“Sad but highly likely, unless there are some amazing technology break throughs.”

A psychological breakthrough is what we need Yabby.

Unfortunately in the absence of this, technological breakthroughs are very likely to actually make things worse, by effectively facilitating population growth and hence taking us further away from sustainability.

This has been the case with most significant technological breakthroughs throughout the history of humanity.

And this why the Clean Energy Council MUST have a lot to say about the need for population stabilisation and for our society to wean itself off of the continuous expansion paradigm.

Sylvia,

The electricity network *already* deals with large-scale intermittency. Individual kettles and air-conditioners are intermittent, but aggregate electric demand is predictable and highly variable. The same applies to the aggregate of numerous widespread intermittent generators. It is no more true that the wind stops blowing everywhere at once, than that a city is dark at night.

Demand management techniques have for decades attempted to match electric demand to big steam-powered generators, smoothing demand variation by encouraging "off-peak" overnight electricity consumption. A significant portion of the "base-load demand" exists solely to take advantage of off-peak tariffs. Demand management would be equally effective in encouraging demand to match a non-flat supply profile.

The cheapest and fastest way to clean up the electricity supply is neither ambient nor nuclear, but improving fuel efficiency by cogenerating wherever there is demand for heat or cooling. Almost anywhere that heat is discarded to the environment, electricity could be generated instead. Wherever electricity is used for heat, fuel can be used instead and electricity generated on the side. Cogenerated electricity is cheaper than base-load and also matches demand.

We already have many gigawatts of hydroelectric and natural-gas-powered peak electricity generation capacity which is turned on when baseload is insufficient, and off when not required. Geothermal generation is likely also to be easily varied.

I've read your posts elsewhere claiming that integration of intermittent supply reduces the efficiency of existing plant -- this is rarely the case; solar and wind correlate with peak demand, so what happens is that expensive peaking generators are displaced before base-load power. Peakers remain available to make up for shortfalls in intermittent generation instead.

By combining cogeneration with intermittent and peaking generators we can displace as much 24-hour coal-fired generation as we like, right up to the point where intermittent generators regularly exceed the total demand on the network -- which will not happen until we have more intermittent generation *capacity* than conventional generation.

Only then need we worry about storing excess electricity. Numerous options are on the table besides pumped storage: vehicle-to-grid, molten salt batteries, vanadium ion flow-batteries, compressed air, hydrogen...

"A psychological breakthrough is what we need Yabby."

Ludwig, I don't think that will happen, without a really
big shock to the system somewhere. As I said before, I think
that people unfortunately often need pain to learn.

Regarding population, I actually do believe that given the
choice, most families are happy with 1-3 kids and realise
the benefits. We can see that in countries where women
have choice, they take advantage of it. Hundreds of millions
of women in the third world, simply still don't have that
choice. We send them food and vaccines, but forget about
family planning. No wonder there is a population explosion
there.

Religion remains the problem with that debate, as Catholics
hope to outbreed muslims, their archenemy. We've heard all
the gloom and doom about demographics etc. What they forget
of course that in more educated countries, no religion is
the most popular choice. Not all brainwashed kiddies, go
on to become religious fanatics. Certainly in my generation,
the majority have opted out.

I'm really tired of the "the wind never stops blowing everywhere" argument. Leaving aside the question of whether it's true, it's not relevant. The question is not whether the wind stops, but whether it reduces to the point where the electricity supplied collectively from wind farms is below the amount required of them. Since weather patterns are large, there are going to be occasions when this occurs.

On the subject of correlation, while it is arguably true that solar panels will be generating power at times of peak demand (from air-conditioning during the day), this is not true of wind generation. Indeed, the greatest demand for air-conditioning is likely to occur at times of low wind.

The specific problem that intermittent generation proponents need to address is that where there is a peak load, sheddable load has been shed, all the existing generation is running (hydro, gas peaking, etc) and the intermittent generators (particularly wind) are not.

To my mind, the primary effect of intermittent generation is to change the economics of fossil fuelled power generation so that more gas/oil fired generators get built, and fewer coal fired generators. This certainly reduces the CO2 output, at some cost, but it is hardly sustainable, because our known reserves of gas/oil are very limited compared with coal.

