TAMERA - The Solar-Power Village – Technology

8/9/2019 TAMERA - The Solar-Power Village Technology

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Imprint:

2nd Edition 04/2009Text: Jrgen Kleinwchter, Charly Rainer Ehrenpreis

Layout: Roland Luder, Sabrina von der ThannenPhotos: Sunvention, Projectgroup SolarVillage

Publisher: Projectgroup SolarVillageMonte do Cerro

7630 Colos, PortugalTel: +351 / 283 635 313

[email protected]


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Contents

Introduction 4

The Solar-Power Village the Technology 61. The Envelope Greenhouse 62. The hot oil storage and the cooking places 83. The medium temperature Stirling machine 94. The Pumping o Water 105. Water Disinection 10

Economical Realization 12

Final observations urther steps 13


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Introduction

The readers o Herman Scheers book Energy Autonomy (Energie-Autonomie) will know that said au-tonomy or sel-suciency represents the most important generic term in the presently unolding solarera. Regionally used energies, produced rom sel-sucient resources, not only allow the liberation rom

heteronomy especially to the poorest and most sun-intensive areas o the world, but also serve the de-velopment o autonomous inter-linked structures right down to village level.

These structures generate local and stable workplaces and at the same time cover the populations oodand energy demands.

Looking at the growing stream o migrating poor rom the South, seeking employment in the au-ent countries o the North, and at the same time looking at the inhumane, unproductive and money-devouring deence measures taken at the borders, the question arises, whether these unds would notbe better invested in sensible undertakings or the development o the South as suggested by the newstructures mentioned above.

During decades o working on R&D, we have developed a variety o solar systems and components whichwe have now assembled to orm an integral, multi-unctional overall system the Solar Power Village.

This system, a symbiosis or plant growth and solar energy production, is designed in such a way to beable to be constructed almost entirely in the user-countries.

To eectively use the enormous and positive potential o thrust, o this and/or other developments othe early evolution o balanced energy and material cycles in solar society, it is o paramount importancethat the user/inhabitant is not only technically, but also socially and culturally integrated. A modern typeback to nature is about to be generated, though stripped o the worldly innocent atertaste o Rousseausdream, since it is based on the easible, realistic and technologically gentle use o sun power.

At Tamera, an international research settlement in the Alentejo in Southern Portugal, the model o a

Global Peace Village has been developed during the past years. It oers ideal conditions or the instal-lation o a Solar Power Village.

On the one hand, the approx. 100 co-workers, around the ounders Dieter Duhm, Sabine Lichtenelsand Rainer Ehrenpreis, have built up a humane model community with strong integrative powers orthe development o international peace settlements to be generated rom the grass roots which today,more than ever beore, are urgently needed.

On the other hand, the Tamera Model will only achieve its intended eectiveness when the energy andood production becomes autarkic and sel-sucient.

Amongst the inhabitants and co-workers o Tamera there are engineers, architects, biologists, medical

doctors, clay- and strawbale builders, perma-culture specialists and excellent crats people. The YouthSchool o Global Learning is attended by many inspired, committed and highly talented adolescents.

At the annual Summer University, requented by international visitors groups especially rom worldregions o conict, the Solar Power Village met with much resonance and palpable need.

Tamera specialists have introduced the technologies o Sunvention to various Portuguese universitiesand institutions where they raised a lot o interest.

For these reasons the frst Solar Power Village is presently (2006) being installed at Tamera. The Tameraworkshop, serving as a model or uture production places in Southern countries, has adapted the indi-vidual components o the system in such a way that local production can realistically be accomplished.

Thus a real platorm or demonstration, training and transer will have been created.


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Around this core installation a complete ecological Solarv illage will be developed which comprisesall aspects o passive and active solar technology; o ecological construction (i.e. clay and straw baleconstructions); o permaculture in terms o sel-sucient energy and ood production and social design.The inrastructure o a corresponding training centre (Aula (university hall), study rooms, workshops,etc.) is presently under construction.

In the near uture Tamera is to receive the status o a Campus o the Gaia University, a university active

worldwide, with an accreditation to IMCA (International Management Centers Association, GB) and tothe Revans University (with Bachelor and Masters degree).

One element o the Solar Power Village the energy greenhouse Envelope has the potential toproduce the basic ood supply (or a vegan diet) or one person on a surace o 200 m.

In case o urther optimisation, which will basically lead to a bionic system, the plants themselves willconstantly give steering impulses to the physical system (optics, flters, humidifer etc.) which in turn willset the bio-parameters that are responsible or the growth o the plants (light, temperature, humidity,CO2 concentration in the air etc.) to the optimum at any given time.

