SEED – School Energy Project

Sponsored By

Public Service Company of New Mexico

In 1996, PNM’s Good Neighbor Program funded the SEED project for school districts in Southern New Mexico. The project seeks to expand student energy education and to involve students in energy conservation in their school and community. The program involves students from K-12 and is modeled after a Texas project developed by the Energy Center at the University of Texas at El Paso.

WATT WATCHERS

Watt Watchers are teams of elementary school students who patrol their schools checking for energy waste. Several times during the school day the students patrol their assigned areas, and should they find lights on in an unoccupied room, the offending responsible party i.e. teacher/administrator, is issued a ticket.

The program begins with a presentation to the school sponsor (teacher/admin.) and students. Participants learn how the energy used in the school is produced, the relationship of fossil fuels and pollution, and the importance of conservation/efficiency. The students also learn how renewable energy can play an important role in their future.

Watt Watcher patrols have consistently reduced school energy use and utility bills, but it doesn’t end there. Everyone in the school becomes more energy conscious and the lessons learned are taken home and implemented. Saving energy reduces pollution and improves our environment.

New Mexico School Districts currently participating in the program include Gadsden, Silver City and Deming.

Student Mentoring

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The 3rd grade students at Chaparral Elementary School are not only very diligent about their Watt Watcher Patrols, they also gave up their recess time to develop an energy presentation for the kindergarten classes.

ENERGY COUNCIL

The High School program begins much the same way except that the sponsor and students are often part of an established group such as the Student Council or Science Club. Projects for High School students include school energy audits, energy displays in school and community, auditing of utility bills, weatherization of homes in the community, and mentoring of elementary school students. The Energy Council “adopts” elementary schools and implements Watt Watcher Programs and more.

Community

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Gadsden High School students spent a Saturday morning weatherizing homes for senior citizens.

Start Saving Energy In YOUR School

Solar Food Drying

The art of drying food using solar energy is a little more complicated than you might think. We have tried to gather some practical information and to provide links to other resources. Although dried food is popular with campers, backpackers etc. this page

is driven by the need for solar dryers in areas where fruit is plentiful in summer months, but because there is no simple and economic method to preserve it, much of it is left to rot, while in the winter there is hunger.

Solar food drying can be used in most areas but how quickly the food dries is affected by many variables, especially the amount of sunlight and relative humidity. There are some basic guidelines to drying food.

Most of the resources we researched recommend pre-treatment of the food, such as blanching, (boiling/steaming). Many experienced users do not pre-treat food.

Wash fresh fruits and ripe vegetables thoroughly.

Effective drying is accomplished with a combination of heat and air movement.

Remove 80 to 90% of moisture from the food.

Typical drying times range from 1 to 3 days, again depending on sun, air movement, humidity, and type of food.

Once the drying process has started it should not be interrupted, do not allow to freeze.

Direct sunlight is not recommended.

Temperature ranges of 100 to 160 degrees will effectively kill bacteria and inactivate enzymes, although temperatures around 110 degrees are recommended for solar dryers.

Too much heat especially early in the process will prevent complete drying.

Food should be cut into thin slices, less than 1/2″ thick and spread out on trays to allow free air movement.

Rotate trays 180 degrees daily for uniform drying. Move dryer food to bottom racks.

Safe tray materials include Stainless steel rack-wood slats-cheesecloth-Teflon -Teflon coated fiberglass-nylon -food grade plastics

Allow food to cool completely before storing.

Store food in air tight jars or plastic containers, and do not expose dried food to air, light or moisture.

Most fruits taste great dried including apples, apricots bananas, grapes etc.

Vegetables are best reconstituted by covering with cold water until they are near original size.
They can be added in their dry form to soups/stews. Vegetables can also be ground into powders and used for instant soups or flavoring.

RESOURCES
http://muextension.missouri.edu/xplor/hesguide/foodnut/gh1562.htm

http://www.cahe.nmsu.edu/pubs/e-322.htm good chart on preparation and drying times.
http://www.agen.ufl.edu/~foodsaf/he520.html

Abstracts
http://www.ariadne-t.gr/phaethon/solar/dryabst/dryabst.html

Proceedings of Ises Solar World Congress
Budapest 1993, Volume 8.Numerous papers on
solar drying of various crops.

Plans
From: Home Power Magazine
http://www.humboldt1.com/~michael.welch/extras/fooddeh.pdf

http://www.uky.edu/Agriculture/Forestry/
AppalFor/tp.html ($2.)

