Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
The Value of Better Wind Information in Investment Decisions Michail Chronopoulos1
Gunnar S. Eskeland1
1 Norwegian
School of Economics, Department of Business and Management Science, Bergen, Norway Research supported by the CenSES and Nord-Star research project at SNF
9 September 2014
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Background Wind farm investment is faced with considerable uncertainties Price uncertainty Regulatory risk Wind speed Technological uncertainty Uncertainties for commodities such as electricity, natural gas, and oil are reasonably well known
Geometric Brownian motion (Pindyck, 1999) Mean–reverting processes (Deng et al., 2001) Regime switching models (Karakatsani and Bunn, 2008) Stochastic volatility (Heydari and Siddiqui, 2010) Two–factor models (Schwartz and Smith, 2000)
Uncertainties pertaining to R&D in new technologies are less well understood The future development path of RE technologies is likely to be different from their progress in the past (Jamasb and K¨ohler, 2008) Modelling wind uncertainty Adkins and Paxson (2013) adopt geometric Brownian motion to model production uncertainty for a renewable energy facility Howell et al., (2011) adopt Brownian motion to model wind resource uncertainty
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Motivation Wind speed uncertainty is typically represented by a Weibull distribution (Covelle et al., 2011)
Better wind information may result in lower volatility and a different mean ex ante Wind speed profile remains uncertain and forecasting error increases with the horizon
N(n , m )
t
N(n , m ) N(n, m)
•n
•
n
•n
n n n m ≤m ≤m
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Motivation Regional changes in climate are likely to result in increased wind speeds (Snyder et al., 2008) Increased concentrations of atmospheric CO2 have resulted in stronger winds (Abraham et al., 2014) We describe wind resource uncertainty via a geometric Brownian motion
An exploration of the wind resource may reduce uncertainty over the power
80
80
70
70
60
60
50
50
Output, Pt
Output, Pt
production, thereby affecting the decision to invest
40 30 20
30 20
10 0 0
40
10
10
20
Time, t
30
40
0 0
10
20
30
40
Time, t
Technological and productivity advances may make wind increasingly valuable with time
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Objective We address the problem of optimal wind farm investment and analyse the impact of
Wind uncertainty
computer modeling limitations limited availability of empirical data incomplete details about terrain wind flow patterns and wind speeds
Survey lags of fixed or random length
Investment lags typically reflect the time to build (Bar–Ilan and Strange, 1996 ; Gollier et al., 2005)
Allowing for a time interval prior to investment may reduce wind uncertainty by allowing for more accurate information regarding wind speed Results indicate that
Survey facilitates investment Reduction in the discounted expected value of the project due to delay Lower wind uncertainty mitigates this effect
An increase in the efficiency of the survey lowers the required abandonment threshold
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Assumptions Assessments of the average wind speed are modelled via GBM dPt = μPt dt + σPt dWt , P0 ≡ P > 0
μ : annual growth rate (small or zero) σ : annual volatility dWt : increment of the standard Brownian motion