This again will reduce the amount o surace needed to eed one person to


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The Solar-Power Village the Technology

The Core Components o the Solar Power Village are:

- (1) The greenhouse with its Sunray and Sunower lens systems

- (2) The hot oil storage tank and the cooking places- (3) The medium temperature Stirling engine- (4) The water pump- (5) The water disinection system

1. The Envelope Greenhouse

The greenhouse (SolarEnvelopeTM) is a light-weightstructure covered with a specially resistant uorpolymeroil. The oil is transparent or the ull spectrum o the

solar radiation including the UV segment, thus there is noneed or pesticides, which are normally employed in con-ventional greenhouses. Besides that UV-radiation is whatgenerates the aroma, thus greatly improving the quality

o the produce.

The optical sys-tems, mountedin the roo o thegreenhouse are protected rom wind and weather, are designedextremely light and inexpensive.

The Sunower and/or Sunray modules are mounted parallelto the shading system under the roo o the greenhouse. The


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optical systems concentrate the direct solar radiation onto receivers thus extracting heat rom the green-house and protecting it rom overheating. Extra cooling systems become thus dispensable; the nightlyneed or heating can be covered system-internally; the remaining diuse enables an optimal growth

o the plants.

Vegetable oil is used as the heat-carrying medium. Aninsulated pipe system transports the oil to a hot-oil

storage tank.

The covered horticulture allows or the modifcationo the growth actors (temperature, humidity, radia-tion situation and CO2 concentration).

While higher temperatures enable a prolongation othe season in the north, cooling is decisive or theharvest results in the south. Nowadays, the largestgreenhouse suraces are to be ound in the Mediter-

ranean countries and in East Asia, but also in the dessert regions the signifcance o covered plantinggrows aiming at the increase o the local supply with vegetables (United Arab Emirates: 1450 ha).

For heating purposes about 300-500 kWh o thermal energy per square metre are necessary while up to3 kg CO2 per kilogramme o produced tomatoes are emitted. The prevalent evaporation cooling needsabout 20 times as much water as is necessary or irrigation thus contributing signifcantly to water scar-city in southern areas.

Further reaching application potentials:

The ocal lines o the two optical systems can both be equipped with:

- Concentrating photovoltaic

A small row o solar cells is cooled rom both sides and pro-duces electricity at a high eciency rate. The cooling aidsupplies a heat storage with heat energy thus reducing theexpense or heating at night.

Attractive alternatives to the roo-integrated photovoltaicat modules or the production o solar energy are available.Already today more than hal o the worldwide solar electri-city production comes rom solar-thermal large-scale powerplants. In Almeria in Spain solar power plants are being built.At the same time the region disposes o the highest green-house density (30000 ha). In uture, the dierent systemsare to no longer compete with one another but symbioti-cally accomplish each other.

Regarding the supply shortages or photovoltaic modulesmaterial-economic, concentrated applications will gain moreand more signifcance.With highly ecient triple junction cells(eciency ratio up to 36%) in the ocal line o the lenses primecosts o signifcantly below 10 -Cents per kWh are to be ex-pected when producing a larger quantity o energy.


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- Thermal Absorbers

With the help o vacuum tubes high temperature heat energyis produced, which can be transormed into electric energy viaheat-power-coupling or serve or heating.

- Spectrum Modiying Pigments

The cultures in a greenhouse can only use specifc wave lengths othe optical spectrum or photosynthesis. With the help o colourpigments the dispensable light is transerred to the absorptionmaximum o the chlorophyll which stimulates the growth o theplants. Again, absorbed heat can be stored.

2. The hot oil storage and the cooking places

The Solar Power Village oers solutions or the supply with heat or cooking, warm water productionand electricity using vegetable oil as heat carrier and storage. The oil which is heated in the Sunray

or the Sunower (up to 220C) circulates rom the absorbers to the cooking places or to the Stirlingmachine which in turn produces electricity. The hot oil storage enables a 24-hours-energy use and isdimensioned in such a way that it secures energy autonomy or several days.

To be able to compete with the existing systems (traditionally: stones around open freplaces but also im-proved stoves) the solar cooker must be adapted to theeating habits and to the cultural and social conditions othe target countries. It is not enough to produce thermalenergy at a high eciency rate. For a good acceptanceo the solar cooker urther requirements must be ulflledlike e.g. an easy and sae handling or a solid and simpleconstruction. The cooker must correspond to the socialstructures: it must be expandable as per customerswishes and exibly usable (indoor and outdoor kitchen),it must take the role o the kitchen as a place o communi-cation into consideration and it must be possible to cookthe traditional meals at the usual time o day and withinthe usual time span. A solar cooker in combination witha heat storage should meet these needs. The experiencegathered in Mali and India with the black cooker confrm this. Our central cookers unction along thesame principle but do allow or an extended number o cooking places, higher temperatures with a goodeciency and longer autonomy.

