about partner teams internships eden jaguarcreek contact
Target Earth
Technical Report

Introduction to Jaguar Creek

By Jim Beard

Jaguar Creek is an Environmental Field Station, Mission and Retreat Center located in Belize, Central America. Nearby is the Blue Hole National Park, adjacent to thousands of acres of virgin rain forest that is protected by Target Earth International and Jaguar Creek through the Eden Conservancy Program. The facility sits on approximately 10 acres in the midst of 700 acres of private sub-tropical rain forest maintained in it's natural state. A pristine stream runs through the site and is used as the primary source for the water supply.

Jaguar Creek is used by Target Earth to host research and education programs. Guests include college students living onsite for up to four months, local and visiting professors, guest lecturers, scientists, short-term volunteer teams assisting in various community projects, and guests attending special retreats or conferences.

Jaguar Creek facilities accommodate up to 50 people in facilities totaling nearly 10,000 square feet. There are two identical two bedroom Staff Cabins, a third three bedroom Staff Unit, and a Staff House. Eight cabins are designed to house both students and guests. The Dining Room and Lodge has a kitchen large enough to prepare food for 100 people, a main dining and meeting room, and a library and study area. The Office and Classroom building is designed to be a multi-purpose facility with seating area for 60 people, storage cabinets, counter space, a sink, and laboratory equipment. Finally, the Operations Building, called the Department of Water and Power (DWP), houses the water and power systems, a central laundry facility, and maintenance equipment.

The Concept of Independent Living

Just a century ago, the homes we lived in, the offices or factories we worked in, and the vehicles we used for transportation were very different than those in use today. At the turn of the century, most homes were "independent" living units, meaning they furnished their own sources of power and fuel for heating, cooking, and lighting. Today we call facilities that are independent of outside utility sources "off-the-grid", or "sustainable" living units. The big advantage of independent living is that we can exercise a responsible choice between long-range environmental consequences (exhaustion of nonrenewable energy resources) and short-term economic impacts ( the cost of alternative energy resources may cost more initially). With independent living we choose to invest in the preservation of our environment by shrinking the boundaries of our basic needs (power, heating, lighting, cooling) and use alternative and renewable energy sources (solar power, wind power, hydropower) to replace more traditional sources such as fossil fuel. In these independent living facilities we become both the energy supplier and the consumer which leads to more responsible decisions in how we equip our homes and utilize these resources.

The concept of "independent living" was the basis for all the infrastructure design decisions that led to selection of the various technologies described in this report. These technologies were thoroughly researched and final equipment selections were made based on long-term environmental impacts (must have minimal or no adverse impact on the environment), reliability (must be able to operate for long periods of time with little maintenance and downtime), and ability to preserve the ambiance of the rain forest setting (must blend sensitively with local ecology as well as native culture).

Electrical System

Background

Today, there are three commonly used renewable energy resources in use throughout the world: hydropower, solar power, and wind power. Each of these sources was evaluated for possible use at Jaguar Creek.

Wind turbines were initially considered as a primary power source but were eliminated as a viable alternative due to marginal to inadequate winds at the site, obstructions created by the native vegetation, and due to concerns over turbine noise that would be disruptive to the native environment (especially wildlife). However, it should be noted, that wind power remains a competitive and viable alternative where site conditions fully favor this power source.

Hydropower was considered as both a primary and as a secondary power source. A pristine stream flows across the southern border of the site. This stream is part of a large underground creek and runs continuously throughout the year. An initial stream bed profile and flow measurements were made and this data showed that the fall of the stream was insufficient to generate the power necessary to serve as the primary power source for the project. However, we may consider developing this resource as a backup for the main power source at a future date. This source meets all the preliminary design criteria established for Jaguar Creek; provided, that there would be no adverse impacts to the creek eco-system resulting from it's installation and operation.

Solar power was determined to be the most viable primary power source for this project. Photovoltaics, one of the most promising solar energy technologies, are used at Jaguar Creek. This technology involves the direct transformation of solar radiation into electric power. Photovoltaic cells are now available that produce significantly more power than the original ones developed in the 1950's for the space program.

