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Prema podacima iz 'IEA Advanced Fuel Cells Technology Collaboration Programme', krajem 2019. godine u svijetu je prometovalo 25 212 vozila na vodikove gorivne članke, pri čemu se većina tih vozila nalazi u Sjedinjenim Američkim Državama, a slijede Kina, Južna Koreja i Japan. Njih 59% nalazi se u Aziji, 32% u Sjevernoj Americi i 9% u Europi. Ukupan broj uključuje osobna i gospodarska vozila, pri čemu su većina osobni automobili (75%), a slijede autobusi (17, 7%) te dostavna vozila i laki kamioni (7, 3%). Europskim tržištem dominiraju osobni automobili iz Njemačke i Francuske s gotovo 50%, dok Velika Britanija, Nizozemska i Norveška imaju po oko 200 osobnih automobila na vodik. Broj svih vozila na pogon vodikom u 2019. godini je porastao za 95% pri čemu je broj osobnih automobila porastao za 69%, dok je ukupan broj punionica vodika povećan na 470, što čini porast od 23%. Analizom broja vozila i punionica vodika u državama s najvećim brojem punionica vodika zaključuje se da je u Koreji, SAD-u i Kini broj automobila po punionici veći od 100, dok je u Japanu taj broj manji od 35. U Europi će u narednim godinama Švicarska biti posebno zanimljiva jer se tamo planira flota od 1600 teških kamiona do 2025. godine. Pogon na vodik uvodi se u sve dijelove prometa, dakle od cestovnog, preko željezničkog i morskog pa sve do zračnog, a vodikove energetske tehnik otišle su toliko daleko da danas postoje i ultralaki gorivni članci i spremnici vodika koji se koriste u zrakoplovima i dronovima. Dakle, vodik i gorivni članci imaju velik, ako ne i ključan potencijal u novoj eri prometa koja slijedi.

This paper deals with the influence of magnetic filed on water electrolysis for green hydrogen production. Experimental setup was design and experimental research conducted. Results of influence of magnetic filed on the energy efficiency of the alkaline electrolyzer is analysed. Average energy efficiency for three cases is calculated and compared. In the first case, water electrolysis was conducted without application of the magnetic field. In the second case, magnetic filed is created with one pair of permanent neodymium magnets and applied on the electrolyzer, while in the third case the same experiment is repeated, but with stronger magnetic filed created by two pairs of neodymium magnets. Each type of the experiment is repeated several times and average values are calculated. Results indicated that magnetic filed is having positive impact on the energy efficiency of the process, and that with application of stronger magnetic field, the increase of energy efficiency is higher.

Do 2050. godine potrebno je osigurati klimatsku neutralnost, što znači da je potrebno potpuno zaustaviti emisije CO2 i drugih stakleničkih plinova u atmosferu. Međutim, sporazumi su jedno, a realizacija drugo. Bogate i razvijene države lakše će pristupiti eliminaciji fosilnih goriva, koja su glavni uzrok emisija stakleničkih plinova. Siromašne države ne mogu se odreći fosilnih goriva jer još nemaju potrebnu razinu ni životnog standarda ni tehnologije, odnosno novca da kupe ili same stvore te potrebne nove tehnologije. Morat će se sklopiti ugovori prema kojima će bogate države pomagati siromašnima da bi smanjenje emisija profunkcioniralo na globalnoj razini. To je ono što se očekuje od COP26. Ključno je ubrzati energetsku tranziciju na obnovljive izvore energije i obnovljivi vodik te provesti sveobuhvatnu dekarbonizaciju transporta i proizvodnje svih vrsta dobara i time pridonijeti izbjegavanju katastrofičnih scenarija. S tim ciljem, ovaj rad donosi pregled trenutnoga stanja vodikovih tehnologija i moguća rješenja za ubrzanje energetske tranzicije., Climate neutrality should be ensured by 2050, which means that it is necessary to completely stop the emissions of CO2 and other GHG into the atmosphere. However, agreements are one thing and realization is another. Rich and developed countries will more easily approach the elimination of fossil fuels, which are the main cause of GHG emissions. Poor countries cannot give up fossil fuels because they do not have the necessary standard of living or technology yet, or the money to buy or create the necessary new technologies themselves. Contracts will have to be made under which rich countries will help the poor to make emissions reductions work globally. This is what is expected from COP26. It is crucial to accelerate the energy transition to renewable energy sources and renewable hydrogen and to carry out comprehensive decarbonization of transport and production of all types of goods and thus contribute to avoiding catastrophic scenarios. With that goal, this work provides an overview of the current state of hydrogen technologies and possible solutions to accelerate the energy transition.

