pi,
we saw the future and ordered six of them.
A corollary to your question might be: why are we capable of delivering the hardware?
We've been working with contract manufacturers for the past few years.
That's not to say that we know everything about manufacturing, but it
is to say that we know who we're going to use on this project. We have
worked with the manufacturers on projects more complex than this, and we
have faith they can deliver only because they do it for us on a monthly
basis already.
Why Are You Doing a Kickstarter?
Like our previous project, we want to build a community around
Arduberry, and get feedback on our project. We believe that the best
projects are responsive and the work of many, not just two nerds working
alone. For that reason, we wanted to get this project out of our
heads, and in the open. We think Kickstarter is the best way to do
this.
Why is the design open? Aren't you afraid someone's going to steal it?
The design is open because we genuinely want to contribute to
learning, and the best way to do that is to show your work. We want to
honor those that made this project possible, in particular the brave
folks that open-sourced the Arduino and the Raspberry Pi. Like all
things in the Arduino and Raspberry Pi community, we hope that people
will use this, and make it better: it raises our game.
Even more importantly, we hope that whoever uses the Arduberry, moves
the open source community forward, and helps folks make their hacking
dreams come true.
What Have You Done and What Is Left To do?
We have hand-made prototypes, and a growing library of examples with
the Arduberry. We have had the design reviewed by manufacturing
engineers for mass production.
If this product is successfully funded, our focus will be on three
things:
Developing software examples. We have found that the best way to
learn with software is to follow examples. We want to produce a solid
library of examples with different shields to make sure Arduberry users
have an easy start. Doing this takes developer time and effort.
Developing tutorials for getting started. Furthering goal number
1, we want to make sure we develop tutorials for a few of the most
popular Arduino shields to ensure that its easy for most folks to get
started with the Arduberry.
Developing a custom image for the Arduberry. The Arduberry needs
a few changes made to the Raspbian image to operate. We found in our
previous project that some folks prefer to have the changes to the image
already made. In order to make the Arduberry as easy to use as
possible, we will develop a custom image for download that will allow
users to get started right out of the box, with minimal setup.
Hardware Delivery Timeline
The timeline can always be affected by the unexpected. However, we
have carefully pre-coordinated our timeline with our manufacturer for
production.
For our project we anticipate the following timetable.
We plan for the campaign to end on approximately 2/14/2014. We will
immediately formalize the order with our manufacturer and begin material
procurement. We need a little under 30 days to secure the PCBs and
components. We allow a 7-day prototyping window in which a sample is
delivered by the manufacturer and approved by our team. Production
afterwards should take 10 days, with an extra 2 days of testing and
QA/QC. Finally, we allow for 14 days of shipping from Asia to the US,
where our team will ship the rewards.
Software Delivery Timeline
We will prioritize the development of the Arduberry Image. We have developed an initial install script (found on our Github site) and will finish testing this mid-campaign. We should have final changes to the image done by the end of the campaign.
We plan to finish the software examples and tutorials by the time the Arduberry is shipping so that it will be ready for backers receiving their rewards.
Hi, I’m starting a business in manufacturing arduino/raspberry pi
compatible electronic ammonia sensors. Does this sound like something
that would be useful to your project? I’d love to hear your feedback
whether it’s something you would want or not.
