Last year marked a significant step for sustainable energy as both new and traditional renewable technologies made further inroads into our international primary energy supply. By the end of 2009, a total capacity of 1247 GW had been installed throughout the world with an estimated annual power generation of between 3940 and 4070 TWh/year (y).

Figures from REMIPEG (Renewable Electricity Market, Installed Power and Annual Electricity Generation) – Lahmeyer International's renewable energy data bank – show that renewable capacity and power generation is still dominated by hydropower, of which approximately 997 GW has now been installed. This is followed by wind energy with around 159 GW.

REMIPEG's annual report examines installed power capacities for renewable energy generation in individual countries and across the world. It includes estimates of the country-specific average annual power generation for each energy source. The data is based on public information from various organisations active in the different renewable energy markets and expert information from consultants in this field.

Most of the aggregated country figures are based on installed capacities up to the end of 2009. Where this was not available, reasonable assumptions have been made to extrapolate from 2008 figures or in-house information about specific countries has been used. With regard to the annual electricity generation, the data bank generally uses country-specific average full load hours, but in some cases supplements this information with national statistics.

This article previews REMIPEG's latest update, carried out in the first four months of 2010, and presents an overview for each renewable sector up to the end of 2009 (for last year's report, see our July/August 2009 issue).

Hydropower

Hydropower retains its position as the largest renewable energy contributor to world electricity generation. Total installed capacity to the end of 2009 was around 997 GW, indicating that around 31 GW was added last year. The total estimated annual power generation from hydropower was around 3299 TWh/y (see Table 1).

Source: Layhmeyer International

The global figure includes large as well as small hydropower plants; the latter contribute an estimated share of 9% – around 91 GW – of installed capacity.

The distribution of hydropower use over the various continents is also shown in Table 1. It is clear that Asia has by far the largest share, both in terms of installed capacity and electricity generation.

Hydropower technology is relatively mature and the major trends from 2008 have continued apace. Major projects (by country) that were started, continued, or concluded construction and/or came onto the grid in 2009 include:

• Germany: Further efforts are continuing to develop and build additional pump storage capacity in Germany and to compensate for partially unpredictable and increasingly fluctuating electricity from wind energy in the grid. Among other projects, this included further planning and tendering for the Atdorf Pumped Storage Plant financed by Schluchseewerk. This project has been strongly supported by Dena, the German Energy Agency;
• Switzerland: Overall reconditioning of hydropower plants in the Swiss Alps by Kraftwerke Hinterrhein. The three plants, Ferrera, Bärenburg and Sils, have a total installed capacity of 650 MW;
• Romania and Turkey: Both countries added around 500 MW to their on-line capacity in 2009;
• Russia: A catastrophic accident at RusHydro's Sayano-Shushenskaya 6400 MW hydropower plant in Eastern Siberia killed 75 people and forced staff to completely shut down all hydropower plant machinery for several months;
• Sudan: The Merowe hydropower plant in Sudan started commercial operations in early 2009. Since the end of February 2010, a total of 1250 MW has come onto the grid. There has also been an extension of the Merowe Irrigation Project financed by the Sudanese Government's Merowe Dams Project Implementation Unit. In 2009, construction of cross-drainage culverts under the future left bank canal began and several other major hydropower projects in the country started or progressed; including the heightening of the Roseires Dam financed by the Sudanese Government's Kuwait Fund for Arab Economic Development, as well as initial studies for the Sennar hydropower plant and dam. Both these projects are also financed by the Merowe Dams Project Implementation Unit;
• Angola: Initiation of major hydropower projects in Angola, including the Lauca and Caculo Cabaca plants, financed by GAMEK (Gabinete de Aproveitamento do Médio Kwanza) for Angola's Ministry of Energy and Water;
• Congo: A major study for the Inga project in Congo was tendered and is expected to start in 2010. The study will analyse the feasibility of a huge hydropower plant with total capacity between 35 GW and 40 GW on the Congo River;
• China: Around 20 GW of additional hydropower capacity was added to the grid in 2009;
• India: A feasibility study and a bankable detailed report (as well as detailed design) for the Kalai-I hydropower plant financed by Mountain Fall India was produced; and
• Iran: Additional capacity of around 2200 MW came on-line in 2009.