One of the main ways to increase the economic viability of hydrogen technologies, perhaps the biggest obstacle to theirs wider affirmation in the world, is to increase the efficiency of its processes, such as water electrolysis. In this work, the experimental laboratory alkaline electrolyzer was built and tested including and excluding magnetic field between two electrodes. The non-homogeneous magnetic field was created by a pair of neodymium magnets with the magnetic flux on the surface of the magnets of approximately 0, 6 T. Effect of the magnetic field on the liquid electrolyte and consequently gases bubbles motion was observed and analyzed. Energy efficiency with and without application of the magnetic field was compared. The application of the magnetic field inside the experimental set-up showed an increase in hydrogen production energy efficiency by approximately 2%.

The rapid development of hydrogen technology over the last decade is the result of the public comprehending the gravity of environmental pollution and global warming necessitating a drastic reduction of greenhouse gas emissions. Hydrogen technology that has the biggest impact in media is a fuel cell electric vehicle (FCEV), no matter its small segment in the overall hydrogen application. For this reason, amongst the other considerable benefits, FCEVs are ideal promotors of a hydrogen society. For hydrogen to progress further into the vehicles industry and for users to comfortably drive FCEVs, it is imperative to build an adequate infrastructure of hydrogen refuelling stations (HRSs). Ergo, the rapidly growing number of HRSs and worldwide interest in forming hydrogen infrastructure, evident through hydrogen strategies incorporated in the newest national policies, are the key indicators of hydrogen technology development overall. This review brings HRSs infrastructure progress over the last decade, the period of the emerging hydrogen market, as well as estimated trends and future perspectives on the global level.

In this work, the focus is on reducing the need for electricity per mole of hydrogen, and on the investigation of the effect of the magnetic field on green hydrogen production, i.e. hzdrogen production via water electrolysis using solar energy, and current density, depending on the different Lorentz force direction. Energy consumption analyzes will be conducted for different types of porosity of the electrode material. The new design of an electrolyzer is to be constructed without a membrane with the additional introduction of a magnetic (and optical) field, which should ensure higher hydrogen production efficiency. Along with improving the efficiency of hydrogen production processes, processes involving hydrogen transportation need to be addressed. Hydrogen transport is a crucial factor in the costs, emissions, and energy consumption associated with hydrogen routes involving the central production at the production plant. At present, transportation to existing pipelines seems to be the most economical solution for transporting large quantities of hydrogen over long distances. All these would allow a drastic reduction in the cost of mass production of hydrogen, which, along with transportation through existing gas pipelines, would make technology in the price range with today’s conventional fuels/energy sources. This would open opportunities for the industry to become involved in the production of the electrolyzers, which would enable job creation and education of experts in this specialized field of hydrogen technology, which would have a direct impact on the economy.

An integral part of green hydrogen production is the use of renewable energy sources in water electrolysis. This paper deals with analyzing the impact of the magnetic field application on the energy efficiency of the alkaline electrolyzer. The research was done by the conduction of the experimental research. The overall experimental research consists of 12 individual experiments, which can be categorized into two groups. The first set of experiments is done without the application of the magnetic field and the second with the application of the magnetic field. The non-homogeneous magnetic field, created by two pairs of neodymium magnets, was applied to the electrolyzer. The magnetic flux density of the space between magnets is measured and presented in detail, ranging from 0, 38 T in the centre of the field to 0, 63 T at the surface of a magnet. The energy efficiency of the electrolyzer is calculated for a group of 6 experiments without the application of a magnetic field and 6 experiments with the application of a magnetic field. the average efficiencies for each set of experiments are calculated with the overall conclusion that the application of the magnetic field resulted in an increase in hydrogen production energy efficiency by 2, 37%.

Due to the fact that transport is not just one of the highest energy consumer but polluter as well, a large effort has been put on transition to the cleaner mobility in order to reduce harmful emissions. This transition has already begun and currently there are a large number of battery electric vehicles on the roads, but thanks to the competitive development of hydrogen technology, i.e. fuel cell powered vehicles, the situation is significantly changing. Hydrogen is considered as an effective alternative fuel since it can be produced (via water electrolysis using renewable energy sources) and used (in fuel cells) with zero harmful emissions. In addition to the introduction of hydrogen as an alternative fuel a vital issue is the implementation of legislations, both on infrastructure and safety. This work presents a synthesis of regulations and directives that have been adopted so far, as well as future strategies. The aim is to provide the access to the existing methodologies of hydrogen vehicle adoption. In this context, the results of this work provide an overview of countries worldwide as examples of good practice that have already begun with their implementation, with critical review on Croatian current position on this issue.