We assume that the output price Et is fixed (fixed feed–in tariffs). ρ : exogenous discount rate τ, τ : optimal time of investment and abandonment respectively Pτ , Pτ : optimal investment and abandonment thresholds respectively F(·) : option value V(·) : project value Investment cost I = Iw + Is Iw is the cost of the wind farm
Is is the cost of the survey, Is = ηh
The reduction in wind uncertainty may be linear or hyperbolic (c1 and c2 are constants) σ = c1 − ψ × c2
σ=
c1 ψa +1 ,
ψ ∈ [0, 1]
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Investment under Wind Uncertainty without Survey Investment
-
F (P; E)
V (P; E)
···
• t 0 τ waiting region active project At time τ, the firm has the option to incur a fixed cost, I, and, thus, receive an uncertain payoff. The expected NPV of the project is ∞ EP V (P; E) = EP −I e−ρt EPt dt − I = ρ−μ 0 where EP is the expectation operator which is conditional on P The value of the option to invest is ⎧ β 1 ⎪ ⎪ if P < Pτ ⎨AP , F (P; E) = ⎪ ⎪ ⎩ EP − I, if P ≥ P ρ−μ τ 2
where β1 is the positive root of the quadratic 12 σ β(β − 1) + μβ − ρ = 0 and 1−β1
A=
Pτ
E
β1 (ρ − μ)
and
Pτ =
β1 I(r − μ) β1 − 1 E
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Option and Project Value High wind uncertainty increases the opportunity cost of investment, thereby raising the required investment threshold Parameter values μ = 0.01, ρ = 0.1, I = 2000, E = 10, c1 = 0.2, c2 = 0.1 2500
Option Value, Project Value
2000 1500
Pτ = 30, σ = 0.2 Pτ = 26.83, σ = 0.15
1000
Pτ = 24, σ = 0.1
500 0 −500 −1000
Option Value Project Value Optimal Investment Threshold
−1500 −2000 0
5
10
15
20
Output, Pt
25
30
35
40
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Investment under Wind Uncertainty and Survey Lags More accurate wind information may reduce uncertainty in power production. Once the survey is complete, i.e., t = h, we can have ( ) Ph < Pτ ⇒ Investment is further deferred
Ph ≥ Pτ ⇒ Investment must be exercised immediately ( )
Investment
@ @ R β1
( ) Ph - V P ;E ( ) P
τ
τ
• • 0 h τ survey lag waiting region The expected value of the project at t = h is ⎧ β1 ⎪ ⎪ Ph ( ) ( ) ⎪
⎪ ⎪ V Pτ ; E , if Ph < Pτ ⎨ ( ) P F Ph ; E = ⎪ ⎪
τ ⎪ ( ) ⎪ ⎪ ⎩V Ph ; E , if Ph ≥ Pτ
V Ph ; E
V Ph ; E
··· ···
t
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Investment under Wind Uncertainty and Survey Lags (cont’d) The expected project value at t = 0 is ⎡⎛ ⎞ ⎢⎢⎢⎜⎜ P ⎟⎟β1 ⎜⎜⎜ h ⎟⎟⎟ ⎢ ⎢ EP F Ph ; E = EP ⎢⎢⎣⎜⎝ ( ) ⎟⎠ P
+ EP
τ
EPh ρ−μ
⎡ ( ) ⎤⎤ ⎢⎢⎢ EP ⎥⎥⎥⎥ ⎢⎢⎢⎢ τ − I ⎥⎥⎥⎥⎥⎥⎥⎥⎥⎥ × PP P < P( ) h τ ⎣ρ − μ ⎦⎦ ( ) − I × PP P h ≥ P τ
where I = Iw + Is (h) Iw is the investment cost for the wind farm
Is (h) is the cost of the survey
By the definition of conditional probability and the characteristics of a GBM process (Etheridge, 2002), we have ⎛ ( ) ⎞ ⎞ ⎛ ⎜⎜⎜ P ⎟⎟⎟ ⎟⎟ ⎜⎜⎜ 1 2 ⎜⎜⎝ τ ⎟⎟⎠ ⎟⎟⎟ μ − h − ln σ ⎜ ⎜⎜⎜ 2 P ⎟ ⎟⎟⎟ ( ) ⎜⎜ ⎜ PP Ph ≥ Pτ = Φ ⎜⎜⎜ ⎟⎟⎟⎟ √ σ h ⎜⎜⎜⎜ ⎟⎟⎟⎟ ⎝ ⎠ where Φ is the cumulative distribution function of a standard normal random variable ( )
The optimal investment threshold, Pτ , is obtained by solving the optimisation problem max EP F Ph ; E ( ) ≥P τ
P
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Impact of Survey Lags on Wind Uncertainty and Investment
Given a maximum survey horizon of 10 years and that initially σ = 0.2, we have σ = 0.2 − ψ × 0.1
σ= where ψ =
0.2 ψa +1 h 10 , i.e.,
0.2
ψ ∈ [0, 1] ⇒ σ ∈ [0.1, 0.2] 31
Optimal Investment Threshold
σ = 0.2 − ψ × 0.1 σ = ψ0.2 a +1
0.19 0.18
Volatility, σ
0.17 0.16 0.15
a=1
0.14 a = 0.5
0.13 a = 0.3
0.12 0.11 0.1 0
a = 0.1
2
4
6
Survey Lag, h
8
10
30 ()
Pτ 29
Pτ (σ = 0.2)
28 27
α=1 26 25 24 0
α = 0.5 α = 0.3 α = 0.1 2
4
6
Survey Lag, h
8
10
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Optimal Survey Period and Probability of Investment
