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Mini Bio-gas System – for homeowners

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Taken from the wonderful world of

Sahas Chitlange, aging 14, from India. here is my homemade cheap and easy to build mini Biogas plant. It burns for approx. 20-30 mins on a bunsen burner. you can add anything from your kitchen waste ( Except Onion peels and eggshells). In 12 hours the Gas is ready for use. It is very easy and cost effective to build (only 2-3 dollars) and gives many useful products.

Biogas at home- Cheap and Easy  by Chitlange Sahas


the end products of this system are:
1) Methane : (Can be used as a fuel)
2) Slurry     : (the spent slurry is excellent manure)

The main components of this system are:

1)  Inlet pipe
2) digester tank
3) gas holder tank
4) slurry outlet pipe
5) gas outlet pipe


You will have to choose a correct size container which will act as a digester tank. My one is 50 litres tank. I got it from scrap.

Image Image  Image

Make holes in the tank for Inlet and outlet. For this I took a old iron rod and heated it to make holes. CAUTION: rod is really very hot.

Or use core-drill bit with e-drill.

Step 3: Fix the inlet and outlet pipes

Image Image Image

Glue the Inlet pipe and the Outlet pipe with any water proof adhesive.

Step 4: Making the Gas holder Tank

Image Image

I took a paint bucket of 20 lts for making a gas holder tank. This tank holds the gas produced. The tank is overturned and fixed with a valve used for plumbing purposes.

Step 5: Time to mix the cow dung !


Mix the cow dung in proportion of 50/50. add 50% water and make a fine slurry. Now put the slurry in the digester tank.

Step 6: Almost finished!


Put the gas holder tank overturned in the digester tank after adding the slurry . REMEMBER: open the valve while putting the gas holder tank. the mini plant takes 10-15 days for the first time to get output. For the first time, the gas in the tank wont burn as it contains Carbon Dioxide gas, if fortunately it burns then good or wait for the second time. You can detect how much gas is there in this system, the gas holder tank will rises up as the gas is produced.


Make a solar garden lamp out of a jam jar

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Make a solar garden lamp out of a jam jar;

Megan Treacy
Technology / Gadgets
March 26, 2013


solar garden lamp

credit: Ugifer

Instructable user Ugifer put together this DIY project for a solar garden lamp for a science experiment that he was doing with his daughter and her friends and he’s given us permission to share it with you all. The skills and lessons taught would make it great for parents and educators to share with kids as an introduction to green tech, but it would also be a great beginner level project for those just getting into making their own electronics.

Ugifer says, “It’s simple and fairly quick to do so although it does involve some soldering I don’t expect that we will have trouble doing this with our small group of carefully supervised 7-year-olds.

The idea for this project was inspired by this article over at Evil Mad Scientist although the circuit is modified to be a little more efficient. Because it’s made up from a simple set of parts it would make an ideal beginner’s electronics kit.

This is a nice, sustainable-energy kit, with all the power for the lamp being sourced from renewable solar energy. It uses scavenged jam-jars as the enclosure but could also use some scavenged parts such as toroids from old CFLs.”

What you’ll need

solar garden lamp kit

credit: Ugifer

The parts that you will need are:


5V 70 mA Solar pannel (around 60x60mm)
Twin AAA-size battery holder
2 AAA-size NiMH rechargable batteries (around 1000 mAh works well)
Circuit board (see last step for Eagle files)
2N3906 general purpose PNP transistor (or equivalent)
2N3904 general purpose NPN transistor (or equivalent)
1N5817 low forward voltage schottky diode (general purpose – e.g. 1N914 – diode would probably work)
Slide switch
Ferrite bead/toroid (scavenge from an old compact fluorescent lamp if you only need a few)
LED (high brightness – diffused ideally but I only had water-clear so scratch it up with sandpaper)
22K resistor*
4K7 resistor*
1K resistor
1nf ceramic capacitor (some parts of this ‘ible refer to a 2n2. Either seems to work fine)
30 cm 22-guage solid copper wire (from an old ethernet or telephone cable works well)

Optional items::

Old (empty) jam or pickle jar to house your circuit (we will assume you are using this).
Sparkly things (e.g. acrylic jewels) for the bottom of the jar (makes it look pretty)
Glass paints (could be included in kit)
Small double-sided sticky pad (optional but useful)


Soldering iron & solder
Drill press or punch
Hot glue gun & glue (epoxy would be fine but slower). I use low-temp hot glue with the kids.
Metal file
A little tape to hold things in place
Medium grade sandpaper (tiny bit)
Helping-hands type tool also very useful

* These resistors may need adjusting depending upon the performance of your solar cell and LED. The 4K7 and 22K make a voltage divider that controls the light level at which your LED comes on. Increase or leave out the 22K for darkest switch-point. Decrease the to switch on when it’s lighter. But be careful – depending on your solar cell you may need a pull-down to make the PNP switch on fully. A 100K trim-pot would probably work well if you wanted to control this.

The circuit

 solar garden circuit

credit: Ugifer

As indicated, the circuit was inspired by this article at Evil Mad Scientist. Thanks to Windell et al. for that.

The schematic is shown in the picture.