Wind power

The market for wind energy continued to grow in 2009. By the end of the year, more than 150,000 wind turbines with an aggregated capacity of 159 GW had been installed worldwide, of which 38 GW were erected in 2009. This newly installed capacity represents an increase of about 40% compared to new installations in 2008. The world market growth rate in terms of total installed capacity was about 32%.

By far the largest national markets were China with an additional 13.8 GW and the USA with 9.9 GW newly installed capacity in 2009. This means that for the first time China is the world's leading wind market. The 2009 figures represent an increase of about 119% compared to 2008. The new installations bring China to a cumulative installed capacity of about 26 GW, bypassing Germany and Spain and taking it into second position behind the USA which has installed with 35.1 GW.

However, there are indications that only about half of the wind turbines in China are really in operation. Many of the wind farms are not connected to the grid because of quality problems or grid weakness, and appear to have been constructed to allow large utility companies to gain incentives in order to expand their coal-fired operations.

Europe is still the leading continent in terms of cumulative installed capacity, as it accounts for about 77 GW, followed by Asia with about 40 GW. In terms of new installed capacity in 2009, Asia's 15.5 GW put it ahead of North America and Europe, where about 11.1 GW and 10.5 GW, respectively, were added (see Table 2).

Source: Lahmeyer International, BTM Consult ApS, World Wind Energy Association.

The whole market is still heavily dominated by onshore projects. Of the total cumulative capacity only 2.1 GW is offshore of which about 689 MW was installed last year. Of special significance are the 209 MW wind farm project Horns Rev II and Germany's first offshore wind farm Alpha Ventus, with a capacity of 60 MW (see Figure 2).

Last year total worldwide electricity generation from wind reached approximately 324 TWh/y. This was obtained using calculations based on either the average specific electricity output of 2008 or in selected countries with reasonable assumptions regarding wind resource potential and making reasonable assumptions for the average power output for wind turbines installed in 2009.

On the turbine manufacturing side, Vestas once again achieved the largest share (12.5%) of the global wind market, representing about 4.8 GW. However, the company has lost ground since 2008 and is now closely followed by GE Wind, whose market share was almost 12.4% in 2009. For the first time there are also two Chinese companies in the top five suppliers list: Sinovel ranks third with 9.2% and Goldwind is fifth with 7.2%.

Technology and market trends

The trend towards larger wind turbines continues, with roughly 82% of all wind turbines installed in 2009 falling into the range of 1.5 MW to 2.5 MW, but growth is slowing.

In countries with good infrastructure, wind turbines in onshore wind farms generally have a range between 2 MW to 3 MW. In areas with poorer infrastructure, larger wind farms with smaller turbines (up to 1.5 MW) are under development or have been installed. The average turbine size in China was below 1.5 MW for the 13.8 GW of installed capacity in 2009.

Of the larger rated turbines, the REpower 6M and the Enercon E-126 are particularly popular. The 6M has a rated capacity of 6.15 MW while the Enercon E-126 is available with 6 MW of rated capacity but there are suggestions that it will be operational at 7.5 MW soon. These turbines are at the start of a series production with about 15 of the E-126 turbines installed and three of the 6M models.

The REpower 5M, on which the 6M is based, has been installed 23 times so far – 9 onshore and 14 offshore – with 6 of those installations at the Alpha Ventus wind farm off the coast of Germany in 2009.

The market is continuing to attract new players and a significant number of new companies in Europe and Asia are developing new wind turbines to enter the market in the coming years. The Chinese market, in particular, now has three manufacturers among the top 10 global players and has shown potential for more new businesses.

The acceptance of new wind turbines on the market depends on their suitability for international trade and the successful operation of their first projects. Most of the new players still have to prove this, particularly regarding the quality and long-term stability of turbine operations.

In mid-2009, the South Korean firm Daewoo Shipbuilding & Marine Engineering (DSME), the world's second largest shipbuilder, announced its entry into the wind energy market by acquiring DeWind for around US$50 million. DeWind is a medium-sized wind turbine manufacturer that has installed around 570 wind turbines in the 500 kW to 2 MW range.

Another trend is the increasing professionalism of the market. One example of this is continuous flow production, which aims to increase output and quality and to decrease costs. Several manufacturers, including GE, REpower, Vestas and Enercon, began this process between 2003 and 2006 but had little success due to the many different wind turbine types needed to satisfy customer demands. Now that products are more standardised, this kind of production is becoming more effective; examples of successful factories include Siemens in Brande, Denmark, and GE in Salzbergen, Germany.

