The climate emergency has prompted rapid and intensive research into sustainable, reliable, and affordable energy alternatives. Offshore wind has developed and exceeded all expectations over the last 2 decades and is now a central pillar of the UK and other international strategies to decarbonise energy systems. As the dependence on variable renewable energy resources increases, so does the importance of the necessity to develop energy storage and nonelectric energy vectors to ensure a resilient whole-energy system, also enabling difficult-to-decarbonise applications, e.g. heavy industry, heat, and certain areas of transport. Offshore wind and marine renewables have enormous potential that can never be completely utilised by the electricity system, and so green hydrogen has become a topic of increasing interest. Although numerous offshore and marine technologies are possible, the most appropriate combinations of power generation, materials and supporting structures, electrolysers, and support infrastructure and equipment depend on a wide range of factors, including the potential to maximise the use of local resources. This paper presents a critical review of contemporary offshore engineering tools and methodologies developed over many years for upstream oil and gas (O&G), maritime, and more recently offshore wind and renewable energy applications and examines how these along with recent developments in modelling and digitalisation might provide a platform to optimise green hydrogen offshore infrastructure. The key drivers and characteristics of future offshore green hydrogen systems are considered, and a SWOT (strength, weakness, opportunity, and threat) analysis is provided to aid the discussion of the challenges and opportunities for the offshore green hydrogen production sector.
The maritime industry is a crucial hard-to-abate sector that is expected to depend on high-energy density renewable liquid fuels in the future. Traditionally, decarbonization pathways have been assessed assuming exogenous cost trajectories for renewable liquid fuels based on an exogenous learning curve. While past studies have looked at the impact of endogenizing learning curves for a specific technology utilizing linear approximation, a fully endogenous direct non-linear implementation of learning curves in a detailed sectoral model (maritime industry) that explores dynamics concerning sensitive parameters does not yet exist. Here, we apply an open-source optimization model for decarbonizing the maritime industry and further develop the model by encompassing a nonconvex mixed-integer quadratically constrained programming approach to analyze the impact of endogenized learning curves for renewable fuel costs following an experience curve approach. We find that global greenhouse gas emissions are significantly lower (up to 25% over a 30 year horizon) when utilizing endogenously modeled prices for renewable fuels compared to commonly used exogenous learning frameworks. Furthermore, we find that conventional modeling approaches overestimate the cost of climate mitigation, which can have significant policy implication related to carbon pricing and fuel efficiency requirements. In a broader context, this emphasizes the potential opportunities that can be achieved if policymakers and companies accelerate investments that drive down the costs of renewable technologies efficiently and thus trigger endogenous experience-based learning in real life.
Wind propulsion systems (WPS) for commercial ships can be a key ingredient to achieving the IMO green targets. Most WPS installations will operate in conjunction with propellers and marine engines in a hybrid mode, which will affect their performance. The present paper presents the development of a generic, fast, and easy tool to predict the propeller and engine performance variation, along with the cost, as a function of the wind power installed in two operation conditions: fixed ship speed and constant shaft speed. Specific focus is directed toward showing generic trends and trade-offs that inform economic decision-making. To this end, a key feature of the presented work is the ability to assess the cost–benefit of both controllable pitch propellers and fixed pitch propellers (CPPs and FPPs). This provides advice on when, in terms of WPS installation size, it is worthwhile to install which kind of propeller. CPPs are found to be more suitable for newly built wind-powered ships (>70% wind power), while a conventional FPP is satisfactory for wind-assisted ships (<70% wind power) and retrofitted installations. The results for a 91,373 GT bulk carrier showed that a WPS unloads the propeller and the engine, which leads to an increase in the propulsive efficiency and a detrimental rise of the engine specific fuel oil consumption. However, propeller gains are found to be greater than engine losses, which result in extra savings. Thus, not only does a WPS save fuel and corresponding pollutant emissions, but it also increases the entire propulsive efficiency.
Offshore wind energy production has seen a significant expansion in the past decade and has become one of the most important maritime activities. However, the implications of offshore wind farm expansion for maritime security have, so far, received sparse attention in the literature. In this article we conduct one of the first thorough analyses of the security of offshore wind farms and related installations, such as underwater electricity cables, energy islands, and hydrogen plants.
