Concentrated Solar Power: its potential contribution

Concentrated solar thermal power (CSP) sits alongside photovoltaic solar energy electricity generation as a commercially available renewable energy technology capable of harnessing the immense solar resource in Southern Europe, the Middle East and North Africa (the MENA region), and elsewhere.

In concentrated solar power a high-temperature heat source is created by concentrating the sun’s rays to produce electricity in a thermodynamic cycle. This study by the European Academies Science Advisory Council has examined the current status and development challenges of concentrated solar power, and consequently has evaluated the potential contribution of CSP in Europe and the MENA region to 2050, and identified actions that will be required to enable that contribution to be realised.

This report summarises the findings of the study and is intended to inform policy-makers in the European institutions – in particular the European Commission and Parliament – and policy-makers at a national level in Europe and the MENA region.

There are various concentrated solar power technologies with different advantages and disadvantages, and concentrating solar power plants need to be designed to optimally meet local and regional conditions.

Worldwide in 2011, 1.3 GW of CSP were operating and a further 2.3 GW were under construction. Currently, base-load electricity generated by CSP plants located where there are good solar resources costs two to three times that from existing fossil-based technologies without carbon capture and storage.

CSP generation costs are on a par with photovoltaics and offshore wind energy , but are significantly more expensive than onshore wind power.

Provided that commercial deployments of CSP plants continue to grow, and that these deployments are associated with sustained research, development and demonstration programmes, Concentrated solar thermal power generating cost reductions of 50–60% may reasonably be expected over the next 10–15 years.

Allowing for some escalation in fossil fuel prices and incorporation of the costs of CO2 emissions in fossil generation costs (through carbon pricing mechanisms and/or requirements to install carbon capture and storage), it is anticipated that concentrated solar thermal power should become cost competitive with base-load fossil-based generation at some point between 2020 and 2030.

In specific locations with good solar resources this point may be reached earlier. Concentrated solar thermal power plants that incorporate thermal storage and/or supplementary firing offer additional potential benefits beyond the value of the kilowatt-hours that they generate, as they can provide dispatchable power, helping the grid operator to reliably match supply and demand, and maintain grid stability.

The value of this capability is context specific, but increases as the proportion of electricity generated by variable renewable sources such as wind turbines and photovoltaics increases. Concentrated solar thermal power with storage may therefore, in future, offer a cost-effective way of enabling the incorporation of substantial contributions of variable renewable sources in electricity systems.

Environmental impacts of concentrated solar thermal power plants are generally low, and may be expected to further improve compared to fossil-fired technologies over time given the relatively early stage of development of CSP.

While the construction of CSP plants is more material intensive than fossil-fired plants, the required materials are mainly commonly available, and readily recyclable, materials such as steel, concrete and glass. Given the likely positioning of CSP plants in arid areas, their use of water, particularly for cooling, is an issue pointing to the need to improve the performance of air cooling systems.

The solar resource in Southern Europe is such that CSP could provide a useful contribution to achieving Europe’s aim of a zero-carbon electricity system by 2050. Solar resources in the MENA region are even better, and far larger. Once CSP achieves cost parity with fossil fired generation, these resources have the potential to transform the system of electricity generation in Europe and the MENA region.

Around half of the anticipated reductions in concentrated solar thermal power generating costs are expected to come from technology developments, and the other half from economies of scale and volume production. Well-designed incentive schemes will be needed, which refl ect the real, timevarying value of generation so that CSP plants are appropriately designed, and which effectively drive research and development activities.

The total amount of incentive payments that will be needed to achieve cost parity will depend crucially on how quickly costs reduce as installed capacity increases. Incentive schemes need to ensure that cost data are made available so that the learning rate, and its underlying drivers, can be established and monitored, and consequently energy strategies and incentive schemes can be adjusted as appropriate.

Substantial investments will also be needed in transmission infrastructure, including high voltage direct current links between the MENA region and Europe, if substantial quantities of CSP electricity are to be exported from MENA countries to Europe.

The development of CSP in the MENA region is a potentially significant component of initiatives to support low-carbon economic development and political progress in the region as reflected in the Barcelona Process, the Deauville Partnership, etc.

CSP technologies (unlike some other renewable energy technologies) lend themselves to high levels of local-deliverables, well-matched to the capabilities of the workforce and industries in the region.

Given the rapidly increasing demand for electricity in MENA countries, much of the electricity generated by CSP plants in the MENA region over the short to medium timescale may, and should, be expected to be used locally rather than exported to Europe, thus avoiding the construction of fossil-fired capacity in the MENA region.

Financing schemes, and associated political agreements between the EU and MENA countries, will be needed to enable these short to medium timescale developments. Without financial commitment in the order of billions of euros from Europe, renewable energy technologies including CSP are unlikely to develop quickly in the MENA region.

The challenge is to take a co-ordinated approach, simultaneously addressing the different bottlenecks (investment protection, energy policy incentives, research and development (R&D), etc.), and to identify options which lower the barriers to entry for other actors (manufacturers, fi nance companies, etc.).

For this purpose, a transformation process should be defined that addresses the technical, political and socio-economic factors necessary to achieve integration of EU and MENA energy systems and to strengthen the implementation of renewable options in the MENA region. Co-funding and co-financing options for CSP in the MENA region should be developed by the EU at a substantial scale as part of its neighbourhood policy.

Incentive schemes in Europe and MENA countries should refl ect the true value of electricity to the grid, effectively drive R&D, and ensure transparency of cost data. R&D should be funded at EU and national levels to complement commercially funded research.

Funding schemes should ensure that market realities are strong drivers of R&D, and that new technologies can progress rapidly from the laboratory, through pilot and demonstration scales, to commercial application.

Further system-simulation studies should be undertaken to look at interaction effects for different shares of renewable energy sources at EU, MENA and EU–MENA levels of power system integration. Understanding from these studies, together with data on the learning rates of CSP and photovoltaics technologies, should be used to guide the development of the optimal mix to harness solar resources.

Capacity-building initiatives should be put in place to support sustainable growth of the necessary technological skills in the relevant countries and regions. Such initiatives may include developing international networks of universities and industrial companies, and programmes for technology transfer from research to industry.