Essentially, the circuit can be divided into the charging part to the left, the light sensing part in the middle and the LED lighting part on the right.

During the day, the voltage across the solar cell is high and current flows through the diode to charge the NiMH battery. Charging at up to C/10h amps (where C is the capacity of the battery in amp-hours) is supposedly safe for continuous trickle-charge. So with 1000 mAh batteries we should be able to handle 100 mA. Our 70 mA solar cell in practice generates 50-55 mA in UK direct summer sunlight so we are safe by a factor of 2 there – pretty much ideal for fairly quick charging but keeping the battery pack in good condition.

When it gets dark, the voltage across the panel drops. This can consume significant current from the battery (so-called “dark current”, which sounds like the evil side of the force to me). Hence the diode. I have used a low vF diode to reduce how much of or energy we burn getting past it. We can tap into this voltage drop to turn on the light when it gets dark. That’s where the PNP transistor comes in.

By making a voltage divider between the solar panel and ground and attaching this to the base of the PNP, we sink a very small emitter-base current when the solar panel stops pulling a voltage. This allows a larger emitter-collector current to flow. The voltage divider between the solar cell and ground can control the switch-point voltage and thus the light level at which our lamp comes on.

Once our PNP turns on, a current flows to the lamp circuit on the right of the diagram (and board).

From here we have a “joule thief” circuit for the LED light. Explanation of this is rather beyond this summary but, once again, Evil Mad Scientist comes to our rescue: see here for a great Joule-thief articleand here on Wikipedia for a more in-depth explanation. The overall effect is that we light a 3V white LED from a 2.4 V rechargeable battery and can continue to use the battery as its voltage drops. The capacitor is not an essential part of the circuit but it’s great for efficiency. Without it I was finding 100mA being drawn from the battery! With a 1nf capacitor that drops to around 18mA but the LED is just as bright.

Finally, the switch isolates the joule-thief part so that we can continue to charge the battery but have the lamp turned off. If you turn this off then the 5-10 mA that are generated in the shade might just allow you to charge the battery in the winter to give you light about one night a week!

Add the panel to the jar lid

 solar garden lid

credit: Ugifer

As a first step, we need to attach the solar panel to the lid of the jar and pass the connecting leads through. We want to do this in a way that will seal the hole so that we can leave our lamp outside without it filling with water or bugs!

We are starting by putting a hole in the jar lid. To do this, I’m using a small drill-press but that’s as much to get small girls comfortable with using power-tools as for any real need. A punch into a block of wood would work well too, I’m sure. However you do it, you’ll want to clean up the hole with a file and thread the wires from the solar panel through.

Next, cover the solder points on the panel with hot-glue or epoxy and then glue the panel to the jar. I’m using blue-sparkly glue so that you can see it but normal glue is fine!

Finally, make sure you fill the hole with glue to keep out those bugs!

Lay down some components

 solar garden board

credit: Ugifer

Next, we want to start populating the board.*

Since my group will be taking turns at the solder station, we’ll do several components at a time. On your own you might prefer to add them individually:

The resistors are easiest and can go in first – either way round. Bend the legs out a little to hold them. I am not using the 22K resistor to ground but if you include it then your light will come on at slightly higher light levels.

The diode is equally easy but needs to go with the stripe at the end shown on the board.

Then add the two transistors. The PNP (marked 3906) goes to the top left and the NPN (marked 3904) goes to the bottom right. Make sure the case goes the same way around as marked on the board (flat edge towards the bottom).

Finally for this step, add the LED. You can leave as little or as much lead length as you wish but the longer lead (positive / anode side) goes nearest the right hand edge of the board. I was expecting that to be marked on the boards but it didn’t come out. It’s on the current version.

Now, for each component, carefully solder the leads to the bottom side of the board and clip them close with side-cutters.

*Throughout this ‘ible, the pictures of the board are of my first “proof of concept” board which had a track missing (long story) and lacked the 1 nf capacitor. The final board design is shown in a later step and is very similar but I haven’t actually had them fab’ed yet.

The Toroidal transformer

solar garden toroidal

credit: Ugifer

The Joule Thief part of the circuit requires a small hand-wound toroidal transformer that we will make and add in this step.

I’m using ferrite beads around 9.8mm wide by 7.5mm deep with an 6.5mm diameter hole. Whatever the size you use, you’ll want enough wire for 6-8 turns. For beads the size of mine, take about 20-30 cm of a pair of insulated 22-gauge solid copper wire (I use wire from an old 3-pair telephone cable). Contrasting colours make life easier. Push the wires through your torus leaving around an inch (2.5 cm) sticking out at one end. Now loop the long ends round until you have made 6-8 loops spread evenly round your bead. My beads are pretty much full after 8 turns of this wire.

I have made a few joule thieves and in my experience the ferrite bead is the most likely part to cause a problem. Some types of beads work and some don’t and I have not yet devised a way to tell before trying them.

Cut down the leads to an inch at most (say 2cm-ish) and strip the ends. At this point it’s handy to use a small sticky-pad to hold the torus in place.

Now take a wire of one colour from one end of the torus and the other colour from the other end and put them into holes 1 and 2. The other ends go into holes 3 and 4 so that the hole in the torus now points across the board. It should fall naturally so that the wires connect from holes 1 to 4 and 2 to 3, but check or it won’t work! Bend the wires out a little to hold them, turn the board over and solder it.

