Optimizing Vehicle Fleet and Assignment for Concentrating Solar Power Plant Heliostat Washing

Journal Article · Thu Aug 12 04:00:00 EDT 2021 · IISE Transactions

DOI:https://doi.org/10.1080/24725854.2021.1966858· OSTI ID:1820583

Wales, Jesse G. ^[1]; Zolan, Alexander J. ^[2]; Newmans, Alexandra M. ^[1]; Wagner, Michael J. ^[3]

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1. Colorado School of Mines, Golden, CO (United States)
2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
3. Univ. of Wisconsin, Madison, WI (United States)

Concentrating solar power central-receiver plants use thousands of sun-tracking mirrors, i.e., heliostats, to reflect sunlight to a central receiver, which collects and uses the heat to generate electricity. Over time, soiling reduces the reflectivity of the heliostats and, therefore, the efficiency of the system. Current industry practice sends vehicles to wash heliostats in an ad hoc fashion. We present a mixed-integer nonlinear program that determines wash vehicle fleet size, mix, and assignment of wash crews to heliostats to minimize the sum of (i) the revenues lost due to heliostat soiling, (ii) the costs of hiring wash crews and operating the vehicles, and (iii) the costs of purchasing wash vehicles. We establish conditions for convexity of the objective function, and then propose a decomposition method that enables near-optimal solutions to the wash vehicle fleet sizing and assignment problem on the order of a couple of minutes. Furthermore, these solutions yield hundreds of thousands of dollars in savings per year over current industry practices.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1820583
• Report Number(s): NREL/JA--5700-77919; MainId:31828; UUID:b610252b-ec96-4794-a69b-c75a680f4585; MainAdminID:61786
• Journal Information: IISE Transactions, Journal Name: IISE Transactions Journal Issue: 6 Vol. 54; ISSN 2472-5854
• Publisher: Taylor & Francis
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
concentrating solar power
decomposition
fleet sizing
mixed-integer nonlinear programming
operations and maintenance optimization
vehicle assignment