1. ENERGIJA Rezerve primarnih virov energije

Transcription

1 1. ENERGIJA Rezerve primarnih virov energije Red velikosti primarnih virov na Zemlji ( vir Lomborg, 2001)

2 Obnovljivi viri so najbolj obilen energijski vir na svetu. Slika omogoča že ob bežnem pogledu bleščečo primerjavo med letnimi razpoložljivimi obnovljivimi viri (sončno energijo in njenimi najpomembnejšimi posrednimi oblikami, biomaso, vetrom in vodnimi salami) in med vsemi razpoložljivimi neobnovljivimi zalogami (nafto, plinom, uranom in premogom). Jasno je razvidno, da je sončno direktno obsevanje (žarki) in razpršeno (nebo) obsevanje največji energijski vir na Zemlji. Resnično, če ocenjujemo samo velikostni razred sončne energije EJ, ki doseže Zemljo oz. atmosfero v primerjavi z zalogami neobnovljivih virov EJ (nafta EJ, plin EJ, uran EJ in premog EJ). Energija ostalih obnovljivih virov je ocenjena na EJ (vodne sile 90 EJ, veter 630 EJ in biomasa (fotosinteza) EJ) je zelo majhen del vsega sončnega obsevanja. Trenutna svetovna raba energije je okoli 425 EJ/a. 80 % vse svetovne rabe energije je danes osnovano na fosilnih gorivih. S tem je povezanih veliko tveganj. Energetska infrastruktura elektrarne, prenosni vodi in postaje,plinovodi in naftovodi so ranljivi zaradi vremenskih okoliščin ali človeških dejanj. V poletju 2003, v enem najbolj vročih in suhih poletij v Evropi zadnjih nekaj let, je mnogo elektrarn, plinskih in jedrskih obratovalo z velikim tveganjem zaradi pomanjkanja vode za hlajenje hladilnikov. Svetovno povpraševanje po fosilnih gorivih (začenši z nafto) bo po pričakovanju preseglo letno proizvodnjo, zelo verjetno že v naslednjih dvajsetih letih. Pomanjkanje nafte ali plina lahko povzroči mednarodne ekonomske in politične krize in konflikte. Zgorevanje fosilnih goriv pomeni izpuščanje emisij v okolje, kar učinkuje lokalno (npr. benzen), območno(aerosoli, plini, ki Se hitro razgradijo) in v svetovnem merilu (toplogredni plini).

3 Ocena deležev energijskih virov (Rimski klub 1970)

4 Les je vsekakor najstarejša oblika energije, ki jo je človek uporabljal v prvi vrsti za pripravo hrane in ogrevanje. V prvi fazi razvoja razsvetljava ni imela velikega pomena; za prvo razsvetljavo so najverjetneje uporabili kar leseno baklo. Asfalt je prvo fosilno gorivo. Že Sumerci so (okoli 6000 pr.n.št.) uporabljali asfalt iz nahajališča blizu Ararata. Kasneje so goriva uporabljali za proizvodnjo opeke in apna in nato za pridobivanje bakra in železa. Približno leta 3000 pr.n.št. zasledimo uporabo goriv za izdelavo glazur in emajla pri lončarskih izdelkih ter proizvodnji porcelana in stekla. Za razsvetljavo so uporabljali živalske in rastlinske maščobe. Obdobje Babilonskega cesarstva (leta 2500 do 538 pr.n.št.) je prvo zgodovinsko obdobje uporabe fosilnih goriv. Takrat so namreč v veliki meri uporabljali asfalt in surovo nafto za proizvodnjo opeke (za zgradbe, mostove in pregrade) in apna. Izkopanine iz tega obdobja vsebujejo razen apna tudi asfalt. Kolikor je znano so premog v tem obdobju (okoli 1100 pr.n.št.) uporabljali samo na Kitajskem, kjer so v tem času dosegli znaten tehnološki napredek. Za proizvodnjo kovin, papirja, sladkorja in smodnika so potrebovali gorivo, lesa pa niso imeli dovolj, zato so ga nadomestili s premogom in zemeljskim plinom. Obstajale so namreč vrtalne naprave za izkoriščanje plitkih nahajališč zemeljskega plina, ki so ga nato s pomočjo bambusovih cevi transportirali do porabnikov. V tem času so Feničani izdelali prve voščene sveče.

5 Kljub uporabi fosilnih goriv je les ostal glavni izvor energije. Zato je bila poraba lesa zelo velika. Tako so n.pr. v Indiji popolnoma uničili gozdove in povzročili nastanek velikih puščav. V naslednjih stoletjih predstavljajo glavno gorivo živalski iztrebki, kar je povzročilo manjšo plodnost zemljišč. Podobno bi se verjetno dogajalo tudi na drugih področjih, če se ne bi pričelo upočasnjevanje, pa tudi stagnacija tehnološkega razvoja. To je bila posledica propada Babilonskega cesarstva, zmage Konfucijeve filozofije na Kitajskem in nastanka kast v Indiji. V Grčiji se je tehnološki razvoj ustavil v 4. stoletju pr.n.št. Okoli leta 500 pr.n.št. se začenja dolgo obdobje industrijske stagnacije. Vendar se je ravno takrat začel razvoj abstraktnih idej, ki doseže vrhunec v moderni znanosti. Grki so namreč položili temelje industrijskemu razvoju, do katerega bo prišlo šele 2000 let kasneje. V tem dolgem obdobju so neprestano naraščale potrebe po mehanski energiji. Rimljani so prvi izkoriščali vodno energijo (mlinsko kolo). To predstavlja, razen uporabe energije vetra za pogon ladjevja, edino mehansko energijo, ki jo v tem obdobju niso pridobili s pomočjo človeških ali živalskih mišic. Mehansko energijo so potrebovali za gradnjo hiš, obdelavo polj, za prevoz in obrt. Sužnji in živali so bili takrat edino sredstvo za zadovoljitev teh potreb. O številu prebivalcev v antičnih državah sicer ni podatkov, vendar je zanesljivo, da je bilo več sužnjev kakor svobodnih ljudi. Glavni plen v vojnah so bili takrat sužnji. Na področju bližnjega vzhoda so Perzijci po letu 500 pr.n.št. opustili uporabo asfalta in apna ter začeli uporabljati nežgano opeko. Okoli leta 1000 so Arabci že izkoriščali vodno energijo in vetrnice, toda niso uporabljali fosilnih goriv čeprav so na tem področju že prej obstajala nahajališča surove nafte in asfalta.

