The role of storage in the emerging Power-to-X Economy: The case of Hawaiʻi

Highly renewable energy systems for island regions provide opportunities to investigate fully self-sufficient energy-industry systems. New perspectives into the nature of 100% renewable energy systems suggest that a Power-to-X Economy may emerge, as renewable electricity will become the fundamental energy carrier. In systems with high renewable shares, the availability of low-cost storage options is essential to balance high shares of variable renewable electricity, especially of solar PV and wind power. While direct electrification is the most cost-effective and efficient solution, indirect electrification through power-to-X processes is required for those demands that cannot be directly electrified. Using the LUT Energy System Transition Model, energy-industry system transition pathways to 100% renewable energy and the role of storage technologies were investigated for the case of Hawaiʻi comparing cost-optimal routes reaching net-zero emissions by 2040 and 2050 to current government projections. Additionally, e-fuel import scenarios are investigated and compared to self-supply scenarios. By installing 39 GW of solar PV, responsible for 96% of total electricity generation of 32 TWh, the levelised cost of electricity in Hawaiʻi can be reduced to 27.5 €/MWh. Total electricity storage capacities, including stationary batteries, pumped hydro energy storage, and vehicle-to-grid batteries, reach 46 GWhcap in 2050, with total throughput at 7.7% of total electricity demand. Due to the low projected costs of these storage options, they only cost 38% of the LCOE in 2050. These results highlight the importance of storage for the Power-to-X economies of island regions such as Hawaiʻi to achieve high levels of energy independence

On the History and Future of 100% Renewable Energy Systems Research

Research on 100% renewable energy systems is a relatively recent phenomenon. It was initiated in the mid-1970s, catalyzed by skyrocketing oil prices. Since the mid-2000s, it has quickly evolved into a prominent research field encompassing an expansive and growing number of research groups and organizations across the world. The main conclusion of most of these studies is that 100% renewables is feasible worldwide at low cost. Advanced concepts and methods now enable the field to chart realistic as well as cost- or resource-optimized and efficient transition pathways to a future without the use of fossil fuels. Such proposed pathways in turn, have helped spur 100% renewable energy policy targets and actions, leading to more research. In most transition pathways, solar energy and wind power increasingly emerge as the central pillars of a sustainable energy system combined with energy efficiency measures. Cost-optimization modeling and greater resource availability tend to lead to higher solar photovoltaic shares, while emphasis on energy supply diversification tends to point to higher wind power contributions. Recent research has focused on the challenges and opportunities regarding grid congestion, energy storage, sector coupling, electrification of transport and industry implying power-to-X and hydrogen-to-X, and the inclusion of natural and technical carbon dioxide removal (CDR) approaches. The result is a holistic vision of the transition towards a net-negative greenhouse gas emissions economy that can limit global warming to 1.5°C with a clearly defined carbon budget in a sustainable and cost-effective manner based on 100% renewable energy-industry-CDR systems. Initially, the field encountered very strong skepticism. Therefore, this paper also includes a response to major critiques against 100% renewable energy systems, and also discusses the institutional inertia that hampers adoption by the International Energy Agency and the Intergovernmental Panel on Climate Change, as well as possible negative connections to community acceptance and energy justice. We conclude by discussing how this emergent research field can further progress to the benefit of society

On the history and future of 100% renewable energy systems research

Research on 100% renewable energy systems is a relatively recent phenomenon. It was initiated in the mid-1970s, catalyzed by skyrocketing oil prices. Since the mid-2000s, it has quickly evolved into a prominent research field encompassing an expansive and growing number of research groups and organizations across the world. The main conclusion of most of these studies is that 100% renewables is feasible worldwide at low cost. Advanced concepts and methods now enable the field to chart realistic as well as cost- or resource-optimized and efficient transition pathways to a future without the use of fossil fuels. Such proposed pathways in turn, have helped spur 100% renewable energy policy targets and actions, leading to more research. In most transition pathways, solar energy and wind power increasingly emerge as the central pillars of a sustainable energy system combined with energy efficiency measures. Cost-optimization modeling and greater resource availability tend to lead to higher solar photovoltaic shares, while emphasis on energy supply diversification tends to point to higher wind power contributions. Recent research has focused on the challenges and opportunities regarding grid congestion, energy storage, sector coupling, electrification of transport and industry implying power-to-X and hydrogen-to-X, and the inclusion of natural and technical carbon dioxide removal (CDR) approaches. The result is a holistic vision of the transition towards a net-negative greenhouse gas emissions economy that can limit global warming to 1.5˚C with a clearly defined carbon budget in a sustainable and cost-effective manner based on 100% renewable energy-industry-CDR systems. Initially, the field encountered very strong skepticism. Therefore, this paper also includes a response to major critiques against 100% renewable energy systems, and also discusses the institutional inertia that hampers adoption by the International Energy Agency and the Intergovernmental Panel on Climate Change, as well as possible negative connections to community acceptance and energy justice. We conclude by discussing how this emergent research field can further progress to the benefit of society

Visualizing National Electrification Scenarios for Sub-Saharan African Countries

Some 630 million people representing two-thirds of all Africans have no access to electricity, which is identified as a key barrier towards further development. Three main electrification options are considered within our work: grid extensions, mini-grids and solar home systems (SHS). A methodology is applied to all sub-Saharan African countries to identify in high geospatial resolution which electrification option is appropriate taking into account datasets for night light imagery, population distribution and grid infrastructure. Four different scenarios are considered reflecting grid development and electrification constraints due to low population density. The results clearly indicate a dominating role of SHS for achieving a fast electrification of the not supplied people. The share of supplied people by mini-grids is found to be rather low while grid extension serves a large share of the population. The decisive factors for these distinctions are population density and distance to grid. We applied several scenarios and sensitivities to understand the influence of these key parameters. The highest trade-off happens between SHS and grid extension depending on the selected thresholds. Mini-grid deployments remain in the range of 8 to 21%

Energy transition for Japan: Pathways towards a 100% renewable energy system in 2050

Abstract This study presents a novel approach to analysing the Japanese energy system transition from a mostly fossil fuels‐based system as of today, to a sustainable renewable energy‐based system by 2050. This research uses a novel technology‐rich, multi‐regional, multi‐sectoral, and cost‐optimal energy system model for the analysis, describing pathways to achieving the Japanese climate neutrality vision by 2050 based on renewables in the most cost‐effective manner. The energy transition of Japan is analysed for both rapid and delayed defossilisation pathways, impact of demand sensitivity, and benefit of sustainable energy imports in the form of electricity from Russia and China or e‐fuels from countries like Australia. The results show that a self‐sufficient energy system is achievable; however, some sustainable energy imports in the form of electricity and e‐fuels can be beneficial in further reducing overall investments, relieve pressure to develop local renewable resources and improving energy system flexibility. In addition, this research highlights the critical advantage of a fully renewable pathway, sector coupling, and high electrification rates as the most cost‐efficient way of achieving the Japanese climate neutrality vision by 2050. The renewable pathway also delivers an energy system with high levels of efficiency gains through direct and indirect renewable electricity usage