Feel free to email me with inquiries: jonaheskin@gmail.com
jonah – this is very interesting idea. Ammonia is important in
aquaponics, but up to this point sensors and solutions have been very
expensive and/or non existent at the micro-controller level and required
a lot of technical knowledge to perform this function. Ammonia would
be great to capture data points on, but it is not the most important
aspect to be tracked in aquaponics. I can look at my fish and tell very
quickly if I have a problem. So the ammonia sensor would be a nice to
have in combination with Nitrates and Nitrites to track the peaks and
valleys of the cycles. As everything in life there is a cost associated
with the convenience. As in the presentation I made at the
international conference in Denver in 2012 my top tier sensors are temp –
water levels and how they impact relays and valves. I am all about
water level control more than environmental factors. I can monitor
those on an as needed basis. Would I like the data – you bet, but at
what cost and how easy of a solution is it to implement. Right now I
will put my money into automation of pumps and valves first then work on
environmental monitoring as cost effective sensors and code are develop
for the micro-controller platform. Would love to check out your
efforts. So will send you a request to learn more at the email you
provided. rik
In Rural Kansas, an Experiment Makes Hitchhiking Safe Again by Jennifer O'Brien — YES! Magazine
What I love best about the sharing economy is how it squeezes good
value out of the unused bits of our society that would otherwise go to
waste. And nowhere do you have so much waste as in our
transportation system. A personal car uses less than 1 percent of its
energy to move a passenger, and 80 percent of our passenger capacity
is driving around empty.
That’s hundreds of millions of empty seats in this country!
Meanwhile, 45 percent of the country has no access to transit. What a
perfect opportunity to share!
Of course, plenty of smart people are already employing new
Smartphone apps to put those empty seats to work. For example, I could
use the Lyft or Uber apps to call up a citizen taxi, or download the
Carma app to share my morning commute. That is, I could do these things
if I lived in a big city like San Francisco or Austin.
Unfortunately, I live in rural Northeast Kansas where we have neither
transit, nor the critical mass of people needed for those apps to
work well.
Hitchhiking is an easy, cheap, and flexible way to get around—in many countries it's a primary mode of transit.
We denizens of the countryside have historically accepted a big
trade-off. Peaceable enjoyment and low housing costs come at the price
of a tremendous amount of driving. And when the car is our only
option, we are incredibly vulnerable to fluctuations in the price and
disruptions in the supply of gas. I spent two years grumbling about
all the driving, but feeling helpless to do anything about it.
Then I heard a radio podcast about hitchhiking and how it’s not
nearly as dangerous as the media have led us to believe. The point was
made that hitchhiking is such an easy, cheap, and flexible way to
get around—in many countries it's a primary mode of transit. So the show
argued, we should give it another chance. For some reason, this
idea grabbed me so fiercely that I thought about little else until I had
designed a way to do just that—mainstream hitchhiking and make it
safe, easy, reliable, and fun. What I came up with was a nonprofit
organization that I called Lawrence OnBoard.
Here’s how it works: participants can sign up as riders or drivers or
both. Drivers can sign up for free. They get a window cling with their
member number. Riders pay a membership fee and we provide them with a
background check, a photo ID and a folding dry erase board branded with
the club logo. The rider can write his destination on the board,
stand by a safe roadside, hold up the board and wait for a passing car
to stop. The rider can then text in the driver’s member number (or
license plate number if the driver is not a member) to Lawrence OnBoard.
That makes a record of the ride which is important as a safety
backup, as a way to leave feedback and it enters the driver in a drawing
for a prize. The prize is a fun incentive for the driver that doesn’t
require an awkward cash transaction and doesn’t turn the driver into
an unlicensed taxi service. Lawrence OnBoard will provide training, a
map of good locations, and a marketing campaign.
With the power of the sharing economy, we now have the chance to build a brand new model for public transportation.
That’s the plan, and in 2013, I conducted field tests to see if it
could work. Twenty-three volunteers went out on 121 test rides in and
around the Lawrence area and the results were pretty astonishing.
Even with random strangers picking up, 95 percent of the volunteers got a
ride in less than half an hour, and our average wait time was less
than seven minutes! In some prime locations, we could reliably get a
ride in less than two minutes. When I saw these results, I know we
were onto something.
I personally used my dry erase board to commute to town for most of
the summer and I found that it was safe, easy, and reliable and saved a
lot of gas. But even better, I met more of my neighbors, learned
what was happening in the neighborhood and even made a couple of
business deals. Building community like this is the big strength of
the sharing economy and it’s something we are sadly missing when we all
drive alone.
Of course, this ridesharing concept does have its limitations. One
shouldn’t do it at night, it’s not good for transporting small children,
and riders need to be over 18 and use good judgment. We still need
to conduct another season of research to back up the preliminary
findings and continue to test and map good locations to ride from.
