Ce diaporama a bien été signalé.
Nous utilisons votre profil LinkedIn et vos données d’activité pour vous proposer des publicités personnalisées et pertinentes. Vous pouvez changer vos préférences de publicités à tout moment.

Repowering and Used Wind Turbines

220 vues

Publié le

* Describes the situation regarding wind power in several regions and countries.
* Defines repowering - replacing small/mid-size turbines on highly productive sites with newer and larger turbines.
* Analyses the developing market for used wind turbines.
* Discusses the option of re-using second-hand turbines.
* Each potential project needs to be discussed individually.

Publié dans : Business
  • Login to see the comments

Repowering and Used Wind Turbines

  1. 1. REPORT - Repowering and Used Wind Turbines Walter Hulshorst Econ International April 2008 www.leonardo-energy.org 1 / 27 REPORT REPOWERING AND USED WIND TURBINES
  2. 2. REPORT - Repowering and Used Wind Turbines Summary In countries that started early with wind energy, old wind turbines were placed at locations where the wind is often very good. Since the best locations for wind in these countries are occupied by old wind turbines with lower energy outputs compared with new wind turbines, programmes were started to replace the old turbines with new ones. With repowering, the first-generation wind turbines can be replaced with modern multi-megawatt wind turbines. In general, many factors speak in favour of repowering programmes: • more wind power from the same area of land: wind power generation is multiplied without the need for utilising additional land; • fewer wind turbines: the number of turbines can be reduced, enhancing the natural landscape. The construction height can be raised; • higher efficiency, lower costs: modern turbines make better use of available wind energy. The cost of production is significantly lowered; • better appearance: modern turbines rotate at much lower speeds and are thus more visually pleasing than older, faster-rotating turbines; • better power grid integration: modern turbines offer much better grid integration, since they use a connection method similar to conventional power plants and also achieve a higher utilisation degree; • wind speed and direction are known: at an existing wind turbine location, wind speed and direction are already known, so it is easy to calculate the expected annual energy production for an existing location. Since Germany is the largest wind energy user, it is reasonable to expect that Germany will provide the major market for repowering. About 90% of the wind power capacity in Germany is located in suitable turbine areas. The German Wind Energy Association (BWE) calculated that up to 2020, with a realistic approach, the on-shore repowering potential in Germany will be about 15.000 MW. As a result of repowering, there is a growing interest around the world in used wind turbines that still have several years’ remaining service life. Growing energy demand in developing countries stimulates the use of renewable energy sources, such as wind power, to provide a sustainable and environmentally-friendly power supply. For most of these countries, projects with new wind turbines have proven to be unaffordable: that is why using cheaper second-hand turbines may be an option. Utilising used wind turbines instead of new ones offers several benefits: • lower capital expenditure saves the investor’s capital resources and reduces the efforts involved in collecting borrowed capital; • shorter project duration reduces the investor’s financial risk, especially valuable in politically and economically unstable conditions; • turbines from 150 to 600 kW can be transported and erected without major problems. However, larger turbines often require specialist equipment that is not available in many parts of the world, while smaller turbines may not be economical to place. Many manufacturers are no longer fabricating turbines of this size. Therefore, buying used turbines is the most common way of obtaining a wind turbine that can be shipped and installed easily; • maintenance work on used turbines can be conducted easily, compared with the latest technology turbines that require both a sophisticated infrastructure and specialists to carry out routine work. Using used turbines means that it is not necessary to make high demands on qualified personnel; • a substantial overhaul and adaptation to regional requirements can take place while the used turbine is being dismantled. This is cheaper than overhauling while the plant is in operation. www.leonardo-energy.org 2 / 27
  3. 3. REPORT - Repowering and Used Wind Turbines CONTENT 1. INTRODUCTION....................................................................................................................................... 4 2. CHARACTERISTICS OF THE WIND MARKET ................................................................................. 5 3. REPOWERING........................................................................................................................................... 8 3.1. AVERAGE WIND TURBINE SIZE CONTINUES TO GROW YEAR ON YEAR.................................................... 8 3.2. WHY REPOWERING ............................................................................................................................. 10 3.3. WHAT IS THE POTENTIAL OF REPOWERING.......................................................................................... 14 3.4. WHAT INCENTIVES ARE NEEDED FOR REPOWERING ............................................................................ 15 3.4.1. What incentives are there in Europe ............................................................................................. 15 3.4.2. What incentives are promising for the repowering of wind energy............................................... 18 4. USED WIND TURBINES......................................................................................................................... 21 4.1. WHY BUY USED WIND TURBINES......................................................................................................... 21 4.2. WHEN BUYING USED WIND TURBINES ................................................................................................. 23 4.2.1. Grid integration of used wind turbines ......................................................................................... 24 4.2.2. General overhaul and maintenance of used turbines.................................................................... 24 4.3. WHAT IS THE POTENTIAL OF USING USED WIND TURBINES .................................................................. 25 5. CONCLUSIONS........................................................................................................................................ 26 6. APPENDIX A - TRADING COMPANIES FOR USED WIND TURBINES....................................... 27 www.leonardo-energy.org 3 / 27
