From an Environmental Viewpoint Large ICT Networks Infrastructure
Equipment must not be Reused
ANDERS S. G. ANDRAE
Huawei Technologies Sweden AB,
Skalholtsgatan 9, 16494 Kista,
SWEDEN
Abstract: - Circular strategies must and will vary for different product groups. Life Cycle Assessment (LCA)
will help show which is the best strategy in any given situation as not all Circular Economy initiatives lead to
universal sustainability benefits. There is a misunderstanding that lifetime extension via remanufacturing and
refurbishment is ecologically effective for Business-to-Business ICT goods like ICT network infrastructure
(ICTNI) products. This is shown herein by typical relations between manufacturing and the use of
environmental impact for ICTNI products as a function of the energy efficiency and lifetime of the product at
hand and the next corresponding product model. Full LCA would come to the same conclusion, as the ratio
between the use stage and the production stage will not change dramatically. To avoid doing very significant
harm to the environment, older than 5 years ICTNI products must not be reused. The reasons are that the
energy efficiency improvement rate of the following generation of most ICTNI products is constant, the
lifetime is usually more than 10 years and the share of manufacturing environmental impact will be relatively
low even when low environmental impact electric power is used for the operation.
Key-Words: - circular economy, energy, energy efficiency, ICT, life cycle assessment, lifetime, material
efficiency, network equipment, refurbish, reuse
Received: October 25, 2022. Revised: March 2, 2023. Accepted: March 24, 2023. Published: April 27, 2023.
1 Introduction
In the ecosphere there is no waste, i.e. Nature itself
is a perfect circular economy (CE). Then on the
other hand in the technosphere, 99% of all new
products become waste after 6 months and less than
≈2 billion tonnes of waste is created annually, [1].
Electronic waste is an important issue as it accounts
for about 5% of all solid waste generated, [2]. So-
called CE business models can help address the
problems of primary resource use. Reuse happens
when a product or its parts, having reached the end
of their first use, are used again for the same
purpose for which they were conceived, [3].
Anyway, striving for a complete CE – especially
involving reuse - is not appropriate for all kinds of
products in all situations, [4], [5]. In other words,
not all CE initiatives lead to universal sustainability
benefits. The benefit or impact of something ‘more
circular’ should be assessed using tools such as Life
Cycle Assessment (LCA), [6], and Product Specific
Rules, [7]. CE metrics and LCA scores are
integrated and compared when they are
implemented at the same time, [8], [9].
Anyway, unless an LCA has been carried out for the
circular solution, there is no certain way of knowing
if the circular solution has a low environmental
impact.
Information and Communication Technology (ICT)
technologies network infrastructure (ICTNI)
products will not become waste until after at least
10 years or longer. Moreover, ICTNI products have
completely different LCA profiles and waste
handling than end-user consumer ICT goods.
Several ICTNI products can be upgraded by
changing the boards but keeping the older chassis.
Moreover, several technologies can be provided by
the same hardware instead of several hardware,
[10]. In other words, ICTNI products have already
adopted several ideas from CE. In 2017 electronics
including ICTNI products used 10% of global
electricity, [11].
Looking at the big picture in Fig. 1, Fig. 2, and
Fig.3, the production of ICTNI products may just be
a few percent of the entire Internet production
impact, [12], [13], which in turn is a much smaller
share than the use stage. In Figures 1 to 3
environmental impact is approximated with
electricity use. However, carbon and weighted
single score methods would likely show similar
shares.
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Fig. 1: Approximate shares of electricity
consumption for internet production and use in
2020.
Fig. 2 shows the breakdown of the use stage shown
in Fig.1.
Fig. 2: Approximate shares of electricity
consumption for the internet’s use stage in 2020.
Fig. 3 shows the repartition of the production stage
shown in Fig.1.
Fig. 3: Approximate shares of electricity
consumption for the internet’s production stage in
2020.
