Alan C. Brent’s research while affiliated with Victoria University of Wellington and other places

The ‘Just Transition’ has emerged as an overarching concept to question traditional supply- and technology-oriented top-down approaches to energy governance in favour of inclusive approaches that can address legacy injustices alongside socio-economic and environmental impacts of proposed infrastructure development, build on local capacities and deliver co-benefits to communities hosting energy infrastructure, as well as drive domestic innovation. An increasing body of evidence suggests that such an approach can facilitate better integrated planning of energy with other sectors, create openings for innovative approaches to demand-side management, and through better and broader social outcomes, can facilitate popular support from both the right and left, ultimately enabling accelerated clean technology deployment. Here we draw on the findings of this Special Issue alongside existing literature to take stock of the technical, environmental and social challenges and opportunities for Aotearoa New Zealand's energy transition in three areas: electrification and the power system, demand for other energy vectors, and future-focussed decentralised energy solutions. We review key justice and equity issues and opportunities in each of these three areas and identify promising research avenues to support the policy and practice of a just and sustainable energy transition in Aotearoa New Zealand.

Agrivoltaic systems, which integrate solar photovoltaic (PV) arrays with agricultural land, present a promising solution to enhance both energy and food security by facilitating the simultaneous production of energy and food. However, there is a lack of comprehensive research on the operational strategies required for the efficient and profitable operation of grid-connected agrivoltaic systems. To address this gap, this paper introduces a new method for optimizing the dispatch strategy of agrivoltaic systems. This includes strategies for temporal energy arbitrage with the grid and maximizing self-consumption of excess solar PV generation. The effectiveness of the proposed method is demonstrated through numerical simulations using real-world data from an agrivoltaic system in Aotearoa New Zealand, equipped with stationary battery storage. A conceptual model of a battery-supported agrivoltaic system is used as a test case, focusing on optimizing hourly dispatch to enhance energy efficiency, demand management, and economic viability. The study employs linear programming to optimize the storage system's performance, utilizing 24-hour forecasts for electricity prices, local energy production, and demand. The goal is to charge the storage system when electricity prices are low and discharge it as needed to minimize costs. The results from the application of the method to the case study in Aotearoa New Zealand demonstrate its effectiveness, contributing to the broader goals of energy and food security by enhancing the profitability and reliability of grid-connected agrivoltaic systems.

The technologies for offshore wind projects have evolved to larger wind turbines, which provide enhanced efficiency and power generation. Permanent magnet synchronous generators with a direct drive design have enabled these advancements. In recognition of deeper insights into their implications, this paper addresses the need for updated life cycle assessments (LCAs) for offshore wind systems adopting large wind turbines. An LCA for an offshore wind project in Aotearoa New Zealand employing 15‐MW turbines, with a total capacity of 1 GW, was undertaken. Different approaches to model the operation of the offshore wind farm were compared. The results indicate a carbon footprint of between 18.4 and 25.2 gCO2eq/kWh, a greenhouse gas payback time ranging from 2.8 to 3.9 years for avoided combined cycle gas turbines and an energy payback time of up to a year. The outcomes underscore the environmental efficiency of the system and position it as an option ideal for facilitating the energy transition. Notably, the manufacturing of components is the primary contributor to the carbon footprint, highlighting a critical area for targeted environmental mitigation strategies in the life cycles of offshore wind energy systems.

This Chapter presents an innovative modelling framework for advancing integrated metaheuristic-based energy planning optimization, with a focus on resilient, renewable community microgrids. The study brings attention to a critical aspect of long-term sustainable energy system planning by illuminating biases intrinsic to consumer preference-based demand response projections. Central to the framework is the emphasis on market-driven sectoral flexibility procurement, achieved through sealed-bid auctions, thereby optimizing social welfare, improving demand response capacity liquidity, and promoting sectoral stability. To this end, the integration of game theory is highlighted as a means to leverage demand-side flexibility for community-level clean energy projects. Further, navigating the uncertainties stemming from non-dispatchable sources and smart grid interventions, the Chapter advocates for a comprehensive evaluation involving holistic uncertainty-aware models for renewable system planning. In this context, a novel probabilistic investment planning framework is introduced, which incorporates climatological, demand, and price uncertainties within a stochastic microgrid sizing model integrated with demand response solutions. The significance of this framework lies in its capacity to address gaps in uncertainty-aware methodologies and the integration of operational and investment planning. By synergizing intricate modelling with practical implementation considerations, the Chapter establishes a guiding framework that not only enriches scholarly deduction, but also aids practical, sustainable energy decision-making. The efficacy of the approach is substantiated through numerical simulations of a case study in Aotearoa New Zealand, to validate the applicability of the results.

As the world shifts to renewable energy sources to mitigate climate change, virtual power plants (VPPs) have emerged as an innovative solution for integrating distributed renewable generation. This study conducted a comprehensive Life Cycle Assessment (LCA) for a 40 MW VPP in operation in Aotearoa New Zealand, comprising residential solar photovoltaic systems with battery storage. Unlike traditional LCA studies that focus on individual components, this study evaluates the full life cycle impacts of a VPP, offering a holistic view of its environmental implications. Additionally, the study considered electricity fed back to the grid, which avoids grid electricity, or electricity generation from natural gas. The findings reveal an estimated life cycle greenhouse gas (GHG) emissions of 45.3–78.9 gCO 2eq /kWh for the VPP, depending on what the surplus electricity replaces. Notably, avoiding natural gas electricity generation by returning surplus electricity to the grid yields a significant credit of −47.3 gCO 2eq /kWh. The life cycle GHG emissions of the VPP are highly sensitive to PV generation. If the systems are operated at their maximum potential, the overall emissions reduce by 17.6%. Conversely, when operated at minimum potential, the emissions increase by 23.2%. Additionally, uncertainties in the energy demand to manufacture the battery cells can alter GHG emissions from a 6.7% reduction to a 14.3% increase. This study underscores the complexity of evaluating environmental performances of VPPs and fills a gap in the literature by presenting the potential environmental impacts and benefits of VPPs, shedding light on their role in fostering sustainability with the energy transition.