6 Maji v Srednji Ameriki niso poznali kovin. Les je bil osnovni material in energetski vir. Toda, ko so izkoristili svoje gozdove je propadlo tudi njihovo cesarstvo. V Veliki Britaniji so uporabljali premog že pred prihodom Rimljanov. Zanimivo je, da so indijanska plemena v današnji Arizoni uporabljala premog že dvesto let pred prihodom Kolumba. V Veliki Britaniji in Evropi je bila uporaba premoga zaradi neznanja in predsodkov precej omejena. Kralj Edvard I (1306) je pod pretnjo smrtne kazni prepovedal ogrevanje s premogom z razlago, da so plini, ki nastajajo ob izgorevanju strupeni. Eno takšno smrtno kazen so tudi izvršili. Smrtno kazen so kasneje ukinili, toda predsodki so ostali. Prepoved kurjenja s premogom je ponekod ostala do 17. stoletja, priporočali so pa kurjenje z lesom. V Franciji so kaznovali kovače, ki so brez posebnega dovoljenja uporabljali premog. Tehnologija je napredovala kljub temu. Leta 1587, ko so obglavili Marijo Stewart, so prvič uporabili koks za ogrevanje stanovanj, leta 1620 pa so izdali britanski patent št. 15 za postopek koksiranja premoga. Čeprav je več stoletij stagnirala, je začela uporaba goriv v tem obdobju naraščati. To ni bila samo posledica uporabe za kuhanje in ogrevanje, temveč tudi za proizvodnjo železa. Ta porast je zahteval nadomestilo lesa s premogom. Menjava energentov je bila na področjih z malim številom prebivalcev (Amerika) in na področjih brez industrije (večji del Evrope in Azija) skoraj neopazna. V Angliji in delu Francije so z odkritjem koksa, ki je nadomestil oglje, preprečili opustošenje teh področij. Premog in koks so začeli množično uporabljati šele v začetku 18. stoletja. Plin, ki so ga pridobili iz premoga so prvič uporabili na Irskem leta 1691, toda preteklo je še celo stoletje, preden je takšen plin dosegel komercialno vrednost.

7 Napredek pri izkoriščanju primarnih oblik energije so postopoma dosegali tudi na drugih področjih. Leta 1627 so odkrili izvor surove nafte v ZDA (država New York). V Italiji (Modena) so dokončali naftno vrtino l To nahajališče so izkoriščali približno 200 let. Leta 1803 so s petrolejem iz te vrtine razsvetlili ulice v Genoviin Parmi. V Romuniji so začeli nafto pridobivati l. 1650, V Galiciji pa l S petrolejem iz Galicije so 70 let kasneje razsvetlili ulice v Pragi. Za začetek industrijskega izkoriščanja surove nafte štejemo l. 1859, ko so usposobili prvo večjo vrtino v Pennsylvaniji (ZDA). L so izdelali v Veliki Britaniji prvo tekoče gorivo iz oljnih skrilavcev, toda komercialna proizvodnja je stekla šele 120 let kasneje v Kanadi. Med leti 1850 in 1860 je bilo v ZDA kakšnih 50 obratov za predelavo oljnih skrilavcev, ki so jih uvažali iz Kanade. Z razvojem izkoriščanja surove nafte so te obrate opustili. Cela stoletja so za razsvetljavo uporabljali lesene bakle, vosek ter rastlinske in živalske masti. Sredi 18. st. so za razsvetljavo izdelali olje iz kitove glave. Takšno olje so uporabljali za razsvetljavo skoraj celo stoletje, dokler ga niso izrinila tekoča fosilna goriva. Plamen iz teh goriv je bil precej nestabilen in neprijetnega vonja. Večjo spremembo zasledimo l. 1784, ko je Argand prvič uporabil stekleni valj. Naslednja večja izboljšava pri plinski razsvetljavi je izum plinske mrežice l (Auer von Welsbach). Takšno mrežico so izdelovali iz tekstila in jo impregnirali s cezijem, torijem ali magnezijem. L Watt začne eksperimentirati s parnim strojem in l uspe izdelati tehnično uporaben parni stroj, kar omogoči pretvorbo energije goriva v mehansko energijo. Ta dogodek je eden od mejnikov v zgodovini in predstavlja začetek industrijske revolucije. Ta izum namreč omogoča pretvorbo mehanske energije neodvisno od pojava primarne energije (energija vode) ter njene jakosti (vodni pretoki, hitrost vetra).

