Imperial College London

DrIainStaffell

Faculty of Natural SciencesCentre for Environmental Policy

Senior Lecturer in Sustainable Energy
 
 
 
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Contact

 

+44 (0)20 7594 9570i.staffell

 
 
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Location

 

202Weeks BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
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117 results found

López Prol J, de Llano Paz F, Calvo-Silvosa A, Pfenninger S, Staffell Iet al., 2024, Wind-solar technological, spatial and temporal complementarities in Europe: A portfolio approach, Energy, ISSN: 0360-5442

Climate change and geopolitical risks call for the rapid transformation of electricity systems worldwide, with Europe at the forefront. Wind and solar are the lowest cost, lowest risk, and cleanest energy sources, but their variability poses integration challenges. Combining both technologies and integrating regions with dissimilar generation patterns optimizes the trade-off between maximizing energy output and minimizing its variability, which respectively give the lowest levelized cost and lowest integration cost. We apply the Markowitz mean-variance framework to a rich multi-decade dataset of wind and solar productivity to quantify the potential benefits of spatially integration of renewables across European countries at hourly, daily and monthly timescales. We find that optimal cross-country coordination of wind and solar capacities across Europe's integrated electricity system increases capacity factor by 22% while reducing hourly variability by 26%. We show limited benefits to solar integration due to consistent output profiles across Europe. Greater wind integration yields larger benefits due to the diversity of regional weather patterns. This framework shows the importance of considering renewable projects not in isolation, but as interconnected parts of a pan-continental system. Our results can guide policymakers towards strategic energy plans that reduce system-wide costs of renewable electricity, accelerating the clean energy transition.

Journal article

Xie J, Martin M, Rogelj J, Staffell Iet al., 2023, Distributional labor challenges and opportunities of decarbonizing the US power system, Nature Climate Change, Vol: 13, Pages: 1203-1212, ISSN: 1758-678X

The transition towards a low-carbon power system presents challenges and opportunities to the workforce with important implications for Just Transitions. Studies of thesedistributional labor impacts could benefit from tighter linkages between energy and employment modeling. Here, we couple a power sector optimization model, an employment impact model, and demographic databases to understand state-level job characteristics and societal implications of low-carbon transitions in the US. While decarbonization brings consistent job growth, it heightens the need for human capital investments and supply chainrestructuring. Major fossil fuel-producing states need to prepare for fewer mining jobs under the US Long-Term Strategy, so other opportunities should be created or seized. Lowest-skilled workers will experience more uncertain employment outcomes. Expanding renewable energy could improve opportunities for women in fossil fuel-dependent states, but not enough to disrupt the national gender status quo. This work provides a new quantitative perspective to inform proactive Just Transition policies.

Journal article

Ward KR, Bamisile O, Staffell I, 2023, Time-averaged wind power data hides variability critical to renewables integration, Energy Strategy Reviews, Vol: 50, ISSN: 2211-467X

Most publicly available wind data are aggregated to a temporal resolution of 30 or 60 min. This is adequate for some purposes, such as large-scale wind integration studies. However, the consequent loss of high-frequency power fluctuations from the data can significantly impact analysis on local and regional scales. The importance of this missing variability to the accurate assessment of renewables integration is increasingly being recognised as wind power is considered for energy autarky and local energy systems. Here, we investigate the statistics of the lost variability using two high-temporal-resolution datasets from France and the US. In particular, we focus on the likelihood that minimum and maximum thresholds are exceeded and illustrate the importance of sub-half-hourly variability for assessing sector-coupling applications, such as wind farm – electrolyser systems. We find that using half-hourly averaged turbine data can underestimate the occurrence of zero power by a factor of two. This matters if a wind turbine is coupled to an electrolyser, either directly or with only short-duration storage, because of dynamic operating constraints. The lower output limit means that half-hourly wind output could overestimate the hydrogen production and energy storage capabilities of alkaline electrolysers by up to 70 %.