Power connectionssolar garden power

credit: Ugifer

All that is left to attach is the power switch, the battery and the solar cell. These go in the marked spots towards the edges of the board.

Place the switch in its holes and hold in place with a little tape. Turn over the board and solder. The switch has much more thermal capacity than anything else we have soldered in this project so the solder tabs will take a moment to heat up – don’t panic!

Same with the two power sources: Red to the + terminal, black to the -, tape in place and solder.

You now have the complete circuit. If you insert charged batteries and cover the solar cell you should see the LED light up.

Final assembly

solar garden final assembly

credit: Ugifer

Finally, hot-glue the board to the back of the battery holder with the LED pointing as you wish. For a very wide-necked jar you could glue the battery holder flat to the underside of the lid and leave the LED sticking “up” (really down) from the board (not pictured).

For most jars you will have to bend the LED past the end of the battery holder and glue the end of the holder to the lid of the jar (as shown).

If you used a water-clear LED you may wish to scratch it up with some medium grade sandpaper at this point to diffuse the light a little.

You can put some acrylic jems, pieces of metal, shiny plastic or glass (or indeed 10 carat flawless diamonds if you wish) into the bottom of the jar to scatter some of the light and give a pleasant effect. Once they are inside, screw up the jar.

Finally, take some glass paints and paint a stained-glass effect onto the jar. Or have your 6-year old do it.

A day of full UK sunshine should provide more than enough charge for one night’s light, and a full battery should hold enough charge for several nights, so in summer you might keep alight every night. In winter that’s not so likely, at least in the UK. There is a surprising difference between the charge developed in shade (5-10 mA) and in full sun (50 mA+) so find a sunny spot if you can.

You now have a pretty, self-charging, LED garden light.

Eco News and Gadgets

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I ofttimes find interesting articles on eco – gadgets that excite or interest me. I thought to share a few.


A Waterless Dishwasher You’ll Never Have To Empty

There are some chores I’ve just never stopped hating. Dishes are one of them, making the bed is another. Although we’ve got a fairly new dishwasher it still takes some doing to get me motivated enough to start the process. We have to be down to our last couple of forks. Even after they’re clean, there’s still the task of taking everything out, making sure it’s really dry, and putting it away.

Although using a dishwasher uses less water than washing dishes by hand, it’s still a major consumer of both water and electrical energy in the household. But what can we do? Dishes have to be clean, and the only way to do that is with hot, soapy water, right? Wrong. The DualWash Bipartite Dishwasher is a complete reinvention of the humble dishwasher. Not only does it operate without water, it doubles as the cabinet so once it’s loaded, the dishes are already put away.


Image via Gökçe Altun, Nagihan Tuna, Pınar Şimşek, and Halit Sancar/Tuvie

I know you’re desperate to know how it works (I was too), so here it is: Instead of hot water, the dualWash would use carbon dioxide. When the washing cycle starts, the carbon-dioxide cycle is activated, and supercritical carbon-dioxide  (liquid CO2) is pumped to the cleaning chamber. “Supercritical carbon-dioxide has a very low surface tension, meaning instead of beading up into a ball like water, it spreads out widely covering all surfaces,” explain the designers. As this review points out, should there be solid particles, the supercritical carbon dioxide is returned to carbon dioxide’s gas phase, and forces and stubborn particles into the filter. When full, just remove the filter and clean it.


Image via Gökçe Altun, Nagihan Tuna, Pınar Şimşek, and Halit Sancar/Tuvie

The great part is that this futuristic dishwasher has not one but two cabinet areas. Simply slide the door over the side that’s due for cleaning, while the clean dishes in the other side are on display. This concept is perfect for single individuals or couples, because it allows you to wash just a few dishes without the guilt of wasting water and energy.

DualWash uses the Carbon-dioxide cleaning rather than water-based cleaning as a reaction to the water shortages of coming decades. When the washing cycle is started, Carbon-dioxide cycle is activated, and Supercritical Carbon-dioxide is pumped to the cleaning chamber. Supercritical Carbon-dioxide has a very low surface tension, meaning instead of beading up into a ball like water, it spreads out widely covering all surfaces.

During the washing cycle, Carbon-dioxide flows around the machine and cleans it. For solid particles, Supercritical Carbon-dioxide is turned to gas phase and food particle filter holds contaminates. The filter can be removed and cleaned.


Environmental concerns drive innovation

zeolite technology;

Revolutionary new developments are rare in the home appliances sector, which makes the BSH dishwasher with Zeolith® Drying System all the more remarkable. The zeolite dishwasher won the inaugural German Innovation Prize for Climate and Environment (IKU) awarded by the German Federal Ministry for the Environment (BMU) and the Federation of German Industries (BDI) in February 2010. This innovation promises to change the market altogether.


Award-winning zeolite technology

Our novel drying technology uses zeolite minerals to reduce dishwasher electricity consumption by 20 percent as compared with what were previously the most efficient appliances in the top efficiency class. All in all, our engineers have managed to halve the electricity consumption of our dishwashers over the last 20 years. Zeolite, a substance formerly used only in industry, adsorbs moisture and releases heat in the process, making it ideal for use inside our dishwashers. The hot air produced dries the load after the rinse cycle without any additional energy input.


