In recent years, an increasing amount of attention has been paid to cost reduction in the CSP industry.
So, what is the role of existing research companies in reducing costs? Is there any role for start-up companies in this area? And what are the prospects for the large-scale deployment of promising cost-reduction activities?
By Andrew Williams
The costs of delivering energy from CSP technologies can be reduced in several ways, including lowering equipment costs, lowering operation and maintenance costs and improving performance. At the National Renewable Energy Laboratory (NREL) in the US, researchers are currently engaged in a project aimed at reducing parabolic trough technology costs by maintaining high performance whilst developing lower-cost components. As Chuck Kutscher, Principal Engineer - Thermal Systems at NREL explains, the costs of parabolic troughs can be reduced by switching to larger apertures, which decreases the number of expensive evacuated receiver tubes required.
"Going to higher concentration ratios and higher temperatures can increase power-cycle efficiency and reduce storage size. But maintaining optical performance in these improved designs can be a challenge," he says.
NREL is also running a project aimed at lowering the cost of heliostat fields, which represent 40% of the installed cost of a power tower. Here, the work is focused on developing smaller heliostats that require minimum drive torque and that can utilize low-cost drive systems.
"We are also investigating a total field-tracking and calibration system that can aim each heliostat accurately without requiring high self-precision within each heliostat [and] are looking at wireless control to reduce wiring costs," says Kutscher.
Role of Start-Ups
In the quest to reduce CSP costs, a number of promising developments have also come from start-up companies. One such company is Danish outfit LN-CSP, which, in collaboration with several external companies, has developed a 'new and improved' alternative to existing glass reflective CSP mirrors. According to Steen Meldgaard Laursen, Marketing Manager at LN-CSP, the company's CSP-solar panel features a patent pending 'sandwich-like' construction, which does away with the need for a supporting frame.
"It's simple, it's aluminium based, it's cheap and extremely lightweight. It goes with any film and coating as well as receptor tubes. The consequence is that everything related to the LN-CSP solar panel becomes cheaper and easier," says Laursen. In his view, it is 'refreshing and important' that start-ups like LN-CSP are around to 'shake up a conservative industry.'
"[There are] no strings attach to a start-up company. So it can really play around with ideas and solutions," he adds.
Kutscher agrees that there is 'certainly' room for 'revolutionary or disruptive ideas that start-ups can help bring to the industry,' but points out that typically 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.
Looking ahead, Laursen is confident that the LN-CSP technology can lead to cost reduction on a larger scale."Depend[ing] on how you calculate the cost of a turnkey solar panel farm - cost could be reduced by 40-60%. Now that is a lot. We are talking millions of Euros for large farms," he claims.
For him, the key barrier to large-scale deployment of innovative new technology is 'probably the conservativeness in the industry,' where none of the major manufacturers can easily change the design of their solar panels. To overcome these barriers, Laursen believes that start-ups should collaborate with 'the most flexible and modern turnkey providers' and have them 'use new panels like LN-CSP.' "Or you have to support smaller solar panel farms to begin with - to get proof of concept. That is possible [in] many places in Europe, especially in Denmark, where new inventions are welcome. Then you can move to bigger solutions," he adds.
Meanwhile, Kutscher explains that all NREL's research work looks at using CSP technology 'in a way the benefits from economies of scale' - but he stresses that the CSP industry currently faces 'numerous barriers.' "Both PV module and natural gas prices are extremely low right now and make for tough competition. Studies have shown, however, that as the grid-penetration of variable generation renewable technologies such as wind and PV gets larger, the capacity value of that generation is reduced," he says.
However, he also explains that the value of CSP with thermal storage remains steady 'regardless of the level of penetration' and points out that recent studies have shown that the flexibility of CSP systems may actually support additional generation of variable PV.
"The challenge for the industry is to continue to reduce costs and market systems in the near-term. [It] will need to focus on those markets where it provides the greatest value-added versus photovoltaics and where natural gas prices are higher," he says.
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