On June 12th 2015, the Wall Street Journal published an article on Concentrated Solar Power (CSP) with the title “High-tech projects fail to deliver”. In this article, some of the statements appear tendentious, the title and some interpretations are misleading, and some calculations are simply wrong, proving a severe lack of techno-economical background. To avoid wasting time on discussions based solely on findings of the mentioned article, some points need to be put in perspective:
1) Solar-thermal technology (or CSP: Concentrating Solar Power) is not “newfangled”: More than 4,400 MW of installed capacity worldwide are producing clean electricity, with the oldest plants operating for more than 30 years.
2) CSP would not “overtake” the role of Photovoltaics (PV) since the technologies are not competitive, but rather complement each other. The approach of power production is completely different: CSP plants are heat collecting machines, they usually include an energy storage, which allows for reliable, predictable und dispatchable delivery of electricity. Power is produced via all the well-known heavy equipment of conventional power stations. PV plants are light-harvesting, modular, fast reacting electronics. When applied in utility scale, PV plants serve as peaking units, covering the mid-day peak (when the sun is shining), but with zero production after sunset. As PV costs came down in the last years, delivery of PV-electricity during daytime for the consumption of the CSP plants is a thoughtful option (several hybrid plants are under development, one in Chile already under construction). This means, the two technologies should be considered as complementary rather than competitive. In addition, with further deployment of PV the mid-day peak will be reduced very cost effectively, but the evening peaks are still looking for their solution. Here CSP can become the preferred technology, as long as other forms of storage are still more expensive. Considering cost of replacement, thermal storages offer higher longevity than any electrochemical storage (e.g. Li-Ion).
3) In the special case of Ivanpah, there was no storage needed nor asked for. To meet local peaking power demand of the off-takers, PG&E as well as SCE, the CSP plant was planned and built as a “peak shaver”. For several other projects in the Southwest of the USA, BrightSource has added molten-salt storage, due to the demand of utilities for additional measures to meet increasing intermittent power generation from PV.
4) Due to the grid-stabilizing effect of CSP plants, more MW´s of fluctuating renewable energy sources (e.g. wind, PV) can be connected to a given substation.
5) In the article costs are compared in a somewhat misleading manner. Comparing the value of LCOE (levelized cost of electricity) of PV and CSP production on a neutral basis: According to NREL the value of dispatchable power to the electric grid is roughly 4 US$cents/kWh higher than the value of fluctuating power. Taking into account that new CSP projects with storage in South Africa, Chile or Morocco signed PPA´s (power purchase agreements) at app. 10 US$cents/kWh, the price gap between CSP and PV (approximately at 5 to 6 US$cents/kWh) is therefore minimal. It is also fair to assume, that with the same capacity installed, LCOE for CSP would experience a similar cost-degression like the one PV saw in the last years.
6) Correct, long term measurement of weather conditions, especially Direct Normal Irradiation (DNI) with local meteo-stations in combination with historical satellite data is of utmost importance. The measurement data set is used to calculate a so called typical meteorological year (TMY), based on which a solar plant is designed and the corresponding financial model is calculated. But even with a precise extrapolation of these historical data, the calculation remains a prediction. The real annual output of a solar plant can always vary due to natural fluctuation of sunshine, clouds or wind. Blaming a specific CSP plant for underperforming during a single year, month, or week, means not understanding the technology.
7)In Ivanpah, as in every (solar) thermal power plant, a planned ramp up process of power production from the first synchronization until final acceptance of the owner is part of the EPC (Engineering-Procurement-Construction) contract. According to statements of Brightsource the full production of 970,000 MWh per year is only expected after four years. This seems to be very cautious, compared to the usual timeline of 1 to 2 years, but is fully acceptable for a “first of its kind” solar thermal power tower at this scale. Actual production data are given below, showing an impressive improvement between the first three months of the year in the first year of operation and the same period in the second year.
8) The environmental permitting procedures for utility scale PV- and CSP-plants are comparable. A positive “Environmental Impact Assessment” is always pre-condition for approval of a plant. Because many different authorities and interested parties are involved in environmental questions, permitting is a time consuming but essential effort. Due to the low impact of solar plants on the ecosystem, compared to other man-made infrastructure projects, these renewable energy projects are usually permitted without major obligations.
9) “Bird carnage” - one can ask, why the author chose this term? In many natural and anthropogenic environments many birds come to death every year: buildings (980 million birds), train/highways/roads (340 million birds), communication towers (6.8 million birds), and not to forget, the sweet little pet cats (1,400 to 3,700 million birds). Are there any articles around mentioning “bird carnage” in such context? An actual report Ivanpah Avian and Bat Monitoring Plan Annual Report, conducted by HT Harvey and Associates, reassures figures of several hundreds of dead birds, not the tens of thousands that were mentioned in the sensational press. Several measures are being considered to reduce this number further: focusing of heliostats during standby with a concentration of only four suns, sonic and smell deterrence, changing to LED lights. Research is ongoing and delivering promising results to further reduce the already low environmental impact.
10) Contrary to the sources quoted in the article, several others are much more optimistic about the worldwide deployment of CSP plants, e.g. the International Energy Agency (IEA). The IEA Report: Technology Roadmap – Solar thermal electricity (2014 edition) envisions the share of CSP in global power production to reach 11% (1,000 GW) by 2050, thus avoiding 2.1 gigatonnes (Gt) of CO2 annually.
11) According to this IEA report, concentrating solar plants (CSP) could be a key technology for mitigating climate change. In addition, the flexibility of CSP plants would enhance energy security and, by using steam turbines, providing most needed ancillary services to the electric grid for our power supply to stay as stable as it is today. CSP plants can also be equipped with backup from fossil and bio fuels delivering additional heat to the system. Due to the long lead times, deployment of CSP plants would remain slow in the next years, but could increase rapidly after 2020 when their systemic advantages turn the power plants competitive for so called peak and mid-merit. But there is still work to be done, since appropriate regulatory frameworks and well-designed electricity markets will be critical to achieve that goal.
Dr. Henner Gladen is an expert surveyor for new technologies and strategic project development in the environmental sector and renewable energies. He co-founded Solar Millennium AG and was appointed Member of the Executive Board until 2010. Since 2010, as Venture Partner in MAMA AG, he is qualifying innovative technology companies, and supporting these start-up companies as member of their advisory board. Furthermore, he was co-founder of ESTELA, the European Solar Thermal Electricity Association. Apart from that, he is also member of the International Energy Foundation and Member of Germany´s Forum for Future Energies. Within the SUPERGRID-project he works as an Advisor to the Fraunhofer Gesellschaft.