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Some thoughts and sites and pictures of Eco – Ideas.

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Checklist for your own home or business; 

CHECKLIST                                                                                                     YES NO
Measuring and monitoring – Have you…                                                                                       
 Reviewed your monthly gas and electricity bills?
 Have you checked that your MIC meets your needs?
 Read your meter frequently?
 Established your baseline/out-of-ours energy use?
 Considered sub-metering?
Large Equipment – Have you…..
 Identified your major energy using equipment?
 Surveyed your large equipment usage/requirements
Lighting– Have you…
 Conducted a survey of your light fittings?
 Considered replacing bulbs and fittings with more efficient bulbs/fittings?
 Considered installing timers and sensors?
 Made the most of available natural light?
Refrigeration– Have you….
 Made sure your refrigeration temperatures are set correctly?
 Ensured fridges and freezers are not overstocked?
 Installed timers on display fridges and vending machines?  
 Installed strip curtains in cold rooms?
 Ensured your fridges/freezers are regularly defrosted?
 Checked that fridge/freezer door seals are in good repair?
Hot water – Have you….
 Ensured pipes and tanks are well insulated?
 Fitted timers?
 Ensured water is heated to o optimum temperature and fitted thermostats?
Heating – Have you…
 Ensured your boiler is serviced regularly?
 Ensured doors and windows are kept closed when heating is on?
 Considered zoning your heating?
Ventilation and air conditioning – Have you….
 Made use of natural ventilation where possible?
 Kept fans, air-ducts etc. in good repair?
Procedures, staff awareness and training – Have you…..
 Communicated to staff the importance of energy conservation?
 Trained staff to switch off equipment when not in use or out-of hours?

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A Solar Energy System That You Can Put Together in Your Garage

by  on OCTOBER 17, 2012 Original article:

  • Wouldn’t it be great if generating solar energy at home was:
  • A Do-it-Yourself project you could build using the tools in your garage
  • Built with inexpensive, commonly available materials
  • Modular like a LEGO block that you can snap in to lots of different places where you need it

It can be.

Here’s an example.  It’s called the Solar Flower.  It’s an open source hardware project that was built by Daniel Connell while in Spain.

What is the Solar Flower?  It’s a system that makes it easy to turn sunlight into heat.

Here’s what it looks like.

As you can see in the picture above, sunlight is captured by a U-shaped reflective surface (technically, a parabolic trough).    This reflected sunlight is then focused onto a black copper tube that runs along the length of the system.

Naturally, this makes the copper tube very hot, which in turn heats whatever liquid you want to run through it.

Of course, the Solar Flower only really works if it is facing the sun.

To do that, Daniel built an ingenious (which is often best measured by how simple the solution offered is) passive solar tracking system.  This system doesn’t use electric motors or sensors to track the sun.

To accomplish this, Daniel built a small solar oven that he filled with ethanol (it expands when heated).   Experiments showed that the sun would heat the ethanol enough to turn some gears that would rotate the main reflective surface.  So, Daniel placed the solar oven in a place where it would only “see” the sun just as it was just passing by the optimal angle for the main surface (angled slightly to the “west” of the angle the Flower was pointing).

That plus some simple modifications makes the Solar Flower a solar energy system that you can install and forget.   To make one of your own, Daniel has put together some excellent tutorials.

What do you Do with a Solar Flower?

Anything that involves heating fluids up.  That includes:

  • Heating hot water for your home.
  • Heating small spaces like a greenhouse.
  • Generating electricity from steam.
  • Purifying water.
  • Smokeless cooking.
  • Making biochar.

Basically, lots of great DiY and easy to assemble project modules that you can plug into it.

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Buy Some Compost and get Free Hot Water?

by on July 12, 2012

Here’s a very cool system that I’m currently considering as part of my home’s resilient make-over.  You might be interested in this too.

What is it?  It’s a system that uses a compost pile to produce hot water.

Specifically, this system turns the waste heat of the compost pile you need for your gardening, into something you can use to wash the dishes or heat an ad hoc greenhouse.

I like it because it allows me to take something I’m already doing (making compost for my garden) and do something else productive with it at the same time.

Compost piles as hot water heaters

How does it work?  Well, we all know that compost piles generate heat as part of the decomposition process.  How much heat?  A large, well balanced (nitrogen/carbon), and aerate compost pile can get up to 120-140 degrees for as long as six months, depending on the size of the pile.

It’s certainly not a new technique, it’s been used for thousands of years by farmers to keep livestock warm during the winter.  However, in the last century, the resilient tinkerer Jean Pain resurrected it as a way to generate a) methane for cooking/driving and b) hot water heat for his home/barn.

In the process, he developed some pretty interesting designs (see right) and reignited interest in it as a way to locally produce energy.

For my purposes, and perhaps yours, the system I’m considering would be much more modest.  The reason?  While I have a need for garden compost, I don’t have the need, space, or time required for a huge pile of loose compost.

Instead, I do have space for a less ambitious small system that can a) pre-heat hot water for home use or b) heat a greenhouse.

