Frequently Asked Questions

Eco-costs are hidden environmental costs that our society bears: the harm to nature, human health, and the depletion of natural resources. In economics, these are known as “external costs,” meaning costs that are not yet included in our economic system. The use of almost all products and services comes with eco-costs. We must reduce this damage drastically to a level that Mother Earth can carry. However, the changes required to achieve this do cost money. The University of Delft has calculated as accurately as possible the money that is needed, under the condition that we take prevention measures urgently. The target norm is the so-called “no-effect level,” and the calculation technique is that of preventive costs. Economically, we don’t need degrowth, provided we redesign our current economy: we should not waste our money on damage itself, but use it to reduce the damage, i.e. we must take prevention measures and must introduce the circular economy.

In the environment, we face more than just the climate problem. There are many different pollution problems related to water, soil, and air. Eco-costs have been calculated for the most significant issues:

The most important issues are:

1. Climate change, where weather systems are thrown out of balance because we, as humans, are releasing far too much carbon into the atmosphere, which was safely stored in our Earth’s crust for millions of years.
2. Biodiversity e.g. in European Natura 2000 areas, where (a) agriculture, industry, and transport have been emitting excessive nitrogen compounds for decades, leading to the overgrowth of unique plants by grasses and weeds, and (b) forests and birds are dying due to acidification from sulfur emissions.
3. Clean water in lakes, rivers, and oceans, where (a) an excess of phosphates from fertilizers causes oxygen depletion in lakes, suffocating ecosystems, (b) toxic substances from industry (chemistry and metals) make all life in rivers disappear, and (c) the “plastic soup” in the ocean severely threatens underwater life.
4. Human health is increasingly affected by the accumulation of deadly and harmful toxic substances in the human body. This may not noticed by individual people, but the devastating effects are evident in medical statistics. It becomes increasingly clear in cities and countries that this cannot continue.
5. Materials scarcity is increasingly a sustainability issue: (a) the growing population in our world needs ever more materials (b) the elimination of fossil fuels goes hand in hand with increased demand of metals,  (c) geopolitical tensions may cause sudden disruptions of supply chains.

See for further information: 
concept and structure, emissions, resource scarcity, energy. land-use, and Social- eco-costs

The concept of damage costs is most suitable to make people (and politicians) aware of the glooming situation of our planet. However it is hardly possible to calculate the damage costs.
As an example: CO2 emissions > CO2 concentration > increase in temperature > all effects > the sum of the costs for each effect.
Especially the damage costs of nature are hard to establish, since these costs can not be valued (different people will allocate different costs to the same damage).
An interesting issue is that all damage based systems (also in “points”) suffer from this unsolvable problem: who decides “what is more serious than what”? What is the required Performance Reference Point? Are the norms and values of an expert panel leading? Or political preferences? Or the opinions of people in the street? This issue is well described in the system of ReCiPe indicator.

The concept of the prevention costs is most suitable to make business people aware of the fact that a product may become too expensive in future in comparison with the green alternative (because of eco-tax or tradable emission rights).
This indicator is suitable for people who are convinced that “something has to be done”, but wonder what it will cost. They are aware that environmental protection should be realised in the most costs-effective way.
Calculation of prevention costs is not simple, but doable.
As an example: max. stable CO2 concentration > max. CO2 emissions > costs of the technical measures to reduce the current emissions.
The weak spot in the prevention based calculation is the level at which the concentration has to be reduced (the Performance Reference Point). For some emissions this level is zero which means that the substance must be banned (examples; DDT, CFKs), but for many substances there is a ‘no effect level’ which is higher than zero. This level, at which the damage costs are per definition zero, is sometimes under heavy scientific debate (example: dust).

The concept of shadow prices is an approach of some economists. The idea is that prevention measures must be taken when the prevention costs are lower than the damage costs. However, when the damage costs are lower than the prevention costs, one should accept the damage. The shadow price is the point where the damage line crosses the prevention line. See Fig. 7.1.
The problem of this concept is threefold:

1.	It is hardly possible to determine the costs-curve of damage
2.	It only can work for damage to human lives under the following condition: the money involved is
	transferred from the party which causes the emissions to the people who suffer from it. It cannot
	work for damage to nature (since loss of nature cannot be compensated with money)
3.	Since the level of ‘willingness to accept compensation’ is much lower for poor people than for rich
	people, it is not possible to put a price tag on it.

