Nature Energy最新文献

The practical application of electrochemical carbon dioxide reduction reaction (CO₂RR) technology remains hindered by poor stability, primarily owing to bicarbonate salt formation at the cathode, which blocks reactant CO₂ mass flow. Here, using operando characterization tools, we tracked the salt formation process and quantified salt precipitation under varying device operational conditions, elucidating a potential mechanism and optimizing anolyte conditions for long-term (>1,000 h) operation CO₂RR to CO under >100 mA cm^–2. Liquid droplets carrying cations and (bi)carbonate ions were observed to migrate from the catalyst/membrane interface towards the backside of the gas diffusion electrode, driven by interfacial gas evolution and CO₂ flow. These droplets eventually dried, forming bicarbonate salt precipitates that blocked the gas flow channels. On the basis of this observation, we applied a hydrophobic parylene coating to the cathode gas flow channel surface, facilitating the removal of the droplets and extending stability from ~100 h to over 500 h under 200 mA cm^–2.

Many groups, including lower-income households and tenants, are often excluded from purchasing solar photovoltaics for their homes. Citizen-financed photovoltaic (CiFi PV) projects are an emerging solution for more inclusive citizen engagement in the energy transition, through the financing of larger-scale solar PV installations. Now, Fabienne Sierro and Yann Blumer from ZHAW School of Management and Law and ETH Zürich present insights from interviews with both project developers of, and participants in, citizen-financed solar PV projects in Switzerland, shedding light on motivations behind participation.

The team conducted semi-structured interviews with 19 citizen participants and 13 CiFi PV project developers involved in seven projects in French- and German-speaking Switzerland to better understand motivations behind participation. The researchers identified 27 motivational factors through a grounded theory approach including four inductive coding cycles. They found motivations to largely fall into categories of: accessibility (with a low threshold for participation and no private PV investment opportunities as drivers), a desire to accelerate the energy transition and address environmental concerns, the perceived positive financial benefits, the local value creation, and a feeling of participation (collective action and belonging), amongst other personal factors. Feedback from interviews with participants highlight a degree of demand for more CiFi PV projects and provides insights on how future project developers may attract citizen investors.

To understand if renewables stabilize or destabilize electricity prices, we simulate European power markets as projected by the National Energy and Climate Plans for 2030 but replicating the historical variability in electricity demand, the prices of fossil fuels and weather. We propose a β-sensitivity metric, defined as the projected increase in the average annual price of electricity when the price of natural gas increases by 1 euro. We show that annual power prices spikes would be more moderate because the β-sensitivity would fall from 1.4 euros to 1 euro. Deployment of solar photovoltaic and wind technologies exceeding 30% of the 2030 target would lower it further, below 0.5 euros. Our framework shows that this stabilization of prices would produce social welfare gains, that is, we find an insurance value of renewables. Because market mechanisms do not internalize this value, we argue that it should be explicitly considered in energy policy decisions.

Electric vehicles are increasingly being adopted in Great Britain and other parts of the world, driven by the perception that they offer a cost-effective alternative to internal combustion engine vehicles while reducing emissions. However, a key element that underpins this perception is the longevity of electric vehicles, which remains relatively under researched. Here we show that although early battery electric vehicles (BEVs) exhibited lower reliability than internal combustion engine vehicles, rapid technological advancements have allowed newer BEVs to achieve comparable lifespans, even under more intensive use. Longevity is also found to be impacted by engine size, location and make of vehicle. We provide parameter estimates for life mileage that can be used to update life cycle assessment and total cost of ownership studies of different vehicle powertrains. Our results also shed light on BEV diffusion patterns, fleet replacement strategies and end-of-life treatment planning, including the increasingly important debate around BEV battery recycling and second-life options.

Biomass is a versatile renewable energy source with applications across the energy system, but it is a limited resource and its usage needs prioritization. We use a sector-coupled European energy system model to explore near-optimal solutions for achieving emissions targets. We find that provision of biogenic carbon has higher value than bioenergy provision. Energy system costs increase by 20% if biomass is excluded at a net-negative (−110%) emissions target and by 14% at a net-zero target. Dispatchable bioelectricity covering ~1% of total electricity generation strengthens supply reliability. Otherwise, it is not crucial in which sector biomass is used, if combined with carbon capture to enable negative emissions and feedstock for e-fuel production. A shortage of renewable electricity or hydrogen supply primarily increases the value of using biomass for fuel production. Results are sensitive to upstream emissions of biomass, carbon sequestration capacity and costs of direct air capture.

Climate action and the energy affordability and security crisis caused by the Ukrainian war have accelerated a shift towards variable renewable electricity generation, such as wind and solar power. These energy sources in turn pose new technical challenges for system operators, who must procure new services to support a renewables-based power system. Here we argue that these services have particular economic characteristics that render their optimal procurement a non-trivial exercise. Drawing on the successful collaboration between economic and technical disciplines in wholesale market design, we propose four areas where future collaboration can prove fruitful for designing and procuring the services necessary for secure system operation at high levels of renewable generation.

Green hydrogen is critical for decarbonizing hard-to-electrify sectors, but it faces high costs and investment risks. Here we define and quantify the green hydrogen ambition and implementation gap, showing that meeting hydrogen expectations will remain challenging despite surging announcements of projects and subsidies. Tracking 190 projects over 3 years, we identify a wide 2023 implementation gap with only 7% of global capacity announcements finished on schedule. In contrast, the 2030 ambition gap towards 1.5 °C scenarios has been gradually closing as the announced project pipeline has nearly tripled to 422 GW within 3 years. However, we estimate that, without carbon pricing, realizing all these projects would require global subsidies of US$1.3 trillion (US$0.8–2.6 trillion range), far exceeding announced subsidies. Given past and future implementation gaps, policymakers must prepare for prolonged green hydrogen scarcity. Policy support needs to secure hydrogen investments, but should focus on applications where hydrogen is indispensable.