Journal article

Staffell I, Pfenninger S, Johnson N, 2023, A global model of hourly space heating and cooling demand at multiple spatial scales, NATURE ENERGY, ISSN: 2058-7546

Journal article

Tillotson P, Slade R, Staffell I, Halttunen Ket al., 2023, Deactivating climate activism? The seven strategies oil and gas majors use to counter rising shareholder action, Energy Research and Social Science, Vol: 103, Pages: 1-14, ISSN: 2214-6296

International oil companies (IOCs) are facing mounting pressure to transition towards low-carbon business models in line with the Paris Agreement's goals to limit global warming. Shareholder activism in oil and gas companies has increased rapidly over the past decade but has not yet been widely researched. This study explores company communication strategies within the context of climate and transition-related shareholder activism at IOC annual general meetings (AGMs). We analyse 123 relevant proxy statements produced by ExxonMobil, Chevron, and BP at their AGMs from 2006 to 2022. This yielded 10 distinct categories of resolution request, and seven common themes of communicative strategy deployed by IOCs. IOCs were generally successful at minimising the impact of climate-related and environmental shareholder activism, with most resolutions unsuccessful, and even successful ones having limited impact on company performance. However, recent shareholder revolts reveal the oil and gas (O&G) sector is experiencing more instances of, and more successful, investor pressure to improve environmental performance. Cases of voluntary changes in company policy and behaviour further indicate the potential for shareholder activism to influence low-carbon transitions. Further research of the phenomenon itself to gain greater understanding of IOC response strategies can yield insights into the nature and likelihood of a transition away from fossil fuels in the future.

Journal article

Dubey L, Cooper J, Staffell I, Hawkes A, Balcombe Pet al., 2023, Comparing satellite methane measurements to inventory estimates: a Canadian case study, Atmospheric Environment: X, Vol: 17, Pages: 1-9, ISSN: 2590-1621

Methane emissions from natural gas production are of increasing importance as they threaten efforts to mitigate climate change. Current inventory estimates carry high uncertainties due to difficulties in measuring emission sources across large regions. Satellite measurements of atmospheric methane could provide new understanding of emissions. This paper provides insight into the effectiveness of using satellite data to inform and improve methane inventories for natural gas activities. TROPOMI data are used to quantify methane emissions from natural gas within the Montney basin region of Canada and results are compared with existing inventories. Emissions estimated using TROPOMI data were 2.6 ± 2.2 kt/day which is 7.4 ± 6.4 times the inventory estimates. Pixels (7 by 7 km) that contained gas facilities had on average 11 ppb more methane than the background. 7.4% of pixels containing gas sites displayed consistently high methane levels that were not reflected in the inventory. The satellite data were not sufficiently granular to correlate with inventories on a facility scale. This illustrates the spatial limitations of using satellite data to corroborate bottom-up inventories.

Journal article

Halttunen K, Staffell I, Slade R, 2022, Climate change and the future of the oil industry: perspectives from the front line of the transition, 12th International Sustainability Transitions Conference. Mainstreaming sustainability transitions: From research towards impact

Conference paper

Halttunen K, Slade R, Staffell I, 2022, “We don't want to be the bad guys”: Oil industry's sensemaking of the sustainability transition paradox, Energy Research and Social Science, Vol: 92, Pages: 102800-102800, ISSN: 2214-6296

The operating model of the global oil industry is not compatible with the goals of the Paris Agreement. For the industry, there is a fundamental tension between two competing mandates: the pressure to contribute to the social goal of climate change mitigation, and the need to perform financially and meet obligations to shareholders in activities that directly contribute to climate change. To explore the range of responses to the tension, we interview professionals from large international oil companies who work or have worked in climate related roles. This is novel data from a professional group that has not previously been interviewed in depth about climate change. We develop a framework of six archetypical responses to tension within the oil industry. Examples of strategic responses include accepting the paradox to choose priorities other than climate change mitigation and confronting the paradox to demand changes to the way the oil industry operates. Examples of defensive responses include the transfer of responsibility and projection of tension to other stakeholders. Responses calling for change in the oil industry are the most common among people who have left the industry and the least common for participants from companies headquartered outside of Europe. In a field marked by controversies and value-based debates, a better understanding of the views of people working on the energy transition inside the oil industry provides new insight into the discussion about possible routes to the sustainability transition.

