By Marco Poliafico

This study presents a market analysis of current hybrid, off-grid and demonstration projects. Unless otherwise stated, all of the data is extracted from the CSP Today Global Tracker (updated November 2012) [1]. In total, over 220 CSP plants are recorded in the Global Tracker database. Over 19% (43 plants) of these plants fall within one of the “special” categories (hybrids, demonstration or off-grid). Together they provide approximately 7% (1113.86 MWe) of the overall capacity installed with CSP technology worldwide as shown in figure 1.
 

The 43 projects investigated here are all developed for demonstration, hybridization or for a special purpose other than the sole supply of electricity to the grid (i.e. off-grid plants). They are classified in the following categories:
• Hybrid CSP-Biomass plants,
• Demonstration plants,
• Desalination plants,
• Enhanced Oil Recovery plants,
• Hybrid CSP-gas or ISCC plants (Integrated Solar Combined Cycle),
• Hybrid CSP-coal (solar augmentation) plants, and
• Steam Generation plants.
A more detailed distribution of the categories included is reported in figure 2.

Regardless of the specific category they fall within, most of the projects highlighted in figure 2 apply some form of hybridization. This concept entails the utilisation of two different fuels as a source in the production of the output (electricity). In some cases the mix employed is formed by two renewable sources (e.g. solar energy and biomass) whilst in others sun derived energy is paired with a conventional fuel (e.g. gas or coal).
Leaving aside the technical aspects and issues of this strategy, there are several benefits prompting energy companies and investors to look into this potentially massive market segment. First of all the peak demand in hot countries is usually recorded in summer, exactly when solar energy plants can provide their best contribution [2, 3]. At the same time conventional plants are still the best option to guarantee stability in electricity output and serve the base load. Therefore, a combination of the two is well suited to follow the demand profile.
Hybrid plants can be developed by retrofitting a solar thermal add-on to already existing conventional power stations. In this case the project’s development could take advantage of the infrastructure already in place (such as roads, grid connection and power block), therefore significantly improving the economy of the CSP investment [3]. Similarly, the project risk would decrease by integrating a concentrated solar power plant with a conventional and therefore far more mature technology [2]. Alongside this benefit, if a company already owns the land (because part of the area occupied by the existing facility) there is scope for further time and effort savings during the permitting process [2]. Finally, from the environmental point of view, hybridizing gives the opportunity to augment the energy production whilst not increasing GHG emissions, therefore decreasing the overall carbon factor of the electricity generated (kgCO2-eq/MWe sent to the grid) [2].
CSP has a strong market potential in desalination applications. In this case the main drivers are related to the double effect that increased water demand (as a result of population growth) and the typically growing energy demand (resulting both from increased modernisation and population growth) would have on the consumption of oil and gas. Sea water desalination is a highly energy intensive process and it needs to be guaranteed 24h/7. Under these constraints, the solar resource and stability provided by hybridization and/or thermal storage would make CSP the most suitable option for this market [4, 5, 6, 7]. Finally Enhanced Oil Recovery is a process employed to increase oil extraction and therefore production. The shortage of natural gas and the energy consumption rate of thermal EOR are the main drivers for the employment of CSP technology in this area. It seems there is a huge market potential for this specific application too [8].
Hybridization attracts the interest of a variety of industrial players within the CSP market. An interesting interpolation of the geography of hybrid plants shows that 76% of the countries in the world equipped with CSP technology have developed at least one of these projects. Furthermore, hybrid or demonstration plants represent at least 50% of the number of plants in 48% of those countries. Figure 3 provides the data backing for this argument.