This work provides an outdoor annual performance evaluation of 960 Wp photovoltaic (PV) power system installed on the roof of Faculty of Mechanical Engineering and Naval Architecture, located in Zagreb, Croatia. Its main purpose is to encourage the use of solar energy based on the obtained results and benefits that it represents towards global aim of reducing greenhouse gases (GHGs) emissions. The system is consisted of 6 PV modules of 160 Wp each, rated at 12.5% efficiency under standard conditions, which are connected to 6 utility-interactive micro inverters of 215 W to convert three phase 230 V AC. Energy performances of these modules mounted in pairs on a fixed, single-axis, and dual-axis solar trackers are compared and analyzed. The experimental data were recorded from January 21st 2016 to January 21st 2017 based on real time observation. In a given period, the solar power plant produced a total of 1.241 MWh of energy with PV panel gains of 378 kWh from fixed installation, 401 kWh from single-axis solar tracker, and 462 kWh from dual-axis solar tracker. The study also analyzed data gathered from the online solar photovoltaic energy calculator, which was used to estimate the monthly irradiance and solar electricity production of a described PV system with equally defined modules tilt and orientation. Assessed yearly energy output is 1.33 MWh of which PV panels on fixed mount, single-axis solar tracker, and dual-axis solar tracker generate 412 kWh, 439 kWh, and 479 kWh electricity. Due to the comparison of estimated parameters to observed experimental results, an insight was given into the accuracy of the predicted performances of potential PV installations.

Proizvodnja električne energije direktnom pretvorbom Sunčeve energije bez popratne emisije ugljikovog dioksida (CO2) bitna je s motrišta sigurnosti opskrbe, ali i s motrišta zaštite okoliša. Osnovne tehnološke komponente u sustavu kojima se danas može riješiti takav zadatak su fotonaponski (F\N) članak, elektrolizator, spremnik vodika, vodikov gorivni članak te voda kao osnovni radni medij. Zbog svega toga u fokusu ove doktorske disertacije nalazi se konstrukcija eksperimentalnog elektrolitičkog članka s otopinom kalijevog hidroksida (KOH) u vodi (alkalna otopina, lužina) kao elektrolitom. U okviru testiranja elektrolizatora snimljena je njegova radna (UI) karakteristika i izračunata iskoristivost koja je u okvirima poznatima iz literature. Uočeno je da se na intenzitet proizvodnje vodika može utjecati promjenom brzine kruženja elektrolita kroz porozne elektrode članka. Osim originalnog dijela ove doktorske disertacije prikazan je i pregled povijesnog razvoja alkalnih elektrolizatora i opisi poznatih tehničkih koncepata njihove izvedbe. U sustavu za proizvodnju vodika elektrolizom vode pomoću Sunčeve energije i fotonaponskog članka (F\NH2 sustav) istraživanja se odnose na eksperimentalno mjerenje i modeliranje F\N članka i elektrolizatora pojedinačno i spregnutih u jedan zajednički sustav. Cilj je poboljšanje iskoristivosti i pojednostavljenje sustava. Istraživanja na F\N članku provode se u svrhu definiranja utjecaja različitih parametara na njegovu UI karakteristiku i putanju točke maksimalne snage (MPP putanja). MPP putanja je putanja točke maksimalne snage u realnim uvjetima promjenljivog globalnog osunčanja. S istim ciljem istražuje se i alkalni elektrolizator također eksperimentalno i numeričkim simulacijama. Iz istraživanih matematičkih modela sustava dobiven je uvid u osnovne parametre potrebne za konstrukciju cijelog sustava, a prvenstveno elektrolizatora. U širem smislu, rezultat istraživanja je i doprinos razvoju metode usklađivanja ova dva sustava (elektrolizator i F\N modul) u jedan sustav koji je jednostavniji, pouzdaniji, jeftiniji i učinkovitiji od sličnih postojećih sustava za proizvodnju vodika bez popratne emisije CO2. A production of electrical energy via direct conversion of Solar energy with zero carbon dioxide (CO2) emission is essential from the aspect of energy supply security as well as from the aspect of environmental protection. That task can be solved by basic technological components of the system such as the photovoltaic (PV) cell, an elektrolyser, a hydrogen storage, a hydrogen fuel cell and water as the main operating fluid. For all that, the focus of this doctoral disertation is a design of the experimental electrolytic cell with potassium hydroxide (KOH) solution (alkaline solution, alkali) as the electrolyte. Within electrolyser testing it was recorded its operating (UI) characteristic with calculated efficiency which is in the known literature ranges. It was observed that intensity of the production and utilization of hydrogen can be affected by changing the electrolyte velocity through the porous electrodes of the electrolytic cell. Apart of the original section of this doctoral disertation it is also given a review of the historical development of alkaline electrolysers and descriptions of the known technical concepts of designs. The investigations of the system for hydrogen production via water electrolysis using Solar energy and photovoltaic cell (PVH2 system) are related to the experimental measurements and modeling of the PV cell and an electrolyser each separately then as the coupled system. The goal lies in the increasing of the system efficiency and its simplification. Performed experiments of the PV cell define the parameters effect on its UI characteristic and on a maximum power point trajectory (MPP trajectory). MPP trajectory is the trajectory of the maximum power point in the real conditions of the intermittent global insolation. Furthermore, an alkaline electrolyser is characterized experimentally and mathematically with the same goal. The basic parameters needed for the system design, particularly for an electrolyser, are obtained from the final mathematical model of the system. From the broader point, the result of the research is a method development for the adjusting of these two systems (an electrolyser and PV module) in one system which is much simple, more reliable, cheaper and more effective in comparison to the similar existing systems for hydrogen production without CO2 emission.