We’re also raising funds through grants and some crowdfunding to launch a
pilot, hopefully before the end of the year. You can help our efforts
by making a donation at RocketHub.
Americans are eager for better transportation solutions. The carless
college students in Lawrence, environmentally conscious families who
want to pare down to one car, and populations who can’t drive are
especially interested in this project, since it focuses on short, local
trips.
When I presented the research findings to the Transportation
Research Board I got an enthusiastic response from transportation
professionals all across the country. Lawrence OnBoard has been
featured on podcasts, public radio stations, blogs, and the news. Most
recently, we were named a finalist in the TEDxFulbright Social
Innovation Challenge and got to pitch the idea on a TED stage!
We are so fortunate to live in this modern age. With the tools and
technology currently at our disposal and the power of the sharing
economy, we now have the chance to build a brand-new model for
public transportation. Imagine a network of neighbors driving neighbors.
This network is nimble and can fill in the gaps between trains,
buses, and bikes. It’s cheap and efficient because it makes better use
of the cars already on the road. And it’s a transportation system
that’s built on our best resource: our human kindness.
Check out on our progress at www.lawrenceonboard.org.
See you on the road! Jennifer O'Brien wrote this article for Shareable.net,
where it originally appeared. Jennifer is CEO of the nonprofit Lawrence
OnBoard, and the owner of CASA Kids Studio in Lawrence, Kansas.
Aquaponics is the use of waste produced by fresh water fish, shrimp, prawns, crabs or lobsters to grow plants. Live fish are used to make fertilizer which produces ammonia that is high in nitrogen and is essential for plant growth. In return, the plants filter the water so that fish can live in it.
Tilapia is the most famous fish that reproduces and grows fast in an aquaponic system, but you can even start with a pair of goldfish. You can either leave the plants floating on the top of your tank or direct the water through pipes using an air pump to your grow-bed that holds plants with a growing medium. Water is then directed back into the tank to complete the tank cycle.
“Aquaponics is a quick, simple and cheap way of growing your food, and you don’t even need a green thumb!” says Abdul Aleem Shekhani, an aquaponicer from Karachi. Shekhani set up his first system in 2010 using his mother, Nasreen Ashraf’s storage boxes and store-bought PVC pipes, fish and other aquarium equipment. After two years, he upgraded his system and bought used bathtubs to turn them into a fish tank. The garden now produces everything from tilapia to cherry tomatoes to giant melons, unlimited sponge gourd, lots of basil and oregano. The set-up can cost anywhere between Rs1,200 and Rs1,500 and may even be cheaper if you reuse supplies.
“The only thing I do regularly is feed the fish and harvest vegetables when they are ready,” says Ashraf who also has a rooftop kitchen garden which needs much more work. “Vegetables that I grow using aquaponics have larger, greener and healthier leaves compared to the ones in the pots.”
Even though the method is relatively new, it is picking momentum globally. Ellezerdo Sarsalejo is a Philippines-based aquaponicer, who lives a few miles away from where the typhoon hit last year. He built a system using PVC pipes, barrels and large water bottles. Unlike Nasreen and Aleem, he did not use any edible fish. Within 75 days of starting his backyard aquaponic system, Sarsalejo was able to harvest dozens of bitter gourd which is remarkably quick. “You can double or triple your harvest if you have a good system,” he says. “I started an aquaponic system back in September 2011 as an experiment and since then it has been very successful.” Now Sarsalejo grows all kinds of vegetables and herbs, including cherry tomatoes, lettuce, basil, eggplants, huge beans, okra and bitter gourds that grow fast using his aquaponic set-up.
It is a well-known fact that during 1150-1350 CE, Chinampas — an ancient agricultural method which used rectangular areas of fertile land to grow crops on shallow lake beds — produced one-half to two-thirds of the food consumed by the city of Tenochtitlan, including maize, squashes, amaranth, tomatoes, peppers and beans. Hence, aquaponicers might be justified in claiming that the method can feed the world one day.