8 Razširitev uporabe parnega stroja je zahtevala povečano pridobivanje premoga, kar je spet omogočil prav parni stroj. Zanimivo je, da so za pogon prvih parnih strojev uporabljali les in oglje, uporabljali pa so jih v rudnikih premoga. Prvo parno lokomotivo so izdelali l in so jo uporabljali za prevoz premoga. Potrošnja premoga je skokovito naraščala. L so v ZDA izkopali 300 ton premoga, 20 let kasneje pa več kot milijon ton. Iz premoga so pridobivali tudi plin. L je bila mreža plinske napeljave v Londonu dolga okoli 200 km, v glavnem za potrebe razsvetljave. V Londonu so iz premoga pridobili dnevno okoli m 3 plina, kar je zadostovalo za plinskih svetilk. V novejšem obdobju so zemeljski plin prvič uporabili v Fredoni ji (država New York, ZDA) za ogrevanje stanovanj. Poraba je bila zelo mala. V večjem obsegu so začeli izkoriščati zemeljski plin šele 1884, ko so plin po 23 km dolgem plinovodu pripeljali v Pittsburgh. Uporabljali so ga za razsvetljavo, gretje in razne toplotne procese. Parni stroj je bil dolgo edini način pretvorbe druge oblike energije v mehansko tam, kjer so to energijo potrebovali. Toda izkoriščanje te energije je bilo mogoče samo v neposredni bližini parnega stroja (jermenski prenosi, zobniki). To velja tudi za izkoriščanje vodne energije.

9 Šele z odkritjem električne energije, ki jo je mogoče enostavno in brez velikih naprav pretvoriti v mehansko energijo (elektromotor), je bilo mogoče energijo prenašati na večje razdalje. Vendar je razvoj bil zelo dolg. Že l je Volta iznašel elektrokemični element, l je Jacobi konstruiral prvi uporaben elektromotor, 1866 so izdelali električni generator (Siemens, Wheatstone) in l prvo električno žarnico z nitko iz oglja (Edison). Toda šele z odkritjem trifazne napetosti in vrtilnega magnetnega polja (Tesla, 1887) nastopi enostavna možnost pretvorbe električne energije v mehansko. L je Tesla zgradil prvo veliko HE na slapovih Niagare. L je zabeležen prvi prenos električne energije na večjo razdaljo (elektrotehniška razstava v Frankfurtu). Razvoj proizvodnje električne energije je bil pogojen s konstrukcijo vodnih in parnih turbin. Prva moderna vodna turbina je imela moč 45 kw (Fourneyron, 1837). Z izboljšanjem njene konstrukcije je nastala prva Francisova turbina (1847) kasneje pa še Peltonova (1878) za velike in Kaplanova turbina (1922) za male padce. Izkoriščanje kemične energije goriv v pravem pomenu je postalo mogoče šele, ko so parne turbine zamenjale parne stroje. Prvo enostopenjsko parno turbino so zgradili 1883 (Laval), prvo večstopenjsko pa 1884 (Parsons). Odkritje parnega stroja je povzročilo razvoj železniškega omrežja, jadrnice pa so zamenjali parniki. Razvoj cestnega in zračnega prometa pa se je začel šele z odkritjem motorja z notranjim izgorevanjem. Prvi patentirani motor z notranjim izgorevanjem je bil dvotaktni plinski motor (Lenoir, 1860). Prvi štiritaktni motor, kot jih poznamo danes je l sestavil Otto. Bencinski avtomobilski motor so iznašli 1883 in prvi motor s kompresijo čistega zraka v katerega se vbrizguje gorivo l (Diesel). Reakcijski motor so prvič izdelali l To je v bistvu specialna izvedba plinske turbine, ki se je razvijala vzporedno s parno.

10 Kontrolirana cepitev uranovih jeder (Fermi, 1942) predstavlja začetek novega poglavja v razvoju energetike. L so dali v pogon prvo eksperimentalno jedrsko elektrarno (Obinsk pri Moskvi). Istega leta je zaplula prva podmornica na jedrski pogon ( Nautilus ). Prva komercialna jedrska elektrarna je pričela delovati dve leti kasneje (Calder Hall, Velika Britanija). Kadar se pogovarjamo o porabi in rezervah energije naletimo na tujko resursi (resources-viri) oziroma nosilci energije (Energieträger, energy carrier). Nosilce energije lahko razdelimo grobo na fosilne in druge. Od njih je odvisno, kako bo svet bodočnosti moral uravnavati svoj razvoj, saj je proizvodnja in poraba energije bodoče družbe tesno povezana oziroma neposredno odvisna od nosilcev ali virov energije.

11 Geotermalna Ostali OVE Toplota iz sonca Raba primarne energije [EJ/a] Elektrika iz sonca Veter Biomasa (napredna) Biomasa (tradicionalna) Energija vode Jedrska energija Plin Premog Nafta Leto Transforming the global energy mix: the exemplary path to 2050/2100 (Source: WBGU, 2003)

12 Premog Po nekajletnem zatišju zaradi nizke cene nafte pridobiva premog na veljavi. Razpoložljive zaloge (10 12 ton) pomenijo pomemben energetski vir. Celotne zaloge strokovnjaki cenijo na ton, hkrati pa so na konferenci za svetovno energijo leta 1977 ocenili, da je v perspektivi razpoložljivih le 6 % teh zalog. Ob trenutni letni porabi 4, ton bi naj te zaloge zadoščale za 200 let. Definitions Coal is a hard black substance, dug from the earth in lumps which can be burt to produce heat or power. Proved amount in place is the resource remaining in known deposits that has been carefully measured and assessed as exploitable under present and expected local economic conditions with existing available technology. Maximum depth of deposits and minimum seam thickness relate to the proved amount in place. Proved recoverable reserves are the tonnage within the proved amount in place that can be recovered in the future under present and expected local economic conditions with existing available technology. Estimated additional amount in place is the indicated and inferred tonnage additional to the proved amount in place that is of foreseeable economic interest. It includes estimates of amounts which could exist in unexplored extensions of known deposits or in undiscovered deposits in known coal-bearing areas, as well as amounts inferred through knowledge of favourable geological conditions. Speculative amounts are not included. Estimated additional reserves recoverable is the tonnage within the estimated additional amount in place that geological and engineering information indicates with reasonable certainty might be recovered in the future.