Apart from Europe, the USA and Asia, other markets for wind energy remain small. Nevertheless, there are remarkable wind farm projects taking shape in the developing world. In South America, the growing markets are mainly concentrated in Brazil, Uruguay and Peru, while the African market is still dominated by Egypt and Morocco.

May 2009 saw a major step forward for Africa's wind business, when Ethiopia and France signed a €210m financing agreement for the 120 MW Ashegoda wind farm, which will consist of 120 Vergnet GEV-HP 1 MW wind turbines.

2009 marked a significant breakthrough for the offshore wind sector in Germany, which installed its first offshore wind farm with a significant distance from the shore, Alpha Ventus. The wind farm consists of 6 REpower 5M turbines and 6 Multibrid M5000 turbines. In the UK, the winners of the Round 3 tender were announced in early 2010, forming the basis for the development of up to 32 GW of additional capacity in British waters.

Solar PV

Over the last decade the solar photovoltaic (PV) market experienced substantial growth and this trend is forecast to continue in the coming years. By the end of 2009, the global cumulative installed capacity had reached 21 GW, of which around one third (7.1 GW) became operational in 2009. Europe has retained its position as the leading continent with nearly three quarters of global installed capacity, followed by Asia (17%) and North America (9%).

Figure 1 shows that most of the world's cumulative installed solar PV power in 2009 was located in just five countries. In 2009, the total estimated electricity output from solar PV power reached an estimated 24 TWh (see Table 3).

Source: Lahmeyer International and European Photovoltaic Industry Association.

Germany was the most important solar PV market in 2009 with 45% of the world's total installed capacity, which compensated for the substantial decline of the Spanish market after the boom of 2008. Around 3.8 GW was installed in 2009 in Germany, double that of the previous year. The 11% decline in Government feed-in tariffs (FiTs) for plants connected to the grid after January 2010 motivated many developers to finish their projects before the end of last year.

Although the new German Government has announced a large reduction in tariffs for plants connected after 1 July and a limitation on available sites, the size of the German market is expected to remain between 3 GW and 4 GW per year due to an assumed decrease of investment-specific costs.

Apart from rooftop installations, which account for around 80% of the market, the installation of several large ground-mounted facilities are worth mentioning, including Lieberose (with First Solar modules and juwi as developer, 53 MW), Strasskirchen (with Q-Cells modules and Q-Cells International as developer, 54 MW) and Finsterwalde I (Q-Cells modules and Q-Cells International as developer, 41 MW).

Italy's market reached 730 MW by the end of the year (compared to 338 MW in 2008). Although the Italian Government announced it would reduce its own tariff as soon as 1200 MW had been installed, many analysts still expect robust growth for the coming years (going up to 1 GW in 2012). They argue that because of high retail electricity prices and high solar irradiation, Italy's consumer market is seen as the first major electricity market with the potential for grid parity to be reached.

France reached 185 MW in 2009 and, with the adjustment of the government's Feed-in tariffs on 10 January and 14 March, the country expects an increase of up to 500 MW over the coming year. The increase could have been even higher if the Government had not cut its tariff for rooftop installations by 24% and defined strong architectonical conditions for plants to qualify as building-integrated PV (BIPV).

The Czech Republic was another hot spot for solar PV in 2009, with a total of 411 MW installed, but the Government's announcement that it would chance retroactive tariffs has slowed down the development of the market.

Until recently, Spain was the largest world market with 2605 MWp in 2008, up 365% on the year before. But in 2009, only a further 69 MW was connected and under the current Spanish financial crisis and the Energy Ministry's declared Feed-in tariff reductions, this trend is unlikely to change in 2010.

Germany's dominance of the market is unlikely to last; 477 MW was installed in the USA in 2009 and it is expected that this market will increase to more than 1 GW in 2011, going up to around 3 GW per year to 2014. States with high electricity rates, large electricity markets and relatively good solar resources, such as California, New York, New Jersey and Texas, are expected to lead growth within the country.