A longer survey period lowers the required investment threshold, thereby raising the likelihood of investment The optimal survey period is decreasing in the survey’s efficiency
10
0.3
Probability of Investment
9
Survey Length
8 7 6 5 4 3 2 0
0.25
0.2
0.15
α α α α
0.1
Is = 0 Is = 10 × h 0.2
0.4
0.6
Efficiency
0.8
1
0.05 0
2
4
6
Survey Lag, h
8
= = = =
1 0.5 0.3 0.1 10
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Investment under a Random Survey Period The lifetime of the survey is exponentially distributed, i.e., h ∼ exp(λ)
λ is the intensity of the Poisson process ! " h is independent of the process Pt , t ≥ 0 Completion of exploration
G(P; E)
-
Investment F (P; E)
-
V (P; E)
• • h 0 τ survey lag waiting region Within an infinitesimal time interval dt
the exploration process will be complete with probability λdt with probability 1 − λdt the exploration process will continue G(P; E)
=
(1 − ρdt)λdtEP [F(P + dP; E)] + (1 − ρdt)(1 − λdt)EP [G(P + dP; E)]
t
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Investment under a Random Survey Period Via Itˆo’s lemma, we obtain the differential equation for G(P; E) 1 2 2 σ P G (P; E) + μPG (P; E) − (λ + ρ)G(P; E) + λF(P; E) 2
=
0
The differential equation for G(P; E) must be solved for each expression of F(P; E), i.e., β 1 2 2 σ P G (P; E) + μPG (P; E) − (λ + ρ)G(P; E) + λAP 1 2
1 2 2 σ P G (P; E) + μPG (P; E) − (λ + ρ)G(P; E) + λV(P; E) 2
=
0
=
0
Solving for G(P; E) we have
G (P; E)
=
⎧ ⎪ 0, ⎪ ⎪ ⎪ ⎪ ⎨ β1 AP − ⎪ ⎪ ⎪ ⎪ ⎪ λPE ⎩
η ρ+λ
(ρ−μ)(ρ+λ−μ)
δ
δ
if P < Pτ
+ BP 1 + CP 2 , if Pτ ≤ P < Pτ −
η+λI ρ+λ
δ
+ HP 2 ,
if P ≥ Pτ
where Pτ , B, C, H are obtained numerically via value–matching and smooth–pasting conditions.
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Option and Project Value
Uncertainty over the outcome of the survey lowers the expected value of the project As λ increases, G(P; E) converges to F(P; E) 150
Value Function, G(P ; E)
Option Value, Project Value
100
Option Value Project Value Optimal Investment Threshold Pτ = 15
λ = 0.3
50
λ = 0.2 λ = 0.1 0
Pτ = 12.7 −50
Pτ = 9.81 Pτ = 8.63
−100 0
2
4
6
8
10
Output, Pt
12
14
16
18
20
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Impact of λ on Optimal Investment and Abandonment The expected duration of the survey is E(h) = 1/λ σ=
c1
a
(1/λ) +1
The impact of λ on the required investment threshold is non–monotonic Higher λ lowers the likelihood of abandonment 9
α α α α
14.5
= = = =
1 0.5 0.3 0.1
Optimal Abandonment Threshold
Optimal Investment Threshold
15
14
13.5
13
12.5
12
0.2
0.4
0.6
Survey Lag, h
0.8
1
8 7
α α α α
= = = =
1 0.5 0.3 0.1
6 5 4 3 2
0.2
0.4
0.6
Survey Lag, h
0.8
1
Introduction
Assumptions
Analytical Formulation
Conclusions/Future Work
Summary We investigate the potential of reducing wind resource uncertainty and analyse the impact of better wind information on wind farm investment Survey lags in combination with reduced uncertainty have an ambiguous impact on the required investment threshold
Lower wind uncertainty increases the incentive to invest A survey lowers the discounted expected value of the project, thereby raising the required investment threshold
Higher likelihood of success decreases the required abandonment threshold by lowering the cost of the survey Further work Stochastic reduction in volatility via regime switching (Boomsma et al., 2012)
Combine wind resource with electricity price uncertainty Sequential investment in storage Research supported by the CenSES and Nord-Star research project at SNF
Introduction
Assumptions
Analytical Formulation
Thank you !
Conclusions/Future Work