Aug 12 2013

Sunday Train: The Myth of Baseload Power

(2 pm. – promoted by ek hornbeck)

cross-posted from the Sunday Train origin station Voices on the Square

In Baseload power is a myth: even intermittent renewables will work, Mark Diesendorf, Asst. Professor and Deputy Director of the Institute of Environmental Studies at the University of New South Wales (Australia), writes:

The old myth was based on the incorrect assumption that base-load demand can only be supplied by base-load power stations; for example, coal in Australia and nuclear in France. However, the mix of renewable energy technologies in our computer model, which has no base-load power stations, easily supplies base-load demand. Our optimal mix comprises wind 50-60%; solar PV 15-20%; concentrated solar thermal with 15 hours of thermal storage 15-20%; and the small remainder supplied by existing hydro and gas turbines burning renewable gases or liquids. (Contrary to some claims, concentrated solar with thermal storage does not behave as base-load in winter; however, that doesn’t matter.)

Anyone who engages in online discussion on issues involving renewable energy for any length of time will encounter the myth that renewable energy is unreliable in supplying base-load demand. This myth is pushed into the discussion with substantial financial investment, directly and indirectly, by vested interests in continued reliance on the Global Suicide Pact power sources of coal, petroleum, and natural gas. Writing from Australia, Mark Diesendorf flags the use of the Murdoch press empire in propagating this myth. Here in the United States, the myth is promoted by both Big Coal and Big Oil funded propaganda mills ~ including those libertarian “think tanks” that argue against the government getting involved in defending our economy from the prospect of collapse in the face of climate chaos …

… because the “free market”, together with billions of dollars of government subsidies for fossil fuel industry and tens or hundreds of billions of unfunded third party costs of fossil fuel consumption, will surely choose best.

Status Quo Bias and the Myth of Baseload Power

So-called “baseload” demand is a fiction. To be more specific, it is a social fiction. Total demand fluctuates during the day, and the height of peak demand and of trough demand during the day fluctuates from one day to the next and from one season to the next. One can draw a line at the average floor for power demand during a twenty four hour day during a season and call that “baseload” demand … but in reality, there are no special baseload electrons needed to supply baseload power demands, following load electrons needed to supply following load  power demands, and peak load electrons needed to supply peak load power demands.

In other words, the electrons needed to meet demands for power are fungible.

Instead of Baseload Power, what exists are baseload generating plants. The “Myth of Baseload Power” is simply that baseload generating plants are required to meet the part of power demand that we presently serve using baseload power generating plants.

The Baseload Power Myth is, in other words, that the way we do things now is the only way things can be done.

Put in those terms, it’s obvious how the Baseload Power Myth serves existing vested interest groups. If people can be conned into believing, or equally well bought into pretending to believe, the Baseload Power Myth, then it becomes possible to pretend that the most cost effective established renewable energy technologies are unable to perform as the basis of renewable, net-carbon-free electrical power supply, because the way that they work is by investing in equipment to harvest abundant, widely available power that is presently going to waste.

After all, those abundant, widely available renewable power sources are “intermittent”, which is to say volatile: they are “use it or lose it” power, and so obviously cannot be relied upon to always “be there” when needed. Because the way we have provided that kind of (almost) always there power is with a system of baseload power generators, following demand power generators, and peak demand power generators, and we cannot ever work out how to do anything in any new ways.

To be fair, that last part, the assumption of global technological incompetence in solving existing problems in new ways, is never said. It is, however, always implied by the Baseload Myth, since if we are not technologically incompetent, and are free to solve the problem in the most effective way possible … its not a problem.


Baseload Power Comes from Capital and Operating Cost Comparisons

While Baseload Power is a social fiction, it is still grounded in physical reality in power generation.

Suppose that you have a power source which is, in  MacGill & Dieseldorf (2013: 9), capable of producing power at a variable (operating and fuel) cost $8-$9/MWh. However, it has a capital cost of $3,000-$4,000 per kW capacity. Suppose you built your entire generating supply with that technology, operating off of black or brown (anthracite or bituminous) coal. Some of that capacity would be running almost all the time, some would be fired up to act as spinning reserve but only operated providing power for a few hours per day.

So how do you get to a more efficient system. Well, replace the kW capacity used the least often by Open-Cycle Gas Turbine power plants, with a capital cost of $700-$800/kW capacity. The variable cost is $12/MWh, but for a certain portion of the load, the capital cost savings more than offsets the higher variable cost during peak demand periods.

And then there is an intermediate fueled technology, Combined Cycle Gas Turbine, which uses the heat from exhaust gas to run a secondary thermal power plant, brings the variable cost down to $5/MWh, but pushes the capital cost up to $1,000-1,200/kW capacity. That is a dominant cost picture, but Australia does not have as abundant Natural Gas supply as coal supply, so you build the gas power plants up to the natural gas supply available and provide the rest from coal. Because of the lower capital cost of the Combined Cycle power plant, you try to run the coal power plants as continuously as possible, and use the natural gas generating plants to cope with swings in capacity.

If Australian domestic natural gas exhaustion was proceeding at a more rapid pace, the coal would drop out of the mix and the Combined Cycle Natural Gas generators would be the “baseload” power. If Australia had pursued a extensive nuclear program (as France embarked in decades ago), with the even greater capital costs and conceivably lower variable costs for nuclear power, nuclear power might be the baseload.

There is, in other words, nothing intrinsic about “Baseload Power”. It emerges from the mix of power demands and power generating sources in use, and:

  • change the mix of power generating sources, and it can entirely disappear.


A System With No Baseload Power

MacGill & Dieseldorf (2013: 9) do not set out to make an argument about Baseload Power. They set out to estimate what would be the least cost way to provide a 100% sustainable, renewable energy supply for the Australian National Energy Market (NEM). The NEM covers five of the six Australian States and the Capital Territory, which were a half century ago a set of five free-standing state-operated power generating systems.