Offshore wind energy production has seen a significant expansion in recent years. With technologies rapidly improving and prices dropping, it is now one of the key instruments in the green energy transition. The implications of offshore wind farm expansion for maritime security and ocean governance have, so far, received sparse attention in the literature. This article offers one of the first thorough analyses of the security of offshore wind farms and related installations, such as underwater electricity cables, energy islands, and hydrogen plants. The technical vulnerabilities of wind farm systems is reviewed and threats from terrorism, crime and State hostilities, including physical and cyber risk scenarios, are discussed. The expansion of green offshore energy production must keep pace with the changing threat landscape that follows from it. Prospective solutions for the protection of wind farms systems, including surveillance, patrols and self-protection are discussed. The current repertoire of maritime security solutions is in many ways capable of dealing with the threats and risks effectively if adjusted accordingly. The analysis builds important new bridges between debates in energy security and maritime security, as well as the implications of climate change adaption and mitigation for security at sea.
Formålet med denne anden version af dette notat er stadig at få de vigtigste fakta om atomkraft i Danmark på bordet. I første version af notatet lagde vi op til en åben debat og inviterede til kommentarer og input. Dem har vi modtaget mange af. Det vil vi gerne takke for. Vi har brugt de mange kommentarer til at rette, forbedre, tilføje og uddybe, hvorfor vi nu kan fremlægge anden forbedrede og udbyggede udgave af notatet. Vi er selvfølgelig stadig åbne for at modtage kommentarer og inputs frem mod en version 3.
Nogle af de væsentligste ændringer i forhold til version 1 er:
Der er blevet spurgt til detaljerne i vores analyser og modelberegninger, da det for mange kan være svært at forstå, hvordan en fremtidig elforsyning baseret på vedvarende energi kan være stabil. Derfor har vi uddybet modelberegninger fra version 1 af notatet i to appendikser og tilføjet nye modelberegninger, som uddyber analyserne i forhold til det danske energisystems rolle i Europa. Desuden har vi tilføjet et helt afsnit om stabilitet, som forklarer, hvordan stabilitet og forsyningssikkerhed sikres i et vedvarende energisystem såvel som i et atomkraftsystem.
Der har været kritik af vores valg af eksempler på atomkraftværker, når vi har identificeret anlægsomkostninger og byggetider. Derfor har vi tilføjet flere til listen og uddybet diskussionen af hvilke omkostninger og byggetider, der er
relevante og aktuelle i en dansk sammenhæng. Et særskilt kritikpunkt har været valg af ’kapacitetsfaktor’. Kapacitetsfaktoren udtrykker, hvor meget et værk producerer igennem en periode sammenlignet med, hvor meget det maksimalt vil kunne producere, hvis det kørte ved fuld belastning (fuldlast) i hele perioden. Ved en kapacitetsfaktor på 100% vil værket køre fuldlast i hele perioden og ikke have ’udetider’, hvor værket ikke kan benyttes f.eks. ved direkte nedbrud, vedligehold eller regulering af driften for at følge behovsprofiler. Vi er her blevet kritiseret for at vælge 75% for atomkraftværker, og i stedet er der blevet peget på 85% som mere retvisende. Vi er også blevet kritiseret for ikke at indregne en eventuel udnyttelse af overskudsvarmen fra et atomkraftværk til fjernvarme, og der er blevet spurgt til, om vi har alle omkostninger til elnettet med. Som svar på disse kritikpunkter har vi foretaget flere beregninger med forskellige kapacitetsfaktorer for atomkraftværker samt analyser med og uden fjernvarmeudnyttelse. Hermed kan man klart se betydningen af disse valg af forudsætninger.
Kilden for vores valg af 75% er Det Internationale Energiagenturs World Energy Outlook, hvor de forudser, at atomkraft i 2050 i det Europæiske energisystem vil have en kapacitetsfaktor mellem 70% og 80%. 85% er teknisk muligt, men vælges typisk når atomkraft ikke indgår i sammenhæng med et energisystem med vedvarende energi.
For at styrke gyldigheden af vores beregninger har vi desuden tilføjet nye analyser af Danmark i en Europæisk sammenhæng, hvor vores beregningsmodeller både optimerer på investeringer i produktionskapacitet og på transmissionsledninger.