Fig. 3 is supported by Fig. 5 and Fig. 6 in [14], for
4G wireless networks in Peruvian cities in which the
embodied carbon footprint (≈manufacturing) for the
corresponding ICTNI products (Evolved Packet
Core/IP Core network, base band units, radio
frequency unit, base band unit cabinet, integrated
battery cabinet, power bank, antennae) is hardly
visible compared to the operational carbon footprint
(≈use).
Fig. 4 shows that the use stage dominates for ICTNI
products both for traditional grid mixes and those
dominated by intermittent sources.
Fig. 4: Typical repartition between the use stage and
upstream for ICTNI products using grid-mix and
low carbon power in the use stage, [4].
Figures 1 to 4 suggest that the use stage is the most
important for typical ICTNI products regardless of
the grid mix used for the use stage.
The waste created by wired and wireless equipment
is rather small as such ICTNI products use around
80% less mass per subscriber per year than the end-
user equipment, [14]. From the literature (Table 2
and Table 3 in [14]) and the useful lifetimes – in
section 2.2.4.11 in [14], – for the equipment used by
a 4G wireless access network, it can be concluded
that the share of the ingoing annual mass flow is
around 80% for end-user equipment and 20% for
ICTNI products. From a primary resource
perspective, however, it is important to recover as
much as possible of the ICTNI products.
Typically for energy-using products is that the new
corresponding product models are almost always
more energy efficient than their predecessors, [15].
This creates a “green” motivation to replace old
products and is particularly important for many
types of ICTNI products, whose use phase impacts
far outweigh their production impacts. In such cases
old products should be removed from circulation
and rather be recycled, [15].
In this context, it has been shown useful to make
trade-off analyses of lifetime and energy efficiency
improvement using a so-called use phase÷
production phase ratio, [4]. For ICTNI products,
which are always on, it does not matter for life cycle
stage dominance which impact category or source of
electricity are used. As shown in Fig.4, the use stage
22%
78%
2020 (Share of TWh electricity for production and use stage for the
Internet)
Production
Use
6%
4% 6%
19%
65%
2020 (Share of Internets annual TWh in Use stage)
Wired (access)
Wired (core)
Wireless (access)
Data Centers
End-user equipment incl.
TVs, WiFi equipment
16%
83%
2020 (Share of Internets annual TWh in Production stage)
Wired (access)
Wired (core)
Wireless (access)
Data Centers
End-user equipment incl TVs,
WiFi equipment
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will dominate (≈80% of life cycle impacts) e.g.
carbon and resources, etc., [4].
Compared to [4], the present research will show the
magnitude of the global electricity risk which will
be introduced if ICTNI products are not replaced but
refurbished.
2 Problem Formulation
The hypothesis is that refurbishment of large ICTNI
products is harmful if the energy efficiency
improves more than 10% between the product at
hand and the next corresponding product model.
3 Problem Solution
The solution is to use typical relations between
manufacturing and use impacts for ICTNI products
as a function of the energy efficiency and lifetime of
original and next-generation equipment. The
lifetime and energy efficiency improvements are
varied.
The relation between manufacturing and use will
vary between ICTNI product types. Based on an
LCA of an enterprise server (Table 2 in [16]), the
weighted impact of the use stage is ≈68% for a four
years lifetime. Of 15 environmental impact
categories (Abiotic depletion minerals,
Acidification, Climate change, Ecotoxicity:
freshwater, Eutrophication: freshwater,
Eutrophication: marine, Eutrophication: terrestrial,
Human toxicity, cancer, Human toxicity, non-
cancer, Ionising radiation, human health, Ozone
depletion, Particulate matter/respiratory inorganics,
Photochemical ozone formation, human health,
Primary energy demand, Resource depletion water),
the use stage is the highest contributor to 8 (Primary
energy demand, Climate change, Photochemical
ozone formation, Eutrophication: terrestrial,
Eutrophication: marine, Acidification, Ionising
radiation, and Resource depletion water).