  4. 4. REPORT - Repowering and Used Wind Turbines 1. INTRODUCTION In countries like Germany, Denmark, or the Netherlands, wind power is already so widespread that few on-shore sites are left on which new units can be built. Two main paths are being followed to further increase the electrical power generated by wind: building off- shore wind parks, and replacing existing wind turbines with new and larger types (3 to 5 MW). The older, replaced types are appearing on the second hand market and will allow other (developing) countries to start using wind power at lower costs. The second booming development in wind energy technology particularly affects countries like Denmark and Germany that are running short of productive sites. In these countries, it is more efficient for investors to replace smaller and middle-sized turbines on highly productive sites with new and larger turbines, rather than just building the new turbines on less productive sites. This process is known as “Repowering”. The successful implementation of wind energy in Europe during the past decade and the continued economical support offered in national legislation has led to a developing market for second-hand wind turbines. Repowering of plant after 5 to 15 years of operation releases a large number of turbines into the market. For developing countries, this is an opportunity to gain experience in working with renewable energy sources, to establish their own wind energy industries and to profit from technology transfer with low capital expenditure. In Chapter 3, this document describes the principle of repowering (as performed in Germany and Denmark), while Chapter 4 focuses on the developing market for used wind turbines. But first, in Chapter 2, this document describes the status quo regarding wind power for several regions and countries in the world, as at the end of 2007, www.leonardo-energy.org 4 / 27
  5. 5. REPORT - Repowering and Used Wind Turbines 2. CHARACTERISTICS OF THE WIND MARKET The Global Wind Energy Council calculated that, at the end of 2007, the worldwide installed capacity of wind energy was 94.112 MW1 . Wind energy contributes to the energy mix in more than 70 countries across the globe. Figure 2.1 shows the development in the growth of wind energy across the world. Global cumulative installed capacity 1996 - 2007 6.1007.60010.20013.600 17.400 23.900 31.100 39.431 47.620 59.091 74.133 94.122 0 10.000 20.000 30.000 40.000 50.000 60.000 70.000 80.000 90.000 100.000 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 MW Figure 2.1 Global cumulative installed wind energy capacity The installed capacity per region is shown in figure 2.2 Annual installed capacity by region 2003-2007 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Europe Asia North America Latin America Africa & ME Pacific MW 2003 2004 2005 2006 2007 Figure 2.2 Annual installed wind energy capacity by region 1 Article on www.gwec.com: continuing boom in wind energy, 20 GW of new capacity in 2007. www.leonardo-energy.org 5 / 27
  6. 6. REPORT - Repowering and Used Wind Turbines While Europe remains the leading market for wind energy, new installations in 2007 represented just 43% of the global total, down from nearly 75% in 2004. For the first time in decades, more than 50% of the annual wind market comes from outside Europe, and this trend is likely to continue in the future. While Europe, North America and Asia continue to see the most valuable additions to their wind energy capacity, the Middle East/North Africa region, increased its wind power installations by 42%, reaching 534 MW by the end of 2007. New capacity was added in Egypt, Morocco, Iran and Tunisia. The countries with the highest total installed capacity are given in Figure 2.3. The countries with the largest growth in 2007 are given in Figure 2.4. Top 10 total installed capacity [MW] Germany; 22247 US; 16818 Spain; 15145 India; 8000 China; 6050 Denmark; 3125 Italy; 2726 France; 2454 UK; 2389 Portugal; 2150 RoW; 13008 Figure 2.3 Top 10 countries’ installed wind energy capacity (end 2007) Top 10 new capacity [MW] US; 5244 Spain; 3522 China; 3449 India; 1730 Germany; 1667 France; 888 Italy; 603 Portugal; 434 UK; 427 Canada; 386 RoW; 1723 Figure 2.4 Top 10 countries development of new capacity wind energy in 2007. Based on these figures, it can be expected that the US will overtake Germany as the leader on wind energy by the end of 2009. The tremendous growing market for wind power in China www.leonardo-energy.org 6 / 27
  7. 7. REPORT - Repowering and Used Wind Turbines has encouraged domestic production of wind turbines, and within China there are more than 40 domestic companies involved in turbine manufacture. In 2007, Chinese domestic production accounted for 56% of the annual market compared to 41% in 2006. It is expected that the worldwide market will exceed 200 GW2 in 2011. Europe will remain the largest market in 2011, with an installed power of 108 GW (Germany and Spain will remain the major markets). North America will be second with 47 GW (USA will be the major market). Asia will be third, with 37 GW (China and India will be the major markets). The installed power of the Rest of the World will be about 11 GW. Asia will have the strongest growth. Despite double digit growth in the wind turbine market, the main challenge for wind turbine manufacturers and their suppliers is to cope with the growth in demand for wind turbines. The main bottlenecks have been in the supply of gear boxes and large bearings. Gearboxes are supplied by a relatively small list of companies. As in the manufacture of wind turbines, there have been few new entrants to this market as, historically, the technology risks have been perceived as high. In addition, turbine manufacturers try to avoid using those new suppliers who can demonstrate only limited industry experience, or who do not have established track records. Over 80% of the profit warnings in the wind turbine manufacturing industry relate to gearbox issues, primarily malfunctioning bearings, but also unforeseen issues with various gearbox designs. Fig 2.5 Example of a wind park3 2 Wind turbine manufacturers, here comes pricing power; Merril lynch, August 2007 3 Windpark Hartel; www.eneco.nl www.leonardo-energy.org 7 / 27
  8. 8. REPORT - Repowering and Used Wind Turbines 3. REPOWERING The first generation of wind energy generating projects that were installed in the US and Europe in the 1980s, have only recently begun to reach the end of their use life. The older technology used in these projects has generally proven to be more durable and longer lasting than was originally anticipated. However, at some older projects, repowering has taken place. Repowering refers to the refurbishment of older wind turbines, or to their removal and replacement with newer, more efficient turbines. Where older turbines have been removed and replaced with newer turbines, this has generally been accomplished by installing fewer, larger turbines. 3.1. Average wind turbine size continues to grow year on year Generally, the size of wind turbines keeps on growing4 . Figure 3.1 shows the development of technology in Germany since 1980.5 Rotor diameter Hub height Rotor diameter Hub height 1980 1985 1990 1995 2000 2005 Nominal power 30 kW 80 kW 250 kW 600 kW 1.500 kW 5.000 kW Rotor diameter 15 m 20 m 30 m 46 m 70 m 115 m Hub height 30 m 40 m 50 m 78 m 100 m 120 m Annual energy yield 35 MWh 95 MWh 400 MWh 1.250 MWh 3.500 MWh 17.000 MWh Figure 3.1 Development of wind turbines in Germany 4 Wind Energy Barometer EurObserveER; Systemes Solaires no 177. February 2007. 5 Renewables made in Germany, Deutsche Energie Angentur (DENA). www.renewables-made-in- germany.com/en/wind-energy/ www.leonardo-energy.org 8 / 27
