Thermalnet Methodology Guideline On Techno Economic Assessment
Thermalnet Methodology Guideline On Techno Economic Assessment
Thermalnet Methodology Guideline On Techno Economic Assessment
assessment (TEA)
Generated in the Framework of ThermalNet WP3B Economics
Maximilian Lauer
Content list
Introduction: ............................................................................................................................... 3
1. Cost assessment...................................................................................................................... 4
1.1 Investment related cost.................................................................................................................................. 4
1.1.1 Investment including planning and consulting cost [I] .......................................................................... 4
1.1.2 Administration and insurance cost [ia]................................................................................................... 5
1.1.3 Periodical cost for infrastructure, location, building etc. [ii].................................................................. 5
1.2 Operation related cost ................................................................................................................................... 5
1.2.1 Fuel cost [oF] ......................................................................................................................................... 6
1.2.2 Labour cost [oL] ..................................................................................................................................... 7
1.2.3 Maintenance cost [oM] ........................................................................................................................... 8
1.2.4 Other cost [oO] ....................................................................................................................................... 9
1.3 General remarks on cost assessment ............................................................................................................. 9
5. Abbreviations used............................................................................................................... 24
Acknowledgement:
The compilation of the guideline was suggested by Prof. AV Bridgwater and was done with substantial inputs
given by experts represented in ThermalNet, especially by Patricia Thornley (ManU).
Introduction:
The intention of this guideline is to enable engineers in research and technical development to
work on techno-economic assessments in a consistent and transparent way.
Compare the economic quality of different technology applications providing the same
service.
From this (incomplete) list it can be seen, that TEA is used for very different objectives.
In this guideline each item is given a specification, a description and practical advice for
doing the assessment (information sources, typical values etc.). There is no specific format
proposed for doing the assessment, because practical calculation uses different methods and in
general is very simple using a spreadsheet program.
In chapter 1 the cost assessment is discussed in general, the terms used are specified, methods
for the assessment are indicated and if possible, default values are proposed. The same is done
in chapter 2 for the benefit (income) assessment. Chapter 3 describes some aspects of risk
assessment. In chapter 4 the TEA methods are discussed, giving a description, showing the
calculation and the interpretation of results.
The influence of taxation is not discussed in the guideline. As a simple rule taxes should be
included in cost and benefit assessment, if they are not refundable (e.g. transport fuel taxes).
Value added tax (VAT) usually is refunded (except for private use) and so should not be
included in TEA.
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1. Cost assessment
For TEA cost are separated in investment related cost (chapter 1.1) and in operation related
cost (chapter 1.2). In chapter 1.3 some general remarks on cost assessment are given.
Investment related costs are independent of operation and operation intensity. They will arise
also from not operating plants.
Cost for planning and consulting is a significant share (~5%) of the investment, even if a
mature and well known technology is used. If the technology is new and unknown, the cost
for planning and consulting could be higher (up to 20 %) especially if the plant size is small
(as usually in demonstration and pilot plants).
Investment cost has to be paid during the construction phase and often is financed by a loan
(see also chapter 4 TEA methods).
Depending on the choice of the owner, the investment can also be the cost for an engineering,
procurement and construction (EPC) contract, the EPC contractor agrees to deliver the
keys of a commissioned plant to the owner for an agreed amount, just as a builder hands
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over the keys of a flat to the purchaser. Choosing this route incorporates a degree of
protection for the purchaser, as the EPC contractor will generally guarantee certain
minimum performance standards for the plant against which liquidated damages would be
payable.
If operation is stopped (e.g. shutdown) no operation related will arise. Some operation related
costs are depending on operation intensity (as fuel cost), some are not or only partially (e.g.
labour cost).
