Technoeconomic assessment of solar technologies for the hybridization of industrial process heat systems using deterministic global dynamic optimization

Abstract

The industrial process heat (IPH) sector provides an opportunity to replace terawatts of fossil fuel energy with solar alternatives, such as parabolic trough collectors (PTC) or photovoltaics (PV) with resistive heating and energy storage (ES) for off-peak deployment. PTCs offer significantly higher thermal efficiency, but have stagnated in cost and efficiency improvements over the past decade. In contrast, PVs have seen significant improvements in cost and efficiency. Additionally, the energy generated by PV can be stored electrochemically in batteries. Current optimization-based approaches for design and investment decision making lack guarantees of global optimality that are necessary to ensure the best-possible solutions are obtained for these general nonconvex dynamical models. We present dynamical models for the formal deterministic global optimization-based design and technoeconomic assessment of solar systems to hybridize IPH and reduce natural gas combustion that serve as a general and flexible framework. We compare hybridization strategies of PTC with thermal ES, PV with thermal ES, and PV with battery ES and explore the impacts of natural gas pricing and process scale. For the low- to medium-temperature IPH, PTC with thermal ES is currently at least four times more economically favorable than alternative technologies regardless of location or process scale.