  9. 9. REPORT - Repowering and Used Wind Turbines The average size of wind turbines has been increasing with rapidly growing demand for turbines in the 1.500 – 2.500 MW size range, and less demand for smaller sized turbines (see table 2.1).6 Table 2.1 Distribution of wind turbines Size 2004 2005 2006 Small WT < 750 kW 5,4% 3,6% 2,4% One MW 750 – 1500 kW 50,9% 48,2% 43,3% Mainstream 1500 – 2500 kW 42,8% 45,8% 49,9% Multi MW > 2500 kW 0,9% 2,4% 4,3% There are two main reasons for this: • for utilities trying to scale-up their wind portfolios and achieve critical mass quickly, there has been a preference for larger turbines. This is also for practical reasons, as the power potential of a wind turbine is determined by the square of the rotor diameter: a large turbine, therefore, delivers much more power than two separate turbines of half the size; • in addition, for off-shore markets to minimise installation costs per MW, a significant proportion of which is the cost of foundation, the largest possible capacity is installed on each foundation unit. In the German market, the average machine size increased by 125 kW between 2005 and 2006, i.e. a mean unit capacity of 1.849 kW. The German market is calling for more and more powerful wind turbines, in order to ensure that the areas that are available for wind park installations as profitable as possible. This evolution is reinforced by the rise in the importance of the market for repowering (136 MW in 2006) on the most attractive sites, those on which the first wind turbines were installed. This evolution is even more significant in the UK where wind turbine size reached 2.103 kW in 2006 (+ 371 kW). This growth is further explained by the very favourable climatic conditions found in the UK. High capacity wind turbines are particularly well adapted for sites with higher average wind speeds. The development of the UK off-shore market in 2006, has also reinforced this evolution with the connection of thirty 3 MW wind turbines at the Barrow off-shore park. The new (2006) French wind farms have also used more powerful wind turbines with an average power of 1.689 kW (+557 kW compared to 2005). The increase in wind turbine size has been lower in Spain (2006), + 33 kW with respect to 2005, bringing the average size of the wind turbines up to 1.375 kW. This can be explained by the less significant constraints and restrictions in terms of the availability of land. It is also explained by the strategic choice made by Spanish industrialists, who are very present on their domestic market, to limit the capacity ranges by proposing, as Gamesa does, either 850 kW wind turbines or 2 MW wind turbines. It is worth noting that, although the average wind turbine size is increasing, for logistical reasons, there are real limits to the size of turbines that can be transported, particularly in on- shore markets. This is particularly true in Asia, where logistical and grid connection issues will mean that the preference for smaller sized turbines will continue in these markets. 6 Wind turbine manufacturers, here comes pricing power; Merril Lynch, August 2007. www.leonardo-energy.org 9 / 27
  10. 10. REPORT - Repowering and Used Wind Turbines However, once the repowering market takes off in more mature markets, a trend for utilising larger turbines will become even more marked, as developers replace small turbines with larger units on the same sites. 3.2. Why repowering In countries that started early with wind energy, old wind turbines were placed at locations where the wind is often very good. Since the best locations for wind in these countries are occupied by old wind turbines with lower energy output compared with new wind turbines, programmes were started to replace the old turbines with new ones. With repowering, the first-generation wind turbines can be replaced with modern multi-megawatt wind turbines. In general, many factors speak in favour of repowering programmes7 : • more wind power from the same area of land: wind power generation is multiplied without the need for utilising additional land; • fewer wind turbines: the number of turbines can be reduced while enhancing the natural landscape. The construction height can be raised; • higher efficiency, lower costs: modern turbines make better use of available wind energy. The cost of production is significantly lowered; • better appearance: modern turbines rotate at much lower speeds and are thus more visually pleasing than older, faster-rotating turbines; • better power grid integration: modern turbines offer much better grid integration, since they use a connection method similar to conventional power plants and also achieve a higher utilization degree; • wind speed and direction are known: at an existing wind turbine location wind speed and direction are already known, so it is easy to calculate the expected annual energy production for an existing location. Additionally, it is often easier to get licences to build a wind turbine (farm) on an existing location than on a new location. However, it should be mentioned that, in Germany, there are some bottlenecks with licenses, because of the height increase of larger wind turbines compared with old wind turbines. But also for government and local authorities, the results of repowering can be positive: • additional wind energy power will create a larger basis for wind energy; • although the wind turbines are higher after repowering, the quality of the landscape is often perceived as being improved, since the number of wind turbines is reduced; • replacement can be used to achieve national (or local) targets for renewable energy or for CO2 reduction. But there are also practical reasons for repowering;8 for example, in situations in which the manufacturer of the wind turbine no longer exists, and no other company can carry out the refurbishment of the wind turbine. Replacement of old turbines with new ones can be done in several ways. According to research performed by Grontmij,9 five alternatives can be used: 7 http://www.wind-energie.de/en/topics/repowering/ 8 Repowering of wind farms in practice, Essent Wind Nederland B.V. www.leonardo-energy.org 10 / 27
  11. 11. REPORT - Repowering and Used Wind Turbines 1. 1-to-1 up-scaling of solitary wind turbines; 2. 2-to-1 replacement, replacement of two smaller wind turbines by one large wind turbine; 3. clustering of solitary wind turbines into farms; e.g. replacement of 20 solitary wind turbines by clustering 6-10 wind turbines at one location; 4. 1-to-1 replacement of wind turbines with similar rates but with newer machines; 5. 1-to-1 up-scaling of wind farms. Each of these alternatives has it own pros and cons. Alternative 1 has the largest electricity production and alternative 4 the lowest. For alternatives 1-3 and 5, grid capacity can be a problem and investment for the grid connection may be required, while for alternative 4 it is not necessary. For each alternative there is a positive impact on the landscape: the best one being alternative 3. However, the following conclusions are presented: 1. Energy: when old installed wind turbines are replaced by larger ones, the total installed wind turbine capacity will increase; 2. Financial issues: in most cases, replacing an old wind turbine with a larger one is economically profitable; 3. Environment: replacing already installed wind turbines has advantages for the quality of the landscape, including: o unity of appearance of the wind turbine; o decrease in the number of wind turbines with a high rpm; o possible decrease in the number of wind turbines; o possible decrease in concentration of visual intrusion and noise; o possible concentration of hindrance by installing wind turbines at locations where they are accepted. The environmental impact of a repowering project is visualised in Figure 3.2.10 Although the wind turbines after repowering are higher, the quality of the landscape after repowering is often perceived as being improved compared with that prior to repowering. 9 Replacement of existing wind turbines (in Dutch); Grontmij, Advies en Techniek B.V. 2000 10 German Wind Market and Industry – Current Developments and Perspectives; German wind energy association (BWE), March 2007. www.leonardo-energy.org 11 / 27
