diplomsko delo
Špela Krnc (Avtor), Marko Čepin (Mentor)

Povzetek

Sončna svetloba je naraven vir energije, ki ga lahko izkoriščamo za proizvodnjo električne energije. Sončno sevanje, ki pride do zemlje, se v sončnih celicah s procesom fotovoltaike pretvori v električno energijo. Sončne celice med seboj povezujemo v fotovoltaične module, ki jim z načinom vezave sončnih celic dimenzioniramo izhodno napetost in tok. Med seboj povezani fotonapetostni moduli tvorijo sončno elektrarno, ki nam predstavlja fotonapetostni sistem povezan z lokalnim in elektroenergetskim omrežjem. Na samo proizvodnjo sončne elektrarne poleg vremena vplivajo tudi lokacija in orientacija elektrarne, naklonski kot modulov, senčenje, letni čas in temperatura okolice. Sončna energija spada med obnovljive vire energije, ki nam predstavljajo trajnostno oskrbo z električno energijo. Težava lahko nastane pri zanesljivosti oskrbe porabnikov in stabilnosti distribucijskega sistema. Sončna elektrarna podnevi proizvaja električno energijo za potrebe gospodinjstva, kar lahko povzroča dvig napetosti in dodatno delo za sistemskega operaterja. Ponoči, ko zaradi pomankanja svetlobe ne poteka fotovoltaični proces, sončna elektrarna ne proizvaja električne energije, zato se gospodinjstvo napaja z električno energijo iz distribucijskega sistema. Z namenom umestitve obnovljivih virov energije v bilančno shemo ter povečanje stabilnosti in zanesljivosti oskrbe porabnikov uporabljamo hranilnike energije. V hranilniku energije se tekom dneva shranjujejo viški energije, ki jih podnevi proizvede sončna elektrarna in jih gospodinjstva ne uspejo sproti porabiti. Shranjena energija se porablja v obdobju, ko je povpraševanje po električni energiji večje od lastne proizvodnje sončne elektrarne. Z ustreznim dimenzioniranjem sistema sončne elektrarne v kombinaciji z baterijskim hranilnikom lahko zagotovimo samooskrbo gospodinjstva in neodvisnost od elektroenergetskega omrežja. Zaradi nihanja proizvodnje sončne elektrarne tekom leta nam optimizacija parametrov baterijskega hranilnika predstavlja izziv. V prvi vrsti moramo določiti priključno moč baterijskega hranilnika in njegovo kapaciteto. Baterijski hranilnik je sestavljen iz več baterijskih celic, ki jih med seboj povezujemo na način, da zagotovimo ustrezno izhodno napetost in ustrezno kapaciteto. Baterijske celice delujejo v obliki galvanskega člena, ki z elektrokemično reakcijo pretvarjajo kemično energijo v električno. Med seboj se razlikujejo glede na material, iz katerega so narejene, in posledično po gostoti energije. Pri izbiri ustrezne baterije primerjamo tudi učinkovitost polnjenja in praznjenja, življenjsko dobo baterije ter njen vpliv na okolje. V diplomski nalogi je bila preverjena ustreznost postavitve že obstoječe sončne elektrarne za oskrbo gospodinjstva ter izvedena analiza za morebitno nadgradnjo sistema s hranilnikom energije. Izračuni temeljijo na podatkih o gostoti moči sončnega sevanja in porabi gospodinjstva za obdobje enega leta v polurnih časovnih intervalih. Namen diplomske naloge je analizirati možnost samooskrbe gospodinjstva s sončno elektrarno in hranilnikom energije. Tekom leta se proizvodnja električne energije iz sončne elektrarne spreminja in posledično tudi stanje napolnjenosti baterije. V zimskih mesecih je poleg manjšega števila sončnih ur tudi gostota moči sončnega sevanja manjša, zato sončna elektrarne ne proizvede vedno dovolj energije za zagotavljanje samooskrbe gospodinjstva. V pomladnem in poletnem obdobju je višja gostota moči sončnih žarkov ter več sončnih ur, zato je tudi proizvodnja sončne elektrarne večja. Proizvodnja električne energije iz sončne elektrarne v tem obdobju zagotovi potrebam gospodinjstva in omogoča polnjenje baterijskega hranilnika. Shranjeno električno energijo gospodinjstvo porabi v nočnem času in na ta način deluje samooskrbno. Negativna plat samooskrbe s sončno elektrarno in težava za sistemskega operaterja je predvsem nihanje napetosti med obdobji s sončnim sevanjem in brez njega ter dejstvo, da poleti proizvedemo petkrat več električne energije kot pozimi, kar je potrebno uravnotežiti z drugimi viri, ker baterije ne zadoščajo.