Canada, which installed 70 MW of new capacity in 2009 and has 103 MW in total, and particularly Ontario, which established a new feed-in tariff last October, is expected to become one of the fast-growing markets in North America. Nevertheless, tariff restrictions require a minimum of 50% of local content, and this is likely to pull the market back as many production facilities are only in the planning stages.

Japan's reinstatement of its Feed-in tariff in November 2009 allowed it to double solar PV installed capacity-reaching 484 MWp. The country is expected to at least double this capacity again in 2010.

Compared to its solar PV production export rates of almost 100%, China has very modest figures for total installed capacity (160 MW in 2009). With the announcement of aggressive solar PV initiatives for China's market development – for example, the government aims to have 20 GW installed by 2010 – this is strongly expected to increase in the coming years.

Solar PV generation is particularly suitable for the electrification of rural areas. In the absence of reliable data, it is assumed that the total installed off-grid capacity in 2009 did not exceed 50 MW worldwide. Should prices for solar PV modules decline further the economics of solar PV in rural areas will improve. As a result, the next annual statistical overview could include countries such as South Africa, which has enjoyed a very attractive solar PV tariff since last year.

The continued growth of solar PV can be achieved by further reduction of the levelised electricity costs. In 2009, the price of modules declined by 20-30%, not only because of a decrease in demand at the beginning of the year and an increase in production capacities, but also due to a dramatic reduction in silicon prices. This price reduction in turn had an effect on technologies focusing on silicon substitution.

Thin-film technologies such as a-Si and μSi have been hard hit by silicon price declines, as they do not yet offer prices as low as current CdTe or prospective CIS/CIGS, so it is more difficult for them to compete with the higher efficiency offered by crystalline silicon manufacturers.

Of the various thin-film technologies, CdTe figures most prominently due to its superior module cost performance (US$1/Wp) and high rates of output from manufacturer First Solar, which has installed almost 1200 MW of annual production capacity in the USA, Germany and South-East Asia. It also performs better in low temperatures than mono- or poly-crystalline modules, due to the better use of diffuse solar irradiation. Its primary disadvantage is that it requires more surface area as it is less efficient.

Crystalline silicon-based modules (both mono- and polycrystalline), with a current share of 78% compared to 22% for thin-film, are expected to continue dominating the market. Thin-film modules will only slightly increase their market share, up to around 25% by 2014.

The concentrating solar photovoltaic (CPV) market remained quite small in 2009 and no major new installations were reported, but some improvements were made in terms of efficiency. For example, Fraunhofer ISE, a solar energy research institute based in Germany, reported 41.1% efficiency for a CPV cell and the University of New South Wales in Australia reported 43% in September.

In 2009, Concentrix started to ramp up its 25 MW production facility in Freiburg, Germany, as a further step towards large-scale and standardised production, which will allow it to reduce levelised electricity costs for CPV. A CPV tariff will be needed to stimulate development of this technology in the short term.

Solar thermal power

The solar thermal power market continued the momentum it gained from 2008 installation figures to grow substantially last year. Altogether a further 176 MW came onto the grid in 2009, which represents a growth rate of around 35% and brought the total installed capacity to 698 MW the end of 2009. The majority of this installed power came from 8 plants in the Mojave Desert totalling 354 MW net (or 372 MW gross), which were installed in the 1980s and are still in operation, as well as Nevada Solar One in the USA which has 64 MW net (or 72 MW gross).

But the growth of this newly installed capacity was predominantly a result of the Spanish market. In addition to the Andasol 1 and Andasol 2 plants, which were both in commercial test phases during 2009, two other 50 MW plants (Puertollano and Alvarado 1) finished construction and started test operations. Together with some small pilot schemes, this means that around 230 MW of concentrated solar plants (CSP) plants are now in operation on the Spanish national grid.

Source: Lahmeyer International.

The major players are large Spanish industry groups such as Abengoa Solar which has three solar towers in operation, two of which are in commercial use (PS 10 and PS 20) and a third which is experimental. In addition to the 31 MW already in operation, Abengoa Solar entered 13 CSP plants, each with a capacity of 50 MW, into the pre-allocation registry in Spain.

These 13 farms are grouped into five solar platforms: Solucar (construction completed), Ecija (construction in progress), Ciudad Real and Carpio Complex (Cordoba) (construction of both to begin in 2010) and Extremadura Complex in Logrosan.