  12. 12. REPORT - Repowering and Used Wind Turbines Before Windfarm Bassens (Lower Saxony) Figure 3.2 Example of environmental impact before and after repowering An example of repowering in Germany11 where twenty 200 kW turbines were replaced with seven 2 MW turbines, indicates that the investment was tripled, but the annual energy production increased fourfold, while the installed capacity increased by a factor of 3,5 as shown in Figure 3.3. As can be seen, production increases more than proportionally with installed capacity. This is because the taller turbines access the increased wind speeds present at higher altitudes, and new wind turbines have better P-v curves. After 11 German wind market and industry: Current developments and perspectives; German Wind Energy Association (BWE), April 2006. www.leonardo-energy.org 12 / 27
  13. 13. REPORT - Repowering and Used Wind Turbines Figure 3.3. Example of repowering in Germany A study of the effects of repowering projects in three regions in Germany is given in Figure 3.4.12 This study clearly shows that the height increases by approximately a factor of 2, while the number of turbines was only half down to one fifth. The installed capacity increased by 12 Repowering: Weniger ist Mehr (in German); Bundesverband Windenergie E.v. June 2007 20 turbines 4 MW 10 millionkWh 6 million Euro 7 turbines 14 MW 16 MW Reduction 70%No of turbines Installed capacity Yield Investment 20 turbines 4 MW 10 millionkWh 6 million Euro 7 turbines 14 MW 16 MW Reduction 70%20 turbines 4 MW 10 GWh 6 M€ 7 turbines 16 M€ 3 fold increase 40 GWh 4 fold increaseInvestment Yield 14 MWInstalled capacity 3,5 fold increase No of turbines Reduction 70% Effects of repowering Decrease Increase4 43 Factor 2 Factor 2 3 Example Schleswig Holstein Example Niedersachsen Example Mecklenburg-Vorpommern Energy Height Power Number of turbines Energy Height Power Number of turbines Energy Height Power Number of turbines Effects of repowering Decrease Increase4 43 Factor 2 Factor 2 3 Example Schleswig Holstein Example Niedersachsen Example Mecklenburg-Vorpommern Energy Height Power Number of turbines Energy Height Power Number of turbines Energy Height Power Number of turbines www.leonardo-energy.org 13 / 27
  14. 14. REPORT - Repowering and Used Wind Turbines between 1,5 up to 3,5 while the annual energy produced increased by between 2,2 and 4,3. Figure 3.4 Overview of effects of repowering at locations in Germany The overall conclusion of repowering projects performed by Essent in the Netherlands was that good locations for wind farms in the Netherlands are limited.13 Wind turbines were installed at the most windy locations, some 15 years ago. Several of these old wind farms require new solutions, because of technical problems, and new subsidy schemes in Holland. Essent was confronted with the need to find solutions for its existing wind farms. The result shows that good opportunities for repowering or retrofit, at reduced costs are available. Restrictions, regarding permits, grid conditions, technical possibilities and others, require customised solutions for each situation. In general it can be concluded that cost reductions of 10% - 30% can be achieved by repowering, compared with new solutions (green field solutions). 3.3. What is the potential of repowering Countries that started early with promoting wind power are now facing the problem that the land with good wind opportunities is occupied by older types of wind turbines. New locations for wind turbines may meet increasing resistance from local residents and local councils, as well as from environmental action groups. Assuming that all parties concerned accept new modern large wind turbines on existing turbine locations, repowering can contribute to the realisation of national targets. Since the new wind turbines have become larger and land with good wind opportunities are rare, the most efficient option could be to replace the old wind turbines with new wind turbines. In Europe, it can be expected that wind turbines older than 10-15 years, either on sites with good wind opportunities or in countries in which no new locations for wind turbines can be found, will be replaced with new types of wind turbines. It can be expected that the countries that first started with wind energy will also be the leading countries concerning repowering, if there are good incentives. It can also be expected that wind turbines will develop during the next 10 years. Knowing that the first off-shore wind farms are built or are planned to be built, it can be expected that these wind farms could also be repowered after 10 to15 years. Since Germany has the largest market for wind energy, it is reasonable to expect that Germany will be the major market for repowering. About 90% of the wind power capacity in Germany is located in suitable turbine areas.14 The German Wind Energy Association (BWE) calculated that, with a realistic approach, the on-shore repowering potential in Germany up to 2020 is about 15.000 MW.15 Figure 3.5 shows the potential for repowering (on and off-shore) for each year up to 2030.16 13 Repowering of wind farms in practice; Essent Wind Nederland BV 14 More wind with fewer wind turbines, German Wind Energy Association (BWE), August 2005. 15 Windenergie in Deutschland, actueller Stand und künftige Entwickelung; BWE, October 2007 (in German) 16 German Wind Industry: Market Development and Perspectives; Verband Deutscher Maschinen- und Anlagenbau - German Engineering Federation (VDMA) March, 2005. www.leonardo-energy.org 14 / 27
  15. 15. REPORT - Repowering and Used Wind Turbines 0 1000 2000 3000 4000 5000 6000 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 InstalledMWperyear onshore onshore repowering offshore offshore repowering Figure 3.5 Potential repowering German wind market (on and off-shore). 3.4. What incentives are needed for repowering Incentives are needed to promote the repowering wind turbines. Several papers discussed and compared the different types of incentives for Renewable Energy Sources (RES) used in several countries. 3.4.1. What incentives are there in Europe In 2005, The Fraunhofer institute investigated the different policy instruments used in Europe17 . Promotion instruments can be classified according to different criteria (i.e. whether they affect demand for or supply of RES or whether they support capacity or generation). So that a common terminology can be applied, at least within this thesis, Table 3.1 provides a classification of these instruments, covering all the currently applied strategies referring to the promotion of RES deployment. A brief explanation of the terminology is provided underneath the table for instruments of high relevance. 17 Monitoring and evaluation of policy instruments to support renewable electricity in EU Member States, Fraunhofer Institute, 2005. www.leonardo-energy.org 15 / 27