Basic Solar Dryer

Solar Cookoff

Solar Cook Off ’97

EPSEA’s Solar Cook Off coincided with Eath Day Festivities in El Paso on April 20. On a beautiful Solar Day, EPSEA not only conducted the cook off but also set up working solar displays which included; PV water pumping, solar distillation, concentrated solar energy, a stirling engine and the “Human Sundial”. Thousands of people visited our booth and left with information about the equipment displayed as well as solar design, hot water and more.

The Human Sundial

Once laid out the human dial holds their hands slightly apart and turns until there is no shadow on either palm.

Lilly Ojinaga, Program Coordinator for Renewable Energy, State Government of Chihuahua, Mexico demonstrates just how easy it is to tell time.

Here are a few photos of the entries from elementary, middle and high school students from El Paso and Juarez, Mexico. Congratulations to all who competed.

Solar Stills

Solar Water Purification Project

In 1995, EPSEA received funding through the State of Texas, State Energy Conservation Office (SECO), for a solar demonstration project. EPSEA’s project demonstrated the feasibility of using solar energy to purify water. The target audience (end users) are the people who reside in colonias along the Texas/Mexico Border. A colonia is an unincorporated settlement, lacking a safe water supply and waste water treatment. EPSEA’s work in solar water purification continued in colonias in Dona Ana County, New Mexico through a collaborative effort with the Southwest Technology Development Institute (SWTDI) at New Mexico State University. In 2000, EPSEA was able to install stills in Juarez, Mexico through a grant from “Border Pact”. EPSEA has since received funding through the U.S. Environmental Protection Agency (EPA) to continue it’s work in solar water distillation.

EPSEA has presented papers and hosted workshops at the American Solar Energy Society’s (ASES) national conferences and the Mexico National Solar Energy Conferences.

The problems faced by many colonia residents include contaminated water, as well as water with very high salt content. The sources of contamination include septic systems, industrial pollution, and run off of fertilizers and pesticides. These problems are seen on both sides of the border and like the resulting sickness and diseases, know no borders. These problems are not confined to only colonias, but it is the conditions that exist in colonias which allows for the proliferation of sickness and disease. The causes of these problems can be traced to pollution, poverty, ignorance and greed.

The Marcos family, Juarez, Mexico
Solar Solutions

EPSEA’s demonstration project is only a small example of the potential role for solar energy in water treatment, and disease prevention. Solar distillation is a proven technology for water disinfection. Systems can be sized for one person, up to community sized systems. They have no moving parts, relying only on the sun for energy, and should last 20 years or more. Larger disinfecting systems which generate chlorine and other gases can be operated in remote locations, using solar energy. It is hoped that through the success of our local project, these technologies will be replicated in other regions currently facing similar conditions.

The heart of EPSEA’s project is a basin solar still. EPSEA’s research resulted in a basin still, with emphasis on ease of replication and readily available materials. The still utilizes standard patio replacement glass (34″X76″), and during the summer months produces over 3 gallons/day. Winter production is about 1/2 that amount. The still has no moving parts, uses only solar energy to operate, and is self cleaning.

Project Update

The El Paso Solar Energy Association’s (EPSEA) solar water distiller projects (under an EPA grant for TX & NM, and Borderpact/Conahec for Mexico are progressing successfully. Only two more stills need to ben installed in the colonia areas of Ciudad Juarez, Mexico to complete the Borderpact project. The EPA project is just beginning Phase II which includes public community meetings and further education via energy fairs, etc., and a hands-on stills construction workshop that will be taught by Mike Cormier at the Water Festival in Columbus, NM in March. Applications are already being accepted by EPSEA from potential still recipients in the Luna, Dona Ana, and El Paso Counties of southern NM and west TX.

A selection process will be used to decide who will receive a still. A cost-share amount of $50-$100 per still (small or large, respectively) will be paid by the recipients who are chosen. A sponsorship and payment plan program is available for individuals who cannot afford the cost-share amount. A recent fundraising breakfast was held at St. Pius Church by the St. Pius Colonia Ministry to aid in achieving funds for such sponsorships.

Border Pact Presentation – PDF Document (327k)

For more information about these projects contact us at 915-772-SOLR email: webmaster@epsea.org

Final Update

Having completed this project, we presented a final paper to the Solar World Summit for the International Solar Energy Society in Orlando, Florida in 2005.

OPERATION

Solar energy is allowed into the collector to heat the water. The water evaporates only to condense on the underside of the glass. When water evaporates, only the water vapor rises, leaving contaminants behind. The gentle slope of the glass directs the condensate to a collection trough, which in turn delivers the water to the collection bottle.

EPSEA Still Cutaway (39k)

The still is filled each day with twice as much water as was produced. The still is fitted with overflow outlets, which allows the excess water to flush the still every day. A major advantage of the basin still is that it does not require a pressurized water supply. Colonia residents often have their drinking water delivered by truck and it is then stored in 55 gallon drums. Still recipients report that the water tastes very good and their children now drink more water than before.