Another large player in Spain, Acciona Energia, has been granted pre-allocation for five CSP projects, each of which also have a capacity of 50 MW: Alvarado (La Risca), Palma del Rio I and Palma del Rio II (Andalucia), Orellana and Majadas (both in Extremadura).

In the USA, there were many reports of activity in 2009 but little newly-installed capacity. Apart from the 5 MW solar tower plant Sierra Sun Tower in California, which consists of two small eSolar modules, no new installations took place in the country last year.

However, there has been substantial movement in the development stages. PG&E signed a power purchase agreement (PPA) for the 553 MW Mojave Desert solar farm, which is expected to start commercial operations in 2011. Since 2008, PG&E has signed PPAs for more than 1900 MW of CSP plants. The countersigning companies include NextEra Energy Resources, Abengoa Solar, NRG Energy and Bright Energy Sources.

The third important market is the Middle East and North Africa (MENA) region. Three integrated solar combined cycle (ISCC) projects continued construction in Algeria, Morocco and Egypt, each with a parabolic trough solar farm with less then 50 MW capacity. All of these are expected to be completed this year. Masdar's lighthouse project Shams 1 in Abu Dhabi, comprising a 100 MW solar parabolic trough project, has not yet started construction. The delay has been caused by the reduction of the energy yield estimates and ongoing discussions in Abu Dhabi regarding the final tariff, which will be defined in the PPA.

On the industry side, some large players continued their expansion into the market. After Archimede's joint venture with Angelantoni Industrie (Italy), Siemens acquired a 100% stake in Israel-based company Solel Solar Systems. Having been in the CSP market since the early 1990s and launched by former staff of the bankrupt energy firm Luz, Solel Solar Systems is the market leader in the production of solar parabolic troughs. It is also involved in manufacturing and installing complete solar fields.

Other significant developments include the acquisition of the US-based collector development company Ausra by French energy firm Areva, as well as RWE Innogy's financial investment in Andasol III together with other German utilities such as Stadtwerke München and Rhein Energie.

Finally, the Desertec Industrial Initiative (DII) took a major step forward when it was officially founded by its 12 original German shareholders. As well as four other shareholders from Morocco, Italy, France and Spain, over 15 associated partners have subsequently joined this major initiative, which aims to foster the large-scale introduction of renewable energy technologies, particularly CSP, in the MENA region. As well as ensuring a more sustainable power supply in MENA countries, the initiative aims to provide around 15% of Europe's power supply in the future.

Biomass

Biomass is the renewable energy source that can be used most widely within the overall energy system. Organic material can be converted with varying degree of difficulty into solid, liquid, and/or gaseous biofuels. These biofuels, which are already beginning to be internationally traded, can then be used for the production of electricity, heat and/or power.

Although the provision of heat is the most traditional use it is still growing on an international level. The conversion of biomass into useful energy has grown in recent years, and this trend is likely to continue in the future as there is still a growing demand for electricity and fuel. This tendency can be observed in industrialised as well as in developing countries.

Source: Erneubare Energien.

Solid fuel

At the end of 2009, at least 41 GW of solid biofuels was used to produce electricity via mono- and co-combustion methods worldwide (excluding waste-to-energy). The electrical power produced is more or less equal in developing and industrial countries. However, in some emerging nations, such as China and India, electricity generation from solid biomass has gained much more prominence in recent years.

Based on installed capacity, between 170 TWh to 290 TWh of electricity is likely to be produced at an average of 4000 to 7000 full load hours per year. Assuming a similar operation scheme in developing as well as in industrialised (i.e. OECD) countries, approximately 241 TWh of electricity has been produced by solid biofuels worldwide. In 2009 around 250 TWh to 270 TWh was produced.

About 44% of the total electricity generated by solid biomass in OECD countries came from the European Union (EU), of which more than half comes from the three densely wooded countries – Finland, Germany and Sweden.

In many countries energy recovery from the organic fraction of municipal solid waste (MSW) is counted as solid biomass. It is estimated that about 26 TWh to 30 TWh of electricity was produced by the OECD in 2009 – based on an installed capacity of more than 10 GW and assuming constant development – which is in addition to the 41 GW stated above.