Disse ekstraanalyser ændrer dog ikke på den centrale hovedkonklusion: At et dansk energisystem med atomkraft er dyrere end et med vind og sol, og at atomkraft tager længere tid at opføre end vind- og solanlæg.
Endelig har der blandt nogle været en forvirring om, hvem vi er, og hvad vores faglighed er i forhold til atomkraftdebatten sammenlignet med forskere, som har en mere specialiseret baggrund i kernefysik eller lignende. Vi er en bred sammensætning af ingeniører, fysikere og økonomer. Vores fælles faglighed er koncentreret om energisystemanalyse, og vores forskningsområde er at analysere, hvordan vi på energiområdet bedst og billigst kan gennemføre den grønne omstilling og hurtigst muligt opnå et CO2-neutralt samfund. Vi er således ikke kun specialister i en enkelt teknologi. Vi er først og fremmest specialister i, hvordan teknologierne spiller sammen, så vi kan finde de bedste løsninger og
optimere det samlede energisystem.
Det er vores vurdering, at det netop er den faglighed og de forskningskompetencer, der er brug for, når konsekvenserne af at investere i atomkraft i Danmark skal sammenlignes med ikke at gøre det. Når trafikforhold skal udvikles og optimeres, er det også trafikforskerens kompetence, der efterspørges, og ikke ekspertise i f.eks. forbrændingsmotorteknologien.
Samlet set er rapporten inddelt i fire kapitler, der fokuserer på forskellige pointer. I kapitel 1 sammenlignes omkostningerne ved at producere en enhed (MWh) el fra henholdsvis atomkraft, sol og vind uafhængigt af resten af energisystemet;
Kapitel 2 har et fokus på de samme teknologier, men hvor de er i drift i energisystemet, og dermed kan betydningen af forskelle i produktionsmønstre fra vedvarende energi og atomkraft kvantificeres. Kapitel 3 fokuserer på den del af energisystemanalyserne, der omhandler forsyningssikkerhed og stabilitet. I kapitel 4 diskuterer vi bygge- og planlægningstider på atomkraft.
Hydrogen can be key in the energy system transition. We investigate the role of offshore hydrogen generation in a future integrated energy system. By performing energy system optimisation in a model application of the Northern-central European energy system and the North Sea offshore grid towards 2050, we find that offshore hydrogen generation may likely only play a limited role, and that offshore wind energy has higher value when sent to shore in the form of electricity. Forcing all hydrogen generation offshore would lead to increased energy system costs. Under the assumed scenario conditions, which result in deep decarbonisatiton of the energy system towards 2050, hydrogen generation – both onshore and offshore – follows solar PV generation patterns. Combined with hydrogen storage, this is the most cost-effective solution to satisfy future hydrogen demand. Overall, we find that the role of future offshore hydrogen generation should not simply be derived from minimising costs for the offshore sub-system, but by also considering the economic value that such generation would create for the whole integrated energy system. We find as a no-regret option to enable and promote the integration of offshore wind in onshore energy markets via electrical connections.
Rumor has it that all technologies needed to build energy islands are ready. Wind turbines are spinning in many large offshore parks, while combinations of sand and concrete have given birth to several entirely new islands. However, not all rumors are true. Not only has the Danish parliament mandated the largest ever infrastructure project in the history of our country. The first Danish artificial island built for energy production will also become the world’s largest renewable energy project. On top of the technical and logistical challenges associated with building something of an unprecedented scale and nature come new concerns. The energy islands are an extreme version of the power system we know today, and therefore represent a Mars mission for the energy system. More than once have large infrastructure projects been plagued by delays and significant additional costs. Often such problems have been rooted in overly optimistic planning, limited knowledge regarding the complexity and interdependencies involved, and not giving enough attention to the development phase relative to the construction phase. For many reasons, it is highly desirable for the energy island projects to perform well. Therefore, we have teamed up to map the key challenges and suggest R&D initiatives to address them. Importantly, these initiatives are not intended as an inserted step before construction. Given the urgency in green transition and ending the reliance on fossil fuels, research and construction must be conducted in parallel. A solid foundation for energy islands On the following pages we invite you to delve into the complexity of constructing and operating offshore hubs for renewable energy. As you will hopefully agree, we are by no means saying that it cannot be done. It can. But only if decisions are based on a solid foundation of knowledge.