A proposed way out is that the party which causes the emission pays to the government. The price is then determined by politics. However is this system politicians appear to judge on the basis “is it affordable for the industry?”, resulting in a price which is far to low (the ‘willingness to pay’ is usually a factor 10 lower than the ‘willingness to accept compensation’).
Concluding: the shadow price is not an acceptable concept, since it doesn’t work in practice and seems to be morally wrong.

What to do with environmental protection in countries outside Europe is a moral choice.
The article in which the virtual pollution prevention costs was introduced as a new single indicator for LCA (Vogtlander et al 2000), ended with the following “call for comments”:
(quote) …………
3. Especially for developing countries, it is possible to make a quick estimate of the pollution prevention costs (1. assess the regional environmental problems; 2. make a list of measures to be taken; 3. determine the marginal prevention costs for each class). This could result in a set of data for each different regions.
Such a calculation model however makes sense only when the Life Cycle Inventory of emissions does take into account the region where the emission occurs, which adds quite some complications to the current LCA methodology. Do you feel there is a need for such an enhancement of the LCA methodology? Why and for which type of situations? Or do you feel that the LCA methodology should be kept simple?
4. The underlying idea of point 3 is that the developing countries cannot afford the prevention measures of the western world, and they don’t need them (because their emission levels are low). However one may argue differently: in order to gain maximum environmental protection, best practices in the field of prevention measures should be applied world wide and “export of environmental problems for economic reasons” should be suppressed. Such an approach would require world wide standards for prevention measures and/or prevention costs (in Euro or US $ per kg equivalent per class).
In such a model regions with high emissions will have a high economic burden to prevent these emissions, regardless of there own sustainability norms and there economic situation. As a consequence the western world has to subsidise the developing countries where necessary.
How should we arrive at such world wide norms? Do we expect then norms which will be totally different from the norms presented in this article, and if so why?
……………….(unquote)

Of the people who commented, 9 out of 10 said that they were in favour of the idea that eco-costs should be a world-wide norm, based on the heavily polluted regions which need the most strict and best technology (Los Angeles, London, Rotterdam, Tokyo, Rhurgebied, Turin, Beijing, Delhi, Calcutta, Cairo, Mexico City, etc.).
The underlying philosophy is (as an extreme example): when the automotive industry develops cars with low levels of pollution, it is not acceptable that old, heavy polluting, jeeps are used at Antarctica (even when concentration levels at Antarctica are still low).
Only 1 out of 10 people followed the argument that poor countries cannot afford the prevention costs, and therefore must have lower eco-costs norms in LCA.

The reaction on the last sentence of the call for comments was, that we should start with the European prevention costs, and find out later whether or not the standards are strict enough for the heavily polluted areas outside Europe.

Nevertheless it is interesting to make calculations on the marginal prevention costs in other regions (simplified calculations have been made in japan, South Korea and a Chinese local area). Background information for such calculations are given in the Thesis, Annex 2a, and answers on questions to a Chinese colleague.

This issue is directly related to the international discussions (United Nations Climate Change Conferences) on who should carry the costs of climate change: the demand of poor countries to get compensation of the rich countries for their costs caused by climate change.

The eco-costs of electricity is not directly related to the price of oil and gas.
The reason is that the marginal prevention costs is primarily based on the replacement of electricity from coal-fired power plants by electricity from windmills parks at sea (the most expensive solution on the road to sufficient CO2 reduction).
The costs of coal is highly related to the actual costs of production and transport, and has been rather stable in the past 70 years. Although speculation has increased the price of coal considerably in the period 1975- 1984, and in the years 2011, 2016 and 2018, this peaks in coal prices stabilized back to the production costs (below. 60 USD/ton in 2020). So it is expected that the price of coal will just follow the general trend of price inflation, as the price of windmills from the sea will do. Therefore, de level of eco-costs of energy is relatively stable and will follow the price inflation.

The main issue, however, in these calculations is the increasing efficiency of windmills with the increasing size and height.

The eco-costs of CO2 are basically not influenced by any subsidy, tax, or Carbon Permit price.
The reason is that the calculations are made on the basis of real costs (excluding tax or subsidy).

The effect of the EU ETS system is that it is likely that a high Carbon Permit price will stimulate the industry to take prevention measures (that are cheaper than the permits). This lowers the total CO2 emissions, but not the eco-costs of CO2. The reason is that eco-costs of CO2 are marginal prevention costs . These marginal prevention costs are stable in time during the transition towards a sustainable society. This is depicted in Fig. A.2.3 of Annex 2c (“Why marginal prevention costs instead of  total prevention costs”) of the Thesis. So the marginal prevention costs (Euro/kg), being the slope of line b at the “norm for sustainability”, will remain constant throughout the total transition process.