The Environmental Footprint Method, [17], has
proposed the following weighting of midpoint
environmental impact categories: Abiotic depletion
7.55%, Acidification 6.2%, Climate change 21%
(GWP100 is the overall indicator, and GWP100CO2
impact indicator for CO2), Ecotoxicity: freshwater
1.92%, Eutrophication: freshwater 2.8%,
Eutrophication: marine 2.96%, Eutrophication:
terrestrial 3.71%, Human toxicity, cancer 2.13%,
Human toxicity, non-cancer 1.84%, Ionising
radiation 5%, Ozone depletion 6.31%, Particulate
matter/respiratory inorganics 8.96%, Photochemical
ozone formation 4.78%, Primary energy demand
8.32%, Resource depletion water 8.51%.
For enterprise servers these weighting factors lead
to the following weighted result for the enterprise
server, [16]:
Abiotic depletion of minerals 10.4%, Acidification
3.45%, Climate change 21.5%, Ecotoxicity:
freshwater 0.78%, Eutrophication: freshwater
0.07%, Eutrophication: marine 3.87%,
Eutrophication: terrestrial 6.62%, Human toxicity,
cancer 0.07%, Human toxicity, non-cancer 0.03%,
Ionising radiation 3.37%, Ozone depletion 0%,
Particulate matter/respiratory inorganics 18.5%,
Photochemical ozone formation 8.61%, Primary
energy demand 22.8%, Resource depletion water
0.03%.
It is sometimes argued that the abiotic depletion of
minerals is an economic problem and that the
impact of material production covers the issue, also
for recirculation of materials and recycled content,
[18]. If abiotic depletion of minerals is not
considered the relevance of the use stage for ICTNI
products would be even higher in Table 4.
Table 1 shows primary energy demand results for
the universal situation for two life cycles for the
enterprise server, [16], with no improvement of the
energy efficiency between the product at hand and
the next corresponding model.
Table 1. 4 years lifetime and no improvement of
energy efficiency for 2nd generation used 4 years for
primary energy demand indicator.
Phase
Impact
M1
15
U1
85
E1
≈0
M2
15
U2
85
E2
≈0
SUM
200
Where
M1 = manufacturing impact of ICTNI product at
hand.
U1 = use stage impact of ICTNI product at hand.
E1 = end-of-life treatment impact of ICTNI product
at hand.
M2 = manufacturing impact of the next
corresponding ICTNI product model.
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U2 = use stage impact of next corresponding ICTNI
product model.
E2 = end-of-life treatment impact of the next
corresponding ICTNI product model.
Table 2 shows what happens if the energy efficiency
of the next corresponding product model is
improved by 18%.
Table 2. 4 years lifetime and 18% improvement of
energy efficiency for next corresponding ICTNI
product model used 4 years for primary energy
demand indicator.
Phase
Impact
M1
15
U1
85
E1
≈0
M2
15
U2
70
E2
≈0
SUM
185
Table 3 shows what happens if the product at hand
is reused with the original energy efficiency. For the
sake of simplicity, the same lifetime of the reuse
period is assumed. U1=U2 if the energy efficiency
of the product at hand cannot be improved in the
refurbishment process.
Table 3. 4 years lifetime of product at hand which is
refurbished and reused 4 years.
Phase
Impact
M1
15
U1
85
E1
0
M2
≈0
U2=U1
85
E2
≈0
SUM
185
The relative shares of M1 and U1 will vary with the
lifetime according to Table 4 showing the
approximate relations for ICTNI products for
weighted impacts.
Table 4. Shares of environmental impact for
manufacturing (M1) and use stage (U1) for different
lifetimes of a typical ICTNI product.
Lifetime of
first life of
ICTNI product
M1 (impact
units)
U1 (impact units)
1
38.33
61.67
2
23.71
76.29
3
17.16
82.84
4
13.45
86.55
5
11.06
88.94
6
9.39
90.61
7
8.16
91.84
8
7.21
92.79
9
6.46
93.54
10
5.85
94.15
11
5.35
94.65
12
4.92
95.08
Table 4 shows that the longer the lifetime, the
higher the share of the use stage. Most LCAs for
ICTNI products would show the pattern of Table 4
for a weighted life cycle impact assessment using
the Environmental Footprint Method, [17].