Biogas

Electricity generation from biogas mainly takes place in industrialised nations. Taking into account approximately 30 TWh of electricity from biogas, which was generated by OECD countries in 2008, estimates for 2009 are between 32 TWh and 35 TWh. The most important players on the biogas market are Germany (ca. 9 TWh), the USA (ca. 7 TWh) and the UK (ca. 6 TWh). Nearly half of the biogas in the EU is generated from landfill, of which almost half is produced in the UK. The remaining biogas is produced by agricultural biogas power plants, mainly using animal slurry and maize silage, and through sewage gas power plants.

Liquid fuels

Only a small portion of liquid fuels is used for electricity generation, mostly in combined heat and power (CHP), and only a few industrialised nations even record statistics for this very limited use. Compared with previous years, the use of liquid fuels for electricity generation in CHP plants stagnated or decreased in some countries. For example, within the EU approximately 3.6 TWh was produced from liquid biofuels in 2008, mostly in small-scale CHP units. This was 19% less than in 2007.

Based on the fact that the EU is the leading market, and assuming that the ongoing sustainability debate and reduced subsidies in some European countries will decrease the use of liquid biofuels for electricity generation, it is likely that less than 4 TWh of electricity are being produced worldwide by CHP plants based on liquid biofuels (like vegetable oil).

International electricity generation from biomass is characterised by a wide spectrum of available technologies. Those used in developing countries are, on average, relatively inefficient and produce relatively high emissions of airborne substances. By contrast, industrialised countries use more innovative and sophisticated technologies with higher overall efficiency and lower airborne emissions due to emission limits set by governments.

Solid biofuels made of wood have the longest history. Due to its favourable fuel properties large quantities can be easily stored, and the combustion and power generation techniques available on the market are technologies adapted from the coal firing industry.

The technology trends in this area include further increases in overall efficiency by minimising heat loss and improving heat recovery from exhaust gases, by increasing conversion rates (at a lower temperature) and through the development of interim heat storage capacities for more flexible CHP operation.

This is especially true for the lower power range (below 5 MW electrical power) due to the decentralised biomass supply and the fact that heat produced in CHP to achieve higher overall efficiencies can only be used locally in limited amounts. The available technology includes units with small steam turbines that are electrically fairly inefficient, and plants using an Organic-Rankine-Cycle (ORC). In the years to come gasification technology, i.e. an improved Güssing concept and an integrated gasification combined cycle (IGCC) based on biomass gasification, is likely to play a larger part.

Due to the fluctuating price of fossil fuels and growing competition for reasonably-priced biofuels, the use of solid organic residues from agricultural and forestry primary production is becoming more prominent. This is further affected by debates about sustainability and fuel versus food. As a result, research is heading towards the development of more efficient conversion technologies for ‘classical’ solid biofuels, in parallel with more specialised technologies able to use unfavourable fuel properties such as high concentrations of nitrogen, chlorine, potassium and/or sulphite.

Furthermore, fuel and logistic concepts based on the use of compacted biofuels with relatively high energy densities, such as pellets, will be more promising in the future and will improve the total efficiency and economy of energy supply concepts. Such fuels will also allow the development of a global fuel market based on a variety of different producers to ensure a more secure supply.

Electricity generation from the organic fraction of MSW will probably become less important in the future because the energy-rich components of the household waste will increasingly be collected separately – at least in industrialised countries. As a result, ‘classical’ electricity generation or CHP from the organic share of MSW via combustion is likely to decrease. Due to more promising concepts, such as biogas production, this decrease is unlikely to be compensated by an increase in developing countries.

Biogas technology has made significant progress during the last decade and it is expected that developments will continue in the years to come. For example, bacteria available on the market are more efficient and able to use less promising substances, and biogas plants are more reliable and robust.

The production of biogas is a win-win situation because it produces organic waste with high water content in parallel with a high energy production. In the food processing industry, for example, waste can be used to produce energy and to provide marketable compost rich in nutrients. Due to increasing international environmental standards and widely-fluctuating energy prices, as well as a more insecure energy supply, more companies within the food processing sector are seriously investigating this option.

The use of biomass within a CHP plant (i.e. a gas engine providing heat and electricity) is also very promising from an efficiency point of view. But experiences in Germany have shown that there is not always sufficient heat demand at the location of a plant, especially when animal manure is used as a substrate. As a result, more biogas upgraded to natural gas quality is being fed into the existing natural gas grid. In this way, it is possible to have high efficiency in each location connected to the gas grid.