Not only are these photovoltaic cells more efficient, they cost only a small fraction of that of the original units. Solar power lets you tap into a secure, economical, essentially inexhaustible, and widely available resource -- the sun. In addition, photovoltaic systems have few environmental impacts, are easy to operate and maintain (no moving parts), and meet all the design criteria established for this project.

Solar System Design Configuration

The solar system selected for Jaguar Creek consists of two similar configurations. The primary system was designed to power critical equipment items such as water pumps, refrigerator, and the Laboratory/Museum Building. The secondary system was designed to power less critical items such as lights, fans, and laundry equipment for the entire facility. Now both systems equally share the power delivery load. The primary system is backed up by a gasoline powered engine generator, because the propane generator we initially bought was too complicated to be fixed here.

At the heart of the solar power system are the photovoltaic modules. These units are mounted on the roof of the DWP. Initially, the concept of mounting the solar panels on the roofs of individual buildings was considered. However, this concept was deemed to be undesirable since it would require considerable clearing of native vegetation around the buildings to provide direct access to the sun, and it was a primary goal of this project design to fit building structures into the native rain forest environment (facilities were literally built around existing trees). In addition, the esthetics and structural integrity of the initial native thatch roofs would be compromised by mounting solar panels on the roof of each building. So it was decided that a central facility (the DWP) would be built to house all solar power, mechanical equipment, water storage, and other appliances such as washers and dryers in one central location away from the other structures. This central location for equipment also has the advantage of providing a higher degree of safety for the occupants of Jaguar Creek than would be afforded by distributed mechanical and electrical systems.

The primary solar system consists of (58) Solavolt 85 watt photovoltaic modules and the secondary system consists of (54) Solavolt 85 watt modules. When installed these solar modules represented "state-of-the-art" solar energy technology. They contain blocking diodes which prevent individual panels from shutting off when partially shaded and transform the sun's energy into low voltage direct current electricity.

The initial design of the electrical system for Jaguar Creek was based on a combination of low voltage direct current (12 VDC and 24 VDC) and standard 110 VAC applications. However, after the initial site layout was completed it became apparent that the distance between facilities was too great (over 400 feet) to economically transmit low voltage direct current. So it was decided to invert the low voltage direct current produced by the solar panels to 110 VAC power by using high efficiency sine wave inverters. These inverters are in common use today and are over 90% efficient. Identical Trace sine wave inverters were selected based on reputation, reliability, cost, and efficiency. Total energy demand was estimated to be about 40,000 watts per day, but is currently 60,000 watts per day.

Since solar energy is only created when the sun is shining on the panels, a source of energy storage was required to allow for continuous system operation. Three days of storage was determined to be most economical battery system configuration. Industrial duty chloride batteries were selected based on their ability to accept deep cycling (draw down of battery storage on a repetitive basis) and because they have an expected life span of 15 years. In 2002 a hurricane wiped out the solar panels of a large hotel in the resort town of San Pedro and we were able to get 4 large batteries (850 lbs each) that approximate the initial battery capacity - thereby doubling our power storage capacity.

At the heart of the solar power control system are two Ananda power centers. These control systems manage the entire solar power system, sending power to the various power busses, charging batteries, and monitoring system performance. A Kohler 6.3 kW propane powered engine generator was bought initially as a backup to the battery system but, replaced by a Honda gasoline generator due to inability to repair the propane generator. Propane was initially selected as a resource to fuel the engine generator because it is much more abundant than gasoline, is a much cleaner fuel from a carbon standpoint, and engines generally last about 50% longer when run on propane.

Solar System Economics

Well, what does all this technology cost? Just 27 years ago, photovoltaic modules were relatively expensive, selling for about $100.00 per watt. But even at that considerable cost, solar systems were still found to be cheaper than extending utility service lines over distances in excess if 1/4 mile. In contrast, the solar modules used at Jaguar Creek cost only $5.00 per watt.