Zahra Ali Husain is a sustainability education specialist, writer and an environmentalist. She tweets @Zahrali
Published in The Express Tribune, Sunday Magazine, February 23rd, 2014
First you need to drill planting holes in the biggest tube. These
have to fit plants through, so you need to cut out circles of around 5cm
diameter. They need to be big enough for the plant to grow from but not
so big they fall out. Once the roots take hold, they will become more
stable.
Then drill small holes in the thin tube. This will act as the watering device, so the holes only need to be small.
Place the large tube in the pot, filling the bottom few centimetres
with gravel for drainage and the rest of the pot with compost.
Place the small tube inside the large tube, and fill the layer
between the two tubes with compost. Do no cover the top of the small
tube.
You can now plant through the large holes into the compost.
To water, pour into the small tube.
From Edible Cities: image by Bernhard Gruber
2. Grow in a pallet
All you need is:
An old pallet (make sure it isn't a chemically treated one, find a heat-treated or untreated pallet)
A roll of landscape fabric
A staple gun and staples
About 2 bags of compost
Flowers, herbs, plants
First you have to cover the bottom, back and sides of the pallet with
the fabric. This prevents soil and the plants from falling out. The
only sides to stay uncovered are the top and the front, where the spaces
between the slates are (this is where the plants go).
It can be good to double up the fabric, so it is thicker and stronger. Staple the fabric around the edges, along the top, the sides and the bottom. Make sure you hold the fabric taut before you staple, and check
that the fabric is secure, so that no soil will be able to fall out.
When planting up the pallet, move it close to where it will finally stand and lay it flat so that you can fill it.
Place the plants where you want them along each row, planting tightly
so they cannot fall out. Fill around them with compost, making sure
they are held in tightly, but without damaging the roots. It can be
easier to plant the top layer first as they grow upwards, and then
continue with the lower rows where the plants grow outwards.
It is a good idea to leave the pallet flat for a few weeks, regularly
watering until the roots have begun growing. This will ensure the
plants stay in place when you lift up the pallet.
3. Plastic bottle tower
These can easily be made with recyled bottles and some scissors or a sharp knife.
All bottles need their caps, as these become part of the watering process.
Firstly drill a small hole in the centre of each bottle cap.
Then cut the bottoms off the bottles, around 2cm off.
Take the first bottle, turn it upside down, cap downwards, and fill
with compost. Be careful to not pack the compost in as it will need to
be loose enough to plant into.
Secure the bottle to the wall or structure it will be next to. As
shown below, a suitable wall or structure could be mesh or netting, as
the bottles can easily be secured with cable ties. You could also tie them to a strong length of string or thin pole that is secure.
Place the next bottle, cap down into the first and fill this one with
compost, then tie in the bottle. Repeat this process until you have the
desired height.
Once filled, each bottle needs a hole cut for the plants. Here a
knife can be more useful than scissors. The hole doesn't want to be too
big, but take a look at the root system of the plants and gauge the size
from them. You don't want to be squeezing the roots in and damaging
them.
Once the holes have been made, your salads, herbs etc. can be planted.
When watering, water from the top, and it will soak through each layer, through the holes cut in the bottle caps.
4. Trellis
The trellis is a well known structure for growing plants vertically.
They are great for many plants, especially climbers. You can grow beans,
squashes, vines, cucumbers and more!
You can build them from wire, bamboo and all kinds of wood. They can
be an arch like the photo below, using the edge of two beds and the
vertical space above the walkway, or they can run up the side of a wall.
They are easy to make to the needs of what you are planting.
Denmark leads the charge in renewable energy | By 2020, the country aims to produce 70 percent of its energy from renewable sources and to make the switch to renewables completely by mid-century. "Today, we're already at 43 percent," said Kristoffer Böttz
But offshore wind farms alone are not enough to meet energy demands, and
so wind power projects have also been expanded on land. Local
resistance to growing wind power plants often prevented further
development in the past, but in 2008 the government introduced new
requirements that brought about greater acceptance.