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Fuel cost is usually predominant in the cost structure of a biomass project. Therefore it has to
be assessed with utmost care. Two elements are very important for doing the assessment:
The specific fuel cost at the plant gate (/GJ or /t etc.) over the lifetime
The assessment of specific fuel cost and its development over the lifetime of the plant is
difficult, as in most European countries no developed market for biomass exists and prices are
very volatile. The production cost for the fuel (e.g. wood chips) is not applicable for fuel cost
assessment, because it illustrates only the absolute cost minimum but not the price that has to
be paid during the technical lifetime of the plant. The best case for the TEA would be
information out of a negotiated contract for fuel supply over the lifetime. This will rarely be
available. A good and practicable information source is to contact fuel suppliers and their
associations (farmer associations, sawmills, wood processing industry) and to ask for their
expectation. Companies using a similar biomass for production uses (e.g. pulp mills,
chipboard industry) are also a good source for information. These companies will probably
give no information on their actual feedstock cost but deliberately talk about their
expectations on price development. This information is exactly what is needed for the fuel
cost assessment.
Mistakes are sometimes made by neglecting the fuel quality necessary for the specific use.
Biomass as fuel can have very different quality in terms of size, water content, admixtures of
soil, metals etc. Also the prices can be quite different.
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The fuel consumption is calculated from the capacity, the efficiency and the availability of the
plant assessed.
For describing the availability of the plant two specifications are used in Europe:
Capacity factor (kWh produced per year / maximum continuous rating x 8760)
Full capacity operations time (kWh produced per year / maximum continuous rating in
kW)
The calculation of the annual fuel amount seems to be relatively simple but is often a source
for wrong TEA results. The reason is a too optimistic assessment of the efficiency in regular
operation and a too optimistic assessment of availability. As an example the full capacity
operation time of a simple industrial process heat boiler will be hardly more than 7000 h/a full
capacity operation time corresponding to a capacity factor of 0,8. This includes a 24 h/d full
load operation near capacity all days per year except some days for operation and
maintenance (and maybe one or two minor failures in operation). On the other hand a
residential heating boiler in Central Europe has a maximum of 1400 h/a full capacity
operation time corresponding to a capacity factor of 0,16. Most biomass to energy plants will
be in between these two figures. If the assessment is done for a project using a new and
unproven technology the utmost care has to be given to a realistic assessment of the
availability. A figure of 5000 h/a full capacity operation time or even more seems to be very
optimistic in this case, at least for the first 5 years.
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The cost per employee depends on the specific national situation and the qualification needed.
Information on specific labour cost can be easily obtained from e.g. national industrial
associations.
Sometimes maintenance cost are indicated as specific cost related to the product (e.g. /MWh).
This is applicable, if there is sufficient experience with comparable plants (size, operation,
technology). In the case of biomass conversion technologies this can only be applied to very
few widespread technologies (as maybe biomass boilers similar in use and size). No values on
this are known from literature.
As maintenance costs are not only related to the production, it seems to be better to do the
assessment based on the investment [I] for the specific equipment.
Usually a share of the investment is taken for the annual cost of maintenance. Indicative
values are given below. They are deduced from a German guideline on some special cases of
TEA (VDI 2067, withdrawn in the meanwhile)
Type of equipment:
Infrastructure
Buildings
Mechanical equipment *)
Electrical equipment
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into consideration the intensity of operation. It should also be remembered that maintenance
cost is rarely evenly spread over the plant lifetime. Certain key components of the power
generation plant will require major overhaul or replacement after a specific period in service
e.g. steam turbines or boiler tubes. Manufacturers recommendations are the best guide to this.
Many large scale systems will require regular inspection of pressure vessels for health and
safety or insurance requirements and this requirement will sometimes dictate the minimum
period that can elapse before a plant is next shut down for maintenance. Such requirements
need to be factored into both availability calculations and maintenance costs.
The first is the difficulty to produce realistic data for the cost components. The biggest
obstacle is the assessment of the investment cost, but in principle it concerns all cost
components. It is specific to research and technical development, that no exact data are known
for the technologies to be developed or tested. So cost assessment can only be made on
comparative basis looking at existing similar technologies or applications with data available.