Journal article

Mehlig D, ApSimon H, Staffell I, 2022, Emissions from charging electric vehicles in the UK, Transportation Research Part D: Transport and Environment, Vol: 110, Pages: 1-16, ISSN: 1361-9209

Understanding how to best integrate electric vehicles (EVs) into electricity systems is key to the success of both sectors. We pair national-scale EV charging data with high resolution electricity generation data for the UK to calculate the average and marginal emissions produced through charging EVs. Considering the average generation mix weighted by when charging occurs, a typical Battery EV (BEV) emitted 41 g CO2, 27 mg NOx and 0.7 mg PM2.5 per kilometre in 2019. A static analysis using annual averages underestimates these values by 4 %. The ‘marginal’ emissions from BEV charging are 25 % higher than average emissions for CO2 and NOx, and 50 % lower for PM2.5. Smart charging was found to reduce average CO2 emissions by 10 % when compared to the typically charged vehicle; however, smart charging strategies may increase marginal emissions. Future smart charging strategies should minimise marginal emissions and will require access to 24-hour opportunistic smart charging.

Journal article

Chatenet M, Pollet BG, Dekel DR, Dionigi F, Deseure J, Millet P, Braatz RD, Bazant MZ, Eikerling M, Staffell I, Balcombe P, Shao-Horn Y, Schaefer Het al., 2022, Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments, Chemical Society Reviews, Vol: 51, Pages: 4583-4762, ISSN: 0306-0012

Replacing fossil fuels with energy sources and carriers that are sustainable, environmentally benign, and affordable is amongst the most pressing challenges for future socio-economic development. To that goal, hydrogen is presumed to be the most promising energy carrier. Electrocatalytic water splitting, if driven by green electricity, would provide hydrogen with minimal CO2 footprint. The viability of water electrolysis still hinges on the availability of durable earth-abundant electrocatalyst materials and the overall process efficiency. This review spans from the fundamentals of electrocatalytically initiated water splitting to the very latest scientific findings from university and institutional research, also covering specifications and special features of the current industrial processes and those processes currently being tested in large-scale applications. Recently developed strategies are described for the optimisation and discovery of active and durable materials for electrodes that ever-increasingly harness first-principles calculations and machine learning. In addition, a technoeconomic analysis of water electrolysis is included that allows an assessment of the extent to which a large-scale implementation of water splitting can help to combat climate change. This review article is intended to cross-pollinate and strengthen efforts from fundamental understanding to technical implementation and to improve the ‘junctions’ between the field's physical chemists, materials scientists and engineers, as well as stimulate much-needed exchange among these groups on challenges encountered in the different domains.

Journal article

Bricout A, Slade R, Staffell I, Halttunen Ket al., 2022, From the geopolitics of oil and gas to the geopolitics of the energy transition: Is there a role for European supermajors?, Energy Research and Social Science, Vol: 88, ISSN: 2214-6296

