Triple-Mode Grid-Balancing Plants via Biomass Gasification and Reversible Solid-Oxide Cell Stack: Economic Feasibility Evaluation via Plant Capital-Cost Target

Yumeng Zhang,Mar Pérez-Fortes,Chengzhou Li,Jan Van Herle,François Maréchal,Ligang Wang,Yongping Yang,Ningling Wang,Tzu-En Lin,Liqiang Duan

doi:10.3389/fenrg.2021.659154

Abstract

Electricity production and consumption must be balanced for the electrical grid. However, the rapidly growing intermittent power sources are now challenging the supply-demand balance, leading to large flexibility needs for grid management. The plant integrating biomass gasification and reversible solid-oxide cell stacks can be potential means of flexibility, which could flexibly switch among power generation, power storage, and power neutral modes. This paper investigates the economic feasibility of such grid-balancing plants, i.e., plant capital expenditure (CAPEX) target, via a systematic overall decomposition-based methodology for real geographical zones and flexibility-need scenarios. The plant CAPEX target (€/ref-stack) is defined as the maximum affordable investment cost for each reference stack (active cell area 5,120 cm2). The results show that, for a 5-year payback time, 5-year stack lifetime, and 40 €/MWh grid balancing price, the plant concept with 10–100 MWth gasifier has high economic potential with target reaching 17,000 €/ref-stack; however, the plant concept with 100–1,000 MWth gasifier has a limited commercialization potential with the target reaching below 1,000 €/ref-stack due to high biomass supply costs. Considering the sale of chemical product, plant CAPEX target can reach up to 22,000 and 3,000–12,000 €/ref-stack for the plants with 10–100 and 100–1,000 MWth, respectively. The plant CAPEX target is decreased by increasing the total capacities of all plants deployed since more and more capacities will be put into power neutral mode (isolated from the electrical grid) via the coordination of multiple plants. The plant CAPEX target can be further increased by higher grid up/down-regulating price and longer payback years.

Highlights

Sustainable renewable energy sources are urgently required to satisfy the rapidly growing energy demand and limit greenhouse gas emissions
The economic feasibility of the W2G plants is evaluated with the plant capital expenditure (CAPEX) target (e/ref-stack), with an overview given first and a subsequent investigation of the effects of the influential factors
The fast internally circulating fluidized-bed (FICFB)-based W2G plants with typical gasifier size of 10–100 MWth biomass feed with the installed capacity factor x below 8% show high economic-potential, with the plant CAPEX target reaching over 16,000 e/ref-stack

Summary

Introduction

Sustainable renewable energy sources are urgently required to satisfy the rapidly growing energy demand and limit greenhouse gas emissions. The penetration of renewables in the global electricity supply has reached a record of 27% in 2019 and is expected to be 49% in 2030 (IEA, 2020). This rapid growth is largely contributed by wind and solar power (IRE Agency, 2014). The high penetration of the intermittent renewables challenges the electricity market in terms of supply-demand balance, transient and frequency stability, the Transmission System Operators (TSOs) will require large flexibility needs for grid management. A renewable energy penetration of up to 50% can be addressed in Texas by employing a storage capacity of average daily energy demand, which is 15% higher than only employing flexible power generators as reserve (Denholm and Hand, 2011)

Methods

Results

Conclusion