Search

Despite all efforts, there is currently no sustainable city in the world. In some cities there are positive changes towards sustainability (RES instead of fossil fuels, using electric cars, waste recycling, reduction of CO2 emissions, etc.), but in order to achieve the sustainability of the Earth as a planet, all cities in the world should be made sustainable, as they account for about 80% of total energy consumption. This means that future sustainable cities will be able to produce all the necessary energy and drinking water using the RES system, applying pump storage hydroelectric (which technology can balance seasonal surpluses and shortages of solar energy), as well as applying seasonal heat storage technologies. On the other hand, despite the efforts of the signatories of the Paris Agreement, it is questionable whether these objectives can be achieved at all due to political, economic and other obstacles. In addition, current EU policy might even take a step backward by trying to introduce a green label for nuclear energy and natural gas (European Commission taxonomy proposal), which calls into question the implementation of The European Green Deal by 2050. Recognizing the importance of this historic moment in stopping climate change, the paper presents a way to address the sustainability of cities in the world, proposing a systematic approach to this problem, taking into account the most relevant criteria: size, climate and natural disasters. Considering that about 50% of the world's population lives within the area 20˚ N and 40˚ N and that over 30% of the population lives in cities with less than a million inhabitants ; but also the fact that cities outside this geographical area may also have relatively large amounts of direct solar radiation ; the cities of Zagreb and Copenhagen (which cities have practically the same amounts of direct solar radiation) were selected as case studies, for which original solutions for achieving overall sustainability were given. In doing so, Seawater Steam Engine (SSE) technology, which uses renewable energy for simultaneous energy and drinking water production, is presented, as well as original strategies for solving the problem of accommodating SSE collectors in cities (with canopies), but also the original concept of energy and drinking water distribution (with loops). However, just as SSE technology is basically open source technology that can use other renewable energy sources, it also means that it could make other cities in the world up to a million inhabitants without enough solar energy completely sustainable, whereby other RES would be used. In addition, the paper presents strategies for resolving cities with more than a million inhabitants all the way to the metropolis. This paper also introduces the next generation of RES technologies, whose originality lies in the fact that, in the future, they can simultaneously produce energy and drinking water which is fully consistent with the new “Philosophy of Sustainability”. With this concept, the cities in the world could become the “basic building blocks” that would "build" the overall sustainability of the Earth.

Radical new technology Seawater Steam Engine presented in this book is a scientific and technological breakthrough with the hopes of stopping climate change. New technology can simultaneously produce energy and drinking water, using only 3 natural forces: Renewable energy sources (RES), Seawater and Gravity. In the next 15-30 years with this technology it will be possible to produce 24, 441 TWh of energy and 244 km3 of drinkable water per year, which are amounts that can satisfy mankind’s needs for energy and drinkable water and save up to 20 Gt of CO2. Seawater Steam Engine technology has an extremely high potential for further development and could in fact become the ‘prime mover’ of third, and last, industrial revolution, which essentially becomes a synonym for realization of sustainable communities.

Radically new technology Seawater Steam Engine (SSE) presents a scientific and technological breakthrough with the intention of stopping climate change. New technology can simultaneously produce energy and drinking water, using only 3 natural forces: Renewable energy sources (RES), Seawater and Gravity. In the next 15-30 years with this technology it will be possible to produce 24, 441 TWh of energy and 244 km3 of drinking water per year, which are amounts that can satisfy mankind’s needs for energy and drinking water and save up to 20 Gt of CO2. Seawater Steam Engine technology has an extremely high potential for further development and could in fact become the ‘prime mover’ of the third, and last, industrial revolution, which essentially becomes a synonym for realization of sustainable communities.

This paper analyses the theoretical aspects of the use of solar energy and water storage for sustainable electric energy supply. Proposed hybrid concept observed as an open energy system that behaves according to the local conditions and renewable energy source technology used. Sustainability of hybrid system is based on stabile water and energy budget of power plant in the planning period. The key relationship for system design and interdependence between electric power of solar generator and working volume of water (energy) storage is set. Water storage is a main functional element of the proposed concept that allows efficient harvesting of sun energy as well as water resources and thus significantly affects on the features of hybrid solutions. The developed theoretical relationships and proposed hybrid system indicators have been tested on two different climate areas, as paradigms of Continental and Mediterranean climate. Based on obtained results it has been concluded that presented hybrid concept of solar-hydro systems provides a promising basis for the development of sustainable energy systems.

Održivi razvoj i “zdravo stanovanje“ ciljevi su koji se žele postići upotrebom građevinskih materijala dobivenih primjenom novih tehnologija i novih znanstvenih spoznaja. Međutim, iskustva iz prošlosti u korištenju materijala vrlo su važna kako sa ekonomskog tako i ekološkog aspekta što je prikazano u ovom radu. Novi pogled na stare pucolane (prirodne zeolite) kao i razvoj tehnologija i materijala u području nanoznanosti omogućuje veći doprinos poboljšanju uvjeta u kojima neposredno živimo kao i u cjelokupnoj zaštiti okoliša.

The paper presents the characteristics of a power plant which combines Renewable Energy Sources (RES), i.e. photovoltaic (PV) power plant and Pump Storage Hydroelectric (PSH), in order to achieve sustainable production of green electric energy equal to those of conventional energy sources. The proposed solution does not produce CO2 and does not significantly use freshwater or other resources. The PSH storage is the main element of the proposed power plant system which provides continuous and reliable supply of green energy. Its size significantly affects the size of the PV generator and operation characteristics of the hybrid plant. The paper elaborates in detail the functional relationship between the choice of the PV generator power and the PSH upper storage volume and presents the basic mathematical relations. The algorithm of the system development is presented, as well as the procedure choice solutions. The results from case study show that the concept is flexible in design, construction and operation.