The resilient home compost heating system?

What would a system like that look like?  Of course, in today’s world, systems that are this innovative aren’t available.  You are going to need to build it as a do-it-yourself project to take advantage of it.

Here are two examples for how to do that.

The pictured system uses hay bales as the walls of the container, garden hose for the piping, and 55 gallon drums as a reservoir.  Pretty slick.

A second approach is to lay out the compost and the piping horizontally, so it can act as the floor of a greenhouse as this family in Oregon did.  They were able to generate at least 90 degree water for 18 months from their system and grow plants outdoors during the winter.

Where do we go from here?

I’d like to see this become a resilient business opportunity.

What do I mean?

Composting is already a big part of the resilient lifestyle (people that don’t compost are throwing wealth away) and efforts to permanently integrate it into a home’s design are already underway.

So, the idea that local professionals will install and maintain permanent composting systems that allow both fast and efficient composting as well as heat isn’t that much of a leap.

It even open ups the potential for deliveries of the composting material you need in bulk (as a supplement to what you already produce), on an annual basis.   For example: a delivery of pulped wood/sawdust or shredded leaves to beef up your home’s supply, in a fashion similar to how a septic tank gets emptied or an oil tank filled, isn’t really that strange of an idea.

Finally, it gets even more interesting when you think about the productive impact of a home scale greenhouses that incorporate composting as a heat source — see picture and click for more info.

Hope this gets you thinking,


Re-using Silica-Gel Bags

Posted on
DON’T THROW AWAY: They’re reusable, just not edible. (Photo: jorho123/Flickr)
We find them everywhere, popping out of all sorts of packaging, lurking like an ugly bug in vitamin bottles and new shoes. Working freight at my store, I touch dozens of silica packets each day and often ask what I can do to recycle them. Couldn’t we collect them and send them off to a manufacturer for reuse?
Silica gel is a desiccant, a substance that absorbs moisture. Despite its misleading name, the silicate is actually a very porous mineral with a natural attraction to water molecules. Manufacturers utilize the gel to keep goods from spoiling, molding or degrading due to humidity. The gel itself is nontoxic, but can have a moisture indicator added (cobalt chloride) which is a known toxin that turns pink when hydrated and is otherwise blue in its dry form. Most silica found in our food and household purchases looks like tapioca beads and is benign unless combined with certain chemicals.
Although silica gel has massive potential for reuse, I haven’t had any luck finding a recycler. But I did discover several great suggestions for using these packs around the house and keeping them from the landfill just a wee bit longer.
  • Put packs in your ammo cans and gun cases/safes to keep dry.
  • Protect personal papers and important documents by putting some gel in a baggie wherever these are stored.
  • Keep with photos to spare them from humidity. Tuck a small envelope in the back of frames to protect even the ones hanging on your walls.
  • Store in camera bags and with film. After snapping photos in cold or wet conditions, silica gel will absorb moisture to keep your lens from fogging or streaking.
  • Leave a couple packs in your tool box to prevent rusting.
  • Use the material to dry flowers.
  • Place with seeds in storage to thwart molding.
  • Stash some in window sills to banish condensation.
  • Dry out electronic items such as cell phones and iPods. Remember after the device has gotten wet, do not turn it back on! Pull out the battery and memory card and put the device in a container filled with several packs. Leave it in there at least overnight.
  • Slow silver tarnishing by using the gel in jewelry boxes and with your silverware.
  • For items in storage, such as cars or anything prone to mildew. Popular Mechanics offers a good suggestion for use in engines of sitting vehicles.
  • Tired of buying big bags of pet food only to have it get soggy? Store your kibble in a bin and tape some silica packs to the bottom of the lid.
  • Cut open the packs and saturate the beads with essential oils to create potpourri.
  • Use in luggage while traveling.
  • Tuck some in your pockets. Hide them in your closet in leather goods such as coats and shoes, and even handbags, to help them survive life in storage.
  • Gather your razor blades and keep in a container with several silica packs to stave off oxidation.
  • Video tape collections will last much longer with these to help keep them dry.
  • Litter is now made with silica. With its fantastic absorption qualities, this litter requires fewer changes and sends less mess to the landfill.
And my personal favorite:
  • Squirrel some away in your car, especially on your dashboard. This will help maintain a clear windshield and leave it less foggy during times of high humidity.
While these packets are annoying and seem like a waste of resources, they can extend the life of many items. Another reason someone needs to be collecting them to recycle: they can be reactivated repeatedly. To recharge, you just need to bake the saturated beads on a cookie sheet, as detailed on
From Mother Nature Network;

Photovoltaic for homes.