13 Svetovne zaloge premoga Področje zaloge [t] ocena 1977 ocena 2005 ocena 2008 zadošča za zaloge [ 10 6 t] zadošča za zaloge [ 10 6 t] Evropa let let Severna Sovjetska ik zveza let let let Azija let let Afrika t 330 let let Južna Amerika t 330 let let Srednji vzhod let Oceanija let zadošča za skupaj svet let let Premoga je v svetu torej še dovolj, problemi pa so z rudniki, saj so jih v dobi cenene nafte povsod opuščali kot nerentabilne. Posebni problem pomenijo pri tem tiste zaloge, ki jih ni mogoče izkoriščati po klasični poti in bo potrebno še počakati na nove tehnološke rešitve (uplinjanje, premogovodi, itd.)

14 Top ten hard coal producers, 2008 (Source: SER) million tonnes China USA 993 India 484 Australia 332 South Africa 251 Russian Federation 246 Indonesia 229 Kazakhstan 100 Poland 84 Colombia 74 Coal used in electricity generation, 2008 (Source: IEA) % South Africa 94 Poland 93 China 81 Australia 76 Israel 71 Kazakhstan 70 India 68 Czech Republic 62 Morocco 57 Greece 55 USA 49 Germany 49

15 Coal and Energy Security Coal has an important role to play in meeting the demand for a secure energy supply. As the Survey shows, coal is abundant and widespread, with commercial mining taking place in about 70 countries. Coal is the most abundant and economical of fossil fuels; on the basis of proved reserves at end-2008, coal has a reserves to production ratio of about 128 years, compared with 54 for natural gas and 41 for oil. Coal is readily available from a wide variety of sources in a well-supplied worldwide market. It can be transported to demand centres quickly, safely and easily by ship and rail. A large number of suppliers are active in the international coal market, ensuring competitive behaviour and efficient functioning. It can also be easily stored at ower stations and stocks can be drawn on in emergencies. Coal is also an affordable source of energy. Prices have historically been lower and more stable than oil and gas prices and coal is likely to remain the most affordable fuel for power generation in many developed and industrialising countries for several decades. Coal can also be used as an alternative to oil. The development of a coal-to-liquids industry can serve to hedge against oil-related energy security risks. Using domestic coal reserves, or accessing the relatively stable international coal market, can allow countries to minimise their exposure to oil price volatility while providing the liquid fuels needed for economic growth.

16 Top coal importers, 2008 (Source: IEA) million Steam Koksanje Total tonnes Japan Korea (Republic) Taiwan, China India Germany China UK Australia is the world s largest coal exporter. It shipped 261 million tonnes of hard coal in 2008, out of its total production of 332 million tonnes. Australia is also the largest supplier of coking coal, accounting for 53% of world exports.

17 Sector CCS contribution in 2050 (Source: IEA) The coal industry is committed to minimising its GHG emissions and action is being taken in a number of areas. Carbon Capture and Storage (CCS) will form a vital part of global efforts to reduce CO2 emissions. CCS technology is the only currently available technology that allows very deep cuts to be made - at the scale needed in atmospheric emissions of CO2 from fossil fuels.

18 Surova nafta Definitions Crude oil is a naturally occurring mixture consisting predominantly of hydrocarbons that exists in liquid phase in natural underground reservoirs and is recoverable as liquids at typical atmospheric conditions of pressure and temperature. Crude oil has a viscosity no greater than mpa.s (centipoises) at original reservoir conditions; oils of greater viscosity are included in Chapter 4 - Natural Bitumen and Extra-Heavy Oil. Natural gas liquids (NGLs) are hydrocarbons that exist in the reservoir as constituents of natural gas but which are recovered as liquids in separators, field facilities or gasprocessing plants. Natural gas liquids include (but are not limited to) ethane, propane, butanes, pentanes, natural gasoline and condensate; they may include small quantities of nonhydrocarbons. If reserves/resources/production/consumption of NGLs exist but cannot be separately quantified, they are included (as far as possible) under crude oil. In the tables the following definitions apply to both crude oil and natural gas liquids: Proved amount in place is the resource remaining in known natural reservoirs that has been carefully measured and assessed as exploitable under present and expected local economic conditions with existing available technology. Proved recoverable reserves are the quantity within the proved amount in place that can be recovered in the future under present and expected local economic conditions with existing available technology.

19 Estimated additional amount in place is the resource additional to the proved amount in place that is of foreseeable economic interest. Speculative amounts are not included. Estimated additional reserves recoverable is the quantity within the estimated additional amount in place that geological and engineering information indicates with reasonable certainty might be recovered in the future. R/P (reserves/production) ratio is calculated by dividing the volume of proved recoverable reserves at the end of 2008 by volumetric production in that year. The resulting figure is the time in years that the proved recoverable reserves would last if production were to continue at the 2008 level. Po ocenah znašajo zaloge nafte vsega sveta ton. Od tega je potrjenih zalog ton, dosegljivih ton, trenutna poraba pa je ton. Ocene zalog, potrjene zaloge in poraba po posameznih področjih so navedene v tabeli Razmerja med ocenjenimi zalogami nafte, letno proizvodnjo in preostalimi zalogami se seveda naglo spreminjajo tako z leti, kakor tudi po področjih. Po ocenah strokovnjakov naj bi tako dosegljive nafte zmanjkalo v tridesetih do sedemdestih letih.

