Bazz,

You are right to focus on those cloudy cold winter periods as they are the crucial times for performance of renewables. If you download the full report and go to section 3.6 p 21 and 22, you'll see graphs of a typical 2 week period in summer, which has only a few hours where OCGTs are needed and a wet 2 weeks in winter where there are about 8 days of shortfalls interspersed with 6 days of surpluses. The surpluses are not sufficient to recharge the storage, so there is a period where OCGT balancing power is required all the time for 5 days straight. This is about as bad as it gets but it's no problem, the OCGT generation is there to balance those shortfalls.

The bar graphs in section 5.3.3 p 59 are also worth a look. Here we graphed the amount of renewable generation for 7 years. The lowest amount in any year is 85.5% and the highest is 90.3%, meaning that for this scenario the OCGT's only generate 9.7% -14.5% of the energy used in any year.

Yes, the NEM (eastern) grid does have the advantages of interconnectors like thoes you suggest. It also has some hydro, so RE would be a bit cheaper over there. We will be costing interconnectors in WA but I doubt they will be cost-effective - cost is 3- 4 billion for an east-west HVDC line. Also they don't eliminate the need for OCGT standby capacity in any grid.

Shadow
I think you are 'clutching at straws'. LCoE and average wholesale electricity costs are quite different and much higher than the variable spot prices. The wholesale cost of electricity from a modernized electricity grid, whether coal or renewable would be about 2c higher, not the 'huge increase' you allege. Once again, read the report right through and you'll see all this explained.

Well guys, thankyou for an interesting discussion; I hope we have all increased our awareness. I will sign out of the thread now.

Thanks Roses,
It looks like the greenies will have to be convinced that some fossil fuels will be needed especially in winter.
Still they will probably throw a tantrum and end up having the housewives chasing them down the street with cold dinners, hi !

That's right Bazz, some form of fast response fueled standby generation will always be needed. Currently fossil (gas) is the most economic fuel for that but in future bio-fuels and other renewable fuels (perhaps hydrogen produced by renewable electricity) will become cost-effective alternatives. As it will be less than 15% of total generation in renewable grids, fuel cost is not as critical as it is for base load technologies.

Wind and PV are now mature technologies, cheaper than new coal. So it's clear where government research money needs to go - finding cheaper renewable fuels and cheaper storage - as standby power for wind and solar systems and also transport.

Cheers

Ben Rose

What of the methane issue, Roses1, methane?!

Also, still not sure whether consumer purchase of BTM batteries and their replacement is included in costing your scenarios. Call me stupid, but it's not quite clear to me.

Hoping you can address these fully before departing this thread (or is it why you are departing?)

Luciferase,

Methane leaks is a very important issue with significant global warming impact as methane is > 20 times more potent than CO2 as a greenhouse gas. That is why we would advocate no more coal seam gas or other types of fracking and more stringent monitoring and rectification of existing gas installations.

We (SEN) also advocate utilization of existing solid bio-mass resources / technologies, establishment of biomass plantations on marginal land and commercialization of new cost-effective bio-fuel and other renewable fuel technologies as quickly possible to replace natural gas wherever possible. OCGT's can also be fueled by liquid bio-fuels, which should be the ultimate aim. Our Study gives details of the amount of land that would be required to grow bio-fuels for this purpose. There is also the option of producing renewable fuels from surplus clean (wind and solar) electricity; some research money should be directed to developing these technologies.

I re-iterate that some OCGT balancing generation is used in all electricity grids including nuclear, which is too slow ramping to follow rapid load changes.

Re costing of the batteries, we have assumed a subsidy of $40/MWh (similar to the existing RECS) be paid by the utilities to battery owners. That would nowhere near cover the cost of the batteries, but they are increasingly cost effective in their own right (as costs are falling), for residential and commercial consumers who can use more of their solar energy and buy in cheap off peak power to charge them. See page 38 of the Study; download from: http://www.sen.asn.au/modelling_findings

Happy reading!

Cheers,

Ben Rose

Load following needs are reduced the greater the level of nuclear in the mix. Also, the newest reactors are nimble and the past is not a reliable guage for the future. No support here for your argument for future OCGT requirements for baseload nuclear energy:

https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-load-following-e.pdf

The whole energy train for the biomass needed for your proposal needs to be looked at, not just the land provision for it.

The EROEI argument bites into battery storage, reducing buffered PV generation to barely break-even in real world experience (Spanish mass installations, Prieto & Hall). Even if your scenarios succeeded there will be little CO2/AGW mitigation.

Whatever, thank you for your prognostications and response.