So, what do these projects hope to achieve? And what are the chances that the results will impact the broader CSP community?

By Andrew Williams

Advanced Collectors
As a part of the SunShot programme, one of the flagship cost reduction initiatives is 3M's 'Advanced Collectors' project - which is focused on developing a new set of solar collector base technologies for next-generation heliostats used in power tower systems.
According to Dr. Attila Molnar, Product Development Specialist at 3M's Renewable Energy Division, one of the main project objectives is the development of a new set of 'technology elements,' including advanced reflective films, optically accurate reflector panels, low-cost space frames, adaptive optics, and accurate tracking drives.
Other key objectives are to design and build a large format heliostat design with these new elements that is suitable for an 'ultra-high concentrating power tower system,' as well as the installation and field testing of the heliostat design at the National Solar Thermal Test Facility at Sandia National Laboratories.
"We are focusing on heliostat design and cost reduction for power tower CSP systems. This focus is driven by the long range goals of the SunShot program of reducing the LCOE (levelized cost of energy) from CSP to a grid parity level of $0.06/kWhr," explains Molnar.
"Because of the high temperatures that can be obtained with power tower systems, the power block efficiencies can be higher than for most other CSP technologies. At the same time, many of the advancements will be suitable for other solar collection types as well," he adds.

Substantially Reducing Costs
In another project, the Jet Propulsion Laboratory (JPL) is currently developing an 'optimized solar thermal collector structure' based on a lightweight collector structure that it is confident will lower structural costs and simplify the installation process. Amongst other things, the project team is seeking to design and develop a low cost mirror module and accompanying support structure, as well as cheaper drive components and concentrators.
Meanwhile, Vermont-based solar outfit Norwich Technologies is heading up a project to develop an innovative receiver for parabolic trough CSP systems that it hopes will dramatically improve performance while substantially reducing acquisition and operation and maintenance (O&M) costs. In doing so, the project team aim to incorporate 'novel materials and design features' to achieve 'lower cost, higher efficiency, and greater reliability.
Molnar says that the 3M project is also aiming to achieve substantial cost reduction, which he hopes will eventually amount to a 50% reduction in solar-field equipment cost, a 30% reduction in field installation cost and a 15% improvement in optical efficiency over existing heliostat designs with the potential to double solar-flux density.
"These components can be used as open source elements for next-generation solar collector designs. The open source nature of the optical technologies is expected to offer a new design space for CSP system designers and drive down the levelized cost of energy (LCOE) by increasing the performance of the CSP solar field," he says.
"We have already demonstrated that we are able to produce new reflective films that have much higher performance than the current generation. High reflectivity translates to cost reduction by allowing the field size to be reduced for the same flux required at the receiver," he adds.

Future Challenges
Generally speaking, Molnar believes that the CSP industry is currently caught in a technology set that was developed in the early 1980's. His view is that the challenge of cost reduction requires thinking out of the box of the existing paradigms.
"We are attempting to do that in our SunShot program. The $0.06/kWhr SunShot challenge demands that," he says.
Meanwhile, Chuck Kutscher, Principal Engineer and Group Manager - Thermal Systems, Electricity, Resources, and Building Systems Integration at the National Renewable Energy Laboratory (NREL), agrees that the challenge for the industry is to continue to reduce costs and market systems in the near-term.
From his perspective, the cost goals that DOE has developed for the SunShot program are very aggressive and, although he thinks they are not impossible to meet with evolutionary changes to existing technology, he says that there is certainly room for revolutionary or disruptive ideas that new projects can help bring to the industry.
"Of course, it is typical that only a small percentage of completely new ideas will make it into the marketplace. But even those that ultimately fail to achieve commercial viability can spur competition and generate spin-off improvements," he says.
"The bottom line is still economics, however, and the industry will need to continue to reduce its costs," he adds.