20

21

22 Regional distribution Reserves 10 6 [t] Production 10 6 [t] R P (eserves) (roduction) Reserves 10 6 [t] Product ion 10 6 [t] 494,5 628,0 325,5 489,6 717, ,8 28,4 R P (eserves) (roduction) Africa North America South America Asia Europe Middle East Oceania ,9 19,9 331,1 395,0 636, ,5 30, ,9 50,3 19,2 17,4 77,9 10,7 World , ,6 41,2

23 The Norwegian Continental Shelf in 2007 (Source: Norwegian Petroleum Directorate)

24 Zemeljski plin Natural gas is a mixture of hydrocarbon and small quantities of non-hydrocarbons that exists either in the gaseous phase or is in solution in crude oil in natural underground reservoirs, and which is gaseous at atmospheric conditions of pressure and temperature. Zaloge zemeljskega plina sestavljajo le 4,8% vse razpoložljive energije. Ob današnji porabi 0, ton naj bi razpoložljivih 2, ton ( m 3 ) zadoščalo še za naslednjih 150 let. To je zgornja meja, saj je velik del teh rezerv le teoretičnih, torej nedostopnih. Proved natural gas reserves as at end-2005 (tcm and % of world)

25 The world s largest reserves of natural gas are held by the Russian Federation, the Islamic Republic of Iran and Qatar, as has been the case for the last five editions of the SER. Fourth place is now taken by Turkmenistan which, according to the latest assessments published by Cedigaz, has overtaken Saudi Arabia in the world ranking list. In absolute terms, the largest changes in proved gas reserves are observable in Turkmenistan (an increase of bcm, attributable to a major reassessment), Iran, where reserves rose by a net volume of bcm between end and end-2008, the USA (an increase of bcm, largely due to a 51% rise between end-2007 and end-2008 in shale gas reserves see the situation report below), and the Russian Federation, where three years production, together with other factors, contributed to a contraction of bcm in gas reserves.

26 LNG flows in 2005: bcm Source: Cediga

27 Regional share of natural gas in primary energy consumption - Reference Case (Source: IGU)

28 Natural gas production by region Reference Case (Source: IGU)

29 Global gas balance (Source: IGU)

30 Definitions Proved amount in place is the resource remaining in known natural reservoirs that has been carefully measured and assessed as exploitable under present and expected local economic conditions with existing available technology. Proved recoverable reserves are the volume within the proved amount in place that can be recovered in the future under present and expected local economic conditions with existing available technology. Estimated additional amount in place is the volume additional to the proved amount in place that is of foreseeable economic interest. Speculative amounts are not included. Estimated additional reserves recoverable is the volume within the estimated additional amount in place that geological and engineering information indicates with reasonable certainty might be recovered in the future. Production - where available, gross and net (marketed) volumes are given, together with the quantities re-injected, flared and lost in shrinkage (due to the extraction of natural gas liquids, etc.). Consumption - natural gas consumed within the country, including imports but excluding amounts re-injected, flared and lost in shrinkage. R/P (reserves/production) ratio is calculated by dividing proved recoverable reserves at the end of 2008 by production (gross less reinjected) in that year. The resulting figure is the time in years that the proved recoverable reserves would last if production were to continue at the 2008 level. As far as possible, natural gas volumes are expressed in standard cubic metres, measured dry at 15o C and mb, and the corresponding cubic feet (at cubic feet per cubic metre).

31 Production 10 9 [m 3 ] R P Reserves 10 9 [m 3 ] Production 10 9 [m 3 ] R P Reserves 10 9 [m 3 ] Production 10 9 [m 3 ] R P Reserves 10 9 [m 3 ] Production 10 9 [m 3 ] R P ,5 946,8 136,7 350,5 969,6 286,7 42, ,9 969,4 149,7 426,8 995,5 358,6 45,3 70,4 9,6 57,8 40,1 56,1 >100 29, ,3 947,7 169,9 511, ,6 457,0 48,4 59,2 10,4 51,6 41,3 52,5 >100 25, , ,3 187,5 579, ,2 541,3 56,3 52,3 10,4 49,2 49,1 50,5 >100 23, , ,1 59, ,7 56, ,7 54,4

32 Jedrska goriva Na svetu obratuje 437 jedrskih elektrarn z inštalirano močjo MW, iz katerih pridobijo okoli 17% vse električne energije. Poglavitna surovina za pridobivanje jedrske energije je trenutno uran. Izkoristek, ki je razmerje med človeku koristno energijo ali delom in vloženo energijo ali delom, je tudi pri rabi jedrskih goriv zelo odvisen od uporabljene tehnologije. Danes porabi povprečni lahkovodni reaktor z močjo 1000 MW v svoji življenski dobi okoli 5000 t urana. Ob ponovni predelavi porabljenega goriva in izrabljanju neporabljenega urana, bi se ta količina lahko zmanjšala na 17 %. Po grobi oceni znašajo zaloge urana 4, t, kar pomeni v lahkovodnih reaktorjih skupno moč 800 GW. As for almost all commodities, uranium market conditions abruptly changed with the onset of the financial and economic crises in At the close of 2009 spot prices were about 35% below their mid-2007 peak of US$ 350/kgU. Yet compared with other commodities, the uranium market weathered the storm fairly well. Uranium is generally better protected against aberrations than other markets. For one thing, short run reactor uranium requirements are relatively stable as existing nuclear power plants are usually the lowest-cost generators on the grid. Hence, stagnating or declining electricity demand does not usually affect nuclear generation. However, the level of global nuclear electricity generation has been slipping slightly during recent years owing to reactor closures, decommissioning and lengthy shutdowns for maintenance and repairs (e.g. the Kashiwazaki Kariwa units in Japan, owing to an earthquake). Lower nuclear generation, longer refuelling cycles and higher burn-ups caused annual global reactor uranium requirements to fluctuate between tu and tu over recent years.