  16. 16. REPORT - Repowering and Used Wind Turbines Table 3.1 Classification of promotion strategies Direct Indirect Price-driven Quantity-driven • Investment incentives • Tendering systemInvestment- focused • Tax Incentives • Feed-in tariffs • Tendering System Regulatory Generation- based • Rate-based incentives • Quota obligation based on TGCs Environmental taxes • Shareholder programmes Investment- focused • Contribution programmes Voluntary Generation- based • Green tariffs Voluntary agreements Investment incentives establish an incentive for the development of RES projects as a percentage above total costs, or as a predefined amount of € per installed kW. The level of incentive is usually technology-specific. Feed-in tariffs (FITs) are generation-based price-driven incentives. This system determines the price per unit of electricity that a utility, supplier or grid operator is legally obliged to pay for electricity from RES. Thus, a national (or provincial) government regulates the tariff rate. It usually takes the form of either a total price for RES production, or an additional premium on top of the electricity market price paid to RES producers. Apart from the level of the tariff, its guaranteed duration represents an important parameter for assessing the actual financial incentive. FITs allow technology-specific and band-specific promotion as well as an acknowledgement of future cost reductions by implementing decreasing tariffs (see, e.g. the German Renewable Energy Act). Quota obligations based on Tradable Green Certificates (TGCs) are generation-based quantity-driven instruments. The government defines targets for RES deployment and obliges the parties involved in the electricity supply-chain (e.g. generator, wholesaler, or consumer) to meet these targets. Once defined, a parallel market for renewable energy certificates is established and their price is set according to demand and supply conditions (which is forced by the obligation to achieve the targets). Hence, for RES producers, financial support may arise from selling certificates, in addition to the income from selling electricity on the power market. Tax incentives are generation-based, price-driven mechanisms that work by offering payment exemptions from the electricity taxes applied to all producers. This type of instrument thus differs from premium, feed-in tariffs solely in terms of the cash flow for RES producers: it represents an avoided cost rather than additional income. Tendering systems are quantity-driven mechanisms. The financial support can either be investment-focused or generation-based. In the first case, a fixed amount of capacity to be installed is announced, and contracts are given following a predefined bidding process which offers the winners a set of favourable investment conditions, including investment subsidies per installed kW. The generation-based tendering systems work in a similar way. However, www.leonardo-energy.org 16 / 27
  17. 17. REPORT - Repowering and Used Wind Turbines instead of providing up-front support, they offer support in the size of the ‘bid price’ per kWh for a guaranteed duration. As well as the regulatory instruments described above, on-going market liberalisation has led to the appearance of an increasing number of voluntary approaches. They are mainly based on the willingness of consumers to pay premium rates for renewable energy. However, in terms of effectiveness so far – i.e. actual installations resulting from their appliance – their impact on total RES employment is negligible. Figure 3.6 gives an overview of the renewable electricity support systems used in the EU. CZ LV EE HU CY RO BG SI DE DK LT LU PT ES GR AT FR SK NL PL IT BE UK SE IE UK NL FI MT SL Quota Tax measuresTender Feed in Tariff Certificate Systems CZ LV EE HU CY RO BG SI DE DK LT LU PT ES GR AT FR SK NL PL IT BE UK SE IE UK NL FI MT SL Quota Tax measuresTender Feed in Tariff Certificate Systems Figure 3.6 Overview of the renewable electricity support in Europe A research study performed by the Anglo-German foundation for the study of industrial society18 tried to find an answer to the question as to why wind power in Germany is considered to be a major success story (Germany has the largest operating capacity in the world and enjoys world leadership in terms of its turbine manufacturing base), while the UK has the best wind resource in Europe, but has little installed capacity and underdeveloped manufacturing. This question was tackled by comparing the energy sector issues, policy dimensions and the factors related to local implementation that affect the industry in the both countries. According this study, it was clear that the German “feed-in tariff” has proved a highly flexible 18 Wind power in Britain and Germany: explaining contrasting development paths, 2006. www.leonardo-energy.org 17 / 27
  18. 18. REPORT - Repowering and Used Wind Turbines and manageable policy instrument. In contrast the UK’s Renewable Obligation (RO) has proved more costly but less productive. Moreover, the RO is making wind power progressively more expensive to the UK consumer at a time when regressive feeding rates are making it cheaper in Germany. Where German policy makers had recognised the need to adjust the levels of feed-in tariffs to changing circumstances, their British counterparts drew few lessons at that time from national experience or international comparison. The effectiveness of renewable energy ‘feed-in tariffs’ in the promotion of wind power is now widely recognised (Commission of the European Communities, 2005). 3.4.2. What incentives are promising for the repowering of wind energy To combat barriers against repowering, it is necessary and useful to consider a proactive policy to encourage repowering; one which would offer an explicit incentive for the repowering of aging wind projects. There are many ways that such a policy might be designed. Since Denmark and Germany currently have successful proactive policies intended to directly encourage repowering, this report summarizes related efforts in both countries. Germany Germany’s wind power boom started later than Denmark’s. Repowering is expected to constitute a major part of the wind market in the years ahead, especially as available new sites for wind development diminish. Stumbling blocks include local government restriction on hub height or total turbine height, and setback requirements between installations and residential areas. Despite these barriers, the wind repowering opportunity in Germany in enormous. Before 2004, German feed-in tariffs provided some encouragement for wind repowering, by offering new wind projects a higher payment than existing projects that had been operating for some time. Since 2004, the feed-in tariff has offered a longer and higher payment level to wind turbines that replace/modernise existing project built before Dec 1995 and that are at least three times the capacity of the repowered turbine. Despite this incentive, repowering has just begun and, given the regulations on siting and the barriers to repowering identified above, the wind industry argues that the feed-in tariff repowering incentive is insufficient. www.leonardo-energy.org 18 / 27