This work describes the application of a solar photovoltaic (PV) system in the urban water sector, especially related to water pumping. The Sun and gravity are two basic natural and renewable sources of energy. It is pure natural energy that has no harmful effects on the environment, spread everywhere and available for use. Solar photovoltaic systems can be successfully applied in many areas in water sector and especially in water supply. Due to the importance of water supply for urban area sustainability, and due to a significant energy consumer whose price is increasing each day, alternative solutions to power systems are sought in the form of water supply systems, such as a PV generator. It is a complex system, whose functioning is defined by a whole range of factors: climate, soil, hydrological, water consumption in the cities etc. It can be optimized only with the application of a systematic approach and the use of adequate tools. The paper will show that the solar photovoltaic systems are efficient in use in urban water sector.

Obzirom da se zgradama od slame promovira manja potrošnja energije i materijala, zatim korištenje obnovljivih izvora energije, upotreba obnovljih i ekoloških sirovina, smanjenje troškova kao i socijalni aspekti poput unaprjeđenja kvalitete življenja, radom je pokazano da bi ona i u Hrvatskoj mogla biti građevinski materijal. Prikazani su i resursi slame, odnosno površine i proizvodnja pšenice u Hrvatskoj te kakve se efekti, u smislu povećanja energetske učinkovitosti, mogu očekivati od zgrada od slame, kao i kakav bi učinak imala njena primjena na emisiju stakleničkih plinova. Pokazano je i da slama ima visok stupanj izolacije, zatim su dati testovi vodljivosti, koeficijenti prolaza topline te prikazana zaštita od buke i rizici od požara. Vrlo važan aspekt u kućama od slame je učinkovita primjena prirodnih zeolita kao elemenata zdravog stanovanja.

This work describes the cost efficiency of a solar photovoltaic (PV) pumping system for irrigation system, in relation to the most effective traditional power system, a diesel engine. Mathematical model for optimal sizing of solar PV pumping system is used for the estimate of the maximum area which can be economically irrigated by the solar PV pumping system. Proposed methodology and model has been applied on two different areas in Croatia, Osijek and Split, as paradigms of continental and coastal Croatia as well as EU. The obtained results show that maximum areas which can be economically irrigated in the Osijek region are greater than in the Split region. Such result indicates that PV irrigation systems can be equally economically applied in relatively cooler climates and with less solar radiation, as well as warmer Mediterranean climate.

The work presents a straw as natural building material that place major emphasis on sustainability and there are no constrains to be implemented in Croatia. The way of achieving sustainability through natural building materials focus on durability and the use of minimally- processed, plentiful or renewable resources, as well as those which, while recycled or salvaged, produce healthy living environments and maintain indoor air quality. It is shown that straw has high insulation level and very good noise and fire resistance, as well as good static characteristics. The work also presented thermal efficiency of straw bale walls. It means that long term running costs can be much lower than conventional types of building and the dependence on fossil fuels can be reduced.

Zgradama od slame promovira se manja potrošnja energije i materijala, korištenje obnovljivih izvora energije, uporaba obnovljivih i ekoloških sirovina, smanjenje troškova izgradnje te unapređenje kvalitete življenja. Obzirom na sve te prednosti, Fakultet kemijskog inženjerstva i tehnologije planira uključenje u razvoj novih prirodnih građevinskih materijala.

In this paper it is showed that straw could also be used as building material in Croatia, since less energy and materials consumption, using renewable resources and ecological materials, reducing costs of living as well as social aspects such as promoting quality of living, is promoted by buildings made of straw. There are shown resources of straw, respectively surface and production of wheat in Croatia as well as effects, such as increasing energy efficiency and effect on emission of greenhouse gasses. It is shown that straw has high insulation level, there are shown conductivity tests, coefficient of thermal conductivity, noise protection and fire risks. Straw buildings also provide conditions for health leaving, which is a very important aspect. A special attention was given to static strength of straw as a building material.

Potrošnja energije u zgradarstvu iznosi preko 40% od ukupne potrošnje u Hrvatskoj, od koje se čak 80% energije troši za grijanje i hlađenje. Energetski standard u zgradarstvu Hrvatske leži daleko ispod današnjih tehničko-ekonomskih mogućnosti, odnosno 85% objekata ne zadovoljava sadašnje propise o toplinskoj zaštiti. Kod novogradnji, a posebno kod zgrada koje se saniraju, raspoloživi potencijal mjera energetske učinkovitosti ne koristi se dovoljno. S druge strane, za sustavno rješenje problema energetske učinkovitosti u zgradarstvu nisu dovoljne opće regulative (pravilnici, akcijski planovi i/ili samo usvajanje inozemnih direktiva), nego se značajni efekti mogu postići tek donošenjem novog standarda. Naime, pravilnici i direktive daju samo opće smjernice (ciljeve) i kvalitativne mjere dok je za projektiranje energetski učinkovitih zgrada potrebno imati standard, koji predstavlja čitav niz konkretnih mjera za postizanje postavljenih ciljeva. Upravo zbog navedenih razloga Hrvatskoj je neophodan novi standard koji bi bio napravljen po ugledu na najzahtjevnije EU standarde na tom području, ali primjeren hrvatskim klimatološkim prilikama te u mnogim elementima i ispred EU standarda. Razvoj tržišnih mehanizama trebao bi potaknuti razvoj i korištenje tehnologija energetske učinkovitosti i obnovljivih izvora energije integriranih u novi standard.