The European Union aims to be climate-neutral by 2050, i.e., an economy with net-zero greenhouse gas emissions. This goal is compliant with European Green Deal and the European Union’s commitment to global climate action under the Paris Agreement. Hydrogen is seen as an important part of the solution to achieve this goal, but the positive impact of hydrogen on the mitigation of greenhouse gas emission relies heavily on the type of technology used to produce it. Methane pyrolysis is the thermal decomposition of natural gas into hydrogen and solid carbon. It produces CO2-free hydrogen, also known as turquoise hydrogen. Methane pyrolysis technologies fall into three categories: thermal, catalytic, and plasma decomposition. The technical challenges in the development of methane pyrolysis technology include the high energetic requirements and the separation of solid carbon in the reactor. This thesis provides a comprehensive overview of methane pyrolysis technologies currently under development. At the moment, plasma methane pyrolysis is the most advanced technology. Monolith Materials has been operating an industrial scale thermal plasma plant since 2020. The other technologies mentioned are still under development and are intended for pilot projects. For every tonne of hydrogen produced, three tonnes of solid carbon are also produced as a byproduct. Depending on the technology, methane pyrolysis can produce different types of solid carbon products, such as carbon black, carbon nanotubes, carbon nanofibers, graphite, graphene, etc. In this thesis, different types of carbon products that could be produced by methane pyrolysis are described in detail, especially their properties, most common present uses and possible future uses. The focus is on carbon black, as this is the largest and oldest market. However, if methane pyrolysis is carried out on an industrial scale, large amounts of solid carbon will be produced, and new markets for carbon products have to be found., Europska unija namjerava postići klimatsku neutralnost do 2050. godine, odnosno postati gospodarstvo s nultim neto emisijama stakleničkih plinova. Ovaj cilj je u skladu s Europskim zelenim planom i predanošću Europske Unije globalnoj klimatskoj akciji prema Pariškom sporazumu. Vodik se smatra značajnim dijelom rješenja za postizanje ovoga cilja, ali pozitivan učinak vodika na smanjenje stakleničkih plinova uvelike ovisi o vrsti tehnologije koja se koristi za njegovu proizvodnju. Piroliza metana je toplinsko cijepanje prirodnoga plina na vodik i čvrsti ugljik. Navedeni proces proizvodi vodik bez emisija ugljikovog dioksida koji je poznat i kao tirkizni vodik. Tehnologije pirolize metana se mogu podijeliti u tri kategorije: toplinska, katalitička i plazma piroliza. Izazovi za razvoj tehnologije pirolize metana uključuju visoke energetske zahtjeve i odvajanje čvrstog ugljika u reaktoru. Ovaj rad daje sveobuhvatan pregled tehnologija pirolize metana danas. Trenutno je plazma piroliza metana najnaprednija tehnologija (do danas je jedino kompanija Monolith Materials 2020. stavila u pogon termalno plazma postrojenje industrijskog razmjera). Ostale tehnologije su u razvoju s planovima za pilot projekte. Tijekom plazma pirolize na svaku proizvedenu tonu vodika, kao nusproizvod, proizvedu se i tri tone čvrstog ugljika. Ovisno o vrsti tehnologiji koja se koristi, pirolizom metana moguće je dobiti različite vrste čvrstog ugljika kao što su industrijska čađa, ugljikove nano-cijevi, ugljikova nano-vlakna, grafit, grafen, itd. Ovaj diplomski rad također detaljno opisuje različite vrste čvrstog ugljika koji bi se potencijalno mogli proizvesti pirolizom metana, točnije njihove značajke, najčešće uporabe danas i potencijalne buduće uporabe. Naglasak je stavljen na industrijsku čađu jer je to najveće i najstarije tržište. S obzirom da implementacija pirolize metana na industrijskoj razini ima za posljedicu proizvodnju velikih količina čvrstog ugljika, potrebno je pronaći nova tržišta za te proizvode.