Hot rocks technology, provided it works, will be non-intermittent base load generation. There would be no earthly point in running solar/wind in parallel with hot rocks, and allowing solar/wind to displace geothermal. It would simply increase the price with no benefit at all in CO2 output.

As for various solutions involving storage. Building vanadium batteries on the required scale worldwide would require more than the entire world known reserves of vanadium. Other solutions may work, but are very much in the development phase. Either way, the causers of the need for storage - the intermittent generators - should be the ones who pay for it. Let those pushing wind and solar admit to the real cost of power supplied that way, and see how well the idea gets accepted then.

Hi Sylvia,

Existing wind generators match today's load profiles quite well; so it is disingenuous as well as incorrect for you to claim the opposite.

http://www.sustainability.vic.gov.au/resources/documents/Greenhouse_abatement_from_wind_report.pdf

You can't have your cake and eat it too. Either intermittent generation reduces the need for peaking generators and saves expensive fuel and valuable hydro storage, or it requires peaking capacity for "firming" and displaces coal-fired base-load generators instead, therefore more effectively reducing carbon emissions.

In practice, the former is true at low penetrations (as we have everywhere in Australia except perhaps South Australia) and the latter at high penetrations (as is the case in Denmark and North Germany).

Either way, intermittent generation is a fuel-saver and, providing it is cheap, a winner therefore. Every kilowatt-hour from an intermittent source is a kilowatt-hour that doesn't have to be generated with fuel or stored water. At high penetrations, it saves coal instead, at the expense of more peaking capacity being required for *occasional* use.

It is certainly justified for intermittent generators to be required to pay for any extra peaking capacity that may be required. Conversely, at low penetrations with good demand correlation, they should be credited with the reduction in peak stored-energy consumption they enable.

Of course it will occasionally be true that wind generation reaches an unexpected minimum when there is a demand peak. How does this differ from occasional unplanned outages of coal-fired or nuclear generators? Coal and nuclear plants have only 85-90% availability. The measures used to cope with these outages are more than sufficient to cope with the comparably rare event of a complete wind outage.

It is true that mineral gas is a less abundant resource than coal or uranium, but biological methane is cheap and potentially very plentiful indeed.

http://biopact.com/2007/02/study-biogas-can-replace-all-eu-imports.html

Moreover, most "clean coal" and biomass technology is more readily adaptable to peaking operation than existing behemoth coal furnaces.

Intermittent generation can't supply all our requirements on its own. But until we have so much that we throw away the excess, more can't hurt.

Ask me again about vanadium when it hurts, OK?

xoddam

The report you cite gives what it states are assumed wind patterns. But even if they are correct they do not support your claim. Except on hot days, the peak load is in the evening, but for at least half the year, the graph in the report shows peak generation in the middle of the day.

In any case, they are averages, and there would be considerable daily variation. You cannot run appliances on average power.

The fact that wind generation produces a requirement for other gas generation that displaces coal generation is something I've already observed. But it does so at a cost - and the cost is considerable. Not only does the wind farm need to be paid for, but the gas powered generators, when running would have to run on gas which is more expensive than coal. Since wind farms have a capacity factor of about 30%, the associated gas generation would be run at a capacity factor of about 70%. That is, twice as much energy would be generated from gas as from wind.

Intermittent power would be a winner if, as you say, it were cheap. But it's not cheap by any stretch of imagination.

Unplanned outages of fossil or nuclear power generation do occur, but this should not be equated to their 85% availability. That figure doesn't mean that they're out of operation 15% of the time due to faults. It just means they have to be taken off line for planned maintenance, upgrades, etc. for that amount of time. Those outages are planned.

As regards the availability of biogas, I note that there is little in the way of concrete data in the article you cited, and particularly noticeable is the absence of any mention of cost.

And cost is the important issue here, because ultimately, it's going to be cost that decides between nuclear and other solutions. At the moment, people are being misled into thinking that solutions like wind farms and solar panels can be used without a significant increase in the price of electricity, but it's just not true.