Aidan
You are quite correct in saying that gas stand-by is cheap. To be more precise the fixed cost (mainly capital) of OGCT (gas) is about $90,000/ MW/ year whereas nuclear is around $1000/ MW/yr. Also aero-derivative OCGT's can reach full power from a cold start in less that 10 minutes, making them ideal as standby power for renewable sources. With nuclear its impossible to do this even in several hours.
In our (SEN's) scenarios, we have 2800 - 3600 MW of OCGT mostly on standby, with a CF of 0.1, quite economically, with no 'base load' generation at all.

Another point worth noting is that nuclear and coal, being inflexible in terms of ramp speed also need OCGT's for load following (on the other hand for renewable gneration it is more for following predictable changes in wind and solar generation). OCGT's are an essential part of all modern electricity generation systems.

"Do you know how many wind and PV power stations there are? Thousands. How many solar thermal powers stations operating? Scores."

Whoopee. Does that mean they should be main-grid? Nup, not when there are better choices.

We've decades and decades and decades to use all known uranium deposits, and more to discover. Well within that time the thorium fuel cycle will be deployed (thermal breeders)in conventional reactors in India (imminent) and China, then in modular liquid salt reactors. Add in plutonium (fast breeders) in Russia and France, and all fuels will be in play, burning up existing nuclear waste and powering growing needs.

To dismiss Gen 4 reactors to make an argument for renewables is plain silly. If the major players are going so hard at it, why shouldn't breeder reactors become ubiquitous? It would only be by the nobbling and stymying of Greens, Big Oil or Big Coal that nuclear is not advanced over the next decade. They even oppose fusion, tho' that looks decades away.

Point is, nuclear can be deployed right now, with the will, and can only get better. It is the only proven way towards a zero carbon world running 24/7.

Just as importantly, it is the cheapest way to run a 24/7 world. Already a loser, when you add in the energy storage issue the wheels fall off the renewables case completely.

Roses, Aidan et al,

The single biggest problem with renewables is their unreliability. A prime example is the German system which recently (May) during a period of sunny and windy weather reached nearly 100% demand supplied by renewable generation.

The fly in the ointment was that in order to achieve this the peak renewable capacity is close to 120% of demand, which generates an average of 30% demand, but during windless nights generates as low as 10% of demand, which given their biomass and hydro capacity says much about the reliability of the cheapest renewables i.e. solar and wind. Notably, during this peak supply they had to pay other countries to take their excess power.

Any system that could supply an average of 85% renewables would require a vast excess of generating capacity, in the order of 250% plus a standby capacity in the order of 75% in order to reach the reliability that the present systems are required to meet.

Once these criteria are met, the LCOE of renewables is vastly higher.

Shadow
Your statement "Any system that could supply an average of 85% renewables would require a vast excess of generating capacity, in the order of 250% plus a standby capacity in the order of 75% in order to reach the reliability that the present systems are required to meet" is broadly correct.

Our 85 % and 91% RE scenarios have 6000 MW of wind, 3000 MW of PV and 3500 MW of gas OCGT, with 8,000 - 42,000 MWh of storage (some battery plus pumped ocean hydro for the 91% scenario). One of our 100 % scenarios has 1200 MW of CST with biomass co-fired molten salt storage and 2300 MW of OCGT. At the above levels of storage it becomes uneconomic to add more as it is not used often enough; the OCGT's are used instead

So yes there is a lot of OCGT capacity. But so what? OCGT's are cheap - as I explained fixed costs are <10% of nuclear's and <20% of coal's. It is therefore cost effective to have that amount in standby to provide balancing power when required (it's CF is about 0.1).

Weighted average LCOE is $128 for the 85% scenario, about the same as a new coal-gas system equivalent to the existing one, which would have 1750 MW of coal, 1800 MW of gas OCGT and 1250 MW of gas CCGT together with <1000 MW of wind and <500 MW of solar PV. The 91% and 100% scenario LCoEs are $138 and $160 / MWh.

You really must read the report and go through the modelled scenarios and costings: http://www.sen.asn.au/modelling_findings

Ben Rose

Granted Roses we are not knee deep in horse manurer.

However after reading your posts I now find myself knee deep in your Bulldust, & it is much more smelly than anything that ever came out of a horse.

Unfortunately for you & your mates, the quiet sun is about to make fools of all of you.

With what's happening in Europe, where now the third hugely expensive offshore wind park is out of production, & their grid struggling, I can't imagine how many people can still push this fool technology.

You should look at history & the blind alleys some technology has proved to be. Stanley steamers did not die because dinosaurs like me didn't like them, but because it was poor technology.

An electric car once held a world speed record, but the technology was not practical, as is the case with electricity cars today, or alternate power generation.

Unfortunately we seem to have very many earning a good living from this scam, but they won't be able to for all that much longer. Isn't it lucky you are at retirement.

Roses,

As a power systems engineer, I find the modeling in your link a complete joke.

Firstly the surplus/deficit scenario means that your system cannot function without connection to the other states to take the surplus/deficit, secondly in rebuilding almost the entire electrical infrastructure, at $100bns for no financial benefit.

Epic fail.