Hybrid CSP plants are widely spread across the globe. The highest numbers are in the USA, Australia (approximately 14% each) and Algeria (just under 12%), followed by China, India and Israel (approximately 7% each). All together these six countries host 60.5% of all the hybrid/demonstration plants as shown in Figure 4. The remaining 39.5% (in number) are distributed throughout 13 other countries including Morocco, Italy, France and Chile amongst others (the full list is provided in appendix A).
There can be a variety of reasons which could explain the particular distribution quoted above. For example the USA has a high level of energy demand associated with relevant dependence on conventional sources alongside strong R&D resources (NREL and EPRI - just to quote two - have carried out important research on CSP hybridization). All the other countries (Algeria, Australia, China, Israel and India) definitely have a lower consumption per capita than the USA. However, they are all heavily dependent on coal and other conventional sources.
For example, coal provides 76%, 65% and 42% of the energy mix respectively in Australia, Israel and India [9, 10, 11]. Likewise natural gas represents 16%, 33% and 7% (countries in the same order as before). Although these numbers refer to 2008 and 2009, it is more than likely that they are still valid now with a high level of approximation. This factor on its own explains the high potential for hybrid plants that could be retrofitted to existing conventional plants to increase their productivity.

Of course, other market or policy factors could also affect the decision to incentivise Hybrid CSP plants. The recent shortage of coal experienced in India could work exactly in this direction, for example [3].
The author of this research further investigated the statistical relationship between the location of a plant and the specific application developed (categories identified in figure 2). Building a bi-dimensional matrix between the 19 countries with hybrid plants and the 7 categories assessed did not identify highly relevant trends (understandably given the very low ratio plants / locations). However, it did highlight some interesting points depicted in figure 5.
For example, the 8 demonstration plants are distributed across 7 Countries. The only place with two of them is France which is not surprising given their strong interest in R&D of CSP technology. Similarly the 17 ISCC plants are located in 11 different countries. Currently Morocco, USA and Israel have 2 projects each, whilst Algeria has 4 of them. The solar augmentation plants are possibly the only ones offering a clear dominant trend. 4 out of the 7 plants included in the database are located in Australia, where indeed the current energy mix alongside the relevant push for Compact Linear Fresnel Reflector (CLFR) technology could work as main drivers for this choice.

However, CSP technology as a whole has strong potential and hybrid or off-grid applications can optimally suit many locations. For this reason several countries are currently introducing solar thermal power plants by developing hybrid projects. This is the case for Brazil, Mexico, Iran and Turkey amongst others [3]. Figure 6 demonstrates this concept by presenting a more detailed version of figure 3.

The lead time for the development of a CSP plant (from planning to real operation) generally varies between 2 and 4 years. Therefore it is interesting to study the current status of the 43 projects investigated in this research presented in figure 7. Approximately 42% of the projects (18 of them) are currently in the planning or development phase. The 10 plants under construction (including the commissioning stage) represent approximately 23.2% of the whole sample whereas almost 34.9% (15 plants) are already in operation. 

A further step of the research in relation to the status of the projects focused on the 3 countries with the highest concentration of hybrid plants, namely Algeria, USA and Australia (as per figure 4). Their 17 plants account for over 39.5% of the total number of hybrid / off-grid power stations.
It is interesting to note that Algeria is the only country where more than 50% of plants are currently within the development stage. For Australia this ratio is inverted, therefore the majority of the projects are already within the construction or even operation phase. Figure 8 displays this aspect of the investigation.
Another way to analyse the current development of hybrid plants is through a bi-dimensional matrix between the status of the projects and the seven different categories. Leaving aside hybrid biomass, desalination and enhanced oil recovery applications (due to the low numbers of these types of plants) as well as the announced, planning and commissioning status (for the same reason), the most recurrent status for the other 29 projects is “in operation” (13 plants, i.e. over 44.8% of them) or “construction” (8 plants, i.e. almost 27.6%). This aspect is represented in figure 9 where the most relevant trends have been displayed. The remaining 8 projects (27.6%) displayed in the graph are in the development phase. Figure 9 does not include the 6 plants in the planning stages (of which 4 are ISCC projects).

The total installed capacity of the 43 (hybrid and off-grid) plants is 1113.86 MWe. Almost 65.6% is provided by ISCC applications and slightly more than 30.8% are projects in development. A more detailed distribution of the capacity of each application and status is shown in figures 10 and 11.