Proizvodnja vodika putem obnovljivih izvora energije predstavlja ključan iskorak u ostvarivanju ciljeva vodikove ekonomije i uspješnog implementiranja vodika kao alternativnog goriva budućnosti. Njegova učinkovita proizvodnja je nužna kako bi mogao konkurirati tržištu fosilnih goriva, kojima ističe „ rok trajnosti“. Jedan od mogućih, učinkovitih načina proizvodnje vodika je elektroliza vode PEM elektrolizatorom. U uvodnom dijelu ovog rada dan je kratak opis procesa elektrolize te su prikazani osnovni termodinamički zakoni kojima se opisuju promjene stanja reakcijskih tvari u procesu elektrolize. Dan je kraći uvod u elektrokemiju, gdje se opisuju fizikalni procesi na mikro razini unutar elektrokemijske reakcije i pojašnjava se utjecaj tih procesa na potrebnu aktivacijsku energiju za uspješno odvijanje kemijske reakcije. U trećem poglavlju opisana je konstrukcija elektrolizatora, potrebne komponente i njihove karakteristike kao i cjelokupni sustav kojim se omogućava rad elektrolizatora i pravilna pohrana produkata. Nadalje, za elektrolizator zadan zadatkom izveden je matematički model kojim se nastoji što bolje opisati i predvidjeti ponašanje sustava i njegovih izlaznih parametara. Dan je kratak osvrt na neke od uvedenih pretpostavki u cilju pojednostavljenja proračuna i njihov utjecaj na proračun. U petom poglavlju je modelirano jedno od mogućih konstrukcijskih rješenja elektrolizatora, sa tehničkom dokumentacijom i prikazanim 3D modelom izrađenom u softverskom paketu Solidworks. Konačno, za projektirani elektrolizator izrađena je simulacija u softverskom paketu Matlab kojom se, uz zadane parametre, izračunavaju i dijagramski prikazuju željeni izlazni parametri te se ti dobiveni rezultati uspoređuju sa podacima elektrolizatora danih od strane nekoliko proizvođača. Utilizing renewable energy sources for hydrogen production represents a key step forward in achieving the goals of the hydrogen economy and the successful implementation of hydrogen as an alternative fuel for the future. Its efficient production is necessary in order to be able to compete with the fossil fuel market, whose reserves are slowly running out. One possible, efficient way to produce hydrogen is with water electrolysis using a PEM electrolyzer. In the introductory part of this paper, a brief description of the electrolysis process is given and the basic thermodynamic laws are described, which we use to define changes in the state of substances in the electrolysis process. A brief introduction to electrochemistry is given, where physical micro processes within the electrochemical reaction are described as is their influence on the required activation energy for the successful conduct of a chemical reaction. The third chapter describes the design of the electrolyzer, the necessary components and their characteristics, as well as the entire system needed for a proper electrolyzer operation and storing of products, hydrogen and oxygen. Furthermore, for the given electrolyzer, a mathematical model was derived whose purpose is to better describe and predict the behavior of the system and its output parameters. A brief overview of some of the assumptions introduced is given in order to simplify the model. The influence of some of these assumptions on the overall error in the mathematical model is also described. In the fifth chapter, one of the possible designs of the electrolyzer is modeled, with technical drawings and a 3D model made in the Solidworks software package. Finally, a simulation was made for the designed electrolyzer in the Matlab software package, which, with given parameters, is used to calculate and plot the desired output parameters and compare these results with the data obtained from several manufacturers.

Danas se uz sve veći broj instaliranih elektrana na obnovljive izvore energije (OIE) javlja problem njihove intermitentnosti. Također, svakodnevno smo svjedoci klimatskim promjenama koje uzrokuju mnoštvo elementarnih nepogoda. Rezultat toga je sve češći pad elektroenergetske mreže koji se danas osigurava uglavnom starim, bučnim i zagađujućim dizel agregatima. Slijedom toga cilj ovog diplomskog rada bio je projektirati energetski „back-up“ sustav temeljen na zelenom vodiku kojim se osigurava konstantno opterećenje sustava od 2 kW 48 sati nakon ispada iz glavne mreže. Taj sustav se sastoji od fotonaponskih modula, PEM elektrolizatora, elektrokemijskog kompresora, PEM svežnja gorivnih članaka te spremnika vodika. Nakon što je detaljno opisan svaki od dijelova sustava, dani su matematički modeli za svaki dio sustava. Pomoću matematičkih modela napravljene su simulacije za svaki dio sustava u MATLAB/Simulink Software-u. Isto je napravljeno za cijeli sustav zajedno gdje su uz referetnu simulaciju napravljene dvije dodatne regulacije samog sustava te tri moguća scenarija. Uvidom u dobivene rezultate simulacije odabrane su tržišno raspoložive komponente energetske jezgre sustava. Za navedene komponente sustava napravljen je koncept eksperimentalne staze te smještaj istih u Laboratoriju za energetska postrojenja Fakulteta strojarstva i brodogradnje (FSB) u Zagrebu gdje se očekuje eksperimentalna validacija samih simulacija. Nowadays, due to the growing number of installed power plants based on renewable energy sources (RES), there is a problem with their intermittency. Climate change is increasing the frequency and severity of natural disasters globally. The result is an increasingly frequent breakdown of the electricity network, which today is secured mainly by old, noisy, and polluting diesel generators. Consequently, this thesis aimed to design an energy "back-up" system based on green hydrogen which ensures a constant system load of 2 kW 48 hours after the breakdown of the electricity network. This system consists of photovoltaic (PV) modules, a PEM electrolyzer, an electrochemical compressor, a PEM fuel cell stack, and a hydrogen tank. After each of the parts of the system is described in detail, mathematical models for each part of the system are given. Using mathematical models, simulations were made for each part of the system in MATLAB/Simulink Software. The same was done for the entire system where, in addition to the reference simulation, two additional regulations of the system and three possible scenarios were made. Insight into the obtained simulation results, the commercially available components of the energy core of the system were selected. For these components of the system, an experimental path was envisaged and their placement in the Power Engineering Laboratory of the Faculty of Mechanical engineering and Naval Architecture (FSB) in Zagreb, where experimental validation of the simulations is expected.