33 Development of uranium spot market price (Source: adapted from NEA/IAEA, 2010 and ESA, 2009*) Top uranium producers in 2008 total production tu [ tu3o8] (Source: WNA, 2009a) Another factor in protecting against aberrations is that most uranium (about 85%) is supplied under long-term contracts, where the pricing is shielded from sudden market fluctuations. New contracts or contract renewals then tend to reflect the current spot price situation as well as other demand and supply factors. During the period 2006 to 2009 average long-term multiannual contract prices were about half the going spot market price.

34 Global annual uranium production and reactor requirements (Source: adapted from NEA/IAEA, 2010) Novi tehnološki ravoj je zato usmerjen v oplodne reaktorje, ki naj bi imeli po predvidevanjih 60 do 1000 krat boljši izkoristek. Pogledi in delo raziskovalcev pa so že uprti tudi v gorilne reaktorje s ciklom uran - torij ter v zlitje.

35 Distribution of Identified Uranium Resources (RAR plus IR) at less than US$ 260/kgU production costs. Total at 1 January 2009: tu (Source: adapted from NEA/IAEA, 2010)

36 Running out of Uranium? The 6.3 mtu of Identified Resources suffices to fuel the global 2008 reactor requirements for about 98 years a reserves-to-production ratio much larger than for most commercially traded minerals and commodities, including oil and natural gas. Even without considering the 10.4 mtu of undiscovered and speculative uranium resources, unconventional uranium occurrences or reprocessing of spent nuclear fuel, uranium availability per se does not pose a constraint to a possible expansion of nuclear energy. However what could prove a factor in limiting supply is timely investment in uranium exploration and new mining capacities, especially if the supply of secondary sources from military stockpiles were to decline at short notice. Unlike the remnants of fossil fuels, spent nuclear fuel when it leaves the reactor still contains some 95% of its original energy content. Reprocessing and recycling of unspent uranium and the plutonium generated during its residence in the reactor can extend the availability of Identified Resources to several thousands of years, depending on reactor configuration and fuel cycle. This does not account for the potential development and commercialisation of Undiscovered and Unconventional Resources which would essentially decouple nuclear energy from any running-out-of-resources concerns, irrespective of the type of fuel cycle deployed (once-through or closed cycle with reprocessing and recycling).

37 Uranium does not occur in a free metallic state in nature. It is a hi reactive metal that interacts readily with non-metals, and is an elem in many intermetallic compounds. Regional distribution Reserves 10 3 [t] Production 10 3 [t] Generation [TWh] R P (eserves) (roduction) Africa 613,1 6,994 11,6 88 North America 704,1 9, ,6 70 South America 171,2 4,000 10,6 43 Asia 819,3 4, ,8 179 Europe 303,3 5, ,0 60 Middle East 0,5 Oceania 670,0 5,984 World 3 281,5 32, ,3 101

38 Recent Developments The last five years have witnessed somewhat contradictory nuclear power trends, specifically a substantial increase in interest in the use of the technology and, at the same time, a slow but steady decline in its share of global electricity supply. And while 2008 was distinctive as the first year since 1955 in which no new reactors were connected to the grid, 2009 was the second straight year with a relatively high number of new construction starts. The eleven construction starts in 2009 were the highest since 1987 (Fig. 6.7). While the order books of vendors of heavy forging equipment are full, with backlogs of 50 months and more, utilities, especially in the United States, have remained reluctant to close the deals as scheduled. Projected construction costs of new nuclear reactors skyrocketed through mid-2008; yet despite high cost estimates and the financial and economic crisis that started in the second half of 2008, upward revisions in projections of future nuclear power growth continued in 2009 as well. In part, these upward revisions reflect continued high interest in starting new nuclear power programmes. Some 60 countries currently without nuclear have expressed to the IAEA interest in exploring or starting nuclear programmes.

39 Construction starts of nuclear power plants (Source: IAEA, 2010a)

40 Hidroenergija Hidroenergija je edini obnovljivi vir energije, pri kateri ekonomičnost energetskih naprav za (spremembo energije vode v električno) v preteklosti ni bila vprašljiva. Prav gotovo pa je v vseh razvitih deželah opazno stagniral razvoj teh naprav, saj so v teh deželah vsi enostavno ali ceneno izrabljivi hidroenergetski potenciali že izkoriščeni. Percentage of technical and economic hydropower potential exploited in 2002, by region (Source: World Atlas of Hydropower & Dams, 2003)

41 Hydropower is currently being utilised in over 160 countries. At end-2008, global installed hydropower capacity stood at about 874 GW. This figure is based upon data reported by WEC Member Committees, supplemented by information provided by national and international sources, including the International Hydropower Association (IHA). As far as possible the data refer to net installed capacity excluding pumped-storage schemes. According to data made available to the IHA, this capacity is derived from some stations, with around generating units. Distribution of installed hydropower capacity at end-2008 (Source: WEC Member Committees, Aqua-Media International and published statistics)