Additionally, the upgraded biogas can also be used within the transportation sector and it is expected that this option will gain more importance in the coming years.

Geothermal

The world geothermal power market has shown steady growth over the last two decades. Between 2005 and 2009 global installed capacity increased by nearly 1.8 GW, with around 200 MW added last year alone. By the end of 2009 the global cumulative installed capacity exceeded 10.7 GW (see Table 6).

Source: Lahmeyer International, Bertani and Ruggero - Geothermal Power Generation in the World 2005-2010.

The USA remains the dominant player in the global geothermal market with an installed capacity of around 3.1 GW. The Philippines was ranked as the world's second largest generator of geothermal energy with an installed capacity of more than 1.9 GW followed by Indonesia (1.2 GW), Mexico (1.0 GW) and Italy (0.8 GW).

Geothermal energy is not used commercially everywhere in the world because not many countries have favourable geological conditions. However, the further development and application of binary plants from medium enthalpy resources and the possibility of using enhanced geothermal systems (EGS) may extend the commercially-viable exploitation of geothermal resources for electricity generation to countries with less favourable geothermal resources.

The USA

The USA, with an installed capacity of around 3.1 GW, remains the dominant geothermal market. The geothermal fields in California and Nevada have shown the highest potential and between them provide around 97% of the country's installed capacity. Besides these two states, another 100 MW of installed capacity is located in Alaska, Hawaii, Idaho, Nevada, New Mexico, Oregon, Utah and Wyoming. In 2009, five new plants with binary processes were commissioned: Faulkner (50 MW), Stillwater (48 MW) and Salt Wells (24 MW) in Nevada, North Brawley (49 MW) in California and Thermo Hot Spring (10 MW) in Utah. New projects with a total of around 2.4 GW are currently under construction or in the advanced planning stages.

Indonesia

The Indonesian market is strongly supported by the Government through regulation and policies to foster the use of its excellent geothermal resources for electricity generation. In 2009 two new plants were commissioned at Wayang Windu and Lahedong, both with single-flash processes. The second unit of the Wayang Windu plant in West Java is now one of the biggest plants in the world with an installed capacity of 117 MW.

The new unit at Lahedong has an installed capacity of 20 MW. An impressive number of projects are under construction or in the planning stages, supported by the government as well as domestic and foreign investors. Indonesia aims to be the first fully-powered geothermal country in the world by 2015 but to achieve this it needs to triple its present capacity, which is unlikely to happen in five years.

Italy

Larderello in the Tuscany region was the first place on earth where geothermal energy was used to produce electrical energy in the early 20th century, and it is a good example to demonstrate the sustainability of geothermal energy. Over the past five years, new electrical capacity of 100 MW has been built, of which 48 MW replaced old decommissioned units. Additional resources have been detected at a depth of up to 4 km.

Turkey

Turkey has been waiting for its feed-in tariff for over a year but since it is expected that this feed-in tariff will include an increase in tariffs for geothermal energy, there has been a geothermal boom in the country. Several pre-developed areas have been sold by the government through the General Directorate of Mineral Research and Exploration (MTA) and more detailed analyses are starting.

In April 2009, a second project based on double-flash technology was commissioned in Turkey called the Aydin-Germencik power plant, which is located in the Germencik Omerbeyli field. Its capacity is declared to be 47.4 MW and this is only the first step of the project; there are enough resources and space to extend the project to 100 MW in the future.

8 production wells and five injection wells guarantee access to a reservoir with a temperature of up to 232°C. Production wells are drilled to depths of between 1000 m and 2000 m. Some injection wells are even deeper, reaching a depth of around 2400 m.

Germany

Germany's increased feed-in tariff for geothermal electricity production in 2008 has not yet resulted in many new plants. In fact, just one plant was commissioned in 2009, at Bruchsal in the Upper Rhine Valley, which has an installed capacity of 0.55 MW. Several new projects are currently under construction or in the advanced planning stages in the Upper Rhine Valley and Molasse Basin in the Munich region. Nevertheless, even with poor natural geology compared to other countries, Germany has shown that proper feed-in conditions can help overcome weak resources.