U ovom je radu provedena ekonomska analiza integracije fotonaponskog (FN) sustava priključenog na mrežu instaliranoga na obiteljskoj kući u Zagrebu. U prvom dijelu rada prikazan je značaj sunca kao izvora energije i njegov potencijal. Također, opisana je teorijska osnova rada FN članaka i sustava. U drugom dijelu rada prikazana uobičajena godišnja potrošnja analiziranog kućanstva, zatim je u PVGIS servisu analizirana ozračenost na lokaciji kuće, te je izračunata snaga sunčane elektrane potrebna da pokrije godišnju potrošnju električne energije kućanstva. Sukladno potrebnoj snazi sunčane elektrane dimenzionirane su komponente sustava. Odabrani su FN moduli i izmjenjivač te je izračunata ukupna cijena postavljanja sunčane elektrane sa svim komponentama uključujući i nosače, naknadu za priključenje i okvirnu cijenu montaže. Nakon toga provedene su dvije analize isplativosti projekta. U prvoj analizi razmatran je postupak u kojemu se 30% proizvedene električne energije odmah potroši za zadovoljavanje potrošnje kućanstva, dok se višak prodaje u mrežu. U drugoj analizi razmatran je postupak neto mjerenja u kojemu se višak proizvedene električne energije prividno pohranjuje u mrežu te se iskorištava u vrijeme kada FN moduli ne mogu pokriti potrošnju električne energije kućanstva. Na samom kraju prikazan je zakonski postupak koji je potrebno proći kako bi se instalirala sunčana elektrana. In this work it was presented an economic analysis of the installation of the photovoltaic (PV) system installed the roof of the family house in Zagreb. In the first part of the work, the Sun is presented as an energy source and its potential is analyzed. Furthermore, the theoretical basis of PV cells and systems was explained. In the second part it was analyzed the yearly electric consumption of a given household, then in PVGIS service it was calculated solar irradiance as well as the power of the solar power plant needed to meet the yearly demands of a given household. According to the required power of the solar power plant, the components of the system were chosen. The PV modules and inverter have been selected, and the price of the whole system was calculated including parts needed for installation as well as the installation itself. After that, two cost-effectiveness analysis were conducted. In the first analysis, it was taken that 30% of the generated electrical energy is used for self-consumption while the rest is sold to the grid. In the second analysis it was used net metering. Meaning that the surplus of generated energy is stored in the grid and that electricity is used when PV system cannot meet household demands. In the end, there are listed all legal requirements one must meet in order to install a solar power plant.

Korištenje fosilnih goriva uzrokuje emisije ugljikovog dioksida (CO2) koje dovode do klimatskih promjena i zagađenja okoliša. Kao alternativa fosilnim gorivima nameću se obnovljivi izvori energije (OIE) sa svojim velikim potencijalom, no zbog njihove intermitentnosti u sustave s OIE uvode se spremnici energije. U tome važnu ulogu dobiva vodik i tehnologije koje se bave njegovom proizvodnjom, pohranom, distrubucijom i iskorištavanjem. U ovom završnom radu opisan je osnovni princip procesa elektrolize za proizvodnju vodika, te termodinamike koja se odvija tijekom samog procesa. Naglasak je na elektrolizatoru s protonski izmjenjivom membranom (PEM), čije su komponente prikazane i opisane u ovom radu, kao i način pokretanja i rada cijelog sustava Ispitan je rad PEM elektrolizatora u realnim laboratorijskim uvjetima, pri različitim parametrima, te su rezultati uspoređeni s podacima navedenim u tehničkoj specifikaciji proizvođača. Climate changes and pollution caused by emission of carbon dioxide (CO2), are the consequences of using fossil fuels. Alternative to fossil fuels could be renewable energy sources (RES) with its great potential. Because of its intermittency, in the RES based systems energy storage is needed. This is where hydrogen and technologies of its production, storage, distribution and usage have an important role. This thesis describes the basic principle of process of electrolysis for hydrogen production, and the thermodynamics that is taking place in this process. The accent is on proton exchange membrane (PEM) electrolyzer, whose components are shown and described. It is also described how to start and operate the whole system. The operating of PEM electrolyzer is tested in real laboratory conditions and compared to the values in technical specifications given by electrolyzer manufacturer.