42 Svetovni hidroenergetski potencial Izkoriščene vodne kapacitete MW GWh/a Neizkoriščene vodne kapacitete MW GWh/a Kot je možno razbrati iz tabele, je skupna možna proizvodnja iz hidroenergije GWh. Nadalje lahko izračunamo, da izkoriščamo trenutno na svetu le 13,9% razpoložljivega hidroenergetskega potenciala. Ta izračun moramo jemati s precejšnjo mero previdnosti, saj vsega potenciala tehnično ni možno izkoristiti. Prav tako je stanje izkoriščenosti različno porazdeljeno. Po ocenah naj bi v Evropi izkoriščali že 75 % hidropotenciala, ta odstotek pa se bo zvišal celo na 80 %, ko bodo zgrajene načrtovane kapacitete. Drugod po svetu omogoča uvajanje nove tehnologije izrabo vodne energije daleč od odjema. Največji takšen hidroenergetski sistem, ki ga že gradijo in deloma obratuje, je Itaipu moči MW. V Indoneziji gradijo na Sumatri kompleks Asakan, v Braziliji so dali leta 1988 v pogon sistem v Balbini z močjo 250 MW, v Kanadi nadaljujejo delo na dodatku objekta z močjo 1900 MW (k 5328 MW enoti LaGranda, ki je eden izmed štirih v MW kompleksu v Jamesovem zalivu). Ravno v kanadskem primeru pa je večja pozornost usmerjena na razširitev enosmerne visokonapetnostne povezave v pet-terminalski 1325 km dolg sistem napetosti ± 450 KV. Prvi svetovni sistem z več kakor dvema simultanima terminaloma bi naj bil v pogonu že septembra Podobne povezave načrtujejo v Novi Angliji, kjer bi naj MW-na povezava s Kanadskim omrežjem oziroma z omenjenim enosmernim visokonapetostnim terminalom rešila probleme pomanjkanja konične moči.

43 Ljudje so izkoriščanje hidroenergije v energetske namene skozi vso zgodovino le izpopolnjevali in večali njen obseg. Rezultat tega razvoja so velike hidrocentrale, ki imajo moči od nekaj 100 do nekaj 1000 MW. Danes se hidroenergija koristi predvsem za proizvodnjo električne energije. 43

44 Definitions Gross theoretical capability is the annual energy potentially available in the country if all natural flows were turbined down to sea level or to the water level of the border of the country (if the watercourse extends into another country) with 100% efficiency from the machinery and driving water-works. Unless otherwise stated in the notes, the figures have been estimated on the basis of atmospheric precipitation and water run-off. Gross theoretical capability is often difficult to obtain strictly in accordance with the definition, especially where the data are obtained from sources outside the WEC. Considerable caution should therefore be exercised when using these data. Where the gross theoretical capability has not been reported, it has been estimated on the basis of the technically exploitable capability, assuming a capacity factor of Where the technically exploitable capability is not reported, the value for economically exploitable capability has been adopted, preceded by a ">" sign. Economically exploitable capability is the amount of the gross theoretical capability that can be exploited within the limits of current technology under present and expected local economic conditions. The figures may or may not exclude economic potential that would be unacceptable for social or environmental reasons. Capacity in operation is the total of the rated capacities of the electric generating units that are installed at all sites which are generating, or are capable of generating, hydro-electricity. Probable annual generation is the total probable net output of electricity at the project sites, based on the historical average flows reaching them (modified flows), net heads, and the plant capacities reported, making allowance for plant and system availability. Capacity planned refers to all sites for which projects have been proposed and plans have been drawn up for eventual development, usually within the next 10 years. Capacity under construction and planned relates to all units not operational but which were under construction, ordered or about to be ordered at the end of 2008.

45 Economically exploitable capability is the amount of the gross theoretical capability that can be exploited within the limits of current technology under present and expected local economic conditions. The figures may or may not exclude economic potential that would be unacceptable for social or environmental reasons. Actual generation is the net output (excluding pumped-storage output) in the specified year. Regional distribution Technically exploitable [TWh/a] Instaled capacity [MW] Actual generation [GWh/a] R P (generation) (capability) Africa North America South America Asia Europe Middle East Oceania ,86 % 42,62 % 17,76 % 11,64 % 27,19 % 3,83 % 18,07 % World ,32 %

46 The increasing need for storage Most hydropower projects were developed to provide base load to the power system, and this pattern will continue in developing countries. However, the variable nature of the growing portfolio of renewables, as well as the costs associated with shutting down thermal energy options (resulting in their being kept running through periods of low demand) means that there is often excess power in a grid at times of low demand. This has led to an increasingly important role for pumped storage hydro, where, to store energy for use in periods of high demand, water is pumped from a lower to a higher reservoir. Currently, there are more than 127 GW of pumped storage throughout the world. Recent reporting in the technical press indicates that at least 15 projects are under construction in nine countries, and that these will add a further 8.8 GW of capacity. The power plants range in size from 150 to MW. It is anticipated that the market for pumped storage will increase by 60% over the next four years. This is a clear reflection of the increasingly important role that storage will play in the future, with increased requirements for peak load and intermittent source balancing. However, as pumped storage is a net user of electricity (it requires electricity to pump the water to the higher storage reservoir), it depends on strong differentials in the market price, between low and peak demand, for its viability.

47 Biomass (peat & wood & other) Peat is a soft organic material consisting of partly decayed plant matter together deposited minerals. The organic component of peat deposits has a fairly con anhydrous, ash-free calorific value of MJ/kg. Wood is a hard substance which forms the branches and trunks of trees and w can be used as a building material, for making things or as a fuel. Other then wood includes agricultural and wood/forestry residues and herbac crops grown specifically for energy but excludes forest plantations grown specifi for energy. It is well known that biomass is a very poorly documented energy source.

