Advancing Zero Fossil Fuel Technologies at LEF

from the Living Energy Farm newsletter, May -June, 2017

We have continued to bring in new tools and organize our shop. We added a nice, old, heavy duty drill press, powered by direct drive high-voltage DC power as we like to do. We also added a winnowing fan and a heavy duty bench grinder to our collection of direct drive tools. We love our direct-drive! Just run a wire from a set of photovoltaic panels (in series to produce high voltage) straight to the motors, and you can do anything you want during daylight hours. It is a simple and cheap setup.

 

We have continued our research concerning a low-cost high-temperature solar storage system for cooking.  We have discovered a material that we think will make a big difference. In considering high temperature solar storage, we have looked at both tracking collectors and a trough system that needs no tracking. The trough is simpler, but leaves a long collector pipe hanging in the air. As the pipe heats, a lot of heat is lost to the air around the pipe. It would make sense to put some kind of insulating glass around the pipe. But the material would need to be able to withstand very high and fluctuating temperatures well beyond what normal or tempered glass would handle. The high-temperature glass used on woodstove doors is much too expensive. And we would either need a fancy frame to hold the glass around the pipe, or some kind of glass tubing. Finding very high temperature, reasonably priced, large diameter glass tubing just was not  happening. Then we found it. The original Pyrex cookware was made with something called borosilicate.  We have found that we can get borosilicate cheaply in large diameter tubings. This should make a huge difference in our high temperature solar collector.

 

We are also re-assessing whether to use steam or oil as the heat transfer medium. Steam has the advantage of being very cheap as it is just heated water. It has the disadvantage of needing pressurized storage tank(s). Oil has the advantage of being capable, at least in theory, of handling and storing much higher temperatures in non-pressurized vessels. Industry uses various forms of modified mineral oil that they call “heat transfer fluid,” or HTFs. The market for HTFs has been evolving rapidly. In just the last few years, more and cheaper HTFs have become available. In our case, we could use a large heating oil tank, pack it full of small, clean rock, and circulate HTF through it. That’s the design concept at least. Hopefully, after we finish the current round of infrastructure improvement, we can focus on this project.

Low Density Nickel Iron Batteries

LEF May-June3
Nickel and Iron plates for a homemade NiFe battery.
Eddie (our technical intern now resident in Pittsburgh) has been working on low-density nickel iron batteries. He has a working prototype. The electrical storage capacity of his prototype is low, so he is working to add more nickel and iron plates to expand the storage capacity of the batteries. If this technology works, and we can build it cheaply, it could give us a way to provide lighting for a lot of people around the world.
LEF May-June2
Prototype NiFe battery.  Cheap, durable, homemade?  We hope so.

Taking the LEF Model to Other Locations

If we hope to expand the LEF model, we need to know where we are going to take it. We have been working with Kate (see previous 2 newsletters) to find sites where we might use what we have learned at LEF to help people in the non-industrial world. Kate has extensive experience working with development and aid organizations around the world. Kate has been traveling in Latin America, and looking for sites where  LEF can help. This seems to make more sense than locations far away. Kate made some good connections, but we have not yet picked a specific site. As we mentioned in the last newsletter, we will stay in touch with Tom (from New Community in Harrisonburg) as he travels this winter to the Dominican Republic.
Advancing Zero Fossil Fuel Technologies at LEF

Batteries and Boilers at Living Energy Farm

from the March – April 2017 Newsletter

Low-Density Nickel Iron Batteries?
We have been continuing our research and work with Nickel-Iron (NiFe) batteries. NiFe batteries are non-toxic, extremely durable, and very tough. Lead-acid batteries are fragile, toxic, and short-lived. Lead-acid batteries dominate the off-grid market, and have largely destroyed it because they die so quickly.

All of the research and development of batteries, NiFes included, has focused on power density- storing a lot of energy in a small space. Thomas Edison made and sold NiFe batteries, intending them for use in electric vehicles and other portable uses where high power density is very desirable. For such uses, short recharge times are also desirable. NiFe batteries have lower power density and longer recharge times than lead-acid. Modern research on NiFe technology has continued to focus on these issues. (There is one substantial research project underway at Stanford University.)