  19. 19. REPORT - Repowering and Used Wind Turbines It must be noted that the German repowering programme is starting slowly compared to the Danish programme. Although it is obvious that Germany has a good potential for repowering, a study performed in 2005 showed that there were some obstacles in the repowering programme.19 The main conclusions were: Denmark Denmark was the first country to actively support wind repowering, in part because wind turbine installation began in the early 1980s, so a large number of aging, small (< 75 kW) wind turbines exist throughout the country. Denmark recognized that these smaller, aging turbines were an obstacle to new project development, and that removing and repowering those turbines would require an overt and explicit incentive. Denmark’s repowering programme has led to repowering two-thirds of the oldest turbines in the country. Denmark’s first incentive programme for repowering wind turbines operated from April 2001 – December 2003. For turbines smaller than 100 kW, “repowering certificates” allowed owners to install three times the capacity removed, and receive an additional feed-in tariff price of 2,3 cents/kWh for the first 12.000 full load hours (about 5 years) of the enlarged wind project. For turbines in the 100 – 150 kW size range, owners could install twice the capacity removed, and receive the same treatment. As a result of this programme, 1480 turbines totalling 121,7 MW were replaced with 272 new turbines totalling 331,6 MW. Some owners of older wind projects also decided to decommission their projects and sell their repowering certificates to other wind developers. Denmark has continued to encourage wind repowering through a policy enacted via the energy policy agreement of March 2004. This new programme intends to repower another 175 MW of aging wind turbines. Under the programme, an extra surcharge is paid for new, on-shore wind turbines on the condition that the owner has a repowering certificate for a 450 kW wind turbine or less, decommissioned between Dec 2004 and Dec 2009. The surcharge is paid for factory new wind turbines connected to the grid between Jan 2005 and Dec 2009. The surcharge amounts to 1,6 cents/kWh and is paid for electricity production corresponding to 12000 full load hours for up to twice the decommissioned wind turbine installed power. The surcharge is regulated in relation to the market price of electricity, and the total of the surcharge and market price must not exceed a specified level. Because of the current low price of wholesale electricity, wind industry stakeholders in Denmark are concerned about the adequacy of this incentive and are calling for a larger incentive. • the current spacing requirements lowered the potential yield increase when emission control requirements are fulfilled; • if the spacing requirements are ignored while the height limit is maintained, the yield increase lowers even more; • if both the spacing requirements and the height limit are maintained, the potential yield does not increase at all in extreme cases. These results are remarkable for a number of reasons: • they show that spacing requirements and height limits result in the loss of enormous economic potential for wind energy; • spacing requirements and height limits make small turbine areas completely unsuitable for modern wind turbines, given the current state of technology; 19 "The Limitations of Repowering With Regard To The Legal Requirements and Procedures for Approval"; Hermann-Föttinger Institute of Fluid Mechanics at the Technical University of Berlin, in cooperation with Ecofys; 2005 www.leonardo-energy.org 19 / 27
  20. 20. REPORT - Repowering and Used Wind Turbines • the repowering incentive offered has no effect, since the spacing requirements and height limits make it impossible to achieve the required tripling of installed nominal capacity; • if yields cannot be increased by a factor of 2.5, then repowering turbines before their technical service life ends (usually 20 years), no longer offers an economic advantage to wind farm operators. It should be noted here, that more than 50 percent of the wind power capacity in Germany was installed after 2000. Maintaining the current spacing requirements and height limits actually preserves the number of existing wind turbines. From the above it is obvious that the repowering of wind energy needs to be supported by the government. To encourage repowering it seems that feed-in tariffs are in favour, and strict height and spacing limitations should be limited, otherwise the necessary increase in installed power cannot be achieved. Figure 3.7 Eneco wind park, Slufter20 20 www.eneco.nl www.leonardo-energy.org 20 / 27
  21. 21. REPORT - Repowering and Used Wind Turbines 4. USED WIND TURBINES Many wind turbines are designed to achieve a service of 20 years or longer. Over the last decade, wind turbines have become larger. Politicians in many countries have focused their attention on up-scaling wind turbines at existing locations. As a result of repowering, interest in used wind turbines with a remaining service life of several years is growing across the world. A fledging new business is now showing signs of gaining sophistication. In the early 1990s, reaction to the efforts of selling used Californian wind turbines to developing countries was decidedly mixed. A strong body of opinion argued forcefully (and in the end successfully) that dumping outdated technology on an inexperienced yet potentially large new market was morally questionable, and likely to be bad for long-term business. Nowadays in Europe, the body of opinion is arguing that sales of well-maintained, older machines, allows new markets to gain positive experiences with wind power at lower commercial risks than the far greater investment needed to buy state-of-the-art technology.21 Replacement turbines are not always installed on the same site as the old machines, with the result that old turbines can either be sold for erection elsewhere, or for continued operation on the existing site by a new owner, who accepts that the output no longer attracts a subsidised price. Others are dismantled entirely and are sold for scrap, recycling, or for their parts. 