U ovom radu razrađen je autonomni sustav za proizvodnju i pohranu električne energije. Sunčeva energija se fotonaponskim (FN) modulima pretvara u električnu energiju koja se dalje koristi za pokrivanje potreba trošila. Kada proizvodnja električne energije nadmašuje potrošnju, višak se koristi za pretvorbu preko elektrolizatora u plinoviti vodik, koji se komprimira i pohranjuje u spremnik. U vrijeme nedovoljne proizvodnje električne energije iz FN modula, aktiviraju se gorivni članci koji troše pohranjeni vodik i time stvaraju električnu energiju za pokrivanje potrošnje. U sklopu zadatka izvršilo se odgovarajuće dimenzioniranje sustava. Ponašanje cijelog sustava se simuliralo u računalnom programu MATLAB/Simulink. Simulacija se vršila za dva reprezentativna dana, jedan u lipnju, jedan u prosincu, kako bi se provjerili modeli i utvrdili rasponi snaga u kojem se sustav mora kretati. Nakon dimenzioniranja sustava napravila se analiza troška komponenti sustava. Model i simulacija mogu poslužiti kao koristan alat za dimenzioniranje budućih autonomnih sustava s drukčijim parametrima.

Vodik je jedan od glavnih rješenja za pohranu električne energije, te je izvrstan link prema obnovljivim izvorima energije (OIE). Električna energija pohranjuje se u vodik na način da se vodik proizvede elektrolizom vode korištenjem OIE. Takav proces u potpunosti je bez popratnih štetnih emisija. U ovom radu naglasak je upravo stavljen na istraživanje značajki laboratorijski izvedenog svežnja elektrolizatora kojega čine tri članka. Prema tipu elektrolita to je alkalni elektrolizator, a prema tipu konstrukcije to je elektrolizator bipolarne izvedbe. Mjerenja su se provodila unutar Laboratorija za energetska postrojenja pri čemu se električna energija potrebna za pogon elektrolizatora dobivala iz laboratorijskog izvora istosmjerne struje. Eksperimentalnim ispitivanjima svežnja elektrolizatora snimala se radna (U-I) karakteristika i koja je uspoređena s U-I karakteristikom elektrolizatora kojega čini jedan članak sličnih dimenzija. Nadalje, ispitana je brzina proizvodnje vodika, te učinkovitost elektrolizatora. Također, s obzirom na to da su ovo prva značajnija mjerenja ovoga svežnja elektrolizatora, posebna pažnja posvećena je na kvalitetu njegova rada. Hydrogen is one of the major energy storage solutions, and is an excellent link to renewable energy sources (RES). Electricity is stored in hydrogen in such a way that hydrogen is produced by electrolysis of water using RES. Such a process is completely free of harmful emissions. In this thesis, the emphasis has been put on investigation of the features of a laboratory constructed electrolyzer stack consisting of three cells. According to the type of electrolyte it is an alkaline electrolyzer, and according to the type of construction it is an electrolyzer of bipolar design. Measurements were carried out within the Power Engineering Laboratory whereby the electricity required to power the electrolyzer was obtained from a laboratory direct current source. By experimental testing of the electrolyzer stack it was recorded the operating (U-I) characteristic which was compared with a U-I characteristic of a single cell electrolyzer of similar dimensions. Furthermore, the rate of hydrogen production and the efficiency of the electrolyzer were examined. Also, since these are the first significant measurements of this electrolyzer stack, special attention has been paid to the proper operation of the electrolyzer.

