The document summarizes four different documents related to solar refrigeration technologies. The first discusses a solar-powered refrigerator called Solar Chill that uses ice storage instead of batteries. The second describes framing systems for mounting solar panels. The third presents experimental results on a thermoelectric refrigerator powered by solar cells. The fourth analyzes the performance of a solar PV-operated domestic refrigerator.

1. SOLARCHILL - A SOLAR PV REFRIGERATOR WITHOUT BATTERY
(Given by: Henrik Pedersen, Soren Poulsen & Ivan Katic)
ABSTRACT
A solar powered refrigerator (Solar Chill) has been developed in an international project
involving Greenpeace International, GTZ, UNICEF, and UNEP, WHO, industrial partners and
Danish Technological Institute. The refrigerator is able to operate directly on solar PV
panels, without battery or additional electronics, and is therefore suitable for locations
where little maintenance and reliable operation is mandatory. The main objective of the
Solar Chill Project is to help deliver vaccines and refrigeration to the rural poor. To achieve
this objective, the Solar Chill Project developed — and plans to make freely available a
versatile refrigeration technology that is environmentally sound, technologically reliable,
and affordable. Solar Chill does not use any fluorocarbons in its cooling system or in the
insulation.
KEYWORDS
Applications and loads, cost reduction, demand-side, devices, PV system, refrigeration,
reliability, standalone systems, storage, sustainable.
LITERATURE REVIEW
The unique feature of Solar Chill is that energy is stored in ice instead of in batteries. An ice
compartment keeps the cabinet at desired temperatures during the night. Solar Chill is
made from mass produced standard components, which results in a favourable cost
compared with other vaccine solar refrigerators. The Solar Chill has undergone intensive
laboratory tests in Denmark, proving that it fulfils the objectives set for the project. In
addition, a field test programme in three different developing countries is ongoing with the
aim to gather practical experience from health clinics. For domestic and small business
applications, another type of solar refrigerator is under development. This is an upright
type, suitable for cool storage of food and beverages in areas where grid power is non-
existent or unstable. The market potential for this type is thus present in industrialised
countries as well as in countries under development. The paper describes the product
development, possible Solar Chill applications and experience with the two types of solar
refrigerators, as well as results from the laboratory and field test.

2. The reason for choosing energy storage in ice was to avoid a lead battery for energy storage.
Lead batteries tend to deteriorate, especially in hot climates, or they are misused for other
purposes. This makes it necessary to install a new battery after a couple of years, and has in
practice been an obstacle for the use of solar powered refrigerators. In addition to that
some pollution of lead might be expected from the used batteries.
REFERENCES
I. PV-POWERED VACCINE COOLER WITH ICE PACKS AS POWER BACKUP Soren
Gundtoft, Danish Technological Institute, 2003
II. Project flyer: http://www.uneptie.org/ozonaction/library/tech/solar chill.pdf
III. Compressor data sheet: http://www.danfoss.com/compressors/pdf/product_ne
ws/bd_solar_09-03_cx30e302.pdf
FRAMING SYSTEMS FOR SOLAR PANELS
(Given By: Peter Stuart Erling)
ABSTRACT
The invention relates generally to framing systems and more particularly is concerned with
systems adapted to mount panels or laminates in an array on a supporting roof structure of
a building exemplified with the mounting of solar electric photovoltaic (PV) panels. The
framing system described uses extruded elongate elements with a sealing element to frame
the PV panel as a weatherproof PV solar roof tile. Individual frame element profiles
effectively embody the PV building integration, (BiPV) or mounting method, of the solar tile
within the frame itself. Only a few additional flashing components are needed to complete
the PV tile array as part of the roof, or with minor variations, as a PV wall cladding. Full BiPV
panel mounting methods show potential to be used for co-generation (PV/T) of solar
thermal energy capture in buildings.
The batten support structures of the solar tile permit variation in roof batten spacing to be
tolerated in retro-fit situations make trafficable roof with the tiles possible and provide long
term weather-ability as a building element through moisture reduction by air flow and
smaller surface contact. Draining of internal roof condensate from the back of the tiles to
the exterior is another feature of the frame system described.

3. KEYWORDS
Plastic, Thermal conductor, Aluminium material, Thermal energy, Solar electric photovoltaic
(PV), Internal roof.
LITERATURE REVIEW
It is common for solar panel frame materials to be made from aluminium material that is
surface treated against corrosion for the arduous climatic exposure it has to endure
however aluminium has a significant embodied energy in its life cycle therefore a framing
system that can use lower cost and lower embodied energy materials like plastics but that
can still endure a long service life is desirable. Plastics also can provide better thermal
insulation between outside and inside conditions of a building when used in the framing of
glass than aluminium, which is a good conductor of thermal energy unlike plastics that are
poor thermal conductors. It would therefore be beneficial to devise systems which can
utilise the advantage of plastics in combination with a lower proportional use of surface
treated aluminium but retaining the desirable and proven long term weather endurance of
aluminium in the solar tile frame system.
In the field of solar PV panels, proposals have been made to form the PV panel to have the
general characteristics of a roofing tile so that the PV laminate may be integrated into a
roof, commonly but not exclusively, a tile roof. An alternative approach is to have a panel
which is adapted to be mounted over a roof However; important considerations to the
design and development of PV panels are the ability of the panels to be effectively
integrated architecturally into a roof design. With in-roof integrated panels there is also
known to be a greater opportunity to beneficially capture solar thermal energy in addition
to PV electrical energy to use within the building on which the PV tiles are installed, a field
of solar energy development known as PV/Thermal or PV/T. Where the panels take the
place of conventional roofing elements such as tiles or metal systems, reliable and
convenient mounting within the roof and effective weather sealing is most important.