In some cases it helps to introduce size factors or country specific factors (cost relations in
different countries) but in general, no specific advice can be given for assessing cost for
technologies not realized before.
The second problem in cost assessment is taking into account contingencies (not expected
cost). Especially assessing new technologies as a broad tendency cost are underestimated in
TEA, even if the cost assessment is done very carefully and based on reliable data. As a
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matter of experience after the realization of a project it can be seen, that the overall cost in
reality are in most cases significantly higher than expected in the TEA. The reason for this is
non expected cost (contingencies). The effect of neglecting contingencies is relatively low, if
various new technologies are compared to each other. But the TEA gives wrong results, if
mature technologies (robust data available) are compared to new technologies (no experience
from realized projects). In this case only the introduction of a contingency factor can help to
avoid a wrong (too optimistic) result of TEA. Contingency factors should be put on the
overall cost. Depending on the experience with the technology and the complexity of the
project contingency factors should be chosen from 1.05 to 1.25.
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2. Benefit assessment
In the case of bioenergy plants TEA the benefit will be the earnings from selling the
product(s) produced. In some cases also the selling of carbon credits or emission certificates
could be an additional benefit (see below).
For electricity production the price is usually clear. A discussion with the purchaser (often the
grid company) will indicate the prices for delivery. For heat production the assessment is very
difficult and depends on the use of the heat, competing alternatives for the contactor etc. No
specific advice can be given for this assessment. Some of the most important facts to consider
are:
Availability of the plant and the heat production (does production rhythm and risk of
failure (maximum time out of service) fit to the needs of the buyer (depends also on
backup possibilities)?
Usually in TEA the price of the heat produced tends to be overestimated. So, the assessment
should be done very careful.
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electricity generated and provide separate revenues. The value of a green certificate is not
fixed and can vary depending on market conditions, although some countries specify a buyout price, which effectively represents a minimum figure, below which the price will not fall
for the duration of the legislation. In most countries where certificates are traded this income
is in addition to any that may be obtained from the carbon credits under European ETS
discussed below. However, in a number of cases national governments are considering
reducing the level of support they offer via certificate schemes in anticipation that the income
generators will receive in the long term from the European ETS will compensate this. Careful
consideration needs to be given to this and other possible legislative changes in the long term.
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3. Risk assessment
Risk assessment is methodically not incorporated in TEA. But risk have to be considered
before doing a TEA, otherwise the results produced would be probably without any relevance.
Risk analysis is dealing with several criteria (examples):
Financial risk
Environmental risk
Technical risk
Social risk
Some of these are interrelated to each other (e.g. technical and financial), some are not.
To illustrate the need to make some consideration of risk related to the project a typical
example is discussed below.
A project is to be assessed on economical availability. Several bioenergy technologies should
be compared. For the choice of the technologies to be assessed some aspects of risk analysis
should be considered:
If the bioenergy plant is a stand alone plant (example: heat production in sawmill for
drying wood) availability and failure risk will be of minor importance for realisation.
So also emerging technologies with some risk of unexpected failure or production
breakdown can be taken into consideration.
So even if risk assessment is not a specific topic to TEA, the risks related to a project should
be kept in mind and respected in the design of TEA.
Most developers will carry out some form of risk assessment as part of their project activities.
Techno-economic assessment can be used to help inform this risk assessment and, conversely
risk assessment can identify key areas that could be tested in a sensitivity analysis as part of
the techno-economic analysis. For example for a novel technology it might be relevant to test
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the robustness of the TEA to availabilities significantly lower than anticipated, particularly in
the early years. These can help guide investment and contractual decisions. In a new market it
might make sense to test the impact of increases in feedstock cost or of having to switch to an
alternative supplier.
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4. TEA methods
Several TEA methods are discussed in this section:
In the chapters the method is described, the calculation discussed and the use and
interpretation in TEA discussed.