Another issue is that of “revealed preferences”.
Revealed preferences in environmental economics is the idea that the general public already accepts the extra costs of a specific prevention measure. So the measure is paid by the public, which is the case in Europe for the extra price of electricity from offshore windmills.
This does not change the fact that the marginal prevention costs (on a real costs basis) is still there, and is still the same:
(a) When governments ease the restrictions of energy production, the markets would fall back to the cheapest system of production (as it was done during the hike in energy prices at the start of the war in Ukraine)
(b) It is an extra reason to implement prevention measures that are less expensive, but still are to be done (a matter of urgency).

Therefore, a revealed preference does not mean that the eco-costs of it is zero. In the contrary: for a lot of eco-costs, the revealed preference has been taken as the Performance Reference Point (see above point 1.2).

Many practitioners of LCA-study struggle with the definition of the functional unit. One of the issues here is whether or not quality aspects must be part of that definition.
In general, the following is advised:
– For comparisons on the basis of eco-costs only, quality issues must be part of the definition of the functional unit, since the products which have to be compared must be identical and must have the same quality. As a result, such comparisons are only useful in the optimization of the application of materials (in innovation of products)
– For comparisons on the basis of the EVR, quality aspects must be kept out of the definition of the functional unit, since quality is part of the value and not of the eco-costs. Such EVR comparisons are to be done in the case of innovation of products, services or total systems (example: the choice between a new building or renovation), since the quality is not the same these different solutions. Note that comparison on the bases of eco-costs only are not possible in these cases.

In most of the standard software packages, the data on transport are only given in the unit “ton.km”. The reason is that all standard LCI databases (like Ecoinvent) only supply data on the basis of tonnes x km. It is, however, good to realise that the LCIs are calculated on the basis of a full load of the truck (or vessel, or plane) and an empty trip back, divided by the maximum load of the transport vehicle. When the density of the freight is relatively low, the truck is full at a maximum volume instead of a maximum weight. In such a case, a correction factor has to be applied, since the energy required for long distance transport is dependant on distance, shape and velocity, and hardly dependant on the weight.

The correction factor must be applied when the density is lower than:
– 160 kg/m3 for airfreight
– 320 kg/m3 for freight in a European standard truck + trailer
– 414 kg/m3 for freight in a standard truck + container (40 ft)
– 843 kg/m3 for freight in a standard 20 ft sea container (take this density for other sea freight as well)

The correction factor to be applied is
“break-even density” / “actual density”
under the condition that this factor is more than 1.

Then, the amount of ton.km for the input of Simapro or CES has to be calculated as follows:

“actual tonnes” x “actual km” x “break-even density” / “actual density”

Example: when 24 tons has to be transported by a standard European truck and trailer (24 tons = a full truck load for high densities), and the actual density is 160 kg/m3, the correction factor is 2. This means that the truck must drive two times to transport this freight. The eco-burden per ton.km of this transport is 2 times the eco-burden per tkm of high density freight.

Note:
The assumption that the average load factor (=occupation) is 50% (the truck is full, but is empty back, on average) is realistic in practice. It is obvious that, from environmental point of view, it must be avoided that the truck is not fully loaded. If this is not the case in a typical situation, a multiplier must be applied in LCA to cope with the partly loaded truck. When, in special cases, the trip of the truck can be combined with other freight on the trip back, the so called “economic allocation” of the eco-burden of round trip of the truck must be applied (which will result in an multiplier less than one for the ton.km).

See also Section 4.1 of the Practical LCA Guide

Sequestration of CO2 in wood and other biobased products (carbon uptake) is a confusing subject in LCA:

The short term carbon cycle versus the long term carbon cycle
Part of the confusion is related to the difference in the so called short term carbon cycle and the long term carbon cycle. The long-term carbon cycle operates over geological timescales, spanning millions of years, and includes the reserves of coal, oil and gas. The short-term carbon cycle operates over much shorter timescales, ranging from days to centuries. The carbon of the short term cycle is called biogenic carbon.
Burning fossil fuels bring carbon from the crust of the earth into our atmosphere, resulting in global warming. It is regarded as a “linear system”: the end-of-life of the CO2 is in the air (although there are carbon sinks of organic matter the ocean that may end in the long term cycle)
Burning biobased carbon brings also carbon to the atmosphere, however this carbon originates from plants that captured the same amount of carbon, so there is a fundamental difference in source and a difference in timespan. It is regarded as a “circular system” in the biosphere. The assumption is that at the end-of-life of the product, the carbon goes back to the atmosphere, either by burning, or by any aerobic bacteriologic process.