4.1. Why buy used wind turbines Growing energy demand in developing countries stimulates the use of renewable energy sources, such as wind power, to provide a sustainable and environmentally-friendly power supply. For most of these countries, projects with new wind turbines have proven to be unaffordable: that is why using cheaper second-hand turbines may be an option. Utilising used wind turbines instead of new ones offers several benefits22 : • lower capital expenditure saves the investor’s capital resources and reduces the efforts involved in collecting borrowed capital; • shorter project duration reduces the investor’s financial risk, especially valuable in politically and economically unstable conditions; • turbines from 150 to 600 kW can be transported and erected without major problems. However, larger turbines often require specialist equipment that is not available in many parts of the world, while smaller turbines may not be economical to place. Many manufacturers are no longer fabricating turbines of this size. Therefore, buying used turbines is the most common way of obtaining a wind turbine that can be shipped and installed easily; • maintenance work on used turbines can be conducted easily, compared with the latest technology turbines that require both a sophisticated infrastructure and specialists to carry out routine work. Using used turbines means that it is not necessary to make high demands on qualified personnel; • a substantial overhaul and adaptation to regional requirements can take place while the used turbine is being dismantled. This is cheaper than overhauling while the plant is in operation; 21 The art of selling repowered turbines; Wind Power Monthly, May 2004. 22 Perspective of reusing wind energy converters in developing countries; N. Peterschmidt, Technical University of Clausthal. www.leonardo-energy.org 21 / 27
  22. 22. REPORT - Repowering and Used Wind Turbines • for developing countries, it is an opportunity to contribute to sustainable development and the reduction of CO2 emissions; • for European investors, it is an opportunity to make connections with a potential future wind power market, and to gain experience of the social and economic environments in developing countries. But disadvantages will also arise: • more efforts will be required to select suitable turbines for specific projects e.g. each used turbine has different characteristics, including such things as equipment and defects that have occurred. These characteristics should meet regional requirements in order to minimize the costs of adaptation. To determine the price of used plant, dynamic measurements can be conducted during operation; • the life expectancy of overhauled used wind turbines cannot be satisfactorily predicted. For this reason, all results of economic analyses are based on assumptions; • the procurement of spare parts may also become an obstacle, as most manufacturers’ technical support expires after 20 years. Centralised storage of spare parts may help to overcome this obstacle. In some cases, dependent on the site and on the plant used, the advantages outweigh the disadvantages, and the utilisation of used wind turbines is advisable. Because of many of the benefits mentioned above, developing countries lend themselves to realising projects with used turbines. Despite increased repowering activities, the demand for used turbines in Europe is estimated to remain low, which means consequently that prices will also follow this trend. In Figure 4.1, representative quotations of used turbines in Germany were plotted in order to give a description of current rates, referring to slightly overhauled plant at the place of storage in Europe without transportation and installation. 0% 10% 20% 30% 40% 50% 60% 70% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Age [years] Priceoftheusedturbinecompared tothepricewhennew Figure 4.1 Age dependent prices of used wind turbines To demonstrate the profitability of a wind farm project with used wind turbines, the profitability of a project using four 10 year old 500 kW turbines is compared with a project www.leonardo-energy.org 22 / 27
  23. 23. REPORT - Repowering and Used Wind Turbines using three new 600 kW turbines. The different number of turbines was chosen to get an equivalent amount of generated power per year for both options. The economic analysis was carried out on the assumption of single payments and periodic expenditures displayed in Figure 4.2. Furthermore the life expectancy after erection was assumed to be 15 years for the used wind turbines and 25 years for the new turbines. The cost of electricity generation was approximately 0,079 Euros for the used turbine and approximately 0,086 Euro for the new turbine, showing the used wind turbine to be more profitable. Of course, this result is not generally applicable for all projects, and an individual approach to the purchase of used or new turbines is necessary. € 0 € 500.000 € 1.000.000 € 1.500.000 € 2.000.000 € 2.500.000 Starting capital annual costs Starting capital annual costs 3 new turbines 4 used turbines other annual costs Annual maintenance Reserves Mains Connection Foundation Transport Overhaul Converter Figure 4.2 Comparison of costs between new and used wind turbines 4.2. When buying used wind turbines Successful utilisation of wind turbines is always dependent on sufficient wind energy potential. This is the basis for both new and used wind turbines. Electrical stability in weak grids with stochastic feeders, limits the permissible load of wind turbines. That is why only small generators in the 150 to 600 kW class are suitable for simple grid connections. Turbines of this size are no longer being manufactured and are only available on the second- hand market. This option allows lower initial expenditure costs, resulting in a shorter project duration, favourable for countries without long-term planning reliability in the initial implementation period23 . Additionally, a certain technical infrastructure is required (cranes, roads, companies for basic maintenance) and access to the national grid should be supported by a sufficient buyback price. 23 Repowering – New changes for wind power implementation; H. Peters, WWEA. www.leonardo-energy.org 23 / 27
  24. 24. REPORT - Repowering and Used Wind Turbines 4.2.1. Grid integration of used wind turbines In most developing countries the operating conditions of turbines are different from those in Europe. Not only will climate changes have an impact on the turbines, but also connection to the grid. In contrast to highly populated industrial countries, electrical power in developing countries is often supplied via long transmission lines of low capacity with large fluctuations. To avoid expensive applications for stabilising the voltage level, it is necessary to choose a site with transmission lines of adequate capacity. Highly productive sites may also be dismissed because of concerns of frequent black outs, that are a strain for wind turbines and diminish the energy supply. 