The total cost of the solar power system installed is about $100,000.00, and this system will produce enough electricity to reliably meet the demands of 40 people on a continuous basis (rain or shine). If a local electric utility service were readily available nearby in Belize, the capital cost for electrical facilities construction and connection are estimated to be about $25,000.00 per mile (50% of similar costs in California). This means that our up-front solar system capital cost of $100,000.00 would be offset by constructing 4 miles or more of local electric utility service. In reality, the distance to the nearest primary utility distribution system is well in excess of 4 miles and now in 2003, over 7 years later, electricity is just now moving down the road to the nearby village of Armenia.

There is also an ongoing cost of about $0.10/ kWh for purchase of electrical power from a utility. At Jaguar Creek, generating our own electricity will save about $50,000.00 over the 25 year life expectancy of the operating system components. So not only is solar power environmentally acceptable it also makes sense from an economic perspective.

Summary of Solar Power Equipment

  • (112) Solavolt 85 watt solar modules
    Manufactured by: Photocomm, Inc., 7681 East Gray Road, PO Box 14670
    Scottsdale, AZ 85267 (602) 948-8003
    Purchased from: Real Goods, 200 Clara Street, Ukia, CA 95482
    Attn: Steve Rogers, Applications Engineer (707) 468-9292
  • (2) Trace 4000 watt sine wave inverters
    Manufactured by: Trace Engineering
    5916 195th NE Arlington, WA 98223 (206) 435-8826
    Purchased from: Real Goods, 200 Clara Street, Ukia, CA 95482
    Attn: Steve Rogers, Applications Engineer (707) 468-9292
  • (8) 1690 AH chloride batteries
    Manufactured by: Batteries, Inc.
    PO Box 6109, Santa Rosa, CA 95406 (707) 546-9909
    Purchased from: Real Goods, 200 Clara Street, Ukia, CA 95482
    Attn: Steve Rogers, Applications Engineer (707) 468-9292
  • (2) Ananda APT5-404 power centers
    Manufactured by: Ananda Power
    14618 Tyler Foote Road, Nevada City, CA 95959 (916) 292-3834
    Purchased from: Real Goods, 200 Clara Street, Ukia, CA 95482
    Attn: Steve Rogers, Applications Engineer (707) 468-9292
  • (1) Kohler 6.3 kW propane powered engine generator
    Manufactured by: Kohler Company
    Kohler, WI 53044 (414) 565-3381
    Purchased from: Solar Self-Help, Inc., 965 D Detroit Ave., Concord, CA 94518
    Attn: Jack West (510) 680-4343

Solar System Design Assistance

The author gratefully acknowledges the invaluable assistance provided by Rich Meyers, Electrical Engineer, for his considerable efforts in preparing the electrical load calculations, system design schematics, and equipment procurement specifications for this project. Rich also supervised the installation and testing of the solar power system.

Lighting and Fans

General area lighting and ceiling fans used for cooling the interior of buildings creates over 60% of the energy demand for the electrical system at Jaguar Creek. In order to keep this demand to a minimum, high efficiency fluorescent lighting are used throughout the project.

High efficiency fluorescent lights can save up to 75% on energy costs. In fact, compact fluorescents use only 25% of the energy of a standard incandescent bulb, and they last over 10 times as long. cabins at Jaguar Creek use a total of only 40 watts of fluorescent lighting, while staff units use only a stingy 53 watts for lighting per living unit (this includes lighting for two bedrooms, a living area, and bathroom). Lighting in the other buildings is equally as efficient.

  • High efficiency fluorescent lights are available at most hardware stores and home centers.

Refrigeration System

Ample refrigeration is an absolute must in any sub-tropical environment such as Belize. However, the typical American built 20 cubic foot side-by-side refrigerator/freezer can consume over 2,000 watts of energy per day, about 6 % of the total household energy budget. This was not acceptable for Jaguar Creek, so we set out to find the most energy efficient unit available. After much research we selected a 19 cubic foot Sun Frost refrigerator that operates on 110 VAC, and consumes a mere 600 watts per day of energy at an ambient temperature of 90 F. The Sun Frost unit is cooled by a pair of highly energy-efficient top-mounted hermetically sealed compressors. The compressors and condenser are top mounted so they cool efficiently without having the waste heat re-enter the cabinet. The walls of the refrigerator contain 3 inches of insulation.