Nowadays, the coastal communities around the world face challenges related to increasing energy consumption, rising energy costs, enchaining of conventional or non-renewable energy resources, climate change, environmental problems, and so on. Therefore, many countries intend to implement different policies to develop clean energy production. There has been a new paradigm in policy from the utilization of greenhouse gases (GHGs), particularly CO2, toward sustainable energy resources to access a high level of security and reliability. This chapter discusses the new trends of hybrid marine power systems and analyzes various sustainable resources, such as PV, tidal turbines, and wind turbines. In addition, the applications of various battery systems to alleviate the randomness and unpredictable features of green energy resources have been studied. In this regard, the capability of various types of energy storage units, such as electrochemical, electromagnetic, and thermal, are presented. The restrictions and opportunities of combining the various technologies in the ship power systems have been investigated from both economic and environmental perspectives. Finally, the energy management problem of two case studies of sero-emissions ferry boats as a promising way to reduce GHGs is presented.
I Danmark har vi en god og lang tradition for en åben demokratisk debat om vores fremtidige energiforsyning.
Gennem årene har vi udviklet et godt fælles grundlag for, at en sådan debat er baseret på fakta om, hvad de enkelte teknologier kan i dag, samt en konsensus om fremtidige forventninger. Teknologikataloget, som løbende opdateres af Energistyrelsen og Energinet i en dialog med relevant faglig ekspertise, udgør en fælles ramme for denne forståelse.
I den senere tid har der været en debat om, hvorvidt atomkraft kan og bør være en del af den grønne omstilling af Danmarks energiforsyning eller ej. Debatten har indeholdt mange modsatrettede udsagn om blandt andet økonomien i atomkraft og dens evne til at være en del af det samlede fremtidige elsystem.
Det er forståeligt, at en sådan debat opstår i lyset af de nuværende klima- og energiforsyningsudfordringer, men det er en fordel for debatten, at den bliver så faktabaseret som muligt. Målet med vores notat er at bidrage til dette.
Vi har fundet frem, hvad vi kunne af relevante fakta om nyligt etablerede atomkraftværker i Europa samt forventninger til atomkraft i fremtiden baseret på data fra det Internationale Energiagentur. Disse fakta omhandler anlægsomkostninger, levetider, driftsomkostninger og byggetider.
På baggrund af en sådan viden samt tilsvarende data om eksisterende vedvarende energianlæg i Danmark i kombination med Teknologikatalogets forventninger til fremtiden har vi foretaget en direkte sammenligning af omkostningerne ved at producere el fra henholdsvis vind, sol og atomkraft.
Det er imidlertid svært direkte at sammenligne sol, vind og atomkraft. Atomkraft er kendetegnet ved kontinuert produktion i modsætning til den fluktuerende produktion fra vind og sol. Der er en umiddelbar relativ fordel ved kontinuert elproduktion. Men atomkraften har også nogle ulemper, hvad angår radioaktivt affald og sikkerhed. Den fluktuerende produktion fra vind og sol afføder et behov for kapacitet til at balancere systemet, når der ikke er forsyning fra vind og sol. Det kan fx være transmissionsnetskapacitet til at balancere over geografiske afstande, kapacitet i form af gasturbiner, der kan køre på grøn gas fra nettet i sådanne perioder og det kan være behov for kapacitet i form af elektrolyse til brintproduktion, så brinten produceres, når der er mest el i systemet.
For at kvantificere den økonomiske betydning af dette behov for ekstra kapacitet har vi foretaget energisystemanalyser og regnet på et fremtidigt dansk energisystem henholdsvis med og uden atomkraft. På den måde kan vi vurdere, hvordan atomkraft vil kunne påvirke det samlede energisystem og dets omkostninger.
Vi ser gerne en åben debat om de data, som vi fremlægger her. Derfor kalder vi også dette skrift for ’første version’, og er der noget, som skal korrigeres eller suppleres, så gør vi gerne det i en eventuelt revideret version.
Under alle omstændigheder håber vi, at notatet bidrager til at gøre debatten mere faktabaseret og transparent. Det er der brug for.