Renewable Energy Sources
Renewable energies are sources of energy that renew themselves constantly through natural processes and, seen on a human timescale, will never run out. Renewable energies come from three main primary sources: solar radiation, heat from inner earth, and tidal power. These three energy sources can be used either directly or indirectly, in particular the form of biomass, wind, wave energy, and ambient heat. Renewable energy sources can be converted into electricity, heat, and also fuel.
Renewables already have made a significant impact on energy systems in different countries all over the world and are projected to continue their growth within the energy mix and making an impact on the energy system, energy trade, and energy security (Galkina et al. 2014).
In 2000, new renewable power installations totaled 3.5 GW. Since then, renewable capacity installations have grown almost tenfold, to reach 32 GW in 2011. Moreover, the share of new renewable energy installations has also increased steadily, from 13 to 71 % in 2011; this represents an increase of 58 % (D’Estaintot et al. 2011).
There are several different types of renewable energy sources used for electric- ity generation. Hydro is the world’s main renewable energy source used for elec- tricity generation in 2012, with a 78 % share of the total renewable output (3,633.4 TWh). Wind power climbs into the number two for the first time and has a share of 11.4 % of the total electricity produced in the world (534.3 TWh). The bio- mass sector is number three, with a share of 6.9 % of the world’s total electricity produced in 2012 (326.2 TWh). Solar is number four, with a share of 2.2 % of the world’s total electricity produced in 2012 (104.5 TWh). Geothermal is number five, with a share of 1.5 % of the world’s total electricity produced (70.4 TWh) in 2012. Other types of renewable energy sources occupy the sixth place with a very small share of the world’s total electricity produced in that year (0.54 TWh) (Worldwide Electricity Production from Renewable Energy Sources 2013). It is important to highlight that the world’s electricity generation using renewable energy sources as fuel increased by 1,000 TWh during the period 1999–2009; the annual growth reported was 3.1 %. The major contributor to this increase is hydro- power, with a total electricity generation of 528.7 TWh (52.8 % of the total).
Analyzing the contribution of all renewable energy sources to electricity generation during the period 1999–2009, the following conclusion can be reached: The best performance over the period considered were put in by solar and wind power, with an annual increase of 36 and 28.9 %, respectively.
Undoubtedly, renewable energy is the fastest growing source of generation of electricity in the IEO (2013) report. According to this report, annual increases in the use of renewables for electricity generation are expected to be 2.8 % per year Renewable Energy Sources 11 from 2010 to 2040. In particular, non-hydropower renewable resources are the fastest growing sources of new generation during that period, in both OECD and non-OECD regions. Non-hydropower renewable, which accounted for 4 % of the generation market in 2010, is expected to increase their share of the market to 9 % in 2040, with much of the growth coming from wind and solar generation. Strong growth in offshore wind capacity is underway, with 883 MW added to the grid in 2010, representing a 51 % increase over the amount of capacity added in 2009 (EWEA 2011). In 2013, offshore saw a record growth, adding 1.6 GW new capacities. However, the outlook for 2014 and 2015 is expected to be stable without any new capacity planned to be installed (EWEA 2014).
Finally, it is important to highlight the following: The use of renewable energy sources has been growing significantly over the past years due to a number of benefits, which lie in various dimensions. First of all, from the perspective of energy security, renewable energy sources can provide with the opportunities of the fuel mix diversification, which is most relevant for the economies which are dependent on imports of fossil fuels. Secondly, with increased use of renewable energy sources, economies can decrease their environmental impact (decrease CO2 emissions per unit of GDP and also decrease air pollution). Thirdly, there could be economic considerations behind more active use of renewable energy sources. As noted by the IEA, “the development and deployment of renewables can form part of a comprehensive strategy aimed at more sustainable economic growth (often called “green growth”). Renewable energy has featured strongly in economic recovery packages put in place in response to the global economic downturn”. Fourthly, it is renewable energy sources, which can be one of the most effective tools in solving the problem of energy access. The key findings in the study of the importance of renewable energy sources for electricity generation worldwide are the following:
• Renewable energy sources are becoming more competitive and, therefore, will be used on an increasingly wide scale;
• This dynamic will not be exclusive for the OECD countries, but will have a
• At the same time, due to the fact that renewable energy sources start their take- off from a modest basis, they will only have a limited influence on the shares of hydrocarbons in the energy mix (Galkina et al. 2014).