The issue of circularity of biogenic carbon
There are three issues in LCA that cause confusion:
Issue (1) the loss of biodiversity in forests, versus the issue of carbon sequestration in forests
Issue (2) the requirements of circularity in the biosphere of biogenic carbon
Issue (3) the time span estimate of the product, i.e. how long does the “biogenic carbon uptake” lasts

Issue (1) The issue of biodiversity is blurred at internet discussions with the issue of carbon sequestration in forests. Keeping forest “untouched” is extreme beneficial for biodiversity, however, anaerobic bacteria might emit methane, which is quite negative in terms of greenhouse gasses (1 kg CH4 is 30 kg CO2 equivalent). This requires well balanced decisions: it does make sense to give biodiversity the priority in forests where biodiversity is high (i.e. topical rain forests), and give carbon sequestration the priority where biodiversity is low (i.e. boreal forests).
Degradation of biodiversity is calculated in eco-costs via land-use change (LUC), see the webpage on this issue at this website

Issue (2) requires to keep 3 different systems apart in the discussions:
(a) In tropical forests: modern rotational harvesting,
(b) In tropical forests: traditional clear cutting.
(c) Boreal forests in the Scandinavian countries: continuous clear cutting of small areas plus replanting.
Only FSC wood guarantees more or less method (a), which is a prerequisite for the assumption of circularity. Other than FSC wood originates unfortunately from method (b), often to create agricultural land, which is far from the circularity requirement. Note: the negative effect of method (b) is handled in the eco-costs system by (i) the land-use change, based on local loss of biodiversity (ii) the average loss of carbon sequestration of 3.45 kg CO2/ kg wood
The boreal forest in in Scandinavian countries, method (c), are continuously increasing their stored carbon in forests. The circularity of this wood is therefore guaranteed (there are more trees planted than harvested). It is a widespread misunderstanding that the period of regrowth of trees must be taken into account: from systems point of view, there is a condition of steady state i.e. for one specific area there might be a specific age of trees, but overall the ages of the trees are equally spread over the country, and that situation does not change much over time.

Issue (3) An arbitrary choice has been made in the LCA community: when the life span of a product is shorter than 100 years, the biogenic carbon belongs to the short cycle, and is therefore regarded as circular (the choice of 100 years is related to the predominant choice of the 100 years GWP midpoint tables). In this way complex calculation on dynamic systems, and the theory on the ‘delayed pulse’ are avoided. PEF follows this simplification as well, but proposes 300 years, instead of 100 years, as cut-off point. The eco-costs / Idemat system proposes 100 years (i.e. wooden beams in buildings are assumed to be there ‘for ever’): in such a case 1.72 kg CO2 per kg dry wood, or 1.51 kg CO2 per kg wood MC 12% should be added for carbon sequestration.
Note: a detailed analysis on the mass balance for wood and bamboo is provided in (Vogtlander, et al 2014). See also the webpage Eco-costs calculations on wood

Two ways to deal with the circularity
In LCA there are two ways to calculate the biogenic CO2 cycle:
(A) Do not count biogenic carbon (e.g. biogenic CO2 = 0), since the short life biogenic CO2 is circular (the biogenic CO2 stays within the boundary limit of your calculation system, and all uptake of biogenic carbon will be released at the end-of-life sooner or later).
(B) Carbon uptake at the moment of harvesting is counted, combined with release of the carbon at the end-of-life that is counted as well. This is the case where the atmosphere is not included in the product system (the biogenic carbon enters the system at the cradle, and leaves at the end-of-life)

The effect on your calculation is depicted in the 3 Figures below (from CEFIC position paper 2022):

The first figure depicts the situation for CO2 from fossil fuels. The second figure depicts calculation (A) for biogenic carbon. The third figure depicts calculation (B), which shows a negative carbon score for e.g. wood or bioplastics.
It is clear that companies like to have a negative carbon score for cradle-to-gate in their marketing (“we are a carbon negative company”). Scientist, however, regard this as greenwashing (misleading consumers) since the score for the total LCA (cradle-to-grave) is positive. So far, PEF rejected the calculation (B).