A separate chest freezer was selected in 2002 for storing frozen food. This unit is electric, but technology has changed producing enough energy saving that we were able to buy a "normal" chest freezer in the US from a regular store and have it shipped here.

Summary of Refrigeration Equipment

  • (1) Sun Frost, 110 VAC, 19 cubic foot refrigerator
    Manufactured by: Sun Frost
    PO Box 1101, Arcata, CA 95521, (707) 822-9095
    Purchased from: Real Goods, 200 Clara Street, Ukiah, CA 95482
    Attn: Steve Rogers, Applications Engineer (707) 468-9292
  • (1) General Electric Chest Freezer

Water System

Water Conserving Design

The opportunity to make Jaguar Creek a model for energy efficiency and conservation of natural resources was carried over into the water system design. Typical water demand in the United States ranges from about 100-200 gallons per capita per day for residential water use. The Jaguar Creek design allotted 25 gallons per capita per day for each resident. This was accomplished by using ultra-efficient low flow plumbing fixtures and composting toilets (described in a subsequent section). Shower heads and sink faucets use only 1.5 g.p.m, while the composting toilets in the cabins use a stingy 1 pint of water per flush. In 2002 we constructed Public Compostable Toilets that use no water to flush.

Water Supply Pump and Storage Tanks

A conventional submersible pump, rated at 10 g.p.m., was selected to transport water from the stream to (2) 700 gallon plastic storage tanks located at the DWP. The water storage tanks are constructed from food grade plastic material which will not leach organic contaminants into the water distribution system. These tanks hold about 1.5 days of water storage, and each can be filled in about one hour. Tanks were initially filled during low energy use time periods to minimize electrical power system demands, but automatically fill thanks to a floating switch.

A rainwater collection system will be incorporated into the DWP design in 2003 to collect rainwater and divert it into separate storage tanks for laundry and maintenance use.

Water Treatment System

During preliminary site studies a thorough analysis of the stream water quality was conducted using USEPA analytical test methods. These tests revealed that the water supply was of very high quality and was not subject to contamination by synthetic organic chemicals such as herbicides and pesticides. The mineral quality as well as the bacteriological quality of the water was also found to be quite good, leading us to designate the stream as a "pristine" water supply. This high level of water quality allowed us to design a water purification system which minimizes the use of chemicals in the treatment process. A tablet chlorinator unit is used to disinfect the water at the point of entry into the on-site distribution system. Chlorine levels are kept to a minimum, and since the organic chemical content of the source water is so low, creation of potentially harmful disinfection byproducts is not a concern. Small amounts of chlorine are required to prevent algae growth in the distribution system.

A triple cartridge point-of-use water treatment system (Subterranean III) is installed on a potable water tap in each housing unit as well as in the kitchen. This system uses a 5-micron prefilter, a ceramic bacteriological cartridge, and a carbon block/lead removal cartridge for filtration and purification. These filters remove sediments, chlorine, lead, VOC's, bacteria, cysts, and Giardia.

Water Distribution System Pump and Pressure Tank

The water distribution system uses a conventional multistage centrifugal booster pump to supply a constant volume of water to each of the buildings. A pressure tank is used to maintain a constant pressure range (30-40 psi) in the distribution system at all times. The pressure tank also prevents the booster pump from cycling on and off too frequently, thereby conserving energy and extending the life of the pump.

Hot Water System

Most of us take hot water at the turn of the tap for granted. Yet most people probably don't realize how much this convenience costs them. The average household in the United States spends an astonishing 20-40% of it's energy budget for water heating. This is true because we insist on keeping 30-80 gallons of water at 120 F all the time. But there is an alternative to this energy wasteful method of heating water -- instantaneous or tankless water heaters. Instantaneous water heaters only go to work when someone turns on the hot water. They sense the water flow through the heater and turn on, heating only the passing water. These units do not store any hot water for later use, but heat it only as needed.

Aquastar tankless water heaters were chosen for use at Jaguar Creek because they are proven reliable, have thermostatic control and flow restrictors that make them perform virtually the same as tank-type water heaters, and all parts are designed to be repairable or replaceable. These units use propane as the fuel source.