Posted on
N° 20-10 
Sol-ion, Europe’s largest PV energy conversion and storage project, moves 
into field trial phase   
• Close collaboration between industrial partners Saft, Voltwerk and Tenesol has 
resulted in the successful development of a prototype integrated energy kit suitable 
for production on an industrial scale  
• EU-backed project is now moving into field trial phase with 75 Sol-ion energy kits 
being deployed in France and Germany from mid-2010 onwards 
Munich, June 10, 2010 – Saft, Voltwerk and Tenesol, industrial partners in the EU-backed Sol-ion 
project, have successfully completed the development phase by creating an integrated energy 
conversion and storage kit, capable of production on an industrial scale, for decentralized on-grid, 
residential solar photovoltaic (PV) systems. The project, which commenced in August 2008, is now 
moving into its test and evaluation phase. This involves the deployment of 75 Sol-ion energy kits for 
field trials across France and Germany. 
The Sol-ion trials will see Li-ion (lithium-ion) batteries used in PV systems on the largest scale ever 
tested in Europe. The trials will be used to assess the performance of the technology, its economic 
viability, the added value of energy storage in an on-grid system and the benefits to stakeholders. 
‘The key to the success of the Sol-ion project is the way that all the individual partners, both from 
industry and from the research institutes, have come together in close collaboration to function as a 
seamless team. So rather than each partner providing a separate element – batteries, energy 
conversion and system management – and then bringing them together, we have focused right from 
the very start on the delivery of a comprehensive, fully-integrated, optimized solution’ says Michael 
Lippert, Marketing Manager of Saft’s Energy Storage activities. ‘We are very excited to be moving into 
the field trial phase as this will provide invaluable practical experience and feedback that will help 
refine our approach as we move a step closer towards making PV energy storage kits commercially 
Currently, the majority of grid-connected PV systems do not include energy storage and the electricity 
produced is fed into the grid directly, in real time. The advantage of the Sol-ion energy conversion and 
storage concept is that solar energy can be ‘time-shifted’ to periods of peak demand or when there is 
no sun, allowing self-consumption or grid support. The field trials will demonstrate the benefits to the 
environment and to stakeholders of storing PV energy. One key benefit will be to reduce the impact of 
intermittent injection to power grids, thus allowing a higher penetration of PV energy in the electricity 
Sol-ion kit 
The Sol-ion kit has been developed to accommodate PV energy production of 5 kWp (peak) with a 
battery rated from 5 to 15 kWh and a nominal voltage of 170 V to 350 V. Li-ion is the only technology 
that meets the project’s need for 20-year battery life in demanding environmental conditions. 
The energy conversion and system management  systems are designed to handle four system 
functions: multidirectional energy flows; self-consumption; grid support; back-up. They are also 
intended to handle requirements for demand side management such as control over storage and 
loads using smart metering, and integration within future smart grids that will need to handle demand 
response and dynamic pricing. The Sol-ion battery is based on Saft’s high energy Li-ion modules, with a nominal voltage of 48 V and 
2.2 kWh capacity. These compact, maintenance-free modules feature an advanced and robust 
industrial design, and they can easily be connected in series or parallel to create the desired voltage 
and capacity for each installation. Saft’s Li-ion  technology has already proven an impressive 97% 
energy efficiency in a recent 2 years field demonstration in residential PV systems in Guadeloupe. 
Saft’s technology partners in the Sol-ion project  are leading PV systems providers and integrators: 
Germany’s Voltwerk has installed over 70,000 PV systems; France’s Tenesol supplies integrated PV 
systems and also manufactures solar panels. E-ON, the German utility, three German research 
institutes (ISEA, Fraunhofer IWES and ZSW) and INES-CEA, the French research institute, are also 
associated with this project. 
Sol-ion has been recognized by the EU/Eureka/Eurogia programme and has the support of the 
French Ministry of Economy, Finance and Employment and the German Ministry of Environment.  
About Saft 
Saft (Euronext: Saft) is a world specialist in the  design and manufacture of high-tech batteries for 
industry. Saft batteries are used in high performance  applications, such as industrial infrastructure 
and processes, transportation, space and defence. Saft is the world’s leading manufacturer of nickel 
batteries for industrial applications and of primary lithium batteries for a wide range of end markets. 
The group is also the European leader for specialised advanced technologies for the defence and 
space industries and world leader in lithium-ion satellite batteries. Saft is also delivering its lithium-ion 
technology to the emerging applications of clean vehicles and renewable energy storage. With 
approximately 4,000 employees worldwide, Saft is present in 18 countries. Its 15 manufacturing sites 
and extensive sales network enable the group to serve its customers worldwide. Saft is listed in the 
SBF 120 index on the Paris Stock Market. 
For more information, visit Saft at
About Voltwerk electronics GmbH 
Voltwerk electronics GmbH is an internationally successful manufacturer of string and central 
inverters, tracking systems and facility monitoring systems. All its products are developed and 
manufactured in Germany. Voltwerk‘s award-winning products have been installed worldwide in 
systems with a total of more than 500 MW of generating capacity. Voltwerk is a provider of innovative 
solutions and pioneering methods for highly efficient photovoltaic systems.  Voltwerk’s success is 
based on precise knowledge of the markets and intensive collaboration with customers and 
engineering teams across the world. Voltwerk is  represented in Bad Vilbel and Hamburg and has 
sales and service support in all the major European markets. Voltwerk electronics GmbH currently 
has nearly 100 employees. For more information visit Voltwerk at
About Tenesol 
A rapidly expanding global player in the field of solar energy (with a turnover of €249 million in 2009, 
+29%), Tenesol works on behalf of businesses, local authorities and private individuals. For more 
than 26 years, Tenesol has been engineering, designing, manufacturing, installing and managing 
