I’ve been fascinated by Stirling and other heat based engines as long as I can remember, which is why I’m excited to announce that these educational alternative energy kits from Exergia are now available in the Maker Shed. These unique kits are assembled using simple hand tools and come with clear English and German instructions. They also have some clever packaging; each comes inside a small can which is later re-used in the build (for most of the kits.)
The Stirling Engine Kit is great for demonstrating principles of thermodynamics and is powered by a small tea-light candle (or your wood burner, provided it isn’t too hot.) If you’ve ever built a Stirling engine, you probably know that they can be a bit finicky. The above engine took me about an hour to assemble and ran the first time I lit the candle and spun the prop.
The Candle Car Kit uses the same principal that powers nuclear space probes (the Seebeck effect.) Instead of using decaying radioactive material and the cold of space, however, the car uses candle and a heat sink. After you build the car, put it on a smooth surface and fill the reservoir with water. Light the included candle and after a minute or so, the resulting temperature deferential across a Peltier junction will produce enough energy to drive the motor. You can increase the speed of the car by using colder water or adding ice cubes, and have it go straight or in circles by adjusting the front wheel.
The Thermogenerator 2.0 also demonstrates the Seebeck effect for power generation. Just build the kit and fill one side of the reservoir with cold water, and the other with hot. The Peltier junction sandwiched between the two aluminum plates will generate enough electricity to turn the prop with just a 10 degree difference. Increasing the temperature differential by using hotter water or ice will increase the speed of the propeller.
This one boggles my mind a bit. The Heatmobile 2.0 converts heat directly into mechanical energy using a continuous loop of Nitinol wire. Nitinol is a shape memory alloy (~50% Nickel, ~50% Titanium) which has the unique property of “remembering” a shape it was formed into at high temperature. When heated to its transition temperature by warm water the wire attempts to return to that shape. This force is enough to drive the propeller until the water cools below the transition temperature. The really interesting part is that this motor is bi-directional; spin the prop clockwise and it will continue clockwise. Spin it counter clockwise and it will continue counter clockwise.
These kits are perfect for tinkerers, students, or anyone interested in alternative energy. Check them all out in the Maker Shed online store.
Scientists working at England’s Bristol Robotics Laboratory have developed a technique for converting urine into electrons, enough to power a cell phone.
Dr. Ioannis Ieropoulus of the the Bristol Robotics Lab explains how mircrobial fuel cells, pictured at right, turn urine into electricity.
The research team has developed microbial fuel cells that consume carbohydrates, nitrogen, potassium, phosphorous, and other compounds that would otherwise go down the drain. If you can get past the gross-out factor, the benefits to places in the developing world and elsewhere that lack reliable (or affordable) sources of electricity are obvious.
The project reminds me of another one showcased at Maker Faire Africa last year: a urine-powered generator.
There’s an added benefit of the microbial fuel cell technology, too. According to researchers, passing the urine through the fuel cells “cleans” it so it can be safely discharged into the environment, eliminating the need for wastewater treatment. Maybe sewage plants could double as power plants. Pee pee becomes a win-win.
If the output of the fuel cells could be expanded, what applications can you imagine for this technology?
Today is Toolsday here at MAKE, so you know what that means – a live Google+ hangout where we will be discussing our favorite tools and workspace essentials. Tune in at 2pm PST/5pm EST on the +MAKE page, or if you’re busy you can catch it later on the MAKE YouTube page.
The main topic of the hangout will be power, in various forms. We’ll discuss a few of the many ways to power your projects, whether it’s with a homemade bench-top supply, a solar panel hanging out of your window, or a kit like the Mintyboost. If you power your projects with wind or water, for example, please share your setup with us in the Make: Forum or participate in the hangout by leaving your questions, comments, and opinions on MAKE’s G+ page.
A group from Vanderbilt University, lead by Professor David Cliffel, claims that a protein found in spinach, called PS1, when combined with silicon found in solar panels to form a biohybrid cell, end up being 2.5 times more efficient than cells lacking the protein. The reaction was first discovered decades ago, but hasn’t been explored in detail until just recently. [via technabob]
Over at the Maui Makers hackerspace, member Ryan K showed up with a mess of Lilikoi fruit (also known as passion fruit). Using anodized bolts (source of zinc), some thin copper pipe, wire, switches, LEDs, and a capacitor, he built himself a battery from the fruit.
The Lilikoi vine produces a massive amount of fruit in Hawaii, often creating a nuisance for home-owners who own a plant. The fruit drop and have to be cleaned up, otherwise they rot and attract insects. Ryan tasted one and noticed it was quite acidic and might be a good candidate for a homemade battery.
The fruit charge a 6800 uf capacitor, and when the volt meter hits 3v, the switch can be thrown, letting the green laser emit a short pulse. For those curious, two days later the charge was down to 1.8v. Obviously this is a supply and demand issue they’ll need to sort out.