However, Customer Premise Equipment used in
homes may show different relations than those
shown in Table 4 for the ICTNI products used in the
field.
4 Discussion
Fig. 5, Fig. 6 and Fig. 7 show after which time
ICTNI products should be replaced depending on
the energy efficiency improvement of the next
product generation.
Fig. 5 shows that ICTNI products should be
replaced after around 2 years if the energy
efficiency is improved by 25%.
Fig. 5: Environmental impact of replacing or
refurbishing the first ICTNI products as a function
of a lifetime with 25% energy efficiency
improvement of replacement.
150
160
170
180
190
200
0 2 4 6 8 10 12 14
Number of years until ICT network infrastructure goods should be replaced
if the energy efficiency is improved 10% in between product models -
general environmental impact units
Impact Replacement Impact Reuse
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Fig. 6 shows that ICTNI products should be
replaced after around 6 years if the energy
efficiency is improved by 10%.
Fig. 6: Environmental impact of replacing or
refurbishing the first ICTNI product as a function of
a lifetime with 10% energy efficiency improvement
of replacement.
Table 5 and Table 6 show how the values are
derived for 6 years in Fig. 6.
Table 5. 6 years lifetime and 10% improvement of
energy efficiency for next corresponding ICTNI
product model used 6 years for primary energy
demand indicator
Phase
Impact
M1
9.39
U1
90.61
M2
9.39
U2
81.6
SUM
190.9
Table 6 shows what happens if the product at hand
is reused with original energy efficiency using
numbers from Table 4.
Table 6. 6 years lifetime of product at hand which is
refurbished and reused 6 years
Phase
Impact
M1
9.39
U1
90.6
M2
≈0
U2=U1
90.6
SUM
190.9
Fig. 7 shows that the ICTNI product should be
replaced after around 12 years if the energy
efficiency is improved by 5%.
Fig. 7: Environmental impact of replacing or
refurbishing the first ICTNI product as a function of
a lifetime with 5% energy efficiency improvement
of replacement.
The energy efficiency has so far improved ≈by 20%
in between product generations for metrics like
(bits/s)/W and for the energy to transport one bit,
[4].
Compared to business as usual with no
improvements, the assumption of 2+2 years for
ICTNI products results in a 9.5% reduced impact
with a 25% improvement of energy efficiency for
the next corresponding product model, and an
11.8% improvement for the reuse business model.
Compared to business as usual with no
improvements, the assumption of 3+3 years for
ICTNI products results in a 10.3% reduced impact
with a 25% improvement of energy efficiency for
the next corresponding product model, and an 8.6%
improvement for the reuse business model. So for
less energy efficiency than 25%, for a 2 to 3 years
lifetime, the CE reuse seems beneficial. However, 2-
3 years is not common for many types of ICTNI
products in networks and data centers.
Compared to business as usual with no
improvements, the assumption of 5+5 years for
ICTNI products results in a 4.45% reduced impact
with a 10% improvement of energy efficiency for
the next corresponding product model, and a 5.53%
improvement for the reuse business model.
Compared to business as usual with no
improvements, the assumption of 6+6 years for
ICTNI products results in a 4.53% reduced impact
with a 10% improvement of energy efficiency for
the next corresponding product model, and a 4.69%
improvement for the reuse business model. So for
less energy efficiency than 10%, for a 6 to 7 years
lifetime, the CE reuse seems beneficial. 6-7 years is
not unrealistic for certain types of ICTNI in
networks and data centers, [19].
150
160
170
180
190
200
0 2 4 6 8 10 12 14
Number of years until ICT network infrastructure goods should be replaced
if the energy efficiency is improved 10% in between product models -
general environmental impact units
Impact Replacement Impact Reuse
150
160
170
180
190
200
0 2 4 6 8 10 12 14
Number of years until ICT network infrastructure goods should be replaced
if the energy efficiency is improved 10% in between product models -
general environmental impact units
Impact Replacement Impact Reuse
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As shown in Fig. 5 and Fig. 6 for typical ICTNI
products having a lifetime of >10 years, replacement
is much more beneficial than reuse.
