#green fraud

We linked to this "report" in a previous post, but it's worth breaking out.  Greenpeace says that Central Europe can decarbonize its electricity system using wind & solar generation, with electrolysis & hydrogen-burning gas turbines for storage, at "low cost" & with "low environmental impact".

Why would they publish such obvious falsehoods?  The rationale is right up front :  it's a propaganda blast against the Hungarian, Czech, Slovak, & Polish nuclear power projects.

For those new to the game, why do we call it an obvious falsehood?  Below a certain wind speed, wind machines generate nothing, & there are periods when large areas of Europe are becalmed.  (Solar we can neglect entirely.)  So the first part of this plan involves building enough gas plants to carry the whole electrical system load.  That's not free!  Then you have to build the electrolyzers & the hydrogen storage tanks, which also aren't free.  THEN you have to build ― how much wind?

Be generous and assume that, on average, only 50% of the power has to be supplied from the gas plants.  Also assume that, because of frequent starting & stopping, they don't achieve the 60% thermal efficiency of the most modern combined-cycle turbine plant running under full load, but more like 30%.  And suppose the electrolysis plant is 80% efficient.

So, build enough wind to supply 50% of the total load, PLUS 50% ÷ (0.3 × 0.8) ― that adds up to 2.5 times the average load.  Allow the wind machines to generate, on average, 25% of their nameplate capacity.  For every megawatt of demand, in other words, you need 1 MW of gas turbine capacity, plus no less than 10 MW of wind machines.

Electricity is dearer than ever in 2022! Experts and politicians demand,

Back to Atomic Power!

And it’s better for the climate

Some people in Germany are beginning to wake up to the fraud which has been perpetrated against them. On the left hand side of Page 2 of BILD (a popular daily with no reputation whatsoever for good journalism) for 7 June is an editorial studded with exclamation marks, acknowledging that the proposal by the Greens to burn more coal makes no sense whatsoever, and that the “20 000 Fukushima deaths” so often referred to in German media were in fact caused by the natural disaster (earthquake and tsunami), not the nuclear accident.

On the right is a report about Russian Government support, via a “climate foundation”, for the anti-nuclear SPD political party in the German State of Mecklenburg-Vorpommern, and the apparent quid pro quo of support from the SPD for the Nord Stream 2 gas pipeline.

Minister-President Söder of Bavaria has come out in favour of prolonging the operation of KKW Isar 2, the only nuclear unit still operating in the State, until “at least the beginning of 2024″. He has been more circumspect about reactivating Gundremmingen 3, which was shut down at the end of 2021. Could this be the thin end of the wedge?

Neefektivita větrné energie

To je přesně ono. V jednom grafu závislost výkonu na rychlosti větru P(v) (Power curve for wind, do cca 4 m/s žádný, pak zhruba úměrný třetí mocnině, od 15 m/s se ustálí na 100% nominálního výkonu, od 25 m/s se z bezpečnostních důvodů zabrzdí). Rozhodující je druhá křivka - histogram rychlosti větru w(v) (Wind Profile at Outstanding Site). Průměrný výkon je pak

<P> = Integrate[P(v)*w(v), {v, 0, ∞}]

Výsledkem je zlomková hodota oproti nominálnímu výkonu.

Zajděte se podívat na solitérní větrník na náhorní plošině u obce Oldřišov. Je to pěkná trasa na 10km pěší výlet z Opavy. Najdete u něj informační ceduli tvrdící, že při zdvojnásobení rychlosti větru se výkon zosmeronásobí. Takové tvrzení je však zavádějící podraz na laiky. Poctivější bylo říci, že větrník typu Vestas V90-2.0MW má nominální výkon 2 MW při dostatečně velké (ale ne zas moc) rychlosti větru (dá se dohledat na výše uvedeném webu výrobce); pod tuto mez klesá se třetí mocninou. Seriózní vysvětlení je však asi nežádoucí, protože nevzbuzuje v laickém příjemci informace (avšak plátci daně) patřičné budovatelské nadšení pro zelenou obnovitelnou energii, která je předurčena nás v budoucnu spasit (aneb spas se kdo můžeš).

Update:

Jednoduchý výpočet: průměrný výkon jedné turbíny je 0.005 TWh / (počet hodin v roce) = 5000 MWh / (24*365) = 0.57 MW, tedy zhruba čtvrtina nominálního výkonu.