Some history on the issue.
In November 2009 It was decided by Ecoinvent to follow the IPCC in their decision in 2006 to apply the calculation system (A) “biogenic CO2 is not counted in LCA”
In the ILCD manual on LCA of 2010, the same approach is followed.
In the EN15804 (the norm for EPDs) allows calculation method (A); carbon uptake may be reported just as as additional information, however, not as an integral part of the LCA calculation.
PEF did follow the EN 15804 approach, for products with a life span shorter than 300 years
IDEMAT follows calculation method (A).  The carbon uptake might be reported separately from the LCA calculation (for wood the uptake is 1.53 – 1.83 kg CO2 per kg dry wood) for products that have a shorter life span than 100 years. Carbon sequestration must be included in LCA for products that last longer then 100 years

Consequences for combustion with heat recovery.
The consequences for the end-of-life calculations on “combustion with heat recovery” is that the end-of-life scores for wood and biobased products become negative. See FAQ 2.4. This is the basic idea of “avoided fossil fuels”: at the end-of-life heat is recycled with a positive effect (a ‘credit’) on the environment (compared to doing nothing).

The basic approach of ISO 14044
Waste that can be burned is dealt with in LCA by “system expansion”. The basic idea is to add an extra step to the chain , where the waste is burned, either in a electrical power plant or in a municipal waste incinerator. To calculate the gross heat, the Lower Heating Value of the waste has to be applied (ISO 14044). This is the philosophy of the “avoided fossil fuels”, similar to “avoided virgin materials” by material recycling. See for a further explanation Section 5.2 of the Practical Guide to LCA.
The following efficiencies are to be applied in the eco-costs system (the best practice in Western Europe):
– 95% to convert heat input to heat output.
– 45% efficiency loss in a municipal waste incinerator (55% efficiency), see ref

Some data
The moisture content (MC) in wood must be evaporated, leading to the following net LHV values:
– 20 MW per kg dry wood (this is an average for softwood, the LHV for hardwood is approx. 10% higher)
– 17,3 MW per kg wood MC 12%, wood in houses (= 0,88 x 20 – 0,12 x 2,25 MW per kg)
– 8,9 MW per kg wood MC 50%, fresh wood (=0,5 x 20 – 0,5 x 2.25 MW per kg)
For other moisture contents, the LHV formula (MW/kg) is: ‘weight per kg’ x (1 – ‘moisture comtent’) x 20 – ‘weight per kg’ x ‘moisture content’ x 2,256

Since wood is a natural product, the biogenic CO2 (and SO2) emissions of combustion are not counted in the eco-costs system (see FAQ 2.3): these emissions are part of a closed loop when the wood stems from plantations (which is the case for European wood types). In Idemat, NO2 emissions are added (since they come from the burners in the system). A norm of 1.27 gram per kg wood is applied.

Consequences for plastics
For combustion of plastics, the situation is basically the same. The difference with wood is that most of the plastics which are applied in products are based on fossil fuels. Therefore the eco-costs of CO2 must be counted. The result is that the positive effect of the generation of electricity (or heat) is counterbalanced by the CO2 emissions. The net result for electrical power plants is slightly positive for some plastics, but negative for many others. See Idemat data. For municipal waste incineration, the result is always negative, because of the lower efficiency. So burning plastics is a municipal waste incinerator is not a good solution for the environment: plastics should be recycled.
When plastics are made from renewable resources (“bio-plastics”), combustion is a good option (since the CO2 is not counted, like wood).

Note that combustion is a better solution than uncontrolled bio-degrading, since uncontrolled bio-degrading has the risk of CH4 emissions (a greenhouse gas, 30 times stronger than CO2). There are two types of controlled bio-degrading:
a. Controlled bio-degrading by anaerobic bacteria in a closed storage tank, where the CH4 is collected and burned. For small rural communities in the 3rd world, this seems to be a good local solution to generate methane for cooking. In the Western world it seems to be that it is not a good solution, since the overall eco-efficiency is lower than combustion in an electrical power plant.
b. Controlled bio-degrading by aerobic bacteria in a closed building, where the CH4 emissions are minimized and captured. This method is applied in Western Europe (the Netherlands, UK, Germany, etc.) for municipal waste. In countries like the Netherlands, there is more compost production than the local market can absorb, so there is a tendency to limit compost production and use the biomass for combustion.

