Viability assessment of small and medium wind turbines in regions with moderate wind speeds

Transcription

1 Viability assessment of small and medium wind turbines in regions with moderate wind speeds Mark Runacres, Tim De Troyer, Vrije Universiteit Brussel Jochem Vermeir, Tractebel Engineering NV Contact: 18/03/2016

2 Outline of presentation Introduc)on Methodology wind climate in Flanders turbine selec)on viability Results and conclusions, including some prac)cal guidelines 2

3 Introduction: Small and medium-size wind turbines Small wind turbines IEC » a system of 200 m 2 rotor swept area or less that converts kine)c energy in the wind into electrical energy» d 16 m» Prated 50 kw Medium-sized wind turbines No strict defini)on, but turbines between 50 kw and 500 kw, could be considered medium-sized Emphasis for this talk: small wind turbines (even if the medium range is really interes)ng too) 3

4 Introduction: Small wind turbines in Flanders There is a legal framework. Currently only a small number of small wind turbines installed. Definite interest, from agriculture and SMEs. Reluctance from local authori)es to grant building permits. Things are changing. E.g. pilot studies in the province of West-Flanders. Planning guidelines. Evalua)on criteria include economic viability. 4

5 Introduction: European wind atlas 5

6 Introduction: the challenge of small wind turbines immature market low height influence of obstacles definite need for careful resource assessment and si)ng low-cost low budget for resource assessment 6

7 Methodology Q: Can small wind turbines be an economically viable source of electricity in Flanders and, by extension, in other regions with moderate wind speeds? Methodology viability defini)on wind climate in Flanders market of small wind turbines and selec)on of sample economic analysis 7

8 Viability We only consider economic viability This is only one aspect of a full feasibility study which would also include planning, grid, sound, shadow flicker, biodiversity, We only consider SMEs 8

9 Viability Metrics: Levelled cost of energy LCOE: pure i.e. without incen)ves Internal rate of return (IRR): discount rate r* so that NPV(N, r*) = 0 (NPV = net present value, N = turbine life)me) Based on total cash flow: includes incen)ves Viability criterion. Depends on client. LCOE below electricity purchase price IRR > 12 % 9

10 Wind climate in Flanders Flanders is a typical region with intermediate wind speeds Values indicate average wind speed [m/s] at 15 m 10

11 Immature The marketmarket of small wind turbines 11

12 You can t always believe the brochure Example: Medium wind turbine (200 kw) C P above Betz-Joukowski limit Use independently measured power curves 12

13 Market survey Turbines < 100 kw 762 turbines and coun)ng To our knowledge: most extensive survey to date HAWT VAWT Other concepts Started in 2010, in the framework of IWT Tetra ( 13

14 Market survey Typical entry: main characteris)cs of turbine + comments: independently measured P-curve,... Use Basis for comparison between small turbines, with es)mate of annual produc)on Select turbines for test fields Help clients select small turbines Sharing wind turbine data with manufacturers Not publicly available 14

15 Sample selection We selected 14 wind turbines with independent measurements of the power curve We obtained costs from manufacturers We calculated LCOE for all site in Flanders with a mean wind speed above 3.5 m/s 15

16 Mean LCOE per turbine 16

17 Viability map of SWT in Flanders Viability map for SMEs Values indicate average wind speed [m/s] Turbine with rated power 10 kw (Hub height 18 m) Red (IRR<8%), Orange (8% IRR<12%), Green (IRR 12%) 17

18 Minimum wind speed + Effect of incentives 18

19 Sensitivity 10 % varia)on of parameters 19

20 Some practical guidelines Carefully assess the wind condi)ons Measure wind speeds if possible. Three months can be enough. 20

21 Some practical guidelines Es)mate error resul)ng from ver)cal extrapola)on of wind speeds Use computa)onal fluid mechanics for microsi)ng (has become very affordable) 21

22 Some practical guidelines Carefully pick the turbine and match to the site Rated power isn t everything 22

23 Conclusions A well-chosen turbine is economically viable in parts of Flanders, but not everywhere There are some basic rules to be followed to avoid disappointment. Some of these rules are obvious. Pilot studies have been started and if successful they may open up the market. Reference Vermeir 2015 (PhD thesis Vrije Universiteit Brussel, available upon request) 23