Construction Cost

EPSEA material costs, with bulk purchasing, are approximately $200 per still. The cost of materials to build a single still should be less than $300. Only basic tools are required.

Construction Plans Available

Solar Hot Water

Most everyone has experience with passive solar water heating. How many times have you turned on the hose in the yard and nearly burnt yourself with hot water? While you weren’t looking, old Sol was quietly working to give you hot water, even if you didn’t want it. Well if it’s that easy, imagine what you can do if you’re actually trying to make hot water. Passive solar hot water systems are probably the oldest commercially available solar systems. At the turn of the century there were large numbers of solar water heating systems on roof tops, especially in Los Angeles and Florida. Very little has changed from the original concept. Put a water holding tank in a box, with glass on the side facing south and fill it with water. No moving parts, nothing to break down, free fuel and no pollution.

The passive solar water heater is known today by many names; PSWH, Batch Heater and Bread Box are the most common and then there is the very technical; Integrated Collector and Storage System (ICS).

The PSWH of today usually starts with a 40 gallon, glass lined tank. These tanks come disguised as ordinary electric water heaters, which are stripped of their appliance shell and insulation. Painted flat black, with high temperature engine or barbecue paint and they’re ready for solar.

The box should be well insulated to prevent energy loss and the amount of insulation should reflect your local climate. The typical box is constructed with 2X4s or 2X6s, using fiberglass batt insulation. The exterior siding may match that of your home, or some other material suitable for your area. The interior sheathing is often ridged insulation, preferably with a foil face facing in which works to reflect more energy onto the tank. Ridged insulation comes in various thicknesses which can help increase your insulation R-value.

The size of the box must be big enough for the tank, but also large enough to allow adequate solar gain. Typical glass sizing is 1 sq. ft. of glass for every 2 to 2 1/2 gallons of water. A standard size, double glazed, patio door replacement glass (34″X76″) is ideal for a 40 gal. water heater. Of course if you already have a piece of glass…….

A water heater has an inlet and outlet and how you attach your plumbing does make a difference. The cold water inlet has a dip tube which extends down nearly to the bottom of the tank, to deliver the cold water to the right place. The hot water outlet takes the hottest water from the top of the tank. If your design calls for the tank to lie on its side be sure that the cold inlet is at the bottom.

Be aware that the 40 gallon tank when filled with water will weigh over 350 lbs. Add to that the weight of the box/glass and it’s time to reconsider putting this monster on your mobile home. Ground mounted PSWH are very common. As always be sure the system will receive full sunshine from 9 am to 4 pm. Remember, if your installing a solar system and you’re working in the shade, there’s something wrong.

If the collector will be installed on a frame roof it’s best to attach in such a way as to spread the weight over a few rafters, and if possible, provide additional support with braces extending up to the rafters from interior walls. The ideal location is as close to the existing water heater as possible.

Shorter plumbing runs are not only more efficient, they decrease the winter freezing potential. The chances of freezing 40 gallons of water are minimal but frozen pipes are a reality. With the tank installed close to the water heater the freezing potential is minimized but not eliminated. All plumbing between the existing water heater and the PSWH is insulated, with more insulation on any pipes exposed to the outside. Also be sure to carefully insulate all plumbing in attic areas.

Plumb the system by first supplying cold water to the solar tank. From there, the hot water outlet is plumbed to the cold water inlet on your existing water heater. As long as the solar water entering your water heater is above the thermostat setting, your water heater does nothing. When the temperature of the solar water entering the water heater is less than the thermostat setting, your water heater makes up the difference.

The temperature of the water from a PSWH depends on many variables. The amount of sunshine, ambient air temperature, the amount of insulation used, the temperature of the supply water as well as the hot water demand all effect outlet temperature. Under ideal weather conditions, and no hot water used since morning, the water temperature at 5 pm can exceed 180 degrees F. You may consider installing a tempering valve which allows you to set the temperature for the water before it reaches the faucet.

How much of your hot water demand will be met by your PSWH varies depending on a number of factors. Have you installed low-flow shower heads and aerators? Have you installed a water heater blanket and set the thermostat to 120 degrees F? When do you use the most hot water? If you normally wash clothes/shower etc. in the evening, there probably won’t be any solar water in the morning. If someone is normally home during the day and clothes washing is scheduled for around solar noon, you can stretch your solar water. After normal water use in the am, the sun heats the water all morning and then that water is used for the laundry (if necessary). This schedule allows time for the water to heat up again during the afternoon.

Be sure your installation meets all local plumbing codes etc.

Solar Distillation
Solar Water Purification for the
Border

Plumbing Diagram