48 Share of bioenergy in the world primary energy mix (Source: based on IEA, 2006; IPCC, 2007)

49 Biomass Resources At present, forestry, agricultural and municipal residues, and wastes are the main feedstocks for the generation of electricity and heat from biomass. In addition, very small shares of sugar, grain, and vegetable oil crops are used as feedstocks for the production of liquid biofuels. Today, biomass supplies some 50 EJ globally, which represents 10% of global annual primary energy consumption. This is mostly traditional biomass used for cooking and heating. There is significant potential to expand biomass use by tapping the large volumes of unused residues and wastes. The use of conventional crops for energy use can also be expanded, with careful consideration of land availability and food demand. In the medium term, lignocellulosic crops (both herbaceous and woody) could be produced on marginal, degraded and surplus agricultural lands and provide the bulk of the biomass resource. In the longer term, aquatic biomass (algae) could also make a significant contribution. Based on this diverse range of feedstocks, the technical potential for biomass is estimated in the literature to be possibly as high as EJ/yr by 2050, although most biomass supply scenarios thattake into account sustainability constraints indicate an annual potential of between 200 and 500 EJ/yr (excluding aquatic biomass). Forestry and agricultural residues and other organic wastes (including municipal solid waste) would provide between 50 and 150 EJ/yr, while the remainder would come from energy crops, surplus forest growth, and increased agricultural productivity. Projected world primary energy demand by 2050 is expected to be in the range of 600 to EJ (compared to about 500 EJ in 2008). Scenarios looking at the penetration of different low-carbon energy sources indicate that future demand for bioenergy could be up to 250 EJ/yr. This projected demand falls well within the sustainable supply potential estimate, so it is reasonable to assume that biomass could sustainably contribute between a quarter and a third of the future global energy mix.

50 Technical and sustainable biomass supply potentials and expected demand (Source: adapted from Dornburg, et al. [2008], based on several review studies)

51 Regional distribution Africa North America South America Asia Europe Middle East Oceania World Land 10 3 [km 2 ] Reserves 10 6 [t] Production 10 6 [t] Consumption 10 6 [t] Peat 58,410 17,000 0,012 0,012 Wood 6 499, ,300 Other 26,025 7,983 Peat 1 354,220 15,0 Wood 5 493, ,800 Other 55,279 16,957 Peat 62,400 80,0 0,015 0,015 Wood 8 742, ,400 Other 88,881 27,264 Peat 331,880 53,0 1,136 1,120 Wood 5 369, ,000 Other 131,197 40,244 Peat 876, ,0 20,105 16,288 Wood , ,900 Other 0,502 0,154 Peat 20,850 Wood 110,000 0,700 Other 0,914 0,280 Peat 9,640 Wood 2 011,000 11,600 Other 19,358 5,938 Peat 2 713,910 21,268 17,435 Wood , ,700 Other 322,156 98,821

52 Development status of the main technologies to produce biofuels for transport (Source: E4tech, 2009)

53 Main international biomass for energy trade routes (Intra-European trade is not displayed) (Source: Junginger and Faaij, 2008)

54

55

56

57

58

59 Sončna energija

60 Nagib Dolžina Širina Debelina Število zvezd S prostim očesom vidimo svetlobnih let svetlobnih 700 svetlobnih let 100 do 300 milijard let 6000 zvezd Rimsdka cesta

61 Zvézda je sijoče plinsko nebesno telo z veliko maso, vidno nanočnem nebu. Zvezdni soj je posledica jedrskih reakcij, katerih oddano energijo ljudje vidimo kot svetlobo ali, v primeru Sonca, čutimo kot toploto. Zvezde so na videz svetleče točke na nočnem nebu, ki utripajo zaradi učinkov Zemeljskega ozračja. V znanstvenem izrazoslovju so zvezde določene kot samogravitacijske krogle plazme v hidrostatičnem ravnovesju, ki ga ustvarja njena lastna energija s pomočjo jedrskega zlivanja. Energija, ki jo v vesoljski prostor sevajo zvezde, je elektromagnetno sevanje (večinoma vidno svetlobo) in tok nevtrinov. Navidezna svetlost je merjena po svetlobi, ki jo oddaja kot svetla točka na nebu in izražena z navideznim sijem. Energijska izsevnost M P = = 63,11 A S MW 2 m T = K notranja temperatura Sonca T = 5777 C temperatura površine Sonca P = 3, W moč Sonca m = 1, kg masa Sonca r S = 6, m polmer Sonca A S = 6, m 2 površina Sonca

62 Zlitje (fuzija) zajema združitev dveh lahkih jeder v jedro, ki je kompleksnejše, njegova masa pa je manjša od vsote preostalih mas izvirnih jeder. Primeri takšnih reakcij, pri katerih se sprošča energija, so: 1H H 1 1 H e 0 1H H 1 2 He 3 + γ-sevanje 2He He 3 3 He H H 1 V prvi reakciji se dva protona združita v devteron in pozitron. V drugi se proton in devteron združita v lahek izotop helija. Da bi prišlo do tretje reakcije se morata prvi dve reakciji dvakrat ponoviti, v njej pa se dve jedri lahkega helija združita v običajen helij. Te reakcije, znane kot veriga proton proton naj bi se dogajale v notranjosti Sonca, prav tako pa tudi v mnogih drugih zvezdah, sestavljenih pretežno iz vodika. Pozitroni, ki so nastali v prvem koraku verige proton proton, trkajo z elektroni; prihaja do uničenja in njihova energija se spremeni v γ-sevanje. Posledica verige je tako združitev štirih vodikovih jeder v helijevo jedo in γ-sevanje. Skupno energijo, ki se pri tem sprosti, lahko izračunamo iz sledečega masnega ravnotežja: Preostala masa 4 vodikovih atomov = 4,03132 ram Preostala masa 1 helijevega atoma = 4,00260 ram Razlika v masah = 0,02872 ame = 26,7 MeV

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80