4.2.2. General overhaul and maintenance of used turbines Climate or geographical changes will have impact on the turbines. In general, in temperatures above 35° C, an advanced cooling system for the gearbox and the generator is required; an extra ventilator for the generator and additional cooling for the gear oil or the whole system are possibilities. To avoid erosion of the blade surface as a result of high fluctuations in temperature (e.g. sandy deserts) the application of special protection-films against erosion is recommended. In the event of sandstorms it is necessary to use sand filters to protect the equipment inside the nacelle. Low air density at high altitude sites reduces the energy output of wind turbines, compared with sites at sea level. The limitation of power generated at high wind velocities takes place at lower output. In order to improve the output, the blade angle can be adjusted. To enable an adaptation to different power frequencies, a wind turbine with generator and electrical converter should be chosen. It can be adapted to 60 Hz easily, just by adjusting the control system of the converter. By contrast, wind turbines with induction generator need to be altered; either the gear transmission ratio has to be adjusted by alternation of the whole gearbox, or an external converter has to be applied to change the frequency. Both solutions are expensive. Different voltages also have to be covered, e.g. by adjustment or even by replacing the transformer. For the project planning of a wind farm or an individual wind turbine with used wind turbines, it is vital to know the performance and the technical condition of a machine, since ultimately the technical condition is the criterion for the financial success of the project. A plant that is permanently generating costs can be hardly profitable. It is, therefore, recommended that the technical condition be verified prior to purchase, preferably before dismantling has started on the original site. There are no one hundred percent damage-free wind turbines. The goal is to keep the number of problems low, and to identify and address existing damage on time. Measures introduced on time ensure maximum life expectancy of the turbine. The actual damage potential of a problem can only be evaluated by specialists. Prior to purchasing a used wind turbine, it is recommended that a status-oriented survey of the wind turbine be carried out. This survey also includes a review of the available documentation, which is designed to give a complete overview of the structure, operation and history of the turbine. As a minimum, the following documents must be available: www.leonardo-energy.org 24 / 27
  25. 25. REPORT - Repowering and Used Wind Turbines • Building permission • Operating instructions • Circuit diagrams and hydraulic diagrams • Commissioning record • Results of former oil analyses • Maintenance specification, including all maintenance and service reports • Logbook with all the service team calls. 4.3. What is the potential of using used wind turbines In countries where repowering programmes have started, different companies have entered the market for selling used wind turbines. If owners of wind turbines decide to go for repowering, in most cases the price of selling the used wind turbines is not important, since they do not depend on the sale of the used turbines. If the fate of the old machines is not economically relevant to the repowering, the owner can try to find buyers, or may eventually sell them for scrap. As mentioned earlier, wind turbines between 150 up to 600 kW offer the best possibilities for re-utilisation in developing countries. Selling older machines can be done by the owner, but this can also be done by the manufacturer of the used machine. Some of the wind turbine manufacturers do have a department for re-selling used wind turbines. Also, new players have entered this market who are focusing entirely on selling used machines. They have become specialists in the market and in inviting potential customers to select their preferred wind turbine, once their project begins to takes shape. Selling used wind turbines to developing countries offers opportunities for all countries concerned. Utilising used turbines in developing countries offers an opportunity to gain experience in working with wind energy technology with low capital expenditure. Establishing their own wind energy industries, assisted by technology transfer from Europe, may help to improve the labour market in these countries. If used turbines find a market in developing countries, repowering activities may increase, and European countries can then extend their wind power generation capacity. This would also contribute to a double reduction in CO2 emissions, (at the location of the repowering, and at the location at which the turbines are re- used). www.leonardo-energy.org 25 / 27
  26. 26. REPORT - Repowering and Used Wind Turbines 5. CONCLUSIONS The recycling of wind turbines preserves the amount of energy and material invested in the equipment itself. The unique combination of increased supply from European countries, coupled with increased demand for smaller and middle sized turbines in developing countries, offers opportunities for exporting reliable wind turbines. The reduced remaining life-expectancy of such turbines does not present significant disadvantages because, in these countries, such turbines fill a niche in their developing and partly insecure markets. Most of the turbines currently placed in Europe need a general overhaul after 6 to 10 years. For the former operator, selling the plant at this age and replacing the existing wind turbines with larger ones, offers the opportunity to avoid overhead costs; which also results in energy gains at the same location. The new investor of the used turbines can carry out all necessary work at the disassembled plant (thus reducing costs). Projects utilising used wind turbines, that have already been realised in several countries, represented the initial step for the long-term alteration of these countries’ energy sectors regarding the introduction of wind-power technology. These projects differ from projects that utilise new equipment, in that certain aspects need to be taken into consideration and evaluated during the project planning. In summary, any project with either new or used turbines can only be undertaken profitably if a number of different crucial basic requirements are met regarding: the existence of sufficient wind speeds; a stable grid; minimum buyback prices; technically qualified personnel; spare parts; and reliable economical and political conditions. In going for the option of re-using second-hand turbines, the main difference concerns simplifying financing, because of the lower initial expenditure. www.leonardo-energy.org 26 / 27
  27. 27. REPORT - Repowering and Used Wind Turbines 6. APPENDIX A - TRADING COMPANIES FOR USED WIND TURBINES This Appendix provides a list of some companies that sell or offer advice regarding wind turbines in Europe. This list is not a complete list of all companies in Europe. Most of the companies listed below are companies operating in countries in which repowering has already started. Company Country Website Description Windpartnersbg Bulgaria www.windpartnersbg.com Consultancy in used wind turbines from 225 kW to 1,5 MW Windbrokers Netherlands www.windbrokers.com Supplier of used wind turbines from 150 kW and upwards Repowering solutions Spain www.repoweringsolutions.com Supplier of used wind turbines from 150 kW and upwards Dansk Vindenergi ApS Denmark https://dansk-vindenergi.dk Sales of used wind turbines between 150 – 250 kW BSgreen Germany http://gebrauchtewindkraftanlagen.com www.usedwindturbine.com Consultancy & installation Dansk Vindmoelleformidling Denmark www.danishusedwindturbines.com Export of wind turbines from 30 kW to 1 MW GFW Germany www.neic.de/wind/gfw-e.htm Sales of used wind turbines P&J Windpower ApS Denmark www.pjwindpower.com Supplier of second hand wind turbines MainWind Netherlands www.mainwind.nl Sales of used wind turbines Bettink Netherlands www.bettink.nl Sales of used wind turbines Immobilen Service Lothar Müller Germany www.wind-park-power.com Sales of used wind turbines www.leonardo-energy.org 27 / 27

×