The energetic-ecological project E-dom will attempt to encourage the development and use of innovative technologies in building construction. A concrete objective of this project, which has basically been introduced by the pilot-project of the hotel building intended for congress tourism in the vicinity of the capital of Croatia, is to show the systematic application of new technologies in order to achieve full power independence (self-supply) and ecological sustainability of the project, as well as providing healthy living conditions in such environment, naturally, with minimum investment costs. The main building materials of E-dom will be natural (wood, straw, clay, sheep wool, etc.), so that the exterior wall of the building will represent the best known insulated structure today. The required thermal energy for heating of the rooms and consumable hot water will be provided parallel from two sources, i.e. with geothermal heat pump and solar thermal collectors, for which flat, vacuum pipe and hybrid thermal-photovoltaic collectors will be used, while on the south side of the building, solar walls with stage alterable materials will be used. In order to achieve full energy independence in relation to electric power, solar photovoltaic collectors and hydrogen storage of electric power are foreseen on the building. All active systems for capture and storage of energy will be optimized, i.e. sized, in order to satisfy in the best way possible, the demands for energy in the climate of the E-dom building. The basic elements of healthy living in E-dom will be provided by controlled ventilation system, where, among other, the radon concentration will be reduced to quantities not deemed harmful for human health. On the other hand, plants in the hotel space (the so-called green walls) will not only contribute to the aesthetic appearance, but will improve the air quality, as the plants will produce oxygen and bind poisonous components.

E-dom je energetsko ekološki projekt čiji je spiritus movens uklapanje u prirodu, korištenje tradicionalnih i novih vrijednosti, očuvanje okoliša i hrabrost, ne samo za osmišljavanje, nego i za primjenu novog i još nepoznatog. U osnovi se radi o manjem hotelu namijenjenom kongresnom turizmu, a koji bi bio izgrađen od prirodnih materijala.Pri tome bi bile upotrijebljene i sve nove tehnologije kojima bi se osiguravala potpuna energetska neovisnost. Uz navedeno, bitan element E-doma bi bilo i zdravo stanovanje.

Za sustavno rješenje problema energetske učinkovitosti u zgradarstvu Hrvatske nisu dovoljne opće regulative (pravilnici, akcijski planovi i/ili samo usvajanje inozemnih direktiva), nego se značajni efekti mogu postići tek donošenjem novog standarda. Naime, pravilnici i direktive daju samo opće smjernice (ciljeve) i kvalitativne mjere dok je za projektiranje energetski učinkovitih zgrada potrebno imati standard koji predstavlja čitav niz konkretnih mjera za postizanje postavljenih ciljeva. Zbog toga je Fakultet kemijskog inženjerstva i tehnologije u pripremi koncepta novog energetsko-ekološkog standarda, u koji bi se uključili i drugi tehnički fakulteti Zagrebačkog sveučilišta, a koji bi bio napravljen po ugledu na najzahtjevniji EU standard na tom području, ali primjeren hrvatskim klimatološkim prilikama te u mnogim elementima i ispred EU standarda jer Hrvatska dosta zaostaje na ovom području.

This paper shows how new building technologies have to be implemented systematically in order to achieve an in advance proposed standard. For the illustration, a residential and business building in Osijek Croatia is chosen. Although all energy systems and technologies in such buildings are interconnected, the calculation procedure and the manner of using structure elements and technologies which gives energy and economic optimum are analyzed first. To achieve minimal heat energy demand, a new generation of materials are used: energy efficient bricks, vacuum insulated panels, energy efficient windows and solar walls as well as the other state of the art technical solutions. The energy needed for heating and cooling is supplied by geothermal heat pumps with vertical soil heat exchangers (in total 1000m). Solar thermal collectors provide an additional heat source for space heating and warm water preparation. Additionally, the excess solar heat can be stored in a storage tank on seasonal basis. Both heat sources are integrated in an energy system using some additional tanks, pumps and heat exchangers. The distribution of heat energy is warranted through ceiling or floor heating and cooling. Low temperature heating and the ventilation system ensure healthy and high quality living conditions in the building. The building automation connects all technical systems in a whole and takes care of its good functioning.

Radom su prikazane tehnologije primijenjene na prvoj energetski učinkovitoj zgradi u Hrvatskoj projektiranoj po švicarskom Minergie standardu. Tim standardom ograničava se potrošnja toplinske energije za grijanje prostora te sanitarne vode, ali i potrošnja električne energije. Ponderirana energetska suma Minergie standarda od 42 kWh/m2god, vrlo je mali iznos u usporedbi sa starijim zgradama u Hrvatskoj koje troše prosječno oko 250 kWh/m2god samo za potrebe grijanja. Energiju potrebnu za grijanje i hlađenje poslovno stambene zgrade uzete kao primjer u ovom radu osigurava postrojenje koje u sebi uključuje geotermalnu dizalicu topline, sunčane toplinske kolektore te odgovarajući sustav kontrolirane ventilacije s rekuperacijom topline. Prikazane su razne tehnologije, od pasivnog hlađenja (freecooling) preko dizalice topline i primjene sunčanih kolektora, sve do sezonskog spremnika topline. Od najnovijih energetski učinkovitih tehnologija prikazani su solarni zidovi i vakuumski izolirajući paneli te vrlo komforan sustav niskotemperaturnog stropnog grijanja i hlađenja. Predmetna građevina mogla bi postati dobar primjer rješavanja problema energetske učinkovitosti i za druge stambeno-poslovne građevine u Hrvatskoj.

U prikazu se daje pregled tema obrađenih na već tradicionalnom kongresu, 21. po redu, "Energija i okoliš 2008." održanom u Opatiji o organizaciji Tehničkog fakulteta Sveučilišta u Rijeci, Hrvatskog saveza za sunčevu energiju i Univerze u Ljubljani, Fakulteta za strojništvo. Teme su se kretale u rasponu od primjene inovacija u energetskom sektoru u funkciji smanjenja klimatskih promjena, energetskih sustava i novih goriva u transportu, pa do korištenja obnovljivih izvora energije.

The main objective of the E-dom project, which has basically been introduced by the pilot-project of the hotel building intended for congress tourism in the vicinity of the capital of Croatia, is to show the systematic application of new technologies in order to achieve full power independence and ecological sustainability of the project, as well as providing healthy living conditions in such environment, naturally, with minimum investment costs. To achieve these objectives, the use of natural building materials and renewable energy sources is central. Wood, straw and clay will form the building structure of E-dom, achieving the best thermal insulation possible. The thermal energy for space and domestic hot water heating will be provided from a geothermal heat pump and solar thermal collectors. To make E-dom fully energy independent in relation to electricity, solar photovoltaic collectors and hydrogen storage of electric power are planned. Finally, to ensure a high comfort of living, E-dom will have a controlled ventilation system and plants on so-called green walls. The latter will not only contribute to the aesthetic appearance but will improve the air quality through production of oxygen and absorption of air pollutants.