From the perspective of how we do things at LEF, power density and recharge time are irrelevant. At LEF,  we store energy in various ways that allow us to minimize the need for stored electricity. We store water in pressurized tanks, so we don’t have to run a water pump at night. Our buildings have massive thermal mass, so we don’t have to run a heating system at night. We will pump irrigation water through the house while the sun is shining, getting free air-conditioning in the summer from solar pumped irrigation water.  We use high voltage DC motors when the sun is out. We use stored electricity for lighting, nothing else. Our NiFe batteries charge all day long from our solar electric panels. It would not matter if their recharge times were slow or if their power density was abysmally low. Big, cheap batteries would be just fine.

A few people have tried “out in the garage” experiments with homemade NiFe batteries. The basic ingredients — nickel, iron, potassium hydroxide (aka potash) — are easily available. We have been looking over Edison’s original manufacturing processes, as well as the documentation of various homemade NiFe attempts. From his shop in Pittsburgh, Eddie is going to continue the research and try to build low-density NiFes in mason jars. We are not so presumptuous as to imagine that we could outsmart the many well-endowed entities that have worked on high-tech batteries over the years. But it is very possible that low-density NiFes have been ignored simply because there is no immediate profit to be made.

If we can make cheap, low-density NiFes, it would be revolutionary. A very small solar electric panel could be wired straight to the batteries. Small houses in villages all over the world could have light with small LED flashlight bulbs designed to run on low voltage. That could be a cheap, very durable way to provide lighting to millions and millions of the world’s poorest peoples. Wish us luck. If the mason jar NiFes fail, we will continue our overseas efforts using purchased NiFes.

Solar Boiler?

Finding a clean, sustainable way to cook food each and every day has proven to be the most challenging aspect of our project. A defining characteristic of LEF is that everything we do has to be as cheap and simple as possible. That is embedded

LEF Boil
Solar boiler is operational, but not adequately effective (yet).  New shop in the background.

in our definition of sustainability. Finding tools and machines that are accessible to most of humanity is not easy.  At LEF, we are using a combination of solar cookers (parabolic and ovens), and wood stoves. Our rocket stoves are very efficient, using about one-tenth of the wood of an old-fashioned wood cook stove. There are numerous organizations working to spread rocket stoves around the world. That’s a good thing.

The rocket stoves work, but they are an outdoor technology. They are a fire hazard. They mean that some ash and soot get into the food, and some smoke gets in the face of the cook. We built a biogas system at LEF a few years ago. (Biogas = methane = natural gas.) It worked, but there are limitations. The gasifier needs to be kept warm. In cold climates, sometimes they are buried. It needs to be of considerable size. It needs to be fed biomass each and every day.

Seeing the limitations of biogas, we have built a prototype solar boiler. We designed a tracking collector that followed the sun, but decided to use a simpler trough system that needs no tracking. The collector reflects light onto a pipe which contains water. The water boils and the steam collects in a storage tank. The steam could be then piped into a steam-jacket kettle in the kitchen to cook our food. Cooking would be as simple as opening a valve leading to the kettle.

We have been making solar steam, but so far, not enough to make it an effective heat source for cooking. We have some design modifications under way that should improve performance substantially. At LEF, we live with these technologies. We are currently eating small amounts of ash and soot in our food almost every day. Such is unavoidable when cooking with wood, and unacceptable in the long run, especially for our kids. The fact that we live with the technologies we espouse gives us a very different perspective than just experimenting with them.

Another advantage of developing the solar boiler is that we need the exact same parabolic trough setup for a solar ammonia ice maker, a super low-tech refrigeration system. We have thus given ourselves a head-start on that project. And we decided we are also going to look at biogas again. It could be a good bridge fuel for times when the weather does not support the solar boiler. Can we do it and still keep it simple and economical? Methane is a potent greenhouse gas. Can we control leakage? What is the impact of that on a larger scale? We will be seeking to answer these questions in the coming months.

Batteries and Boilers at Living Energy Farm

Commune Dads Episode 3 – Tech, Kids, and Moderation

Commune Dads Episode 3 – Tech, Kids, and Moderation