For a 10% improvement in energy efficiency, the
border lifetime is between 5 and 6 years.
Moving to the macro scale, what will replacement
or refurbishment mean for the global electricity use
of ICTNI?
Fig. 8 derived by updates of earlier studies, [13],
[20], shows that enormous amounts of electricity
will be used globally if worn-out ICTNI products
are not replaced by new energy efficient equipment.
A refurbishment scenario - with no improvement in
energy efficiency - would use thousands more TWh
than replacement! This is excluding TWh from
other ICT and electronics.
Fig. 8: Electricity to be used by ICTNI products in
the use stage under different energy saving
scenarios.
The expected case scenario assumes that the energy
efficiency (expressed as global data traffic over
electricity used) is improving by 10% per year from
2018 to 2050 and the best case assumes that the
energy efficiency is improving by 15% per year for
the same period. The “no improvement scenario” in
Fig.8 is an impossibility but is shown as a reference
to the risk of refurbishment. As shown by Fig.8 -
with the continued growth of data generated - if
decisions are taken to reuse old equipment, with no
improvement of their energy efficiency, the World
risks using >3000 extra TWh of electricity in 2030
and >600000 TWh in 2050. As far as ICTNI
products are concerned, this underlines that energy
efficiency is one of the key mitigation measures to
save energy.
Is the software-related upgrade to improve the
energy efficiency of refurbished ICTNI a realistic
strategy, i.e. U2 in Table 2 and Table 6 can be
reduced so that U2≠U1? Given the rapid
development of technology for new products, it is
unlikely that such upgrades are possible.
Refreshing ICTNI products with refurbished
equipment generally does not make sense, but needs
to be analysed case by case.
Safety issues must also be investigated for
refurbished products.
Moreover, the manufacturing environmental impact
could change marginally between M1 and M2 for
the replacement scenario due to changes in
manufacturing technology. If M2 is increased by
5%, Figures 5-7 do not change significantly.
Apart from this, maintenance will be more costly for
refurbished ICTNI products beyond their expected
average durability.
5 Conclusion
Reuse of ICTNI products with an expected
durability lifetime of >6 years is inappropriate from
an ecological viewpoint if the energy efficiency
between the product at hand and the next
corresponding product model is improved by >10%.
To avoid doing very significant harm to the
environment, old worn out ICTNI products must not
be reused, but should be recycled as far as feasible.
6 Outlook
The present research is also linked to LCA
modelling of reuse. Each product has a total lifetime
irrespective of the number of owners. If reused a
product causes less manufacturing related
environmental impacts per year than if the same
product is not reused. However, the reused product
will often cause higher use stage related
environmental impacts than the next corresponding
product model. Both the absolute LCA of the
lifetime extension of one product and the
comparative LCA of several lifecycles may be
relevant. Straightforwardly standardizing this
modelling is a challenge but would be useful for
customers seeking the environmental footprint of
reused products.
As a next step, using different lifespans for the
reuse of the product at hand and the next
corresponding product model should be modelled,
and the environmental impact expressed per year,
e.g. for 4+4 years for a replacement and 4+2 years
for reuse. Upgrades within the first life of the ICTNI
product could also be investigated in this kind of
modelling. The link between system architecture-
600
5000
650000
1300
30000
400
6000
1
10
100
1000
10000
100000
1000000
2010 2020 2030 2040 2050 2060
Global Electricity use (TWh) of ICT Network
equipment from 2018 to 2050
No improvement of energy efficiency Expected case Best case
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Contribution of Individual Authors to the
Creation of a Scientific Article (Ghostwriting
Policy)
The author contributed in the present research, at all
stages from the formulation of the problem to the
final findings and solution.
Sources of Funding for Research Presented in a
Scientific Article or Scientific Article Itself
No funding was received for conducting this study.
Conflict of Interest
The authors have no conflict of interest to declare.
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