Švicarski Minergie standard ograničava ukupnu potrošnju energije u zgradama na 42 kWh/m2 godišnje (što je ekvivalent od 3 litre loživog ulja na m2 godišnje), a kojim se, uz potrošnju energije za grijanje prostora, ograničava i potrošnja tople vode, zatim električne energije (dodatnim ograničavanjem veličine primarne energije, propisuje se i nužna uporaba obnovljivih izvora energije bez kojih nije moguće postići traženi standard).

Svi dosadašnji pristupi problemu projektiranja i izvođenja energetski učinkovitih građevina u Hrvatskoj, uglavnom se mogu svesti na nastojanja da se poveća izolacija zgrada i koriste energetski učinkovitiji prozori. Međutim, pri tome se nije moglo znati i kolike će se energetske uštede stvarno i postići pa je takav pristup bio više proizvoljan i odraz entuzijazma pojedinaca. Za razliku od takvih pristupa, ovom se studijom izvodljivosti po prvi put u Hrvatskoj polazi od unaprijed određenog standarda (odabran je trenutno najzahtjevniji švicarski Minergie standard) koji ograničava ukupnu potrošnju energije u zgradama na 42 kWh/m2 godišnje (za grijanje, potrošnu toplu vodu, električnu energiju i primarnu energiju – predstavljajući tako jednu mješavinu učešća pojedinih energija) i upravo njemu se onda prilagođavaju sve primijenjene tehnologije energetske učinkovitosti. Taj pristup, koji je uobičajen pristup energetici zgrada u razvijenim EU zemaljama, se predviđa i na Lameli 1 Višestambene građevine s poslovnim prostorima u Osijeku, investitora „ Agria“ iz Osijeka. Iako su svi energetski sustavi i tehnologije međusobno povezane, studijom se najprije proračunavaju i primjenjuju oni građevinski elementi i tehnologije koje će u energetskom i ekonomsko-tehničkom smislu dati najpovoljnije rezultate. Zato je primijenjena energetski učinkovita cigla, VIP izolacije, energetski učinkoviti prozori i solarni zidovi kao najsuvremenija tehnološka rješenja na tom području, a sve kako bi potrebna toplina za grijanje zgrade bila što manja. Glavni izvor osiguranja te preostale toplinske energije, odnosno grijanja i hlađenja građevine, je geotermalna dizalica topline, pri čemu se po prvi put u Hrvatskoj primjenjuju vertikalni izmjenjivači topline (sonde) dubine preko 200 m. Kao dopunski izvor topline predviđeni su solarni kolektori koji će osiguravati toplinsku energiju i za grijanje prostora i za potrošnu toplu vodu. Međutim, radi što učinkovitijeg korištenja viškova toplinske energije iz solarnih kolektora, po prvi put u Hrvatskoj se predviđa i sezonsko skladište topline, također najnovije tehnologije ekonomičnog korištenja toplinske energije. Oba izvora toplinske energije su povezana strojno-energetskim tehnologijama (spremnicima i izmjenjivačima topline) u jedan cjeloviti sustav. Nov je i način distribucije energije u stanovima, odnosno po prvi put se primjenjuje i stropno grijanje i hlađenje u stanovima. Pri tome je grijanje niskotemperaturno, a koje sa sustavom ventilacije, kvalitetu i zdravo stanovanje dovodi na najvišu razinu. Sustavom automatskog vođenja procesa su svi tehnološki sustavi povezani u jedan cjelovit sustav. Međutim, kako je zgrada Agrije ujedno i pilot-projekt, preko istog sustava se predviđaju i mjerenja relevantnih veličina (na izmjenjivačima u zemlji, na tehnološkoj opremi, meteorološka mjerenja, mjerenja kvalitete stanovanja, mjerenja vodikove kogeneracije, mjerenja koeficijenata prolaza topline, itd.), a sve u svrhu stjecanja iskustava u hrvatskim prilikama te trasiranja puta prema inovacijama i njihovom transferu prema domaćem gospodarstvu.

The previous methods for optimal sizing of photovoltaic (PV) irrigation water pumping systems separately considered the demand for hydraulic energy and possibilities of its production from available solar energy with the PV pumping system. Unlike such methods, this work approaches the subject problem systematically, meaning that all relevant system elements and their characteristics have been analyzed: PV water pumping system, local climate, boreholes, soil, crops and method of irrigation ; therefore, the objective function has been defined in an entirely new manner. The result of such approach is the new mathematical hybrid simulation optimization model for optimal sizing of PV irrigation water pumping systems, that uses dynamic programming for optimizing, while the constraints were defined by the simulation model. The model was tested on two areas in Croatia, and it has been established that this model successfully takes into consideration all characteristic values and their relations in the integrated system. The optimal nominal electric power of PV generator, obtained in the manner presented, are relatively smaller than when the usual method of sizing is used. The presented method for solving the problem has paved the way towards the general model for optimal sizing of all stand-alone PV systems that have some type of energy storage, as well as optimal sizing of PV power plant that functions together with the storage hydroelectric power plant.