Abe and Josie Connally are two of my maker heros. Their infectious positivity and passion for preserving the environment fuel their unfaltering dedication to living the DIY off-grid homesteading dream. They’ve built their homestead from the ground up in the hills of Chihuahua, Mexico, and they relish in sharing their know-how with the greater maker community through their site, Vela Creations. Their names have appeared in at least 11 volumes of MAKE, and they’ve taught us how to make wind generators, seed starters, honey cows, solar food dryers, compressed earth brick floors, fabric-formed posts, solar wax melters, and more. We recently caught up with Abe to get a window into off-grid life: building, growing, teaching, and raising two beautiful kids.
1. What was your first foray into off-grid living?
We bought 20 acres of pristine desert in southwest Texas, where we met. There was nothing on or near it — no structure, water, electricity, phone, sewage, etc. It was 30 miles from the nearest population and 60 miles from the closest town. We started off living in a small bus, retrofitted with solar panels, kitchen, bed, table, and shelves. Piece by piece, we built our own amenities: an adobe house, rainwater catchment, a power system with solar and wind, composting toilet, garden, goats, and chickens. As we figured out how to handle each aspect of living off-grid, we became increasingly addicted.
2. Tell us about the homestead you and your wife Josie have created.
We have lived on our current property for 5 years now. This is our second off-grid homestead built from scratch. We started off building small: one room, one water tank, a small power system, a basic garden. We called it the “off-grid starter kit.” Each year we have added to each system, integrating them as much as possible to increase efficiency.
The house (now very spacious at 1300 square feet) is half buried on the north, with huge windows on the south. In winter, the solar gain from the windows and hot water pipes under the brick floors heat the house, while the roof insulation and thermal mass of the earth keeps that heat in. In summer, it stays cool. Windows are placed for maximum through-breeze, while the thermal mass, insulation, and eaves over the windows prevent the heat from getting in.
We catch rainwater from the roof. We currently have 8000 gallons of storage capacity (including the tank on the rabbit shed), although those are already almost full after one month of rain. That is enough to last us through the nine dry months of the year. However, we plan to add more tanks this year, so that we can have gardens, fish, and orchards year round. We also have two new ponds, one of which is in the animal pastures, that are starting to fill. We have a solar water heating system that not only provides us with plenty of hot water, but also heats the floors in winter.
Our electricity comes from the wind and sun. We can run any appliance we want, although we are naturally conservative and never waste power needlessly. Both our fridge and freezer are super efficient, and we use low-energy appliances where possible (like laptops).
We produce a large part of our food requirements, and are currently working towards increasing that supply. So far, we have gardens, some fruit trees, pigs, rabbits, and poultry. We hope to include fish and more perennial vegetables this year.
Our waste streams are pretty low. We compost everything organic, or feed it to the earthworms and black soldier flies. And as for inorganic wastes, we either try to avoid or reuse them. We still have a ways to go before being completely self-sufficient, but we’re getting there, step by step.
3. How did you learn the homesteading skills you have?
We read and research a lot, both via books, magazines, and online. And then we jump in. Whatever we can’t learn from others, we figure out through trial and error (the error part often being the most instructive).
A lot of it was upbringing, too. We both had parents who encouraged us to learn and do things for ourselves. They took away the fear of trying something new. We have a natural curiosity about the world around us, and that helps us figure out how things work or should work.
The projects at Maker Faire always run the gamut, with a healthy balance between the whimsical and the practical. Maker Faire Detroit, taking place this weekend, July 28 and 29, at The Henry Ford, is no exception. Last week we got a window into the Great American Horn Machine, mobile platform of awesome whimsy, and this week we chat with Hubert Gillespie, whose contribution to the field of alternative energy comes in the form of the practical Kinetic Push Mill.
1. What inspired you to make the Kinetic Push Mill and how long did it take to build?
The Push Mill is part of a larger vision of a “Generator Gym” concept where a workout will produce appreciable amounts of electricity as an output. This piece of equipment was the most direct example we could think of that demonstrated the increased output of a team working together creating energy. It took us about six months to design the individual pieces making up the unit, six months to assemble, and another six months of testing and modifications to get to this point.
2. Describe the Mill components and how it works.
The Mill is made up of three basic operating components: the turnstile, the gearbox, and the generator head. Eight to 16 individuals push together on eight arms extending from the turnstile. The turnstile transfers this kinetic energy into the gearbox, giving output of 1800rpm to the generator head, creating 220V AC. The generator is 10kW, and we are still testing the full output we can achieve with this device.
3. Have you made other kinetic projects in the past? What’s the biggest challenge in building something kinetic?
This was the first kinetic project we have attempted so far. We have some other ideas in mind, but want to get this one further down the development path before we begin on the next one.
4. You brought the Mill to Maker Faire Detroit last year. What types of reactions did you receive?
We had a great reception at last year’s Maker Faire. It was amazing how drawn to this the kids were, to grab onto an arm and start pushing, and adults as well were curious about how the unit worked and how it could tie into a bigger vision of energy creation. We were honored to receive recognition from the event organizers for our exhibit.