solar energy systems including production  and consumption of supplied systems  (Off-grid sites, 
general grid supply via direct connection, solar water heating) for its customers around the globe. A 
benchmark player in its sector, Tenesol currently  has a staff of over 1,000 employees across 20 
subsidiaries including 2 production facilities. For more information visit Tenesol at
Press contacts 
Jill Ledger, Saft Communications Director, Tel: + 33 1 49 93 17 77  
Marie-Christine Guihéneuf, Saft IBG Communication Manager, Tel: + 33 1 49 93 17 16 
e-mail :
Andrew Bartlett, Six Degrees, Tel: + 44 (0) 1628 480280 
e-mail: andrew.bartlett@sixdegreespr.comBACKGROUND INFORMATION
The role of each partner
Saft is responsible for the design and manufacture of the energy storage system. The battery is based 
on Li-ion battery modules connected in series to obtain the energy and voltage required by the 
application. This concept provides a high level of modularity offering a wide energy window without 
additional development. Each module includes an  electronic board for data acquisition (voltage, 
temperature, ..) and cell balancing in order to optimise the battery life time and to allow 
charge/discharge control, state of charge measurement, etc. 
This electronic board is connected to the system management function that controls the battery. The 
interfaces have been developed in cooperation with Tenesol and Voltwerk. 
Saft is delivering the batteries both to Voltwerk and Tenesol. These two PV system integrators will 
produce the other components and will assembly the  Sol-ion kits (battery + inverter + system 
Voltwerk and Tenesol 
With their extensive knowledge in the production  of inverters, Voltwerk and Tenesol have specified 
and developed the inverter and the energy management system to meet the customers’ 
requirements. The system design allows the inverter to either feed the electrical power into the public 
grid or store it in the battery for later use. 
Voltwerk is producing and installing 25 systems  in Germany. Tenesol will  produce and  install 50 
systems in various demonstration sites in mainland France and overseas departments. Finally, field 
test demonstration supervision  and data acquisition will be carried out for system monitoring and 
future system improvements 
E-on is providing access to its network in Germany and is contributing to the development of the 
system’s interface with the network. 
Research institutes 
These organisations are responsible for modelling the system and its impact on the network, and for 
the analysis and utilisation of the test results. 
Organisations involved in the project 
Partner Core business 
Saft – Project coordinator Batteries 
Voltwerk Renewable energy products integrator 
Tenesol PV systems integrator 
E-ON Utility 
Fraunhofer IWES Research Institute 
ZSW Research Institute 
ISEA Research Institute 
INES-CEA Research Institute 
All the partners have confirmed their strong interest in the development of grid connected PV 
systems, associated with a storage function and recognize that this concept offers new business and 
market perspectives. The role of energy storage in renewable energy systems
Example of residential PV system with energy storage 
PV installations with a permanent connection to the electricity grid are categorised as ‘on-grid’ 
applications. This is the most popular type of  solar PV system for homes and businesses in the 
developed world. PV can be installed on top of a roof or integrated into the roofs and facades of 
houses, offices and public buildings. An inverter is used to convert the DC power produced to AC 
power for running normal electrical equipment. 
Private houses are a major growth area for roof systems as well as for Building Integrated PV (BIPV). 
A typical 5 kWp panel in southern Germany delivers approximately 5,000 kWh/year – sufficient to 
supply nearly all the annual electricity needs of an energy conscious household. 
Connection to the local electricity network allows  any excess power produced to be sold at peak 
hours to the utility. Electricity is then imported from the network outside daylight hours. 
The role of energy storage in an on-grid application is to store excess PV energy until it is needed. 
Effectively, energy storage will ‘time-shift’ PV energy produced during the day, peaking at noon, to 
make it available on demand. This will both maximise local consumption and enhance the efficiency 
of the PV system. Surplus energy can also be fed back into the grid, for which the owner of the PV 
system would be remunerated at a higher tariff. 
Energy storage will also increase security of supply while making individual consumers less 
dependant on the grid. It will also help to boost the development of energy self-sufficient houses and 
buildings and contribute to the continuous growth of PV as part of the global energy mix. 
The main benefit of on-grid energy storage for utilities is that it will reduce the peak load on their grid 
while at the same time making PV a source of predictable, dispatchable power that they can call on 
when needed. Reduced grid losses, i.e. the energy lost by transporting power from a centralised 
generator to the point of use, will result in some energy savings. Savings due to reduced consumption 
in PV powered households are anticipated to be 10 to 20 per cent. Rationale for on-grid energy storage
The change in emphasis for on-grid PV production has created an increasingly sound rationale for 
energy storage that maximises local consumption by time-shifting PV power from the peak production 
to the evening, when it is most needed. Furthermore, the more of its own-produced power that the 
household uses, then the more independent it becomes from the grid and the more secure its supply. 
Energy storage will also enhance the efficiency of PV production and will play a role in improving 
power quality and power ability. 
Any surplus energy can also be injected into the grid for which the household will be paid at a high 
The utility will also benefit from its consumers having energy storage since this will reduce peak loads 
on the grid. It will also enable it to make use of PV as a predictable, dispatchable, form of power. The 
utility will be able to call on this stored energy at  periods of high demand. Yet at periods of peak 
production and low demand, the utility will not have to accept the excess power, and this will avoid 
any potential overloads on the grid. 
Socio-economic impacts 
Energy storage could offer a number of socio-economic benefits. Mainly, it will help to stimulate the 
continuous growth of PV as part of the overall energy mix. It will also help to reduce grid losses and 
encourage reduced consumption in PV households.