Obzirom da u ukupnoj energetskoj potrošnji sektor kućanstva u većini EU zemalja kao i u Hrvatskoj predstavlja najvećeg potrošača energije, logično je koristiti izuzetno povoljne tehnološke i ekonomske mogućnosti koje na tom području stoje na raspolaganju i koje će u konačnici imati značajan doprinos u smanjenju potrošnje fosilnih goriva te posljedičnog zagađenja okoliša. Na osnovi nove EU zakonske regulative kojom se regulira područje energetske učinkovitosti u zgradarstvu, te činjenice da su postojeći profili stručnjaka koji rade u graditeljstvu sve više suočeni sa kompleksnim pitanjima iz područja energije u zgradarstvu i održivosti, u posljednje vrijeme su se u EU počeli pojavljivati novi poslijediplomski studiji kojima se rješava predmetna problematika. U tom smislu je ovim radom prikazan koncept Studija arhitektonske energetike u Hrvatskoj kojim bi se dobili novi stručnjaci, tzv. arhitektonski energetičari. Oni bi spojili znanja iz područja arhitekture, građevine, strojarstva, elektrotehnike i ekologije, a sve na načelima održivosti. Predmetnim studijem bi se obrazovali kadrovi koji bi mogli proračunati energetska svojstva zgrada, kontrolirati njihovu organizaciju i izvođenje, savjetovati investitore i projektante, sudjelovati u projektiranju te baviti se obrazovanjem budućih stručnjaka i svim poslovima koji obuhvaćaju tematiku energije i održivost u zgradarstvu.

This paper analyses and situates the role of the Agency for energy efficiency and renewable energy sources (Agency). In this sense the paper examines the coordination of the Agency's objectives of national programs for energy efficiency and renewable sources with the required financial support for their realization. Considering that Croatia spends a relatively high percentage of its Gross Domestic Product for the importation of quality energy sources, it is evident that it is necessary to undertake a series of measures for more efficient energy uses and to commence production from renewable sources. In Croatia a potential for more efficient uses of energy exists in all three main sectors of energy consumption, i.e. industry, transport and household. The paper also discusses the administrative aspect of the Agency and its aims and objectives, namely appropriate projects and initiatives. The Agency's organizational structure is also dealt with, in which local Agencies would play a particular role. It is understood that the relationship will be based on a partnership and that classical subordination will be avoided. This means that a cooperative working relationship will be undertaken in the sense of encouragement and support of local initiatives and projects in order to achieve the realization of common objectives.

Dosadašnje metode za određivanje nazivne električne snage fotonaponskih (FN) crpnih sustava primjenjenih u navodnjavanju počivaju na nomogramima proizvođača i/ili odgovarajućim proračunima, čiji su osnovni ulazni parametri: zahtijevana hidraulička energija, mjesečne srednje dnevne vrijednosti Sunčevog zračenja i karakteristike FN crpnog sustava. Međutim, u takvom postupku, odvojeno se promatraju potrebe za hidrauličkom energijom i mogućnosti njene proizvodnje FN crpnim sustavom iz raspoložive solarne energije. Također, ne uzimaju se u obzir dinamičke karakteristike vodozahvata iz bušotine, kao niti rezerve vode u tlu tijekom sezone navodnjavanja. Sve ovo rezultira u nesustavnom te zato i prilično nepreciznom postupku dimenzioniranja sustava, pri čemu se u tome nerijetko pretjeruje, a što se posljedično odražava na povećanu investiciju i eventualnu ekonomsku opravdanost takvih sustava. Ovim radom dan je znanstveni postupak dimenzioniranja optimalnog FN crpnog sustava u navodnjavanju. U tom smislu sustavno se analizira predmetni problem te cjelovito sagledavaju svi relevantni elementi sustava i njihove karakteristike, odnosno karakteristike FN crpnog sustava, vodozahvata, lokalne klime, tla, biljnih kultura i sustava za navodnjavanje. Postavljen je cilj minimiziranja maksimalne nazivne električne snage FN generatora (MIN-MAX postupak), a primijenjen je hibridni simulacijsko-optimizacijski model u kojem se za optimiranje koristi dinamičko programiranje, dok se neophodna ograničenja rješavaju simulacijom. Pri tome promatra se sustav bez akumulacije vode i/ili energije, zatim navodnjavanje metodom kapanja, zahvat vode iz bušotine te FN crpni sustav s potopljenim crpnim agregatom druge generacije. U svrhu verifikacije predmetnog modela optimiranja i dobivanja odgovarajućih istraživačkih rezultata te stjecanja spoznaja o mogućnostima primjene FN crpnih sustava u navodnjavanju u Hrvatskoj odabrane su parcele na područjima Osijeka i Splita. Varijacijom različitih parametara pokazano je da ovakav model uspješno uzima u obzir sve karakteristične veličine i njihove odnose u cjelokupnom sustavu te da se njime može, na zadovoljavajući način, odrediti optimalna veličina FN crpnog sustava u navodnjavanju. Recent methods for the determination of nominal electric power of photovoltaic (PV) water pumping systems for irrigation have been based on graphic tools of manufacturers and/or proper calculations, whose basic incoming parameters are: hydraulic energy demand, monthly average daily solar irradiation and characteristics of PV water pumping system. However, in this procedure has been separately considered the demand for hydraulic energy and possibilities of its production from the available solar energy with the PV water pumping system. Further, it have not been considered the dynamic characteristics of boreholes as well as the water storage in the soil during the season of irrigation. All of this has resulted in an unsystematic and therefore rather imprecise procedure of the system sizing, whereby it has been often overrated, which consequently reflected the higher investment and eventual economic sustainability of those systems. Through this dissertation was given the scientific procedure of the sizing of the optimal PV water pumping system for irrigation. In this sense, it is systematically analysed the subject problem and completely considered all the relevant system elements and their characteristics, i.e. characteristics of PV water pumping system, water supply from boreholes, local climate, soil, crops and irrigation methods. The objective function is the minimization of the maximal nominal electric power of PV generator (MIN-MAX procedure) and the hybrid simulation-optimization model was applied, wherein for the optimization was used the dynamic programming, while the constraints are defined by the simulation model. For all that, the system is viewed without the water and/or energy accumulation, further the irrigation system by trickle distribution method and for the PV water pumping systems of the second generation submersible motor-pump subsystem. For the purpose of the verification of the model optimization and reaching appropriate researching results, as well as gaining the knowledge of the applying possibilities of PV water pumping systems for irrigation in Croatia, were chosen the locations in Osijek and Split areas. By variation of different parameters was shown that this model successfully takes into consideration all characteristic values and their relations in the integrated system, whereby through this model could be, in satisfactory way, determinated the optimal value of PV water pumping system for irrigation.