4. EXPERIMENTAL INVESTIGATION ON A THERMO-ELECTRIC REFRIGERATOR DRIVEN BY
SOLAR CELLS
(Given by: R.Z. Wang, L. Ni)
ABSTRACT
Experimental investigation and relevant analysis on a solar cell driven, thermoelectric
refrigerator has been conducted. To make the device portable, daytime use and nighttime’s
use of the refrigerator are treated in different ways. Solar cells are applied to power the
refrigerator in the day. Storage battery, assisted by an a.c. rectifier, is used to provide
electric energy in the night and in cloudy or rainy days. Experiment results demonstrate that
the unit can maintain the temperature in the refrigerator at 5–10 °C, and have a COP about
0.3. It is expected that the refrigerator would be potential for cold storage of vaccine,
foodstuffs and drink in remote area or outdoor applications where electric power supply is
absent.
KEYWORDS
Thermoelectric refrigeration; Solar cells; Insulation rate; cooling production
LITERATURE REVIEW
A solar panel is a photovoltaic module which is built up by a certain combination of solar
cells. The material of the solar cell for the solar panel used in this research project is multi-
crystalline silicon. A solar panel functions by directly converting the solar radiation into
direct current electricity. In this project, a combination of four solar panels is applied to
build a solar array, in which two units are configured in series and another two in parallel.
Such combination is essential for efficiently charging the lead acid batteries and then
operates the refrigerator. Each of the solar panels with the specifications of 17.5V
(maximum power point voltage), 5.7A (maximum power point current), and 100W (nominal
peak voltage) is used in this PV system.
REFERENCES
Dai, Y.J., Wang, R.Z., Ni, L. (2003). Experimental investigation on a thermoelectric
refrigerator driven by solar cells.
Kaushika, N.D., Gautam, N.K., Kaushik, K. (2005). Simulation model for sizing of stand-alone
solar PV system with interconnected array.
Min, G., Rowe, D.M. (2006) Experimental evaluation of prototype thermoelectric domestic-
refrigerator.

5. PERFORMANCE ANALYSIS OF A SOLAR PHOTOVOLTAIC OPERATED DOMESTIC
REFRIGERATOR
(Given by: R. Saidur, H.H. Masjuki, M. Hasanuzzaman, T.M.I. Mahlia, C.Y. Tan, J.K. Ooi and
P.H. Yoon)
ABSTRACT
This paper describes the fabrication, experimentation and simulation stages of converting a
165 l domestic electric refrigerator to a solar powered one. A conventional domestic
refrigerator was chosen for this purpose and was redesigned by adding battery bank,
inverter and transformer, and powered by solar photovoltaic (SPV) panels. Various
performance tests were carried out to study the performance of the system. The coefficient
of performance (COP) was observed to decrease with time from morning to afternoon and a
maximum COP of 2.102 was observed at 7 AM. Simulations regarding economic feasibility of
the system for the climatic conditions of Jaipur city (India) were also carried out using RET
Screen 4. It was observed that the system can only be economically viable with carbon
trading option taken into account, and an initial subsidy or a reduction in the component
costs – mainly SPV panels and battery bank.
KEYWORDS
Thermoelectric refrigeration, Solar powered refrigerator, photovoltaic system
LITERATURE REVIEW
A thermoelectric refrigerator which is developed in standalone photovoltaic system for
domestic usage has been presented in this paper. The photovoltaic sizing required for
efficiently running the thermoelectric refrigerator with energy consumption 520Wh is
including 4 solar modules of 5.7A, 17.5V and100W; 4 lead acid batteries of 12V and 100Ah, a
solar charge controller of 12A and 24V; and an inverter of 24V and 150W. For maximizing
the electricity generation, the photovoltaic array should be oriented at 15 degrees from
horizontal and is installed facing south. The peak power produced by the photovoltaic array
is 230 watt. It has been shown that the battery bank is able to act as a backup energy
supplier for 3 autonomous days.
The thermoelectric refrigerator can maintain the temperature in refrigerated space at 1~7 o
C and at averagely 4o C. The warm up time for the cooling temperature to increase back to
ambient temperature after being switched off is about 4 hours. Instead of using vapour
compression refrigerator, thermoelectric refrigerator is applied due to its lower starting

6. power, environmental friendliness, and noiselessness. The performance of this refrigerator
can be improved by adding insulation to the refrigerator’s body as well as improving its heat
exchanger efficiency. It is recommended for not opening the photovoltaic driven
thermoelectric refrigerator more than 30 seconds each time.
A solar charge controller is applied in this solar powered domestic refrigerator system. It is
installed between the solar array and the battery bank. A solar charge controller’s primary
function is to protect the battery bank from overcharging and under discharging that will
permanently damage the battery bank. It has the specification of 12A (maximum charge &
load current) and 24V (system voltage).
RESEARCH QUESTIONS
1. Do we have any Solar Energy technology installed in your home?
2. How do solar photovoltaic panels work, and are they really as efficient as everyone
says?
3. What are building-integrated photovoltaic and are they a legitimate alternative to
photovoltaic panels?
4. How much space will a solar photovoltaic system require?
5. Do solar energy systems need a lot of maintenance?
6. How much will a solar photovoltaic system cost me and how long will it take for it
to pay for itself through energy cost savings?
7. How long do photovoltaic (PV) systems last?
8. What's the difference between PV and other solar energy technologies?
9. Can I use photovoltaic (PV) to power my home?
10. How much does a solar energy system cost, and how much will I save on utility
bills?