The cooking place consists o a double-walled aluminium pot throughwhich the hot oil ows. A manually regulated valve opens and closesthe hot oil cycle as per the actual need and enables a fne regulationo the cooking heat. The oil shall have a temperature o at least 150Cin a way that deep rying, roasting and baking become possible. Forboiling water 100C would be enough.


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3. The medium temperature Stirling machine

A Stirling machine is a mechanical system basing on a closed thermo-dynamic cycle between two fxtemperatures with a cyclic expansion and compression o a so-called working gas. It is able to transormheat energy into (physical) activity energy or vice versa to transorm power into warmth and cold.

- The principle o a classical Stirling machine

A closed cylinder, flled with a working gas is permanently heated on the hot side (H) and permanentlycooled at the cold side (K). The displacer (V) periodically pushes the gas through the regenerator (R)rom the hot to the cold side and back. The unction o the regenerator is to temporarily store the heat.The gas is thus periodically heated and cooled ina thermo-dynamic reversible interplay. Thereby,uctuations o pressure are created in the closedpiston. These pressure uctuations produce theenergy which moves the working piston (P) thatreleases the thermo-dynamic energy rom inside

o the cylinder to outside o the cylinder thus pro-ducing physical work.

The ideal Stirling machine has the ollowing characteristics:

- No thermal losses happen.- The our phases consist o: isothermal expansion (3-4), isothermal compression (1-2) each

with two fnalizing isochoric phases (2-3, 4-1).- The regenerator is ideal and reversible without loosing any pressure o the gas owing

through.- No power input is necessary to move the gas within the cylinder rom cold to hot and vice

versa.O course, all real machines produce losses. The challenge is the optimal choice o geometries, spaceratio, mechanisms and material which enable the closest approach to the ideal process.

Since energy is input and output in this process a cynematic energy storage is necessary which takes upand releases energy in an alternating cycle. The solution that suggests itsel would be a crankshat (C)which connects the working piston (P) and the displacer (V) typically with a phase shit o 90 degreestransorming the linear into a rotating movement at a constant angular speed. When displacer and wor-king piston are steered by crankshat drives they execute continual, sinusoidal movements. This meansa deviation rom the ideal Stirling process, i.e. a weakening o the perormance. With slowly rotatingmachines though, more avourable discontinual movements are possible.

- Our Third World Machine

The technology developed by BSR Solar Technologies or medium and low temperature Stirling engi-nes moves away rom the conventional engines, which work with high temperatures, requencies andpressures. Our technology works with low requencies and pressures and reaches eciency degrees atlow temperature which conventional machines only reach at rather high temperatures. This opens newapplication potentials as or example energy production rom exhaust heat, and allows or simpler andless expensive systems.

They produce at a lower cost, need less maintenance and start to be rentable when produced in relativelysmall quantities.

While the classical Stirling engine works with temperature dierences o between 300 and 600 K, a lowtemperature (NT-) system works with a temperature dierence o as little as 50 to 100 K. Looking to the


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ormula or the thermal eciency degree o the Carnot pro-cess one realizes the heat-dependent nature o such machi-nes: A Stirling engine which works with a heating temperatureo 873 K and a cooling temperature o 373 K (T=500 K) couldthus achieve a thermal eciency o 57%.

A low temperature machine with a heating temperature o

373 K and a coolingtemperature o 293 K(T=80 K) in comparisononly reaches an idealthermal eciency o21%. From the tech-nical point o view it

is thereore important to realise as much as possible o the idealeciency degree. Slowly moving, discontinually working machi-nes have an advantage: In the p-V-diagram our phases are visiblewhile continually working machines reveal oval diagrams, which

signifes a loss o surace and thus a loss o perormance under thesame conditions. Since the low temperature machine works withair and low pressures the use o the expensive helium is avoided.It produces electricity or light and communication apparatuseswith the help o a generator as well as mechanical energy, e.g. orthe direct operation o grain mills.

4. The Pumping o Water

The majority o the population in the sunny developing countries lives o agriculture. High productivity

o the small lots and the preparation o new land or agriculture are essential - and both requires irrigation.Intensive eorts or the amplifcation o the watering potential lead to the insight that large-scale pro-

jects are outdone by individual solutions when it comes to eciency andcosts. While investment intensive canalisation systems lead to conict-bearing distribution problems small armers go or reasonable individualsolutions where the ownerships are unambiguous and no large-scaleinterventions in nature are necessary.

The solar water pump Sunpulse meets these requirements as a sustai-nable means. Sunpulse pumps water rom storage lakes or ground watero up to 60 metres deep thus ensuring the irrigation o an average amily

business. As energy source it simply needs the sun which is not onlyprotecting the environ-ment but also savingoperational expenses.

Pumping water in agri-cultural countries uses alarge part o the produ-ced electric energy. Withthe low temperatureStirling machine the

growing need or energy in southern countries can be

supplied by renewable resources.