Dosadašnje metode za određivanje nazivne električne snage fotonaponskih (FN) crpnih sustava primjenjenih u navodnjavanju počivaju na nomogramima proizvođača i/ili odgovarajućim proračunima, čiji su osnovni ulazni parametri: zahtijevana hidraulička energija, mjesečne srednje dnevne vrijednosti Sunčevog zračenja i karakteristike FN crpnog sustava. Međutim, u takvom postupku, odvojeno se promatraju potrebe za hidrauličkom energijom i mogućnosti njene proizvodnje FN crpnim sustavom iz raspoložive solarne energije. Također, ne uzimaju se u obzir dinamičke karakteristike vodozahvata iz bušotine, kao niti rezerve vode u tlu tijekom sezone navodnjavanja. Sve ovo rezultira u nesustavnom te zato i prilično nepreciznom postupku dimenzioniranja sustava, pri čemu se u tome nerijetko pretjeruje, a što se posljedično odražava na povećanu investiciju i eventualnu ekonomsku opravdanost takvih sustava. Ovim radom dan je znanstveni postupak dimenzioniranja optimalnog FN crpnog sustava u navodnjavanju. U tom smislu sustavno se analizira predmetni problem te cjelovito sagledavaju svi relevantni elementi sustava i njihove karakteristike, odnosno karakteristike FNFN crpnog sustava, vodozahvata, lokalne klime, tla, biljnih kultura i sustava za navodnjavanje. Postavljen je cilj minimiziranja maksimalne nazivne električne snage FN generatora (MIN-MAX postupak), a primjenjen je hibridni simulacijsko-optimizacijski model u kojem se za optimiranje koristi dinamičko programiranje, dok se neophodna ograničenja rješavaju simulacijom. Pri tome promatra se sustav bez akumulacije vode i/ili energije, zatim navodnjavanje metodom kapanja, zahvat vode iz bušotine te FN crpni sustav s potopljenim crpnim agregatom druge generacije. U svrhu verifikacije predmetnog modela optimiranja i dobivanja odgovarajućih istraživačkih rezultata, te stjecanja spoznaja o mogućnostima primjene FN crpnih sustava u Hrvatskoj odabrane su parcele na područjima Osijeka i Splita. Varijacijom različitih parametara pokazano je da ovakav model uspješno uzima u obzir sve karakteristične veličine i njihove odnose u cjelokupnom sustavu te da se njime može, na zadovoljavajući način, odrediti optimalna veličina FN crpnog sustava u navodnjavanju.

Nacionalnim tehnologijsko-razvojnim projektom Hrvatska solarna kuća predviđena je izgradnja kuće-laboratorija za mjerenje tokova energije i karakterističnih veličina novih tehnologija. U centru razmatranja su mjerenja relevantnih svojstava pasivne kuće, odnosno meteorološka mjerenja, mjerenje prihvata i potrošnje toplinske energije za grijanje prostora i vode, mjerenje električne energije po pojedinim vrstama potrošača, mjerenje potrošnje hladne vode i mjerenje karakterističnih parametara udobnosti stanovanja/boravka, te mjerenje karakterističnih veličina fotonaponsko-vodikove tehnologije. Sustav za upravljanje, nadzor i prikupljanje podataka u kući-laboratoriju je u osnovi distribuirani sustav koji se sastoji od komunikacijske mreže na koju će biti spojeni svi senzori i aktuatori te SCADA sustav kojim će se prikupljati i spremati podaci sa senzorima te slati upravljački signali prema aktuatorima.

The project Croatian Solar House (CSH) has a strategic value for the Croatian society and state due to its wide reaching solutions of the energy and environment problem in Croatia, which are technically feasible and economically practical. The goals of the CSH project are in total accordance with the strategic decisions of the EU toward the "sustainable development" on the way of the energy consumption rationalization, the essential ratio raiseof the pure renewable sources, as well by the CO2 and other pollutants reduction. Unlike the non-ambitious energy strategy, which could lead to the 70% energy import dependency of Croatia by the year 2030, the CSH project, through a wide range of planned constructive actions, demonstrates and proves the possibility of totally different approaches and strategies. Through the proposed solutions can be achieved the goals of the "sustainable development" atatining and an energy dependency as well as the CO2 emission reduction near the Kyoto protocol.

Projekt "Hrvatska solarna kuća" je u osnovi tehnologijsko-razvojni projekt kojim se predviđa razvoj i primjena tehnologija energetske učinkovitosti u zgradarstvu kao i intenzivnija primjena obovljivih izvora energije. Jedan od važnih ciljeva projekta je i orjentacija hrvatskih graditelja u pravcu usvajanja novih tehnologija građenja.

Građevine u Hrvatskoj troše relativno mnogo energije po jedinici površine, proizvodeći u tijeku cijelog životnog vijeka velike količine ugljičnog dioksida, plina koji je najodgovorniji za izazivanje efekta staklenika. Radom su predstavljene glavne ideje projekta Hrvatska solarna kuća, koji u osnovi predstavlja program energetskog razvoja sektora kućanstva, u periodu do 2030. godine. Odgovarajućim tehnikama građenja moguće je smanjiti potrošnju energije u ovom sektoru, čime bi se smanjila i ukupna emisija CO2 za 7.4 MT te bi se time, samo na račun kućanstava, koja u Hrvatskoj čine 1/3 ukupne energetske potrošnje, uspjela dostići i granica Kyoto protokola.