Remarks
(A) The Ecoinvent database in combination with Recipe has the characteristics that the benefit of combustion of wood cannot be taken at End of Life. The debate is that this would result in double counting, since biomass is already taken into account at the “market mix” of electricity. From macro-ecologic point of view this is right. However, the issue is that LCA is normally applied to micro-ecologic issues: when a designer decides on wood since it can be burned at the EoL, it is a good decision as such, regardless of the fact what happens on average in Europe. It is an issue of applying marginal instead of integral mass-balances.
The eco-costs system is meant to be for designers, purchasers, business people and consumers who have to take their marginal decisions. Therefore, the eco-costs system incorporates the positive effect of combustion of wood at the EoL stage, being the general approach of practitioners for LCAs of products.

(B) An important issue for the far future is that the credit of ‘combustion with heat recovery’ will lessen when hydrogen will become the main source of industrial heat (natural gas is now the main source of industrial heat), since the credit is related to the “avoided heat source”.

This section is being updated and reviewed

Structuring recycling and end-of-life in LCA
The basic difference of “linear” systems and “circular” systems is depicted in the figure at the left below.
The LCA of a linear system starts with the cradle (mining of ore, or production of oil), and ends with the stockpile of sorted waste materials at the end-of-life, which is the cut-off point in the Idemat calculation (as it is in EN 15804). There is no carry-over to the next product life cycle.
The LCA of a circular system starts with the stockpile of sorted waste materials, which are to be recycled (eco-costs= zero at this starting point) into a new product. The end of the cycle is the stockpile of sorted waste, which is the cut-off point.

The figure at the right depicts the same basic idea, but gives all recycling and end-of-life options. The numbers in this figure relate to the “Delft Order of Preferences”, a list of the 10 major systems for End of Life, used for structured and systemized analyses of (combinations of) design options (Vogtlander et al, 2002):
1. Extending of the product life
2. Object renovation
3. Re-use of components
4. Re-use of materials
5. Useful application of waste materials (compost, granulated stone and concrete, slag, etc.)
6. Immobilization with useful appliances
7. Immobilization without useful appliances
8. Incineration with energy recovery
9. Incineration without energy recovery
10 Land fill.

It is important to realize that for big, modular objects (like buildings), there is not “one system for End of Life” but in reality there is always a combination of systems.
Two basic rules for allocation in the eco-costs model are (see figure at the right):
– eco-costs of all activities marked with ‘b’ are allocated to the End of Life stage of a product (transportation included).
– eco-costs of all activities in the block marked with ‘a’ are allocated to the material use of the new product (so are allocated to the beginning of the product chain).
In line with the aforementioned allocation strategy, the ‘bonus’ to use recycled materials is taken at the beginning of the product chain, where the new product is created. Material depletion is caused here when ‘virgin’ materials are applied, material depletion is avoided when recycled materials are applied.
The benefit of recycling options must always be calculated by benchmarking of (two or more) total recycling-production loops, starting at the stockpiles of materials that are to be recycled. Other attempts to calculate the benefit of recycling are doomed to fail.

The recycling credit
Most of the thermoplastics can be recycled. This can be dealt with by “system expansion” in the End of Life stage, like combustion of waste, see FAQ 2.6. The advantage of recycling plastics is that it will replace the “virgin” plastics, so overall less plastic will be made out of fossil oil.
In the eco-costs system we call that the “recycling credit” = (eco-costs of recycled plastics) – (eco-costs of virgin plastics). These eco-costs are negative (having a positive effect of the total eco-costs of the chain). See for more information Section 5.2 of  a Practical guide to LCA.
A list of the eco-costs of recycling credit of plastics is given in the Idemat excel files, however, it is better to refrain from the recycling credit in your calculations: take the benefit of recycling at the beginning of the production chain, by applying the data of recycled plastics in Idemat (instead of  virgin plastics). This allows for applying the real recycled/virgin mix in your calculation. See FAQ 2.6. Note that double counting (taking recycled plastics at the input, plus applying the credit) is not allowed.

Two types of recycling
There are two types of recycling:
(a) mechanical recycling, i.e downcycling, resulting in e.g. rPET, rPE, rPP, rPVC
(b) chemical recycling, i.e. upcycling, resulting in virgin quality
Mechanical recycling without much loss of quality is only possible when a plastic is not contaminated with another type of plastic and when the material has no color. Mechanical recycling is downcycling: the quality is degraded at every recycling loop. Upcycling is possible for the full range of plastics by “pyrolysis”, however, this solution is energy intensive and expensive. Upcycling data in Idemat are based on pyrolysis, except from upcycling of PET (which is done by the process of Ioniqa).