Ocean and tidal power

Marine renewable technologies are currently at the transition stage, moving from applied research projects at coastal science research laboratories and prototypes into the demonstration and pre-commercialisation phase. The drivers behind these developments are either small technology venture companies or spin-offs from research initiatives. Given their limited finances, these companies often have to seek funding from governments or venture capital investors. Over the last few years, large players such as Voith Siemens, SGL Carbon, Nordex, REpower, E.ON and RWE have become involved.

SeaGen, the 1.2 MW experimental tidal station near Portaferry in Northern Ireland, exceeded operational 1000 hours last year. This converter is the first marine energy device of megawatt size. Its operator has achieved a capacity factor of 66% and so far has delivered 800 MWh into the transmission grid.

Other device developers such as Atlantis Resources Corporation are also heading – mostly after a considerable period of testing at facilities such as the European Marine Energy Centre (EMEC) in Orkney – into the commercialisation of megawatt-sized turbines. Recent deals and developments show that project developers have a strong focus on horizontal-type turbines with blades directed perpendicular to the stream direction.

A similar development can be observed with wave energy devices; Pelamis Wave Power may settle a deal with a large European utility for supplying next generation devices, although these devices would still need to be tested at EMEC. The ocean energy wave buoy approach has successfully passed the two and half years test stage and now appears to be ready for commercialisation. During demonstrations the devices have been proven to withstand extreme waves.

There is still a wide diversity in different turbine concepts and wave energy converters, which shows that there is a delay in consolidation and commercialisation. Although many projects have successfully shown the feasibility of a particular technology, the developers often face difficulties when it comes to commercialisation and mass deployment.

The most remarkable announcement in the ocean energy sector last year was by the Norwegian utility company Statkraft, which opened the world's first osmotic prototype plant. The plant generates power by exploiting the energy produced by mixing fresh water and seawater. The prototype has mainly been built for testing and development purposes and only has a limited production capacity, with the aim of constructing a commercial osmotic power plant within the next few years.

Conclusion

Despite the world financial crisis, renewable energy markets saw significant growth in 2009. Table 7 shows an overview and comparison of international installed capacities and estimated annual electricity generation for the technologies covered in this article. The figures show that the total cumulated installed capacity of systems using renewable sources of energy was around 1247 GW at the end of 2009.

Around 83 GW of new capacity came on-line in 2009, representing an average growth of 7% on 2008 figures, which is remarkable given the difficult international economic situation. If traditional large hydropower is excluded, the average growth rate, at 26% compared to 2008 cumulated figures, is much higher.

Compared to the total electricity generated in 2009 worldwide (around 20800 TWh/y), estimated renewable annual electricity generation in 2009 (between 3900 and 4100 TWh/y) has a share of between 19 and 23% of total electricity generation. This represents a share of 2.7% of total primary energy demand worldwide (147000 TWh/y).

These estimates are based on data from the International Energy Agency, because no figures from public organisations for worldwide electricity generation and primary energy consumption for 2009 are available. We also assumed that the economic crisis led to a compensation of additional demand increase and therefore overall primary energy consumption and electricity generation dropped worldwide by around 1%.

Traditional hydropower still contributes the largest amount to the above figures, with an 80% share of cumulated installed power capacity and 82% of annual electricity generation. Wind is second, followed by biomass, solar PV and geothermal energy, all in terms of cumulated installed capacity at the end of 2009.

However, in terms of newly installed capacity, wind (38 GW) has surpassed hydropower (31 GW) last year. With more than 7 GW, solar PV also made a significant contribution to newly installed capacity in 2009. Overall, the 2008 trend for new renewable energies (excluding large and small hydropower) overtaking hydropower in terms of newly installed capacity continued apace.

About the authors:

• Dr Andreas Wiese is executive director and shareholding partner of Lahmeyer International GmbH;
• Dr Patric Kleineidam is head of wind energy at Lahmeyer International GmbH;
• Kuno Schallenberg is head of renewable energies at Lahmeyer International GmbH;
• Aike Jan Ulrich is assistant engineer at Lahmeyer International GmbH;
• Prof Martin Kaltschmitt is managing director of Deutsches Biomasseforschungszentrum in Leipzig and head of the Institute of Energy and Process Engineering at the Hamburg University of Technology.

This article first appeared in Renewable Energy Focus, Volume 11, Issue 4, July-August 2010.