Consumption of energy in Croatia is highly above the energy production from domestic sources, which leads to dependence on imports and insecurity of safe energy supply. In addition, too large emission of CO2 in Croatia results in breaking limits of Kyoto agreement. In 2001 the R. Boskovic Institute and four Zagreb faculties launched an ambitious energy-conservation-ecological project Croatian Solar House (CSH), and in 2002 the Fisibility study was completed. General objective of this project is to construct the test and demonstration object CHS, containing original scientific/technical solar products. The building is designed according to 'passive house' principles. For water heating a new type of hybrid PV/Thermal collector was produced. It has a semi -transparent a-Si:H solar module deposited on glass which is the cover of the building-integrated conventional solar thermal collector. For solar production of electricity at CSH the original, 4th generation a-Si:H solar cells are designed, having degradation in exploitation of less than 10%. Although the object will be grid-connected, an additional hydrogen system, containing PV production of hydrogen, its storage and fuel cell for reverting it back to electricity is also included into the project. The CSH project offers a number of original scientific (technological) solutions regarding reduction of heating demands of households and in solar production of energy. The project is expected to make a significant impact in Croatia, raising awareness for sustainable development and utilization of clean renewables, and in the same time helping the Croatian industries to enter new attractive fields.

Dan je prikaz projekta Hrvatske solarne kuće sa naglascima i uvjetima gradnje koji odgovaraju tzv "pasivnoj kući" sa elementima korištenja dobre izolacije, kvalitetne gradnje uz poseban dizajn i uz upotrebu obnovljivih izvora energije, naročito iskorištavanjem sunčevog zračenja za dobivanje potrošne tople vode i izvora električne struje.

Projekt Hrvatske solarne kuće ima važnost za hrvatsku državu jer otvara prostor rješavanju problema na području energetike i zaštite okoliša, pri čemu je u potpunom suglasju s modernim europskim stremljenjima. Kratkoročni ciljevi projekta su izgradnja inteligentne energetski neovisne kuće, kao laboratorijskog oglednog objekta, kojim se želi dokazati održivost primijenjenih tehnologija. Međutim, dugoročni cilj je izgradnja novih objekata u Hrvatskoj na principima pasivne solarne arhitekture, kao i dodatno izoliranje starih objekata, što će uz intenzivnu primjenu novih obnovljivih izvora energije do 2030. godine stvoriti situaciju da kućanstva više ne budu potrošači energije

Tehnologijski istraživačko-razvojni projekt "Hrvatska solarna kuća" (HSK) u osnovi je energetsko-ekološi projekt koji ima kao glavni cilj smanjenje potropnje energije i njenu proizvodnju iz novih obnovljivih izvora i smanjenja emisije CO2. Ishodište projekta je "Green Paper" (European Commission 2000), a koncepcija potpuno usklađena sa suvremenim europskim stremljenjima kao u programu "Inteligent Energy For Europe". U centru istraživanja su kućanstva, čija potropnja energije Čini preko 30% ukupne finalne potropnje energije u Hrvatskoj, a koja će se nastojati značajnije reducirati primjenom novih tehnologija racionalizacije energije (kao u EU programu SAVE). Međutim, u HSK će se primijeniti i nove tehnologije za proizvodnju energije iz obnovljivih izvora (kao u EU programu ALTENER) i to iz fotonaponskih i hibridnih fotonaponsko-termalnih kolektora (na osnovi vlastitih patenata), ali i iz vodikovih gorivnih ćelija (iz elektrolitičkog i/ili reformiranog vodika). Kao građevinski objekt, HSK je solarna pasivna kuća, koja svojom arhitekturom i tehnologijama građenja (izolacije, staklenici, prozori i drugi građevni elementi) osigurava maksimalnu potropnju za grijanje do 15 kWh/m2/god. Ostatak topline, osigurat će se kombiniranim sustavima prihvata, spremanja i distribucije energije (solarni termalni kolektori, dizalice i rekuperatori topline, itd.), dok će se uptede na el. energiji ostvariti primjenom energetski racionalnih potrošača. S druge strane, osnovni model solarne pasivne kuće bit će opremljen i nadograđen novim tehnologijama sve do energetski vrlo racionalne, odnosno inteligentne energetski neovisne kuće. Nakon izgradnje, HSK će imati vipe funkcija i to: od oglednog objekta za demonstraciju navedenih tehnologija, zatim laboratorija za mjerenje energetskih tokova i drugih procesnih veličina u kući te istraživanja mogučnosti daljnjih tehnologijskih poboljpanja do nacionalnog centra za certificiranje solarno-vodikovih uređaja, koji će biti uklopljen u mrežu sličnih centara u Europi i odgovarajućih asocijacija. Zbog svega toga, u njoj će se oformiti Centar za solarno-tehnologijska istraživanja, koji će biti povezan s drugim zainteresiranim ustanovama u zemlji i tijesno surađivati s gospodarstvom kojem bi razvoju projekt trebao dati značajni doprinos.

Posljednjih je godina tehnika dojave požara značajno napredovala. To se odnosi kako na standardne tehnike, koje su još u uporabi, tako i na pojavu inteligentnih sustava. Daljnji će razvoj vjerojatno ići u pravcu evolucije senzorske tehnike, zatim u analizi požara podržanoj računalom, te primjeni ekspertnih sustava, neuralnih mreža i neizrazite logike. Paralelno tome ići će se i prema daljnjoj minijaturizaciji vatrodojavnih uređaja i pogodnom odnosu decentralizacije i centralizacije vatrodojavnih sustava. Ograničavajući faktori primjena novih tehnologija najčešće su norme koje u pravilu kasne, te njihove prihvatljivosti sa stanovišta projektanata, instalatera i korisnika. No, krajnji je cilj svakako "inteligentna zgrada".

In this paper the Intelligent House as an energy efficiency solution is discussed. Under the term Intelligent House, nowadays we mean an environment in which all house systems and devices aimed at comfort, security, recreation and communication are capable of learning on basis of life situations and react to them adequately. An intelligent system control enables economical, qualitative life and security. House intelligence, among other choices enables control energy, which results in savings of heat and electrical energy.