For example, said Böttzauw, residents are now directly compensated for
any loss. If a house loses its value after one of the 150-meter high
wind turbines pops up nearby, the operator must compensate homeowners
for that loss. In addition, at least 20 percent of the shares in the
project must be offered to local residents, giving them a direct stake
in the investment.
Finally, said Böttzauw, the community receives a direct allocation per
megawatt of power generated. All these measures have greatly increased
acceptance of wind farms in the local community, he said, as they "bring
direct benefits to the community and its citizens if they give their
support."
Benefits for local citizens have led to greater acceptance of wind farms
The Danes have also taken into account objections to increasing power
lines, solving that problem with underground cables. Böttzauw admitted
that it's an expensive solution, but said locals could not be expected
to put up with new utility poles in addition to the towering turbines.
The only exception will be the large offshore wind farms, which will
make use of three new power lines to distribute electricity throughout
the country. Intelligent storage concepts
Böttzauw admitted that the biggest problem with the abolition of fossil
fuels will be in the transport sector. But, he said, increased
electromobility will help solve the problem. "You can't decide when the
wind blows," he said. "But you can use electric cars to store the power
generated by wind energy." When the grid is running low, car batteries
will be able to send stored energy back into the system.
Electric cars can be used for energy storage
Denmark is also looking into using heat pumps for storage, so
that when wind farms are generating excess capacity, the extra
electricity can be stored in the form of heat and later be used to heat
homes and businesses.
"When the wind is really blowing, there is no cheaper electricity than
wind energy," said Böttzauw. And when the wind isn't blowing, Denmark
might be able to turn to the sun instead. For that reason,
Energistyrelsen has increasingly invested in solar energy systems. To
meet the rest of Denmark's energy demands, the country makes use of
biomass, supplemented by energy savings and energy efficiency.
The plan seems to be working: According to the country's Department of
Energy, the Danish economy has grown by 78 percent since 1980, even
though energy consumption has remained nearly the same. Exports and job creation
In Germany, a popular argument against renewable energy is the lack of
competiveness: consumers are obliged to pay a surcharge in the name of
renewable energy, while energy-intensive industries are exempt from the
levies. Greenpeace's Austrup says it's outrageous. "At the moment, the
German industry is the biggest winner of the energy transition. They
haven't seen such low electricity prices for at least 10 years. "
With its energy mix, Denmark wants to show that renewables are feasible
The Danish government has chosen a different path. Companies
receive a subsidy if they use renewable energy and increase their energy
efficiency, a policy that encourages creativity and leads to savings.
In 2010, the Danish energy technology sector accounted for about 10
percent of the country's exports. In order to continue being a market
leader, Denmark has invested heavily in research and the promotion of
renewable energy, energy-efficient technologies and renewable heat
supply systems. Every year, the sector is responsible for creating
around 6,000-8,000 new jobs in the country of 5.5 million people. Serving as a model
Denmark's success has caught the attention of other countries around the world,
including China.
Böttzauw told DW that the two countries have been cooperating on energy
projects since 2006, starting with wind energy but expanding into the
development of renewable energies in 2010.
"China has expressed a great interest in our district heating systems,
along with biomass technology and offshore wind turbines," said
Böttzauw. He's pleased that China has shown interest - as well as with
the success of Danish energy technology, which includes everything from
pumps to wind turbines, insulation technology to thermostats.
But economic interests were not the focus of the cooperation, said
Böttzouw. "We went to China to help deal with the energy and climate
problems caused by economic growth there" - the same motivation that has
driven Denmark's energy policies. "We just want to show that it's
feasible."
My
interest is in using the glass evacuated tubes not as a component of a
commercial collector, but as an insulated collector for a DIY parabolic
trough concentrating collector. With the addition of a rotatable
tracking parabolic trough behind a single evacuated tube, it is possible
to increase the heat capture significantly, up to 8-15x safely. In this
manner, it would be possible to do things that are not possible with a
flat plate or an evacuated tube system - making steam for example. In a recent demonstration I showed that temperatures of over 630°F are possible on an experimental DIY basis. 