The energy transition is changing the corporate positioning of European international oil companies (IOCs). Developments such as Russia's invasion of Ukraine in 2022 and the gas market volatility of 2021 have brought energy geopolitics to the fore and further complicated the landscape in which these companies operate. By combining data from literature and semi-structured interviews with key experts, this work explores how the influence of the European IOCs on the geopolitics of oil, gas, and renewable energy sources might evolve in the transition. We find that European IOCs continue to have geopolitical influence, but it has been diminished by the rise of national oil companies. If fossil fuels are phased down globally, the reduction in oil activities of these companies is likely to further reduce their geopolitical power. While European IOCs may continue to be active in the gas market, this is unlikely to render them significant geopolitical influence given that they may become common rather than dominant market players. The same is true for the IOCs' role in renewable energy markets, although here European IOCs may seek to gain more influence by becoming significant intermediaries and global experts. As the energy transition progresses, many experts expect the political and market landscape around energy to become more fragmented, reducing the overall geopolitical influence of IOCs. Recent events such as the war in Ukraine do not change the overall conclusions, although it remains to be seen whether they will slow down or speed up the IOCs' involvement in the energy transition.

Journal article

Jansen M, Duffy C, Green T, Staffell Iet al., 2022, Island in the Sea: The prospects and impacts of an offshore wind power hub in the North Sea, Advances in Applied Energy, Vol: 6, Pages: 1-14, ISSN: 2666-7924

Europe's offshore wind capacity is increasing rapidly, with larger turbines installed further from shore. TenneT proposed an innovative concept, the North Sea Wind Power Hub, in which several farms are connected to an artificial island which has interconnection to surrounding countries. This aims to reduce overall costs, but studies have so far evaluated hypothetical designs rather than the specific system operators’ proposal, and focused primarily on construction costs rather than ongoing system-wide impacts. Here we develop a bottom-up capital cost estimate to compare the Power Hub with conventional point-to-point connection for offshore wind farms. We quantify its consequential impacts on regional electricity prices, the value of wind generation, fossil fuel generation and carbon emissions in 2030 using a pan-European electricity market model. We find that the Power Hub is cheaper if more than 10 GW of wind is built, as the avoided cost of multiple converter platforms offsets the cost of building an artificial island. It has profound impacts on electricity markets across Europe, especially in Britain and Ireland if they gain more interconnection to continental Europe. This impacts the economic viability of wind and gas power stations particularly, and saves 10Mt CO2 per year through reduced curtailment.

Journal article

Jansen M, Beiter P, Riepin I, Musgens F, Guajardo-Fajardo VJ, Staffell I, Bulder B, Kitzing Let al., 2022, Policy choices and outcomes for offshore wind auctions globally, Energy Policy, Vol: 167, Pages: 1-17, ISSN: 0301-4215

Offshore wind energy is rapidly expanding, facilitated largely through auctions run by governments. We provide a detailed quantified overview of utilised auction schemes, including geographical spread, volumes, results, and design specifications. Our comprehensive global dataset reveals heterogeneous designs. Although most auction designs provide some form of revenue stabilisation, their specific instrument choices vary and include feed-in tariffs, one-sided and two-sided contracts for difference, mandated power purchase agreements, and mandated renewable energy certificates.We review the schemes used in all eight major offshore wind jurisdictions across Europe, Asia, and North America and evaluate bids in their jurisdictional context. We analyse cost competitiveness, likelihood of timely construction, occurrence of strategic bidding, and identify jurisdictional aspects that might have influenced auction results. We find that auctions are embedded within their respective regulatory and market design context, and are remarkably diverse, though with regional similarities. Auctions in each jurisdiction have evolved and tend to become more exposed to market price risks over time. Less mature markets are more prone to make use of lower-risk designs. Still, some form of revenue stabilisation is employed for all auctioned offshore wind energy farms analysed here, regardless of the specific policy choices. Our data confirm a coincidence of declining costs and growing diffusion of auction regimes.