Note 1. Recycling of plastics can only be done efficiently in big volumes. Therefore, a “closed loop system”, where the plastics are used for the same product (don’t enter the market) is not a realistic option for the vast majority of products. Only mechanical recycling of bottles is done in closed loop, to avoid quality degradation by contamination.
Note 2. Idemat does not have recycling credit tables for mechanical recycling, since mechanical recycling results always in quality degradation.

Downcycling in LCA
There is an on-going debate on how to deal with such examples of downcycling in LCA, partly because of the interests of the industry, partly because of the challenge to model it in science. This is the field of ‘attributional modelling’, where the debate is focused on economic allocation methods down the recycling cascade, see for details the ILCD Handbook of  Life Cycle Assessment – Detailed Guidance, Annex C. In this LCA handbook, a practical approach is proposed, following the rule in ISO 14044 that output of combustible material may be transformed into an energy output. In the case of paper and paper products it does make sense to take the electricity output of a municipal waste incinerator as a norm.
Such a chain is shown in the figure below.

The waste paper products are depicted here as part of the total paper chain. Recycling rates (2022) are: 2.5x in EU, 2.1x in USA, 3.8x in NL(ref. Milieu Centraal).
The waste paper products are ‘additional applications’ in the paper chain. It does make sense to give:
(a) this additional application no eco-burden of its material source (e.g. apply the cut-off at the stockpile of waste, like it is done in EN 15804),
(b) allocate 1/3 of the credits for End of Life (incineration) to the waste paper when the waste paper is 3x recycled. The eco-burden of such a secondary product is only its transport, processing, use, waste processing, and part of the EoL credit.

The same principle may be applied to other examples of real downcycling such as:
•mechanical recycling (re-melting) of clean and pure plastics (e.g. PET)
•street furniture pressed from different kind of coloured plastics
•hardboard plates made from old, discarded, wooden planks
•consumer products directly made from waste, like bags and garments made ofdiscarded clothing
•aggregate from concrete

Note 1. In such an approach, the grade of the waste – not to be confused with the grade of the secondary (recycled) material – is not relevant for the eco-costs of the waste (the eco-costs of waste to be recycled is 0, regardless of its quality, see the LCA guide,  Appendix V).
The quality of the grade becomes part of the value of the new product, and/or causes more or less activities in the upgrading process of the recycling step, but the quality of the waste is not affecting the eco-costs of the waste as such. This approach is similar to the approach of virgin materials in the ground (iron ore, copper ore, coal, oil, gas, etc.). These materials start also with no eco-costs (‘eco-costs = 0’) in LCA, regardless of the specific economic value (the grade).

Material residence time
The situation for metals seems on the first sight similar to the situation of plastics (see FAQ 2.6).
However, there is a complicating factor, especially for metals, since the lifespan of metal products is rather long (many years). Therefor the “residence time” of materials in the use phase of system must be taken into account.
The figure below depicts a typical case for stainless steel.

The issue is that the demand of metals has been growing for the last decades, and is expected to grow further. Take the example of stainless steel of the figure below:
– the average residence time of the steel in the use phase is approx. 20 years
– nearly 100% of the stainless steel is being recycled (since it is an expensive material)
– however, 100% of the production of stainless steel 20 years ago, is about 40% of the current demand

It is therefore far from realistic to state that “100% will be recycled in future” in our calculation. We must take only the eco-costs of recycled stainless steel as it is used in our current production.
On average, it is a far more realistic approach to take the “market mix” (40% recycled, 60% virgin), calculate the eco-costs of that mix, and take that as input of the production system

There is, however, a logic exception on the approach to take the market mix: in cases where the actual amount of virgin and recycled is known. The actual system mix of virgin and recycled materials for production has to be applied then.
Manufacturers strive for a high recycled content:
(a) when the material is expensive and recycling is relatively easy, or
(b) when a manufacturer tries to gain a competitive edge in the market with a green product.

Recycling indicators in statistics
Because of the effect of residence time that is described above, there are various recycling indicators:
(a) EOL-RIR: end of life recycling input rate – the fraction of secondary material in the total material input
(primary and secondary) to the production system. It measures the proportion of total material available
to manufacturers that comes from recycling of end-of-life products.
(b) EOL-RR: end of life recycling rate – the the share of a material in waste flows that is actually recycled. It provides information about the performance of the collection and recycling to recover materials at end-of-life and it is thus useful from a recyclers’ perspective

Most of the data on recycling rates are EOL-RR, but take care: in LCA we need to apply the EOL-RIR (see the figure above).