More than 82 % of the increase in the use of renewable energy sources for electricity generation is in the form of hydroelectric power and wind power. Besides the fact that hydropower currently makes up a substantial share of the total amount of electricity generated, the arguments for continued and increased utilization of hydropower are based on its advantages when compared to other sources of energy. The key positive characteristics of hydroelectricity are a low-cost, effective, and sustainable, and it is the renewable energy resource that can be stored in large quantities and which plays a major role in power system management. However, it should be noted that hydropower projects have also been known for their negative effects concerning environmental and social issues, and for this reason, there is not too much possibilities to increase the participation of hydropower in the energy mix within the whole EU during the coming years.
The share of hydropower within the total electricity generation varies considerably between countries, ranging from negligible to more than 90 %. The com- position of types of hydropower plants installed for energy production is also not equal. These differences in countries and categories reflect both geographic and climatic constraints and suitability as well as, to some degree, political guidelines in operation (Lehner et al. 1998).
Looking at the future, in Eastern Europe and the former Soviet Union, most of the development of hydroelectricity in the short to medium term is expected to occur as expansion or refurbishment of existing hydroelectric plants (EIA 2000), as the persistent economic problems interfere with the construction of new hydropower plants. In East-Central Europe, hydroelectricity already represents a substantial source of power in some countries such as Albania (96 % of total electricity generation), Croatia (59 %), or Romania (37 %). Most of the potential for future hydropower expansion lies in Albania, Bulgaria, and Romania, as well as in the former Yugoslav republics. But despite a very large potential for future expansion, as yet, these countries have found it difficult to secure financing for such projects (EC 2000).
The Nordic European countries generally show good suitability for hydroelectricity production, both from geographic and climatic aspects, and already have high shares of hydropower forming part of their energy supply. However, in the case of Sweden, for example, there is no scheme for building new large hydro- power plants, as proposals for this meet strong public opposition. Only old units are refurbished and some new small units are installed. Consequently, no major additions to the current production capacity are expected during the coming years (UNIPEDE 1998). Also from Norway, only small increases of the cumulative volume of power plants are expected to occur (Lovseth 1995). In Western Europe, most of the region’s hydroelectric resources have already been developed (EIA 2000). In some cases, however (e.g., Italy), there is evidence of some hydropower plants being constructed or planned in the near future (Eurelectric 1997b).
Summing up the following can be stated: Due to political and economic rea- sons, the prediction of the future development of Europe’s hydropower park is dif- ficult. Nevertheless, whatever changes are expected, there is clear agreement that a dismantling of the existing hydropower plants is unlikely, but rather that they will continue to operate and perhaps their number and capacities will be slightly increased in some countries during the coming years.
The contribution of wind energy, in particular, has grown swiftly over the past decade, from 18 GW of net installed capacity at the end of 2000 to 117.3 GW of installed wind energy capacity in the EU in 2013: 110.7 GW onshore and 6.6 GW offshore. The installed wind capacity in 2013 represents an increase of 6.5- fold with respect to 2000. A total of 11,159 MW new wind power capacity (worth between €13 and €18 billion) was installed in the EU-28 during 2013. However, these new capacities compared with the capacities installed in 2012 represent a decrease of 8 %.
Despite to this setback, the EU power sector continues its move away from fuel oil and coal with each technology continuing to decommission more than it installs. The wind power capacity installed by the end of 2013 would, in a normal wind year, produce 257 TWh of electricity, enough to cover 8 % of the EU’s electricity consumption. Of the 4.6 trillion kWh of new renewable generation added over the past years, 1.3 trillion kWh (27 %) corresponds to wind. The slight majority of wind generation growth (58 %) occurs in the OECD.
According to D’Estaintot et al. (2011), Europe maintains the largest amount of cumulative installed wind capacity in the world and remains the second biggest annual market. It is expected that wind power will grow primarily in the form of large wind farms that centrally feed into the transmission grids with 20–30 GW installed power by 2010s. Large offshore wind farm sites, with rated power up to 1,000 MW, are currently under investigation to be installed in the North and in the Baltic Seas.
Within the EU, wind power capacity increases were led by Germany, where 2,086 MW of new capacity was installed during 2011. The UK came in second with 1,293 MWe followed by Spain with 1,050 MW, Italy with 950 MW, France with 830 MW, Sweden with 763 MW, and Romania with 520 MW. Among the emerging Central and Eastern European markets, after Romania, Poland installed the second most capacity in 2011 (436 MW). Both remain among the ten biggest European markets for the second year running.
High construction costs can make the total cost to build and operate renew- able generators, higher than those for conventional power plants, something that is affecting the increased use of renewable energy sources for electricity generation in several countries. The specific characteristics of wind and solar, in particular, can further hinder the economic competitiveness of these energy resources, as they are not operator-controlled and are not necessarily availa- ble when they would be of greatest value to the system. However, improving battery storage technology and dispersing wind and solar generating facilities over wide geographic areas could mitigate many of the problems associated with intermittent energy supply over a longer period. Despite of this limita- tion, several analysts predict that 700 MWe of non-subsidized solar PV power will be built this year globally, with no subsidies required in most parts of the world by 2020.
