SALVAGE VALUE OF PHOTOVOLTAIC SYSTEMS
Lalita Nayagam, Zuhair Almumattin
MAE 598 Solar Commercialization
Mentor: Steven Trimble, Ronald Roedoel
School for Engineering of Matter, Transport and Energy
Goal:
Basic Concepts and Steps:
To answer the following questions:
Process:
• Modules are shredded into large pieces before
being crushed by a hammer mill to pieces typically
smaller than 5 mm in order to break lamination
bonds.
• Semiconductor films are removed in a slow rating
leach drum in a process taking 4–6 hours.
• Weak sulphuric acid and hydrogen peroxide is
added to the glass to achieve an optimal solidliquid ratio. The films are etched from the glass
during the leach cycle.
• Glass is separated from the liquids in a classifier.
• The material is then moved to a vibrating screen
separating the glass from the larger ethylene vinyl
acetate (EVA) pieces.
• The EVA is deposited into another conveyor and
collected, whereas the glass falls through the
screen to a chute where it is taken to the rinsing
step;
• After being cleaned, the glass is deposited into
containers for recycling and the rinse waters are
pumped to a precipitation system for metal
recovery;
• The metal compounds are precipitated in three
stages at increasing pH using sodium hydroxide.
When the solids have settled and been made into a
metal rich filter cake, it is sent off for processing by
a third party where they can be processed to
semiconductor grade raw materials for use in new
solar modules
• The cost of the process is about $3/KW
1)
Is it possible to salvage PV?
2)
Are the processes involved efficient
3)
What are the barriers in the salvaging
process
4)
Who can make it possible.
5)
Is the process paying for itself
6)
What policies are required to get this
done?
Introduction:
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Modules are expected to last about 30 year
There is a concern about disposing them in
municipal landfills because they may
contain small amounts of regulated
materials (e.g., Cd, Pb and Se)
Recycling PV systems at the end of their
useful life adds to the environmental
benefits and can further enhance market
support
Recycling answers public concerns about
hazardous materials in PV modules which
can create barriers to market penetration.
The feasibility of collection and recycling of
spent PV modules is explored in this paper
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Based on the study we realised that Salvaging
PV is technically possible but not economically
feasible as of today.
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There are no government incentives to promote
this In dispersed operations, small quantities
and high transportation costs make this option
relatively expensive deal.
•
The processes are not extremely efficient
hence increasing the cost in the market
•
But recycling PV is extremely favorable to us in
the long term
Fig . PV Scrap and Module recycling options
Barriers in Process:
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Ref: First Solar website
Currently, economic incentives may be
inadequate to move the PV industry into
voluntary recycling. However, this may change
in future, as more economic incentives may be
given to developing clean technologies and
reducing carbon dioxide emissions.
Several States have started programs in
support of recycling electronic equipment;
discarded electronics are described as
resource instead of waste and the States assist
in building up recycling infrastructure and
market
Conclusions:
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Table: Percentage recovery from Salvaged Photovoltaic
Ref: Renewable Energy magazine, April 2014
Policy implications:
Recycling Process:
Absence of streamlined methodologies for
home owners and other PV installers.
Absence of enforced government policies
Cost of the salvage process is not self paying
Inefficient processes
Improper disposal-which is cheap-its extremely
harmful to the environment
Unavailability of economic incentives
In dispersed operations, small quantities and
high transportation costs make this option
relatively expensive.
Recommendations:
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Policies must be introduced such that the
recycling costs will not be a market barrier for
the system. Currently, the prices are
significantly high
Policies must be introduced for the collection
and disposal or recycling is proportional to the
weight of the recycled materials
Battery recycling program especially for
residential solar must be introduced
Environmental disposal and waste handling
regulations, logistics and economics of product
recycling and waste disposal affect the
reasoning and practicality of recycling.