Journal article

McKenna R, Pfenninger S, Heinrichs H, Schmidt J, Staffell I, Bauer C, Gruber K, Hahmann AN, Jansen M, Klingler M, Landwehr N, Larsen XG, Lilliestam J, Pickering B, Robinius M, Trondle T, Turkovska O, Wehrle S, Weinand JM, Wohland Jet al., 2022, High-resolution large-scale onshore wind energy assessments: A review of potential definitions, methodologies and future research needs (vol 182, pg 659, 2021), RENEWABLE ENERGY, Vol: 190, Pages: 1128-1128, ISSN: 0960-1481

Journal article

Halttunen K, Slade R, Staffell I, 2022, What if we never run out of oil? From certainty of “peak oil” to “peak demand”, Energy Research and Social Science, Vol: 85, Pages: 1-6, ISSN: 2214-6296

The COVID-19 pandemic sent the oil industry into turmoil on a scale not seen since the 1970s. While the sector appears to be recovering, questions remain about the extent to which the pandemic has offered a glimpse into the possible future of the industry. This future is critical to the success of climate change mitigation, which requires significant cuts to the carbon dioxide emissions from using oil for energy. Therefore, it makes sense to consider future scenarios in which global oil demand peaks and then declines alongside scenarios of continued demand growth. This is a significant departure from historical development of oil demand and the dominant discussion of many decades about “peak oil” and the fear of demand outstripping readily available supply. The implications of peaking oil demand would be massive, not only for the oil industry but also for society as whole. There is not enough understanding of what the impacts would be, or how to prepare for them. The research community needs to take a clear-eyed view of potential futures of oil, which includes considering scenarios in which demand goes into long-term decline.

Journal article

McKenna R, Pfenninger S, Heinrichs H, Schmidt J, Staffell I, Bauer C, Gruber K, Hahmann AN, Jansen M, Klingler M, Landwehr N, Larsén XG, Lilliestam J, Pickering B, Robinius M, Tröndle T, Turkovska O, Wehrle S, Weinand JM, Wohland Jet al., 2022, High-resolution large-scale onshore wind energy assessments: A review of potential definitions, methodologies and future research needs, Renewable Energy, Vol: 182, Pages: 659-684, ISSN: 0960-1481

The rapid uptake of renewable energy technologies in recent decades has increased the demand of energy researchers, policymakers and energy planners for reliable data on the spatial distribution of their costs and potentials. For onshore wind energy this has resulted in an active research field devoted to analysing these resources for regions, countries or globally. A particular thread of this research attempts to go beyond purely technical or spatial restrictions and determine the realistic, feasible or actual potential for wind energy. Motivated by these developments, this paper reviews methods and assumptions for analysing geographical, technical, economic and, finally, feasible onshore wind potentials. We address each of these potentials in turn, including aspects related to land eligibility criteria, energy meteorology, and technical developments of wind turbine characteristics such as power density, specific rotor power and spacing aspects. Economic aspects of potential assessments are central to future deployment and are discussed on a turbine and system level covering levelized costs depending on locations, and the system integration costs which are often overlooked in such analyses. Non-technical approaches include scenicness assessments of the landscape, constraints due to regulation or public opposition, expert and stakeholder workshops, willingness to pay/accept elicitations and socioeconomic cost-benefit studies. For each of these different potential estimations, the state of the art is critically discussed, with an attempt to derive best practice recommendations and highlight avenues for future research.

Journal article

Biancardi A, Di Castelnuovo M, Staffell I, 2021, A framework to evaluate how European Transmission System Operators approach innovation, ENERGY POLICY, Vol: 158, ISSN: 0301-4215

Journal article

Green R, Staffell I, 2021, The contribution of taxes, subsidies, and regulations to British electricity decarbonization, Joule, Vol: 5, Pages: 2625-2645, ISSN: 2542-4351

Great Britain’s carbon emissions from electricity generation fell two-thirds between 2012 and 2019, providing an important example for other nations. This rapid transition was driven by a complex interplay of policies and events: subsidized investment in renewable generation, regulation-driven closure of coal power stations, rising carbon prices, and energy efficiency measures. Previous studies ignore the interactions of these simultaneous measures with each other and with exogenous changes to fuel prices and the weather. Here, we use Shapley values—a concept from game theory—to disentangle these and precisely attribute outcomes (changes to CO2 emissions, electricity prices, and fossil fuel consumption) to individual drivers. We find the effectiveness of each driver remained stable despite the broad transformation of the power system. The four main drivers each saved 19–29 MtCO2 per year in 2019, reinforcing the view that there is no “silver bullet” and that a multi-faceted approach to deep decarbonization is essential.