Their model uses wind, solar, hydro and biomass power availability from 2010, broken up according to the five regions of the NEM. They use a “genetic algorithm” to determine the least cost mix of 100% renewable power, taking into account the limits in the availability of hydropower and biogas. They perform their simulation at two discount rates ~ 5% and 10% ~ and with two sets of costs for renewable energy, based on estimated ranges of likely costs of various renewable power sources in 2030, with “low cost” taking the low end of the range and “high cost” taking the high end. I will give the results in terms of percentage energy supplied, with percentage power capacity in parentheses, for the low and high cost results at 5% interest rates:

  • Wind: 48%-59% (32%-41%)
  • Photovoltaic: 15%-20% (24%-28%)
  • Concentrated Solar Thermal: 14%-22% (8%-12%)
  • Pumped hydro: 0.2%-0.4% (1.9%-2.1%)
  • Hydro: 5.4%-5.6% (4.3%-4.6%)
  • Gas Turbine: 6.2%-6.5% (20-21%)
  • Spilled: 4%-12%

They also estimate a benchmark fossil fueled system for comparison. Under their comparison, the 100% renewable power system would cost on the order of $10b more for Australia per year than the fossil fuel system, with a carbon cost of $50/ton-$100/ton sufficient for cost break-even between the two. However, that benchmark system includes existing subsidies to the fossil fuel industry, which is on the order of about $10b/year in Australia, so shifting the fossil fuel subsidy to renewable power would itself be sufficient to cover the gap, and any appreciable carbon price would put the 100% renewable system ahead.

This is, of course, without including the fact that allegiance to the fossil fuel power industry is a social suicide pact for any economy that hopes to survive until 2100 AD as a subcontinental industrial society, and without including the substantial third party costs which act as a de facto tax in kind paid to the fossil fueled power system by the population of the societies addicted to fossil fuel generated power.

Now, this is Australia, not the US. The Australian context is particularly favorable for solar power, and particularly for Concentrated Solar Thermal, with thermal storage capacity built into CST. And one way to read earlier research by the UNSW Institute of Environmental Studies is that for part of the year, the thermal storage of CST would be working as baseload power supply during winter.

However, in this new modelling, that goes away. There is no baseload power in this system at all.


Where Did The Baseload Power Go?

Someone used to the current system, and thinking in those terms, might ask, “where did the baseload power go?”

But remember, Baseload Power as such does not exist. Rather “Baseload Power Generating Plant” is a role that certain power generators play because of where they fit into the economics of power generation given the mix of available power sources.

So rather than Baseload Power “going” anywhere, its rather a case that with this mix of power sources, the “baseload power” role simply never emerges.

Wind and Solar Photovoltaic power are the bottom of the merit order. They are “use it or lose it” power, and the cost of one extra Megawatt when the wind blows harder or the sun is shining brighter is very low. So you use them first.

Then you use Concentrated Solar Thermal, which is “use it soon or lose it”, but its generation is well correlated with peak power demand, so you normally need it when it is available, or need it not long after it becomes available, or there is some neighboring state that needs it.

And on many days, and during many nights, both peak demand and “baseload” demand, that’s enough. However, there are overcast days followed by relatively still nights when that’s not enough. That’s when you tap (1) surpluses available from neighboring power regions and (2) the dispatchable power supplies from hydro, reverse pumped hydro, and biogas Gas Turbine.

In their least cost 100% renewable system, the majority of “back up” power comes from conventional hydro and biogas, and only a modest amount from the stored energy in reverse pumped hydro. 99.9%+ Power Availability is achieved with dispatchable capacity that is roughly 60% of peak power demand. When they assume the higher cost of renewable power sources, which would include the higher cost estimate for power storage, it emerges that it is more cost effective to over-supply wind power to increase the wind power during “slower” periods, even at the cost spilling 12% of that power. However, if we prove to be more competent technologically, and are operating on the lower end of their renewable power estimates, then the least cost portfolio only “over-investing” in volatile power sources to the point of spilling 4% of our total sustainable renewable power generated.

One element of this model that is of particular interest for the Sunday Train and Steel Interstate proposal is that it includes region to region energy transfers. This is a key element of the system, since with a National Energy Market covering 90% of the Australian population, a particular state can have a shortfall of volatile energy sources, but if at the same time another state has a surplus, there is no need to dispatch power from the limited supply of conventional hydro and biogas.

But in any event, although this study is not setting out to debunk the Baseload Power myth, it does so quite effectively. Simply by pursuing the most cost-efficient sustainable power system, the end result is an energy portfolio that does not have any power generators that play the role of “Baseload Power Supply”.

And this is an important point. If a sustainable, renewable system was designed to serve a Baseload Power role, that would be a more expensive system than it has to be. In other words, someone insisting that sustainable, renewable power perform this role, is imposing a hidden tax on sustainable, renewable power. And is therefore, wittingly or unwittingly, an accomplice with the Climate Kamikazes and their Industrial Society Suicide Pact.


Conversations, Considerations and Contemplations

As always, rather looking for some overarching conclusion, I now open the floor to the comments of those reading.

If you have an issue on some other area of sustainable transport or sustainable energy production, please feel free to start a new main comment. To avoid confusion among those who might be tempted to yell “off topic!”, feel free to use the shorthand “NT:” in the subject line when introducing this kind of new topic.

And if you have a topic in sustainable transport or energy that you want me to take a look at in the coming month, be sure to include that as well.

1 comment

  1. BruceMcF

    … what do you believe, what do you believe is true?

    You take all the trouble you can afford … at least you won’t have time to be bored.

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