Solar iPhone/ iPod Charger;

Posted on

Solar (Altoids Tin) iPhone/ iPod Charger; Original Article;

Step 1What You Need

For this project I’ve stolen a charging circuit from an Emergency iPod charger I got off ebay.  You can find these all over the place.  The key is to find one that will work with an iPhone.

Apple decided to have it’s newer iDevices not follow USB standards.  When an iDevice is plugged in it checks the data tabs on the USB to see what it’s plugged into.  Depending on what it finds it sucks more or less power, which makes sense but is annoying because NOTHING ELSE DOES THIS.  Thus no charger out there has any power flowing to the data tabs.

So the key is to find one that works for your newer iPod or iPhone.  If you have an older iPod or iPhone when you don’t really need to worry all that much.

Altoids Tin

Soldering Iron
Hot Glue Gun
Wire Strippers
Protective Goggles

Charging Circuit
2x AA Battery Holder
2x Rechargeable Batteries
1N914 Blocking Diode
Solar Cell greater than 4V
Stranded Wire Tape.

If we use two rechargeable AAs that put out a total of 2.4Vs we’re going to need a solar panel that is at least 3 – 4Vs just to meet basic levels of charging. The higher the voltage of our solar cell (or cells) the less light we need to charge up our batteries.

First strip your wires. Cut off 1/3rd of the wire from the battery holder and then strip some coating off the end.
Now cut a couple lengths of wire about 8 inches long.  Strip the coating off each end.

Solder The Solar Cell

First wrap one of your 8inch wires around your diode.  Look at the diode.  One side has a black bar.  This is the negative end.  Wrap your wire around that end.

Then just solder the wire to the negative end of the diode.
The positive end of the diode should then be soldered to the solar panel’s positive tab.

Use your second wire on the negative point on the solar cell.

Take the red wire (positive) from the battery pack and twist it together with the positive wire from the solar cell.
Take the black wire (negative) from the battery pack and twist it together with the negative wire from the solar cell.

This is the most difficult part of the project.

Look at the circuit.  You should be able to find a Positive (+) and a Negative (-) point on it.  Just look for the battery tabs.

Now you don’t have to remove the battery tabs, you can leave them where they are.  Usually they are very easy to break off and it does save you some space.

Now just solder the positive cluster of wires to the positive point on the board, and the negative cluster of wires to the negative point on the board.

Now the big problem I see people having with projects like this is that they use too much solder. .

Lets refresh how we solder so we don’t cause any shorts

Touch your soldering iron to the wires and wait five seconds.  Then touch the solder to the wires.  DO NOT directly touch the soldering iron with the solder.  The goal is to heat up the wires.  When they’re hot enough the solder will flow nicely.

You don’t need a lot of solder to get the wires to stick.  Just a dab.

Now that we’re all done you can tape things up.

Use some electrical tape and tape up your solar cell.  Cut off any extra diode or wire.

If you’re using a tin it wouldn’t be a bad idea to tap up the area where you’re going to put the circuit.  Just on the off chance that you might get a short because of the tin surface.

The top right corner is a good spot to put the circuit.

BUT WAIT!  Before we glue down why not test out the circuit to see if it’s working?  You can even just throw in some regular AA batteries to see if everything is charging up well.

Throw some hot glue down on the far left side of the tin where your battery holder will be.  Then, put the battery holder down.

TAKE BATTERIES OUT BEFORE YOU DO THIS.  Otherwise they’ll probably get glued down as well.

Now throw some glue down where you want your circuit to be.  Place the circuit on top of it and hold it down.  You want it as far back as you can in the tin.

Once the glue is dry we’re going to go back for Round 2.  We want to make sure the retractable cable is nice and secure.  I usually scrunch the cable into the back corner and then throw down a whole lot of glue over the top of it.  This was I don’t have to worry about pulling the cable off.

Once that’s dry you’re totally done.

Before Using

Before you start using the charger you should do a couple of things.

1st, charger up the batteries.  You can do this either through large amounts of sun or by using a wall charger.

I’ve found that if the batteries get low on power the iPhone will throw out an error message saying “Not compatible for charging with iPhone” and then refuse to charge.  Just charge up the batteries again and life will be good.

2nd, figure out how everything fits in there.  The retractable cable will lay flat on the bottom if you’ve got everything spaced out correctly.  The solar cell will also fit inside the tin.

If you’re having issues with the solar cell try turning it around clockwise.  This bunches up the wires and allows for it to fit in a bit better.

It can sometimes be a tight fit, but believe me, everything fits.

3rd, if you’re having issues with your iPhone or iPod and charging try using some regular batteries.  If they work then that means that your rechargeable batteries just need a recharge.  Also keep this in mind.  In a pinch you can always throw in regular batteries to charge up your phone.  Like if zombies are attacking at night.

Finished article.

It's finished!

Origional article