Journal article

Trask A, Wills K, Green T, Staffell I, Auvermann O, Coutellier Q, Muuls M, Hardy J, Morales Rodriguez D, Martin R, Sivakumar A, Pawlak J, Faghih Imani SA, Strbac G, Badesa Bernardo Let al., 2021, Impacts of COVID-19 on the Energy System, Impacts of COVID-19 on the Energy System

This Briefing Paper explores the impactthe COVID-19 pandemic had on the UK’senergy sector over the course of thefirst government-mandated nationallockdown that began on 23 March 2020.Research from several aspects of theIntegrated Development of Low-carbonEnergy Systems (IDLES) programme atImperial College London is presented inone overarching paper. The main aim isto determine what lessons can be learntfrom that lockdown period, given theunique set of challenges it presented inour daily lives and the changes it broughtabout in energy demand, supply, anduse. Valuable insights are gained intohow working-from-home policies,electric vehicles, and low-carbon gridscan be implemented, incentivised, andmanaged effectively.

Report

Ludlow J, Jalil-Vega F, Rivera XS, Garrido RA, Hawkes A, Staffell I, Balcombe Pet al., 2021, Organic waste to energy: Resource potential and barriers to uptake in Chile, SUSTAINABLE PRODUCTION AND CONSUMPTION, Vol: 28, Pages: 1522-1537, ISSN: 2352-5509

Journal article

Balcombe P, Staffell I, Kerdan IG, Speirs JF, Brandon NP, Hawkes ADet al., 2021, How can LNG-fuelled ships meet decarbonisation targets? An environmental and economic analysis, Energy, Vol: 227, Pages: 1-12, ISSN: 0360-5442

International shipping faces strong challenges with new legally binding air quality regulations and a 50% decarbonisation target by 2050. Liquefied natural gas (LNG) is a widely used alternative to liquid fossil fuels, but methane emissions reduce its overall climate benefit. This study utilises new emissions measurements and supply-chain data to conduct a comprehensive environmental life cycle and cost assessment of LNG as a shipping fuel, compared to heavy fuel oil (HFO), marine diesel oil (MDO), methanol and prospective renewable fuels (hydrogen, ammonia, biogas and biomethanol). LNG gives improved air quality impacts, reduced fuel costs and moderate climate benefits compared to liquid fossil fuels, but with large variation across different LNG engine types. Methane slip from some engines is unacceptably high, whereas the best performing LNG engine offers up to 28% reduction in global warming potential when combined with the best-case LNG supply chain. Total methane emissions must be reduced to 0.8–1.6% to ensure climate benefit is realised across all timescales compared to current liquid fuels. However, it is no longer acceptable to merely match incumbent fuels; progress must be made towards decarbonisation targets. With methane emissions reduced to 0.5% of throughput, energy efficiency must increase 35% to meet a 50% decarbonisation target.

Journal article

Auger T, Truby J, Balcombe P, Staffell Iet al., 2021, The future of coal investment, trade, and stranded assets, Joule, Vol: 5, Pages: 1462-1484, ISSN: 2542-4351

Coal is at a crossroads, with divestment and phase-out in the West countered by the surging growth throughout Asia. Global energy scenarios suggest that coal consumption could halve over the next decade, but the business and geopolitical implications of this profound shift remain underexplored. We investigate coal markets to 2040 using a perfect competition techno-economic model. In a well-below-2°C scenario, Europe, North America, and Australia suffer from over-capacity, with one-third of today’s mines becoming stranded assets. New mines are needed to offset retirements, but a new commodity cycle in the 2030s can be avoided. Coal prices decline as only the most competitive mines survive, and trade volumes fall to give more insular national markets. Regions stand to gain or lose tens of billions of dollars per year from reducing import bills or export revenues. Understanding and preparing for these changes could ease the transition away from coal following 150 years of dominance.

