Hydrogen infrastructure strategic planning using multi-objective optimization

Abstract

Increasingly, hydrogen is being promoted as an alternative energy carrier for a sustainable future. Many argue that its use as a transportation fuel in fuel cell vehicles offers a number of attractive advantages over existing energy sources, especially in terms of well-to-wheel greenhouse gas emissions. Following this interest, several of the leading energy companies, like BP, have started investigating strategies for its introduction. The challenge of developing a future commercial hydrogen economy clearly still remains, though: what are the energy efficient, environmentally benign and cost effective pathways to deliver hydrogen to the consumer? Establishing what these “best” pathways may be is not trivial, given that a large number of technological options exist and are still in development for its manufacturing, storage, distribution and dispensing. Cost, operability, reliability, environmental impacts, safety and social implications are all performance measures that should be considered when assessing the different pathways as viable long-term alternatives. To aid this decision-making process, we present a generic optimization-based model for the strategic long-range investment planning and design of future hydrogen supply chains. By utilizing Mixed Integer Linear Programming (MILP) techniques, the model is capable of identifying optimal investment strategies and integrated supply chain configurations from the many alternatives. Realizing also that multiple performance criteria are of interest, the optimization is conducted in terms of both investment and environmental criteria, with the ultimate outcome being a set of optimal trade-off solutions representing conflicting infrastructure pathways. Since many agree that there is no one single template strategy for investing in a hydrogen infrastructure across the globe, emphasis is placed on developing a generic model such that it can be readily applied to different scenarios, geographical regions and case studies. As such, the model supports BP's strategic hydrogen infrastructure planning using high-level optimization programming, and is coined bpIC-H2. The features and capabilities of the model are illustrated through the application to a case study.

Introduction

Driven by concerns over urban air quality, global warming caused by greenhouse gas (GHG) emissions and energy security, a transition from the current global energy system is receiving serious attention. Increasingly alternative economies are being suggested, whereby the growing energy demand of the future is met with greater efficiency and with more renewable energy sources such as wind, solar and biomass. This implies a gradual shift away from the reliance on conventional hydrocarbon-driven technologies towards more innovative carbon-neutral sustainable ones.

Using hydrogen in fuel cell applications offers a number of advantages over existing fuels and other emerging competitors, especially in the transportation sector. It is a high-quality carbon-free energy carrier, which can achieve improved efficiencies at the point of use with reduced or zero GHG emissions over the entire “well-to-wheel” (WTW) life cycle. These benefits are even further underpinned by the fact that hydrogen can be manufactured from a number of primary energy sources, such as natural gas, coal, biomass and solar energy, contributing towards greater energy security and flexibility. Based on these attributes, a number of long-term strategic initiatives have been undertaken to promote the development of national and regional hydrogen economies [1], [2], [3].

Despite its benefits, the challenge of developing a future hydrogen economy is clear: what are the most energy efficient, least damaging and cost effective pathways to deliver hydrogen to the consumer? For hydrogen to succeed as the fuel of the future, we need technical and commercial breakthroughs not only in vehicle technology but also for the creation of an entirely new fuelling infrastructure. The introduction of any new transportation fuel requires a significant capital investment and long-term commitment while facing high risks of poor short-term returns. It requires a simultaneous delivery of the new fuel at the refuelling stations and introduction of new vehicles on the road, since neither is of any use without the other. Vehicle manufacturers require high density hydrogen refuelling stations before investing in mass production of fuel cell vehicles (FCVs), while energy companies are hesitant to install hydrogen production, distribution and refuelling infrastructures without having the assurance of profitable demand levels.

The challenge is even further complicated when trying to select the optimal delivery pathway, given that a large number of technological options exist for hydrogen delivery. Timing of the investment over the next 10–30 years will also be critical. The transition to a sustainable hydrogen economy is therefore a complex strategic planning problem with considerable economic consequences. It is essential to model these interactions in advance so that the number of options can be reduced to a manageable set for further detailed analysis.