Ključne besede

sončne elektrarne;sončne celice;fotovoltaika;baterijski hranilniki energije;baterijske celice;samooskrba;univerzitetni študij;Elektrotehnika;diplomske naloge;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.11 - Diplomsko delo
Organizacija: UL FE - Fakulteta za elektrotehniko
Založnik: [Š. Krnc]
UDK: 621.311.243(043.2)(0.034.2)
COBISS: 206312707 Povezava se bo odprla v novem oknu
Št. ogledov: 31
Št. prenosov: 9
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Self-sufficient electric power supply with a solar power plant and energy storage
Sekundarni povzetek: Sunlight is a natural source of energy that can be utilized to produce electric energy. Solar irradiation reaching the Earth is converted into electric energy in solar cells through the process of photovoltaics. Solar cells are connected to form photovoltaic modules, which are dimensioned for output voltage and current based on the connection method of the solar cells. Interconnected photovoltaic modules form a solar power plant, representing a solar power system connected to the power grid. The production of a solar power plant is influenced not only by the weather but also by the location and orientation of the plant, the tilt angle of the modules, shading, season, and temperature. Solar energy is a renewable energy source, providing sustainable electric energy. However, issues arise regarding the reliability of consumer supply and the stability of the distribution grid. During the day, a solar power plant produces electric energy for household needs, perhaps causing voltage rises and power system operator activities. At night, due to the lack of light and the cessation of the photovoltaic process, the solar power plant does not produce electric energy, so the household is supplied with energy from the distribution grid. To integrate renewable energy sources into the balance scheme and increase the stability and reliability of consumer supply, energy storage systems are used. During the day, excess energy produced by the solar power system that the household does not consume immediately is stored in the energy storage system. The stored energy is used when the demand for electric energy exceeds the production. By appropriately dimensioning the solar power system in combination with a battery storage system, self-sufficiency of the household and independence from the power grid can be achieved. Due to the fluctuation in solar power system production throughout the year, optimizing the parameters of the battery storage system is a challenge. Firstly, the connection power and capacity of the battery storage system must be determined. The battery storage system consists of several battery cells connected to ensure adequate output voltage and capacity. Battery cells operate as galvanic cells, converting chemical energy into electric energy through an electrochemical reaction. They differ in material composition and, consequently, energy density. When selecting the appropriate battery, the efficiency of charging and discharging, battery lifespan, and environmental impact are also compared. In the thesis, the suitability of an existing solar power system for household supply was examined, and an analysis was conducted for a potential upgrade with an energy storage system. The system analysis was conducted on an annual basis, providing insight into system performance for different time periods with their characteristic weather conditions. In the thesis, the suitability of the setup of an existing solar power system for household supply was examined, and an analysis for a potential upgrade of the system with an energy storage system unit was conducted. The calculations are based on data on the power density of solar radiation and household consumption over a one-year period in half-hour intervals. The purpose of the thesis is to analyze the possibility of household self-sufficiency with a solar power system and an battery storage system unit. Throughout the year, the electric energy production from the solar power system varies, and consequently, the state of charge of the battery also changes. In the winter months, there are fewer sunlight hours and the power density of solar radiation is lower, so the solar power system does not always produce enough electric energy to ensure household self-sufficiency. In the spring and summer periods, the power density of solar radiation and the number of sunlight hours are higher, thus the production of the solar power system is also greater. The electric energy production from the solar power system during this period meets the household's needs and allows for the charging of the battery storage system unit. The household consumes the stored electric energy during the nighttime, thus operating self-sufficiently. The negative side of self-sufficiency with a solar power plant and a problem for the system operator is primarily the voltage fluctuations between periods with and without solar radiation and the fact that we produce five times more electricity in the summer than in the winter, which needs to be balanced with other sources because the batteries are not sufficient.
Sekundarne ključne besede: solar power plant;solar cells;photovoltaics;battery storage system;battery cells;self-sufficiency;
Vrsta dela (COBISS): Diplomsko delo/naloga
Študijski program: 1000313
Komentar na gradivo: Univ. v Ljubljani, Fak. za elektrotehniko
Strani: 1 spletni vir (1 datoteka PDF (46 str.))
ID: 24892297