Hybridization or off-grid CSP plants are usually small scale projects. The average installed capacity of the 43 analysed is less than 26 MWe. To better investigate the typical capacity of these energy facilities the author identified 7 different statistical classes (<5, 5 - 9.9, 10 - 24.9, 25 - 49.9, 50 - 74.9, 75 - 99.9 and > 100) and investigated the plants’ distribution amongst them.
The results in figure 12 show that 10 of the projects assessed fall within each of the first two categories (<5 and 5 - 9.9). Conversely the two largest classes (75 - 99.9 and > 100) count for only 3 projects. 

An even more effective visualization of this aspect can be achieved by displaying the cumulative curve of the selected distribution classes. Figure 13 shows that 23.3% of the whole sample belongs to the first class (<5). However summing the number of all the projects with installed capacity < 10 MWe it is possible to group already over 46.5% of them. Further reading of the graph indicates that almost 62.8% of the 43 plants have installed capacity of less than 25 MWe.
Furthermore the market analysis investigated whether or not there was a relationship between the capacity classes identified above and the status of the projects. A bi-dimensional matrix was created by the author and the groups presenting the most relevant data were identified. This analysis showed that over 47.2% of the capacity of hybrid / demonstration / off-grid plants under planning or development is related to projects of less than 75 MWe. The same threshold applies to almost 26.5% of the capacity of power facilities in construction or operation. Around just 11.2% of the capacity under development is linked to plants larger than 75 MWe and the same threshold applies to approximately 15% of plants in construction or operation. The relevant capacity classes are grouped in figure 14 to achieve further clarity.

Finally the market research examined the technologies used for various applications. Figure 15 depicts the distribution of the number of plants and capacity installed for each of the four technologies. 

The last part of the analysis investigated the existence of a relationship between the technology used and other factors such as the location, the size, the status of the project and the application. As previously stated, the low number of plants (43 in total) impeded the identification of relevant patterns.
However, the bi-dimensional matrix between the technologies employed and the application developed contains some prevalent aspects that are highlighted in figure 16. For example parabolic trough systems are employed in over 51% of the 43 projects considered (as shown in figure 15) however this percentage increases to 100% of the biomass - hybrid projects and over 83% of the steam generation ones. Conversely Fresnel technology dominates solar augmentation applications (over 85.7%).
Although not reported in the graph below, the only desalination project employs Fresnel technology. This might be due to the lower cost requirements of this option when compared to others. Tower technology is used in 50% of the demonstration projects, market segment in which Fresnel technology achieves 37.5%.

In conclusion, the current trends show that hybrid and off-grid projects are assuming more and more importance within the overall CSP sector. Not only do they have significant potential for maximising the exploitation of renewable energy sources (hybrid) but also the utilisation of solar energy in tailored applications like desalination.

APPENDIX A - List of Hybrid and Off-Grid Plants

LIST OF REFERENCES

1 VV.AA., 2012. Global Tracker. CSP Today.
2 Robbins, J. (*), 2012. Solar Augmentation as a Path for CSP Growth. Web article on www.power-eng.com, (*) Senior director sales, AREVA Solar.
3 Hashem, H. (*), 2012. India makes a solar hybrid comeback. Web article on http://social.csptoday.com, (*) Freelance journalist.
4 VV.AA., 2012. Masdar Institute looks at solar thermal desal. Web article on http://iwsabudhabi.com.
5 Hashem, H. (*), 2012. CSP secures large portion of Saudi’s solar market. Web article on http://social.csptoday.com, (*) Freelance journalist.
6 VV.AA., 2007. AQUA-CSP - Concentrating Solar Power for Seawater Desalination. Report produced for the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety of Germany by DLR, Germany in collaboration with an international team of experts.
7 VV.AA., 2010. The CSP-DSW Project, An Overview. The Cyprus Institute.
8 Hashem, H. (*), 2012. How feasible is CSP for oil production?. Web article on http://social.csptoday.com, (*) Freelance journalist.
9 Niv, Y. (*), . Renewable Energies, Natural Gas and Israel’s Energy Mix of the Future. Presentation, (*) Commissioner, Electricity Administration, Ministry of National Infrastructures.
10 VV.AA., 2011. Australia’s Electricity Generation Mix 1960-2009. Report by Green Energy Markets for Environment Victoria.
11 VV.AA., 2012. information online. www.eia.gov.