Obzirom na temperature okoline zimi i ljeti, u ovom radu se na temelju dopuštenih temperaturnih raspona za siguran rad pojedinih komponenti odredilo koju rashladnu/grijaću opremu treba ugraditi u kućište prve hrvatske punionice vodika instalirane na Fakultetu strojarstva i brodogradnje Zagrebu, osmišljene kao samostalan PV-H2 sustav. Opisan je princip rada punionice i uređaja od kojih se sastoji, te sama konstrukcija. Kako bi se odabralo najbolje tehnološko rješenje projekta upravljanja toplinom, a koje će održavati optimalnu temperaturu unutar kućišta punionice po zimi i ljeti, provedena je detaljna analiza termodinamičkih parametara komponenata sustava. Odabrana je izolacija kućišta, vrsta rashladnih jedinica i grijača pomoću normi HRN EN 12831 i VDI 2078, te režim rada sustava grijanja i hlađenja temeljen na unutarnjoj temperaturi zraka u kućištu. Izračunate su godišnja potrebna toplinska energija za grijanje i hlađenje prema normi HRN EN ISO 13790. Na kraju je provedena analiza dobivenih rezultata proračuna i ukupne potrošnje energije punionice vodika. Regarding to environmental temperature during winter and summer months, and based on allowed temperature range for safe operation of components, in this work it was defined both cooling and heating equipment needed to be installed in the housing of first Croatian hydrogen refuelling station installed at the Faculty of Mechanical Engineering and Naval Architecture in Zagreb that was designed as autonomous PV-H2 system. In order to improve the energy efficiency of the first Croatian hydrogen refuelling station installed at the Faculty of Mechanical Engineering and Naval Architecture, designed as a stand-alone PV-H2 system, an optimal thermal management strategy was proposed. First chapter, after introducing heat management basics, begins with an explanation of refuelling station operating principle and the equipment of which it consists, ending with the description of construction itself. In order to select the best technological solution for thermal management project, which will maintain optimal temperature inside of housing in winter and summer, a detailed analysis of the system components thermodynamic parameters was performed. Insulation, type of cooling units and heaters are selected according to the HRN EN 12831 and VDI 2078 standards, while regime of the heating and cooling system is selected based on the station indoor air temperature. The annual required heating and cooling energy is calculated according to HRN EN ISO 13790 standard. To conclude, an analysis of the calculation results and the total energy consumption of the hydrogen refuelling station were performed.

Nakon izrade prvog hrvatskog bicikla na vodik logičan slijed događaja bila je izgradnja prve hrvatske punionice vodika kako bi se pokrile potrebe bicikla. U ovom je radu predstavljen prijedlog izvedbene projektne dokumentacije samog kućišta punionice koji svojim jedinstvenim izgledom kemijsku formulu vodikove molekule.Ponuđen je i prijedlog povezivanja radnih komponenti sustava u funkcionalnu cjelinu s pozicijama u kućištu. Opisani su načini rada podsustava za proizvodnju električne energije preko fotonaponskih (FN) modula, te podsustava za proizvodnju vodika elektrolizom vode na samoj lokaciji. Punionica tako ispunjava zahtjeve za autonomnim radom. U radu je dan opis testiranja bicikla na vodik s pripadajućim rezultatima koji će se puniti na novoinstaliranoj punionici. Pomoću proračuna FN modula i podataka o potrošnji bicikla predstavljeni su podaci o potencijalu proizvodnje vodika u punionici. After making of the first Croatian hydrogen bicycle, a logical step was the construction of the first Croatian hydrogen refuelling station to meet the needs of the bicycle consumption. This work presents the proposal of the project design documentation of the hydrogen refueling station, with its unique appearance inspired by a molecular scripture of the hydrogen molecule itself. Paper also presents the functional scheme of system components to a functional unit with the positions suggestions of every part in the housing. The subsystem for the production of electricity through the photovoltaic modules and the subsystem for the production of hydrogen by electrolysis of water at the location were described. Hydrogen refueling station thus fulfills the requirements for autonomous work. Finally, there was description of the hydrogen bicycle testing with the corresponding results to be replenished in the newly installed hydrogen refuelling station. The calculation of photovoltaic module power production projections and bicycle consumption data were used to calculate full potential of hydrogen production in the HRS.

The objective of the 14th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES) is to provide a world-wide forum for experts, researchers and those interested in learning about the sustainability of development, to present research progress and to discuss the state of the art, the future directions and priorities in the various areas of sustainable development. This includes the improvement and dissemination of knowledge on methods, policies and technologies for increasing the sustainability of development, taking into account its economic, environmental and social pillars, as well as methods for assessing and measuring sustainability of development, regarding energy, transport, water, food and environment systems and their many combinations.

The objective of the series of conferences on Sustainable Development of Energy, Water and Environment Systems (SDEWES) is to provide a forum for world-wide specialists and those interested in learning about the sustainability of development, to present research progress and to discuss the state of the art, the future directions and priorities in the various areas of sustainable development. This includes the improvement and dissemination of knowledge on methods, policies and technologies for increasing the sustainability of development, taking into account its economic, environmental and social pillars, as well as methods for assessing and measuring sustainability of development, regarding climate, energy, transport, agriculture, water and environment systems and their many combinations. The reason for the forum having such a wide scope is due to the need for holistic integrated solutions encompassing several or all sectors.