In general the guideline in hand is made for the use of technical scientists. Sometimes not all
aspects of some economic issues and methods are used, so it may seem to be in contradiction
with classical economics. These cases are indicated in the text. The reason for this is to keep
the guideline as simple as possible.
A list of abbreviations used in the guideline is attached as chapter 5 in order to have a better
overview and a connection between the calculation in section 4 and the description in sections
1 and 2.
Calculation:
r =b tot ctot
with:
b tot = b el + b th + b other
ThermalNet TEA Methodology Guideline
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ctot = cinv + c op
using:
cinv
= A + ia + ii with L A =
I
n
cop = oF + oL + oM + oO
Interpretation and use:
Static cost benefit assessment is very easy and quick to do without needing tools such as
computers (or even calculators with higher power functions). Neglecting interest rates and
inflation rates makes the result quite imprecise (in general too optimistic), especially in cases
with high interest rates or a big difference between inflation rate and interest rate. It can only
be used for a preliminary check e.g. of an idea, just to investigate whether further
investigation should be done or not.
Sensitivity analysis:
Due to the imprecise results of this method with the unavoidable underestimation of
investment related cost, a sensitivity analysis based on TEA done with static cost benefit
assessment is not sensible..
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account any changes or diminution in the value of the incomes received or costs expended
each year.
Calculation:
r = b tot c tot
with:
cinv = A + ia + ii L with L A = a I
Using
p (1 + p )
a=
(1 + p )n 1
n
cop = oF + oL + oM + oO
Interpretation and use:
The annuity method is very useful for simple TEA, rather realistic in results as long as
inflation rate is not too high and not too different to the interest rate. The results of TEA on
different projects are easy to compare with each other and the calculation is transparent and
easy to understand. A disadvantage of the annuity method is that it is not possible to
distinguish variations in costs and benefits from one year to the next the same net benefit is
applied to every year. Also the time delay between investment and first year of regular
operation can not be considered (at least not without loosing the transparency). The annuity
method is widely used in continental Europe by technicians (not by economists and financing
specialists) for preliminary project assessment.
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Sensitivity analysis:
By changing parameters of the assessment the sensitivity of the results can be easily
investigated. In practice the influence of parameter changes should be investigated for one
parameter after the other, so the influence of the specific parameter variation on the results
can be seen. Doing this the sensitivity of the results to changes of different parameters can be
investigated.
It is frequently found that fuel price and product selling price (sometimes also availability) are
particularly significant parameters for sensitivity variations and so special care should be
taken with these values.
Calculation:
An example for the calculation of the net cash flow (NCF) is given in the table below. In this
a project is shown assuming a development and construction phase of 2 years (when the
investment is done) and a technical lifetime starting in year 3 and ending after year 8 (six
years).It is assumed that the investment is paid from own capital (without bank loan). In case
of using a bank loan, the cash flow for the investment in year one and two would be zero (=
paid out of the loan) but in the years 3 to 8 an annuity (or another form of payback of capital
and interest) would be added to investment related cost
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Sum 1-8
benefits [btot]
6.000
12.000
12.760
13.483
14.293
15.150
5.000
5.250
5.513
5.788
6.078
6.381
1.000
1.030
1.061
1.093
1.126
1.159
15.000
15.000
15.000
15.000 6.000
6.280
6.573
6.881
7.203
7.541
-15.000
5.720
6.187
6.602
7.090
7.609
-15.000
3.208
-5.000
sum 18
-10.000
-15.000
-20.000
Years from project start
In the first two years the net cash flow is negative, because of the investment (money is paid
out, no income), in the third year the first benefits (income from selling products), but due to
production start with limited availability (so NCF =0) and from year 4 to 8 the production is
working properly. In the example shown the development of income and cost elements over
the years is assumed to be different (different rates of increase). It would also be possible to
include reinvestments during the lifetime or include the value of the investment after technical
lifetime (as benefit) and other linear or non-linear effects.