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5. Water Disinection

Next to drinking water purifcation the UV disinec-tion also serves industrial application and specialapplications like: process water recycling, coolingwater cycles, waste water disinection. Regarding

private use it can serve to keep swimming poolsand ponds clean.

UV systems are increasingly used in air-conditioningappliances, too, since the biocides which are ejectedby normal ACs get into the air that we breathe andcause stress or the human health in the long run.

In warm water systems the UVitt systems caneciently fght legionels thus preventing the le-gionnaires disease. The air chamber around theUV radiator and the glass tube through which the

water ows enable the disinection o warm water without aecting the lamps eciency. The patentedsystem enables a quick, turbulent ow through thus preventing microbiological debris.

Ultraviolet light has a strong germ-killingeect in an area o 254 nm. The energyintensive radiation causes a damage tothe cells by changing the DNA. Micro or-ganisms which cause diseases die within ashort period o time.

Another method o water recycling or pu-rifcation consists in adding ozone, whichoxides organic compounds thus neutra-lising them. While the ozone is normallyproduced externally the UVitt systemallows or a combined production withinthe UV chamber. The O

3developing at a

wave length o 200 nm is added to the dis-inection chamber, the residues are thendetracted.

From this results a reliable drinking water purifcation which can contribute to the worldwide improvemento the hygienic situation in an ecient, inexpensive way without requiring specifc expert knowledge.


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Economical Realization

The Solar Power Village is structured in a modular way, in a way that the equipment and the peror-mance can be completed as per the individual user(s) need. It can also be accomplished by cooling orwater purifcation systems via solar UV radiation.

For the most part the Solar Power Village technologies can be produced in the countries o their appli-cation. This allows or local economic development and the acquiring o skills; the dependency onoreign countries decreases. The Solar Power Village can be realized as a supply coop, where the usersas members o the co-operative pay or the services/commodities they use (heat, water, electricity).The system remains in the ownership o the co-operative which assures the maintenance and acquiresurther fnancial means. Jobs are created within the region in a way which maintains the buying power.The coop structure can be enlarged and applied on urther economic activities like ood production anddistribution as to urther a decentralized and independent development basing on sel-aid.


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Final observations urther steps

Not only shall the technology, training and transer centre (TTT-Plattorm) Tamera continually expandand demonstrate the idea o autonomy at village level all over the world during the coming years,thereby cooperating with research and development groups rom all over the world, via training and(know-how) transer Tamera shall also help to build up real, sel-sucient settlements, particularly in

the poorest crisis areas o the world. Simultaneously, the Solar Power Village technology, exemplarilydescribed or arid zones in the present pamphlet, shall also be adapted to other (tropical or subtropical)climatic situations. In the dialogue with the latter users and with the help o their direct co-developmenta variety o locally adapted technologies will be developed this way.

The building up o another SolarVillage as a Peace Village in the Middle East (www.prvme.org) is underpreparation.

In its company agreement the internationally operating U.S. business Sunvention, whose intention isto leverage the technological principle o multiunctional energy greenhouses to a breakthrough in themarket in the wealthier countries, established the ethic stipulation to give 10% o their proft or thesponsoring o Projects or the South as described in this brochure.


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For fnancial support:

Portugal:

Account holder: Associao para um Mundo HumanitrioBank: Caixa Crdito Agrcola S. TeotnioNIB: 0045 6332 4021 9980 8662 0IBAN: PT50 0045 6332 4021 9980 8662 0 BIC: CCCMPTPL

Germany:

Account holder: Karl-Rainer Ehrenpreis - Forschungsgemeinschat TameraBank: GLS Gemeinschatsbank BochumAccount-No.: 400 635 2400, Bank Code (BLZ): 430 609 67IBAN: DE02 4306 0967 4006 3524 00, BIC: GENODEM1GLS

Switzerland:

Account holder: Stitung FGB, Verein Netzwerk - Tamera

Bank: Freie Gemeinschatsbank, BaselAccount-No.: 400.631.3, Clearing-No.: 8392, Postcheque Basel: 40-963-0IBAN: CH20 0839 2000 0040 0631 3, BIC: RAIFCH22XXXTax deductible receipts or Switzerland are available or donations made to this account.

USA:

Through the IHC (International Humanities Center), a non-proft organisation with 501 [c],you can get a donation invoice or the USA.Cheques:please send them directly to: IHC - International Humanities Center, PO Box 923, Malibu, CA 90265, USA.As reason or payment, please write: IHC/IGFCredit cards:please call: +1-310-579.2069; Fax: + 1-206-333.1797,

Steve Sugarman: [email protected]

Thank you or your supportThe Projectgroup SolarVillage


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TAMERA - The Solar-Power Village – Technology

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