If you like the idea of an evacuated tube which is open at both ends with expansion bellows fitted: Dezhou Mingnuo New Energy Co., Ltd., Dezhou City, China offers a 4000mm receiver tube of this type.UPDATE: The link no longer works. I have written to the company to get info. "Sun Island" Haining Chaoda Solar Collector Tubes, Ltd
is another manufacturer. These do not have bellows, or an absorptive
coating. Open both end tubes are rare and you would have to import a
case lot. The open at one end tubes are much more commonly available, at
least in North America. I searched "open both ends solar evacuated
tube" to find these.
The
(open one end) tubes that I have measure ID 43.5mm OD 58mm and 71
inches (1803mm) including the pinch off but not including the heat pipe.
This seems to be a size common to at least three of the manufacturers
listed above, so we could assume this size might be also available from
others? I cannot find a specific international specification for the
tubes alone. If anyone knows this spec, please let me know. 
I
can only give pictures of the construction of the evacuated tubes that I
have at hand but others I have seen, although different in some of the
details, are similar. Here I am removing the "guts" of the tube by
pulling on the bulb of the heat pipe. With this particular tube, the
innards pulled out readily. With others, the heat pipe (the copper tube
assembly in the center) comes out of the aluminum absorber leaving it
behind in the evacuated tube. With those, I had to pick away at the
fiber glass "bung" until I could grab the absorber with pliers and pull
it out. 
Here
is an end view of the aluminum absorber. The heat pipe is held in the
center of the evacuated tube, supported down it's entire length by this
formed sheet aluminum part with also improves heat coupling from the
inside wall of the evacuated tube to the heat pipe.
In
this view, I have shown the bulb end of the heat pipe. The heat pipe
dia is 0.317" / 8.04mm. The bulb dia is 0.943" / 23.97mm and has a
length of approximately 3.905" / 100mm. The fiberglass bung can also be
seen.
Here
is the other end of the heat pipe, the aluminum absorber support and
the evacuated tube. The evacuated tube has a shiny metallic "getter" on
the inside which will be familiar to readers old enough to have worked
with electronic vacuum tubes. The getter is a metallic coating which
removes impurities in the vacuum after the tube has been sealed. It is
also a diagnostic for the quality of the vacuum since it will turn to a
powdery white appearance as it is depleted. If the vacuum is good the
getter will be bright and shiny like this one.
The
bung which seals the top of the evacuated tube is a powdery brittle
compressed bit of what looks to be fiberglass? Hopefully it is not
asbestos? It basically flakes apart when you remove it so is not
reusable. Winding fiberglass pipe wrap into a cylinder was found to be a
useful replacement for the bung and also able to accommodate an inlet
and an outlet tube as was done for the test of an insulated concentrator. So
where do you get yourself some evacuated tubes for your own
experiments? I don't think that you will yet find these at your local
home center unless you are in the southwest USA or Mexico. 
Simpler side channels
I show how to use a standard angle profile in a very strong and precise
joint that can be made by hand or machine. Different materials can be
used, to suit what is locally available. The resulting reflector
assembly is robust yet light weight and completely grips the reflective
sheet along the long edge and supports it accurately from below. 
Insulated, high temperature collector option I show how to suspend a standard glass evacuated tube
at the focus and use it as a large thermos bottle to surround the
collector. Higher temperatures and or winter use are thus made possible
with this design. 
Jennifer O'Brien wrote this article for Shareable.net,
where it originally appeared. Jennifer is CEO of the nonprofit Lawrence
OnBoard, and the owner of CASA Kids Studio in Lawrence, Kansas.
From Edible Cities: image by Bernhard Gruber 
Benefits for local citizens have led to greater acceptance of wind farms
Electric cars can be used for energy storage
With its energy mix, Denmark wants to show that renewables are feasible
Feel free to email me with inquiries: jonaheskin@gmail.com