The EWEA wants to aim for 230 GWe by 2020, including 40 GW of off- shore wind, which would meet 20 % of the region’s electricity demand. If cur- rent growth rates continue, the use of renewable energy sources could meet between 35 % and 40 % of total consumption in Europe by 2020, generating around 1,400 TWh.
The EU remained the main focus of solar PV installation in the world in 2012, but it accounted for only a little over one-half of the global market (about 58 % out of a total of 28.9 GWp), whereas in the previous year, its share was almost three- quarters (of a total of 30 GWp). The EurObserv’ER 2013 report puts newly con- nected capacity in the EU at 16,693 MWp, which is a 24.4 % year-on-year slide. At the end of 2012, the installed capacity to date in the EU was 68,902 MWp. This additional capacity naturally implies an increase in solar PV power output, which rose to 67.1 TWh in 2012 (48 % more than in 2011), which currently covers more than 2 % of EU electricity consumption.
The European market declined in 2012, but showed that the market forecast made for that year was not over-pessimistic. Certain markets stood up well despite offering less attractive tariffs, such as France and Greece, which are close to or have passed the one-GWp mark. The Danish and Dutch markets also took off in 2012, through the success of net metering. This also applied to the Bulgarian mar- ket, even though its growth will not continue through 2013, because of the sharp drop in the feed-in tariff (FiT) (halved on 1 July 2012) and the introduction of taxes on complete power plants. Another source of satisfaction is that yet again, Germany broke its own installation record and clung to its top world slot for one more year. According to the Working Group on Renewable Energy Statistics from the German Environment Ministry, AGEE-Stat, the country set a new installation record, beating 2011s figure of 7,485 MWp by connecting up 7,604 MWp to the grid in 2012. Germany’s on-grid solar PV capacity is now 32,643 MWp.
BSW, the German Solar Industry Association, says that the average purchase price to the final consumer of a roof-mounted solar PV system up to 10 kWp was €1,751 per kWp in the fourth-quarter of 2012 compared to €2,197 per kWp in the fourth-quarter of 2011, a drop of more than 20 % in twelve months. Nonetheless, the country is braced for significant market contraction in 2013 when antidumping measures are implemented against Chinese imports of mod- ules and cells.
The market for solar thermal systems designed to produce hot water and heating is struggling to gain a new lease on life in Europe. The findings of the EurObserv’ER survey show that the market in 2012 contracted for the fourth con- secutive time since 2009. The current estimate for 2012 is about 3,395,420 m2, compared to 3,594,580 m2 in 2011—a year-on-year drop of 5.5 %. The surface area covered by solar thermal collectors in service is about 42.3 million m2 that equates to 29.6 GWth of capacity.
On the other hand, not all EU member states have developed their biofuel markets, and the bulk of EU biofuel production and consumption is dominated by five countries: France, Germany, Italy, Spain, and UK. In 2010, EUROSTAT reported that 1.4 % (177 ktoe) of all EU consumed biofuels was produced from wastes, residues, non-food cellulosic, and lignocellulosic material, although other unofficial statistics indicate approximately 9 %, including recycled cooking oil. Given the high relevance of bioenergy for the EC, there is a strong and urgent need for new and comprehen- sive studies at the national and EU level that fully address, in an integrated manner, the sustainable implementation potential. National-level studies would, at the same time, assist future updates of the NREAPs adopted by each EU member state. These urgently needed new studies at national and EU level should specifically consider:
• All land use sectors and uses of biomass (i.e., energy, food, feed, and material uses) in an integrated manner, taking into account both global and local dynamics;
• All three pillars of sustainability should be covered: (i) environment, (ii) society, and (iii) economy;
• Economic and implementation potentials;
• New and improved data as they become available.
Due to their importance for climate mitigation and energy policy, both EU and national-level bioenergy assessments should be:
• Regularly updated;
• Comparable among each other;
• Interlinked with each other (e.g., EU-level studies could use the results or interim results from national-level studies) (BEE 2011).
Finally, it is important to highlight the following: The net power generation capacities added in the EU-28 in 2013 are shown in Fig. 1.4. According to this figure, wind and solar PV are the two energy sources with the highest increase in new power generation installed capacity in 2013. The role of fossil fuel in the generation of electricity within the EU decreased significantly in that year.
1.6.5 Status of Renewable Energy Technologies: Characteristics and Costs A summary of the status of the different renewable energy technologies, its char- acteristics, and costs is given in Table 1.1.