Note that recycling data are hard to calculate because of import and export of countries, because of “diffusion” (materials that disappear) and because of the residence time (amount that is in use in our society). It is extremely difficult to make correct mass balances.

These data are valid for offshore regions with windclass 6 or 7.(at 80m height).
Global maps for 80 m (as well as 10 m) are given at http://www.stanford.edu/group/efmh/winds/global_winds.html

Another issue is the size of the windmill in the case of an inland location. Under the assumption that the capacity factor is 0.20, the eco-costs (euro/kWh) have been calculated for the 4 windmills which are available in the Ecoinvent database. See the Fig. 7.12 for eco-costs, ‘normalised’ at a capacity factor of 0.20. (Note a capacity factor of 0.20 is a normal design criterion for onshore windmills in areas with windclass 3 and more; note that for offshore windparks the capacity factor is 0.40 – 0.50)

The key to translation of the Swiss data to other areas are maps on solar irradiation (also called insolation). There are 3 types of maps:
– maps on the irradiation on the flat horizontal surface
– maps on the irradiation on a (fixed) tilted panel
– maps on ‘peak sun hours’ (often presented for the worst month of the year), often for fixed tilted panels

When we assume that the Swiss panels are located in the middele of Switserland (near the city of Bern), the irradiation is approximately 1350 kWh/m2 per year.
The first orde approximation of the eco-costs (in euro/kWh) at any other location on earth is

eco-costs of electricity from PV panels (euro/kWh) = 0.0164 x 1350/(annual local irradiation)

in which the annual local radiation is expressed in kWh/m2

The same applies to the carbon Footprint, the CED and Recipe Points.

There are detailed maps of irradiation on tilted panels for each country within the EU, see http://re.jrc.ec.europa.eu/pvgis/cmaps/eur.htm .
The annual irradiation in The Netherlands ranges from 1200 (kWh/m2) in the North – West of the country to 1100 (kWh/m2) in the South – East.
Deatiled horizontal irradiation maps for Africa are available as well on the EU website http://re.jrc.ec.europa.eu/pvgis/cmaps/afr.htm
A good overview of all countries around the globe is given for horizontal irradiation at http://www.helpsavetheclimate.com/solar.html

Economic allocation is preferred (exception: mass based allocation for mining of ‘companion metals’ ), to prevent greenwashing in product LCAs.
The issue is simple:
Many products have by-products (or waste) with a small positive market price, but a high volume. In economic allocation these type of by-products (waste) do play a negligible role. However, in mass based allocation, these mass flows can be considerable, so that a big portion of the eco-costs is allocated to these by-products (or waste), lowering the eco-costs of the main product. It is no doubt that this supports greenwashing op products.

The following advise is given on “strategies to find prices of products with missing or distorted markets” (Table 3.9.2.1 from Handbook on Life Cycle Assessment, Guinée (editor), 2002):

Problem		Solution
1.	Market prices not known	Look for public sources, preferably FOB (Free On Board) prices
2.	Fluctuating prices	Use three-year averages, or use prices at futures market
3.	Inflation	No problem, as long as the same base year is used in each process
4.	Trends in real prices	No problem, as long as the same base year is used in each process
5.	Different currencies in different processes	No problem, as long as the same currency is used in each process
6.	Locally diverging prices	Choose prices at relevant process locations or calculate averages for the relevant region
7.	Market prices available only further downstream	Use gross sales value method
8.	Partially missing prices	Construct prices from costs and known prices
9.	Economically based market distortions (e.g., Monopolies)	Use actual market prices, correct in very exceptional cases only
10.	Regulations-based market distortions	Accept prices as they are, use value or cost of close alternative for missing market prices
11.	Tax-like financing of activity (e.g., Sewer systems)	Treat as ‘missing market, public provision’
12.	Taxes and subsidies on products	Use the price the seller actually receives
13.	Taxes and subsidies on activities	Do not correct for taxes and subsidies on activities.
14.	In-firm prices not known	Use gross sales value method
15.	Missing markets with public provision	Construct prices based on costs
16.	Developing markets for recycling products	Use current prices of similar products to specify the price of future recycled products
17.	Markets not yet in existence	Use expected future market prices