Journal article

Halttunen K, Slade R, Staffell I, 2021, The future of the oil industry in a "Well Below 2 Degree" world: a company-level agent-based simulation, Energy, COVID, and Climate Change, 1st IAEE Online Conference, Publisher: IAEE

Conference paper

Johnson NJ, Gross R, Staffell I, 2021, Stabilisation wedges: measuring progress towards transforming the global energy and land use systems, Environmental Research Letters, Vol: 16, ISSN: 1748-9326

15 years ago, Pacala and Socolow argued that global carbon emissions could be stabilised by mid-century using a portfolio of existing mitigation strategies. We assess historic progress for each of their proposed mitigation strategies and convert this into the unit of 'wedges'. We show that the world is on track to achieve 1.5 ± 0.9 wedges relative to seven required to stabilise emissions, or 14 required to achieve net-zero emissions by mid-century. Substantial progress has been made in some domains that are not widely recognised (improving vehicle efficiency and declining vehicle use); yet this is tempered by negligible or even negative progress in many others (particularly tropical tree cover loss in Asia and Africa). By representing global decarbonisation efforts using the conceptually simple unit of wedges, this study helps a broader audience to understand progress to date and engage with the need for much greater effort over the coming decades.

Journal article

Mehlig D, ApSimon H, Staffell I, 2021, The impact of the UK’s COVID-19 lockdowns on energy demand and emissions, Environmental Research Letters, Vol: 16, Pages: 1-9, ISSN: 1748-9326

Around the world, efforts to contain the COVID-19 pandemic have profoundly changed human activity, which may have improved air quality and reduced greenhouse gas emissions. We investigated the impact of the pandemic on energy demand and subsequent emissions from electricity and gas throughout 2020 in the UK. The daily pattern of electricity demand changed in both lockdowns, with weekday demand shifting to that of a typical pre-pandemic weekend. Energy demand in 2020 was modelled to reveal the impact of the weather and the pandemic. The first lockdown reduced demand by 15.6% for electricity and 12.0% for commercial gas, whereas the second lockdown produced reductions less than half. Domestic gas demand did not change during the first lockdown, but increased by 6.1% in the second, likely due to increased domestic heat demand. The changes in demand for gas resulted in little change to overall gas consumption emissions during the pandemic. For electricity, large emission reductions occurred during the two lockdowns: up to 22% for CO2, 47% for NO¬x ¬, and 29% for PM2.5. Yet, the largest CO2 emission reduction for electricity in 2020 (25%) occurred before the pandemic, which happened during a warm and stormy spell with exceptional wind generation. These observations suggest that future similar changes in activity may result in little change for gas demand and emissions. For electricity, emission reductions through changes in energy demand are made possible by the generation mix. To enable further emission reductions in the future, the generation mix should continue to decarbonise. This will yield emission reductions in both times of lowered energy demand, but more importantly, during times of high renewable output.

Journal article

Gholami MB, Poletti S, Staffell I, 2021, Wind, rain, fire and sun: Towards zero carbon electricity for New Zealand, Energy Policy, Vol: 150, Pages: 112109-112109, ISSN: 0301-4215

Journal article

Green R, Staffell I, 2021, The contribution of taxes, subsidies and regulations to British electricity decarbonisation, Publisher: Elsevier

Great Britain’s carbon emissions from electricity generation fell by two-thirds between 2012 and 2019, providing an important example for other nations. This rapid transition was driven by a complex interplay of policies and events: investment in renewable generation, closure of coal power stations, raising carbon prices and energy efficiency measures. Previous studies of the impact of these simultaneous individual measures miss their interactions with each other and with exogenous changes in fuel prices and the weather. Here we use Shapley values, a concept from cooperative game theory, to disentangle these and precisely attribute outcomes (CO2 saved, changes to electricity prices and fossil fuel consumption) to individual drivers. We find the effectiveness of each driver remained stable despite the transformation seen over the 7 years we study. The four main drivers each saved 19–29 MtCO2 per year in 2019, reinforcing the view that there is no ‘silver bullet’, and a multi-faceted approach to deep decarbonisation is essential.

