Spodaj je povzetek zelo dobre simulacije nizkoogljičnega koncepta nemškega elektroenergetskega sistema in ocenjenih cen električne energije za dva scenarija. Bengt J. Olsson iz švedslega Adelfors AB je simuliral dve nizkoogljični varianti nemškega elektroenergetskega sistema: (1) samo OVE brez jedrske (SWETH) in (2) z OVE in jedrsko (SWENTH). V modelskih simulacijah je simuliral samozadosten zaprti sistem brez uvoza, pri čemer je simuliral pogoje zanesljive oskrbe in stabilnosti sistema na osnovi urnih bilanc proizvodnje in porabe. V SWETH konceptu glavnina elektrike pride iz vetra, nato iz sonca, nihanja v proizvodnji in izravnavanje razlik med proizvodnjo in porabo pa izvajajo termoelektrarne (CCGT) na vodik (baterije so neprimerne in predrage za ta namen). Simulacije (ki sicer slonijo na zelo, zelo optimističnih cenah elektrolizerjev za proizvodnjo vodika in nerealistični predpostavki, da se elektrolizerje splača uporabljati ob izkoriščenosti pod 15 %) kažejo, da bi bila LCOE cena elektrike iz SWETH koncepta brez jedrske energije za okrog četrtino dražja od elektrike iz SWENTH koncepta z jedrsko energijo. Pri čemer v izračunih niso upoštevani stroški nadgradnje distribucijskega in prenosnega sistema, ki so v razpršenem konceptu SWETH izjemno visoki.

Naj spomnim, da smo v naših izračunih SAZU-GZS za slovenski elektroenergetski koncept upoštevali tudi stroške nadgradnje omrežja in uvoz (Slovenija nima naravnih danosti (solne kaverne) za velika skladišča vodika), kjer pa so cene manjkajoče elektrike v času, ko je potreben uvoz (ob slabem vremenu, ponoči in kurilni sezoni), zelo visoke. To poviša sistemski LCOE in privede do tega da so cene elektrike v čistem OVE konceptu za 60 do 80 % višje kot v konceptu OVE + jedrska energija.

Avtor na koncu zaključi, da je:

težko […] razumeti, zakaj Nemčija ne upošteva sistema SWENTH, ki bi bil boljši od sistema SWETH, tako glede na njegove značilnosti in lastnosti kot tudi glede njegove gospodarske učinkovitosti.

Kratek povzetek ugotovitev. Polna analiza je dostopna tukaj.

A balance model approach, with no import or export allowed has been used to compare two power system approaches for Germany. Both systems provides 500 TWh of fossil free power per year. One system (SWETH) is based mainly on renewable power (that is wind and solar) and the other system (SWENTH) uses nuclear as the major power source. Both systems uses a hydrogen storage system with electrolyzers to consume overproduction of power and hydrogen CCGT as backup when the other power sources can’t supply the demanded power.

A simplified LCOE approach is used to estimate the system LCOE of the produced energy. Even though the absolute LCOE is quite subjective and dependent on the choice of parameters, the difference in system LCOE should be less subjective.

The result is that the SWENTH (nuclear based) system have a system LCOE that is 23-26% lower than the system LCOE for the SWETH (only wind/solar power) system.

This difference is further enlarged if considering the much higher transmission network costs for the SWETH system.

If import should be considered, the SWETH system requires much higher interconnect capacities to not get a deficit (or “black-out”) if the hydrogen store runs empty.

The simulation is based on German solar and wind power production from 2020-2021. These two years are just a sample of possible weather years. There have been better years, but certainly also worser years. Hence the SWETH capacity numbers should be considered as minimum values.

Transmission network

Another important aspect that makes a huge difference in the two cases is the transmission network needs. They are not quantified in this model but it is very clear that the network costs for the SWETH system is much higher than for the SWENTH system. This is due to two factors that works in disadvantage for the SWETH system

1. Geographical dispersion. The SWETH system with its high degree of wind and solar power will require a much more dispersed transmission network. For example expensive submarine cables to the offshore wind power farms. Contrary, in the SWENTH case, the nuclear plants could be built close to consumption centers with much smaller transmission needs.
2. Peak power requirements. Due to the strong power variations in the SWETH case, the transmission capacities must be much higher than in the SWENTH case. This means that the utilization of the transmission resources will be lower and hence costlier. To some extent this can be avoided by having the storage and hydrogen production/generation facilities at the right places, but the options for these are more limited due to the geological conditions for salt caverns.

Both these factors will contribute to increase the already large system LCOE difference between the two systems.

System services

The SWENTH system also provides system services, such as inertia, to a much higher degree than the SWETH system which has to rely on more volatile and fragile power electronics plus software for this.

It is hard to understand why Germany do not consider a SWENTH system that is superior to a SWETH system, both with respect to its characteristics and features as well as to its economic performance.

Vir: Bengt J. Olsson, Adelfors AB