Croatian Solar House (CSH) is basically an energy-ecological project with the main goal reduction of energy consumption, its production by renewable energy sources, having as a consequence benefical lowering in CO2 emission. It follows the “ Green paper” of European Commission 2000, and its concept is in full accordance with current European trends, described in the program called “ Intelligent Energy for Europe” . As 32% of total final consumption in Croatia corresponds to households, they will be in focus of our interest. In this sense, we shall apply new approaches for energy efficiency in households (like in the European program SAVE) which can save substantially energy in our country. Additionally, in CSH we will also use new technologies for energy production, using renewable energy sources (as in the European program ALTENER), namely photovoltaic and renewable energy sources (based on our own patents) as well as hydrogen fuel cells (from electrolytic and/or reformed hydrogen). As a construction facility, CSH is defined as a passive solar house whose architecture and constructional technologies (insulation, greenhouses, special windows and doors as well as other building elements) provide almost complete energy needs for heating from surroundings, aup to the maximal thermal consumption of 15 kWh/(m2yr). The rest of the thermal energy requirements will be covered by combined systems of energy reception, storage and distribution (solar thermal collectors, heat pumps and recuperators, ventilation etc). On the other hand, saving in electrical energy will be achieved by using the most efficient electrical appliances and lighting. The basic model of CSH will be upgraded by new technologies until it becomes energy rational house, i.e. “ Intelligent energy independent house” . After construction, CSH will be a multifunctional building: (i) a demonstration facility of the above mentioned technologies, (ii) a laboratory for measurement of energy flow and other process variables inside the house, with studies of possible improvements in new technologies, (iii) a national centre for certification of solar-hydrogen devices, which will be incorporated in the network of the corresponding centres in Europe. In order to comprise all these functions, the Centre for solar-technological research in the CSH will founded, closely collaborating with institutions in this field, as well as with industry.

Faster development and more intensiveimplementation of photovoltaic (PV) technologies in Croatia is the main goal of a complex technological project titled: " Development of Stand-alone Photovoltaic Systems". Technologically, it encompasses component development and system organization, and economically, an analysis will be required for determination of limiting capacities, commercially viable in respect of our climatic conditions. The project is composed of 10 sub-projects taking into account equal representation of all Croatian regions as well as diversity of applications the most appropriate to a specific location. Thus, a PV pumped irrigation system is envisaged in Osijek, a railroad PV-powered signal crossing in Daruvar, a drinking water system in Pazin, a PV-pumped water supply for cattle on the island of Krk, a sea water desalination unit on the islan of Hvar, PV public lighting in the vicinity of Dubrovnik as well as a general purpose mobile PV electricity generator. A Laboratory PV pumping system will be built at the Faculty of Electrotechnics and computing in Zagreb for measurements and analyses as a support to development as well as those for development of intelligent processing and expert systems also, as a support to development of applicationsand commercialization of solar photovoltaic systems.

U radu su sistematski navedene usvojene metode proračuna globalne energije Sunčevog zračenja na južno orjentirane plohe. Određene su vrijednosti na 23 lokaliteta u Hrvatskoj za nagibe prihvatnih ploha od po 10^0 prema horizontali. Izvršena je optimizacija metoda proračuna i odabrana je ona koja ima najmanju mjesečnu kumulativnu pogrešku u odnosu na izmjerene vrijednosti Zagreba (Grič), Osijeka i Splita. Pri tome je korišten proračun kuta deklinacije Sunca koji je red veličine točniji od do sada prihvaćenih.

The application of photovoltaicly-powered water pumping system for irrigation can not be observed separately from other influential magnitudes such as local climate, soil type and crop kinds. This paper comprises them all and there is also a developed procedure determining the basic parameters neccessery from system designing. The optimization this complex system has been carried out by the dynamic programming method. The aim of the method is to achieve the optimal soil moisture by irrigation, i.e. the higest crop yield to which are connected all relevant parameters of PV system (power and optimal panel inclination as well as parametersof motor and pum). A hybrid simulation-optimization model has been used for this purpose.Dynamic programming is used for optimization, whereas simulation is used to define the functional limmits.

Od svih mogućih konfiguracija fotonaponskih pumpnih sistema kao pogonskih sistema uređaja za navodnjavanje, u ovom su se radu isključivo razmatrali "direktni sistemi", odnosno oni koji nemaju akumulatore za skladištenje električne energije jer se njeno skladištenje uglavnom predviđa u obliku potencijalne energije vode. Razlozi za primjenu ovakvih sistema nalaze se u njihovoj relativno većoj pouzdanosti i ekonomičnosti. Analizom gubitaka energije unutar komponenti sistema došlo se do četiri varijante direktnih sistema i to: sistemi s fotonaponskim ćelijama, istosmjernim elektromotorom i centrifugalnom pumpom kod kojih se optimizacija komponenti postiže variranjem otpora armature, zatim upotrebom tragača maksimalne snage te sistem s fotonaponskim ćelijama, istosmjernim elektromotorom i volumnom vijčanom pumpom uz upotrebu čopera, odnosno tragača maksimalne snage. Primjena pojedinih konfiguracija u konkretnom slučaju ovisit će o karakteristikama izvora vode, ali i o karakteristikama korisnika, odnosno sistema za navodnjavanje.

The paper summaries an analytical model of the direct connection of a photovoltaic system comprising a centrifugal pump, a DC electric motor with permanent magnets and a photovoltaic array. It undelines the adventage of the analytical approach in searching the operating point of the whole system, creating a sound mathematical basis for the calculation of water, pumped by system as a function of solar radiation intensity and the parameters of system components.

Prolaskom kroz realnu atmosferu lokaliteta ekstraterestičko zračenje slabi apsorpcijom, raspršavanjem i refleksijom do vrijednosti ukupne ozračenosti što se u praksi najčešće određuje Angstroemovim koeficijentima a i b. U radu su na temelju višegodišnjih mjerenja određene njihove vrijednosti za Osijek.