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Net cash flow analysis can only be applied to specific projects with very good information on
all benefit and cost issues available. It is not sensible to use the method for comparative
technology assessment or to investigate the economic viability of a technology application.
Even if the net cash flow analysis is a valuable instrument for illustrating the development of
benefit and cost and the cash flow over project development phase and technical lifetime, the
sum of all cash flows gives only indicative information on the economic viability of a project,
because the sum of the net cash flows over the period is not the value of the project for the
investor. For this the net present value of the cash flows over the years has to be calculated
(see chapter 4.4).
Sensitivity analysis:
Assumptions on different developments of prices and cost can be integrated easily. The
influence of these parameters can be investigated in a sensitivity analysis by varying them in
the net cash flow table.
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It is calculated by discounting the cash flows in the net cash flow table (see chapter 4.3) by
the discount rate and by making the sum over the project period. The discount rate varies
depending on who is investing and how they should be set at a level that represents what
value the investor places on receiving money now rather than in the future. For a limited
number of publicly funded bodies this might equate to something similar to an inflation rate,
for a low risk commercial project it will always be higher than the prevailing interest rates
(why would one invest my money in this project if one could stash it in bonds and be
guaranteed a return of x) and for most projects it will be significantly higher than prevailing
interest rates unless there is an external agenda in terms of subsidy, intervention, third party
interest or whatever.
In typical techno-economic project assessment the discount rate should be set at least two
percent above the interest rate of a bank loan.
Calculation:
The net present value of every year is discounted to the year 0 by the discount rate using
the formula
NPV n =
NCF
(1 + d ) n
The net present value of the project NPVtot is the sum of the discounted cash flows for
every year of the project period.
n
NPVtot = NPVn
1
Practically these calculations are done using the same worksheet as it is established for
calculating the net cash flow table.
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The net present value NPV should have at least the value zero. In this case the investor
exactly recoups all his cost over the lifetime of a project (using the assumed discount rate).
If the NPV is positive, the investors property will be increased by this value after the project
lifetime. If NPV has a negative value, the project is not to be realized without suffering losses
taking into account the assumed discount rate.
As all methods using cash flows, the net present value NPV or discounted cash flow
should only be used for assessing very specific projects with all information available. It
is an excellent tool for comparing different projects.
Sensitivity analysis
The effect of input parameters can be investigated in a sensitivity analysis by varying them in
the spreadsheet calculation.
The Internal Rate of Return is the average annual return rate on the initial investment
when considering all costs and benefits over the given project period. It is calculated on
present money value. It uses discounted cash flow techniques to answer the question: At
what discount rate does the net present value (NPV) of my project equate to zero? This is
a useful measure for investors: if they invest the initial capital for the project period they
will receive a return on their investment equivalent to the IRR each year of the project.
The method is widely used by professional project evaluators and investment consulters.
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Calculation:
The IRR is the discount rate for which NPVtot is zero (see section 4.4). The calculation
practically is done iteratively by variation of the discount rate in the NPVtot worksheet
calculation.
It allows some judgments of the efficacy of the investment. If the IRR is low (less than
could be obtained with bank cash deposits) it would be pointless investing in a project
where the capital was unsecured and the return not guaranteed to get only that rate of
return. For a project to be an attractive investment the IRR should be higher than other
options the investor has for investing that money, taking into account the degree of risk
associated with the investment.
Sensitivity analysis
By varying the input parameters of the cash flow model, a sensitivity analysis can easily be
done.
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5. Abbreviations used
A
annual cost for paying back the investment cost (see chapter 4.2)
annuity factor = the share of the investment, that has to be paid on a annual basis to
pay off the investment (constant repayments over the technical lifetime) (see chapter
4.2)
btot
bel
bth
bother
other benefits per year (e.g. from selling carbon credits) (chapter 2)
ctot
cinv
cop
ia
ii
periodical cost for infrastructure, location building, (given as annual cost; chapter
1.1.3)
oF
oL
oM
oO
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