We have experienced some problems with these since our water pressure is not as high as city water systems in the US. The result has been irregular supply of hot water, most noticeable in the showers. We are currently working on the solution to this problem.

Summary of Water System Equipment

  • (1) 10 gpm, 4" Goulds submersible source water supply pump
    Manufactured by: Goulds Pumps, Inc.
    Seneca Falls, NY 13148
    Purchased from: Pump Repair Service Company
    405 Allan Street, PO Box 34327, San Francisco, CA 94134
    Attn: Alan Bonkowski (415) 467-2150
  • (1) 15 gpm, Grundfos multistage centrifugal pump
    Manufactured by: Grundfos Pumps Corp.
    2555 Clovis Avenue, Clovis, CA 93612
    Purchased from: Pump Repair Service Company
  • (1) V250 Goulds Aqua Air Tank
    Manufactured by: Goulds Pumps, Inc.
    Purchased from: Pump Repair Service Company
  • (12) Subterranean III triple cartridge filter systems
    Manufactured by: TerraFlo
    938-952 Washington Street, Allentown, PA 18102
    Purchased from: Real Goods, 200 Clara Street, Ukia, CA 95482
    Attn: Steve Rogers, Applications Engineer (707) 468-9292
  • (11) Aquastar 80 and (1) Aquastar 125 tankless water heaters
    Manufactured by: Controlled Energy Corporation
    Fiddler's Green, Waitsfield, VT 05673 (800) 642-3111
    Purchased from: Real Goods

Wastewater System Design

Initial geological site investigations at Jaguar Creek revealed that soils were of clay composition with poor permeability. This led to concerns about containing any wastewater discharges on-site and preventing any site runoff into the nearby stream. Ideally, if we could eliminate the typical septic system associated with sanitary waste discharges, then we could minimize any adverse impacts of runoff on the stream water quality and eco-system. To resolve this design challenge we researched alternative wastewater technologies available. Composting toilets were found to be the answer.

Composting toilets have been around for a number of years but have only recently come into popular use, largely due to significant advances in the composting technology which has led to more reliable units that cost less. Sun-Mar composting toilets are used at Jaguar Creek. These systems use a conventional looking ultra low flush (one pint per flush) toilet mounted in the bathroom in traditional fashion. From the inside this unit looks like any other porcelain commode. The heart of the system is the composting chamber, or bio-drum which is located under the housing units. Waste is piped to the nearby composting unit and is fully contained in the process chamber.

Composting toilets use very little water. This system totally eliminates any blackwater waste discharge, only a small amount of condensate is leached into the ground adjacent to the composting units. These toilets use natural processes of decomposition and evaporation to recycle human waste. Waste entering the system is over 90% water content, and this is evaporated and vented to atmosphere (virtually no odors). Heat, oxygen, moisture, and organic material (pine wood chips and shavings from a local mill) facilitate the biological decomposition process. The end product is a natural fertilizer that can be used on-site. Minimal maintenance of this system is required.

Graywater leach-fields were constructed to dispose of graywater produced by showers and sinks. These leach-fields were designed using the current standards for graywater leach-fields published by the State of California, Resources Agency, Department of Water Resources. There are individual leach-fields dispersed around the site, keeping transportation of graywater to a minimum and assuring that we don't create any adverse impacts on the stream water quality or eco-system.

Summary of Wastewater System

  • (12) Sun-Mar Centrex NE composting toilet systems with Sealand ultra low flush toilet
    Manufactured by: Sun-Mar Corp.
    900 Hertel Avenue, Buffalo, NY 14216, (905) 332-1314
    Purchased from: Real Goods, 200 Clara Street, Ukiah, CA 95482
    Attn: Steve Rogers, Applications Engineer (707) 468-9292
  • (5) graywater leach-fields using 3" PVC perforated pipe and drain rock constructed in accordance with graywater standards published by the State of California, Resources Agency, Department of Water Resources.

Home | About Us | Partner with Target Earth | Teams | Internships | Eden Conservancy | Jaguar Creek | Contact Us