Working paper

Halttunen K, Staffell I, Slade R, Green R, Saint-Drenan Y-M, Jansen Met al., 2020, Global assessment of the merit-order effect and revenue cannibalisation for variable renewable energy, Publisher: Elsevier

The rapid growth of wind and solar power has been a major driver for decarbonisation worldwide. They tend to reduce wholesale electricity prices, both the time-weighted average (the merit‑order effect) and their own output-weighted average (price cannibalisation). Whilst these effects have been widely observed, most previous studies focus on single countries. Here, we compare 37 electricity markets across Europe, North America, Australia and Japan and explore variations between them.Merit-order and cannibalisation effects are observed in nearly all countries studied. However, only in Germany, Spain, Poland, Portugal, Denmark and California can renewable output explain more than 10% of variation in wholesale electricity prices. The global average merit‑order effect is €0.68±€0.54 /MWh per percentage point increase in variable renewable energy penetration, and this falls with higher penetration. Revenues captured by wind farms decrease by 0.23% (€0.16 /MWh) for each percentage point increase of wind penetration and by 1.94% (€0.90 /MWh) for solar PV.

Working paper

Saint-Drenan Y-M, Besseau R, Jansen M, Staffell I, Troccoli A, Dubus L, Schmidt J, Gruber K, Simões SG, Heier Set al., 2020, A parametric model for wind turbine power curves incorporating environmental conditions, Renewable Energy, Vol: 157, Pages: 754-768, ISSN: 0960-1481

A wind turbine’s power curve relates its power production to the wind speed it experiences. The typical shape of a power curve is well known and has been studied extensively. However, power curves of individual turbine models can vary widely from one another. This is due to both the technical features of the turbine (power density, cut-in and cut-out speeds, limits on rotational speed and aerodynamic efficiency), and environmental factors (turbulence intensity, air density, wind shear and wind veer). Data on individual power curves are often proprietary and only available through commercial databases. We therefore develop an open-source model for pitch regulated horizontal axis wind turbine which can generate the power curve of any turbine, adapted to the specific conditions of any site. This can employ one of six parametric models advanced in the literature, and accounts for the eleven variables mentioned above. The model is described, the impact of each technical and environmental feature is examined, and it is then validated against the manufacturer power curves of 91 turbine models. Versions of the model are made available in MATLAB, R and Python code for the community.

Journal article

Jansen M, Staffell I, Kitzing L, Quoilin S, Wiggelinkhuizen E, Bulder B, Riepin I, Muesgens Fet al., 2020, Offshore wind competitiveness in mature markets without subsidy, Nature Energy, Vol: 5, Pages: 614-622, ISSN: 2058-7546

Offshore wind energy development has been driven by government support schemes; however, recent cost reductions raise the prospect of offshore wind power becoming cheaper than conventional power generation. Many countries use auctions to provide financial support; however, differences in auction design make their results difficult to compare. Here, we harmonize the auction results from five countries based on their design features, showing that offshore wind power generation can be considered commercially competitive in mature markets. Between 2015 and 2019, the price paid for power from offshore wind farms across northern Europe fell by 11.9 ± 1.6% per year. The bids received in 2019 translate to an average price of €51 ± 3 MWh−1, and substantially different auction designs have received comparably low bids. The level of subsidy implied by the auction results depends on future power prices; however, projects in Germany and the Netherlands are already subsidy-free, and it appears likely that in 2019 the United Kingdom will have auctioned the world’s first negative-subsidy offshore wind farm.

Journal article

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