Overview of possible solutionsMartin F.G. van der Jagt

Aqua-Aero WaterSystems

• PV and compressor system• Heat driven systems (Sun or bio-

fuel):o Absorptiono Steam engine – mechanical compressoro Solar Stirling – mechanical compressor

Ref. http://www.areed.org/training/technology/solar_ice/ice_2.pdf

• Is available • but expensive

PV Ice Production:  The Luis Leon reservoir in the heart of the Chihuahuan desert with the Chorreras ice-house. The Chorreras community at the inauguration of their 2.4 kWp PV ice-making system in March, 1999. Everybody appreciates a little extra shade in the desert as well. Ref. http://www.re.sandia.gov/en/pb/pd/Icemaker_final.pdf

ISAAC Solar Ice MakerThe ISAAC Solar Icemaker is an Intermittent Solar Ammonia-water Absorption Cycle. The ISAAC uses a parabolic trough solar collector and a compact and efficient design to produce ice with no fuel or electric input, and with no moving parts.The ISAAC Solar Icemaker operates in two modes. During the day, solar energy is used to generate liquid ammonia refrigerant. During the night, the generator is cooled by a thermosyphon and ice is formed in the evaporator compartment as ammonia is reabsorbed to the generator.

Six ISAAC Solar Icemakers in the Coastal region of Kenya. The purpose of installation is to preserve milk so the farmers can transport their milk to market before it spoils. This will increase the income of the farmers and decrease poverty in the area.

ISAAC Solar Icemakers in Kenia

ISAAC Solar Icemakers in Kenia

Parameters: Life cycle cost analysis of a diesel operated icemaker (investment US$15,000) compared to 18 ISAAC solar icemakers (investment US$72,000), both producing 0.9 Tons of ice per 24hrs. Discount rate is 15%, economic life is 20 years, scrap value is US$0,00 and at year 10 a new Diesel generator will be purchased at a cost of US$5,000. It is assumed that local assembly will make the ISAACs available at US$4,000 each. Because of the country specific cost for transportation, import tax, maintenance and labour costs, these cost are assumed equal for both operations and therefore not taken into account in this cost comparison. Assumed energy use is 90kWh/ton of ice and the efficiency of the generator is assumed at 3kWh/liter of Diesel.

5hp steam engines from

Methamatics of Scheffers Parabole

Explanation Der Spiegel ist ein kleiner, seitlicher Ausschnitt eines wesentlich größeren, runden Paraboloids. Durch die schräge Schnittführung entsteht dabei die typische elliptische Kontur des Scheffler-Reflektors. Das von diesem Ausschnitt des Paraboloids reflektierte Licht fällt von der Seite auf den ein Stück weit entfernten Brennpunkt.Die Achse für die tageszeitliche Nachführung liegt in Nord-Süd Richtung parallel zur Erdachse und läuft durch den Schwerpunkt des Reflektors.So ist er immer im Gleichgewicht und das mechanische Uhrwerk muß nur mit einer geringen Kraft angetrieben werden um ihn synchron mit der Sonne zu drehen.Damit sich der Brennpunkt dabei nicht bewegt liegt er auf der Rotationachse. Der Abstand zwischen Brennpunkt und Reflektormitte hängt von der gewählten Ausgangsparabel ab.Das konzentrierte Licht wird so während des Tagesverlaufs nur um sein eigenes Zentrum rotieren, sich aber in keiner Richtung seitlich bewegen. Der Brennpunkt bleibt also fixiert, was natürlich praktisch ist, da der Kochtopf nun auch nicht bewegt werden muß.

Solar Powered Stirling Generators:Direct E production!

Cummins Power Generation of Columbus, Indiana. 5 kW free-piston engine dish/Stirling system. The concentrator incorporates 24 stretched-membrane facets (5 feet in diameter). A slight vacuum is drawn between the membranes to obtain an approximately spherical shape.

German/Saudi 50 kW dish/Stirling system ; These machines are located at the Solar Village of the Saudi Arabian National center for Science and Technology, near Riyadh. The solar concentrator is a single facet stretched membrane dish 17 mtrs in diameter. The engine used is a 50kW United Stirling 4-275. The max operating temperature is 620 deg C and max gas pressure 2175 psi. Eficiency of 23% solar to electric have been achieved at an insolation of 1000 W/m2.

• ISAAC: $ 12- 15.000 ; massprod. $ 4.000, 50 kg ice/day

• PV –compressor: € 30-35.000; 500 kg ice/day

• Sol. Steam-compr.: € 15.000 +12.000; 300 kg ice/day

• Sol. Stirling-comp: € ??????

What is the best option?How can we realize this option?

• Solar Steam -> E -> Ice (300 kg/day)o 5 HP steamengine from Indiao Ice machine from the Netherlandso Solar Steam from Germany?

• What must be the form of the Ice• Building Pilot                                   0,5 year• Testing Pilot: how simulate the sun? 0,5 year• Pilot in Gambia: Aqua-Aero WaterSystems

    

This presentation is 4 years old. To day I am convinced, that solar ice production is possible, but too expensive.I prefere now to use a biogas fired 10 kVA steamgenerator, connected to an icecube machine.

Apeldoorn11-03-2013