Rooftop Solar In South Australia Met One Third Of State’s Daily Electricity Demand

Power to the people
Right on
   -John Lennon

Someones gonna have to pay the price
   -Journey


Greetings

   Here's some pretty cool news.  Solar and Wind  are producing lots of power in Australia.   Around 40% according to this article.  They are shooting for 50% by 2025.

   All very nice.  Presumably while the wind blows or the sun shines, there is no need to run the coal and gas plants that provide back up.  So less CO2 is emitted than would have been.

  Solar and wind generation continue to get cheaper, so we should expect them to make greater inroads.

     So how does this fit in with the fact that Google dropped its project of replacing fossil plants with renewable energy?  After 5 years of study, they walked away.  Why so gloomy?  Here's what the Google engineers said

"At the start of RE<C, we had shared the attitude of many stalwart environmentalists: We felt that with steady improvements to today’s renewable energy technologies, our society could stave off catastrophic climate change. We now know that to be a false hope—but that doesn’t mean the planet is doomed.

As we reflected on the project, we came to the conclusion that even if Google and others had led the way toward a wholesale adoption of renewable energy, that switch would not have resulted in significant reductions of carbon dioxide emissions. Trying to combat climate change exclusively with today’s renewable energy technologies simply won’t work; we need a fundamentally different approach. So we’re issuing a call to action. There’s hope to avert disaster if our society takes a hard look at the true scale of the problem and uses that reckoning to shape its priorities".

OK, so the Google folks couldn't accomplish what they wanted.  What they wanted was  a renewable setup without the coal and gas backup.    In other words they needed a battery,  and they wanted one that would be cheap enough so the entire system would be cheaper than coal.

   So, batteries that cheap just aren't available today.    But surely technology marches on!  Surely Google would think so.

    And they did.  They took a look at the future, factoring in likly improvements based on

"...a study on the impact of clean energy innovation, using the consulting firm McKinsey & Co.’s low-carbon economics tool. Our study’s best-case scenario modeled our most optimistic assumptions about cost reductions in solar power, wind power, energy storage, and electric vehicles. In this scenario, the United States would cut greenhouse gas emissions dramatically: Emissions could be 55 percent below the business-as-usual projection for 2050.

  Then they ran the numbers against the goal of Harson's goal of 350 ppm

"Even if every renewable energy technology advanced as quickly as imagined and they were all applied globally, atmospheric CO2 levels wouldn’t just remain above 350 ppm; they would continue to rise exponentially due to continued fossil fuel use. So our best-case scenario, which was based on our most optimistic forecasts for renewable energy, would still result in severe climate change, with all its dire consequences: shifting climatic zones, freshwater shortages, eroding coasts, and ocean acidification, among others. Our reckoning showed that reversing the trend would require both radical technological advances in cheap zero-carbon energy, as well as a method of extracting CO2 from the atmosphere and sequestering the carbon.

As I see it, the major problem is cost.   It's not that we couldn't come up with the batteries.  Its that we would be willing to pay for it!    It will only come to pass, if the technology can be delivered at "high profit margin"  

"In the electricity sector, that bottom line comes down to the difference between the cost of generating electricity and its price. In the United States alone, we’re aiming to replace about 1 terawatt of generation infrastructure over the next 40 years. This won’t happen without a breakthrough energy technology that has a high profit margin. Subsidies may help at first, but only private sector involvement, with eager money-making investors, will lead to rapid adoption of a new technology. Each year’s profits must be sufficient to keep investors happy while also financing the next year’s capital investments. With exponential growth in deployment, businesses could be replacing 30 gigawatts of installed capacity annually by 2040.

This type of analysis has some merit, I think.  First  Google has an incentive to try to find the "next big thing", so I have no reason to think they would down play something usefu;.  Second their assumption that it woun't happen unless someone makes a profit, is pretty well in tune with the modern ethos,  and in particular the approach of the folks who now control both houses of Congress.  

     So, my take away, is not necessarily that it can't be done.  It just won't be cheap.  And if we aren't willing to accept that  here's  their best guess map of the future






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By Giles Parkinson on 12 January 2015

We’ve documented the growing impact of rooftop solar on the electricity market in South Australia on many occasions, but on Boxing Day just passed it may have hit a new record.

According to this graph from the Australian Photovoltaic Institute’s Solar Map, rooftop solar contributed up to one third of total demand in the state in the middle of the day, and at least 30 per cent from 11.30am to 3.30pm.

The South Australian grid operator has recognised the benefits of rooftop solar on the grid – it says it has pushed the peak back much later in the day, reduced the breadth of peak demand (much to the chagrin of the conventional generators who relied on the peaks for income), and reduced stress on the grid at peak times.

Indeed, this graph here shows over the three days around Boxing Day. It registers only grid demand, so not rooftop solar.  Notice the dips during the day – from the grid’s point of view, off-peak now comes in the middle of the day.

But here is what the total electricity demand looks like with solar included – courtesy of the APVI Solar Map data and some chart-work from energy analyst Hugh Saddler at Pitt&Sherry.

It shows that wind accounted for nearly half of total demand on December 26. Which means that wind and solar accounted for around two thirds of total demand for large parts of the daytime hours, and just over half over the 24-hour period.

Saddler notes that total electricity demand in SA on December 26 was low for summer because the day was relatively cool (maximum temperature in Adelaide 23.4 deg. C) and also a public holiday.

“That said, the data show that there is no technical impediment to renewable sources of generation supplying a high proportion of total electricity requirements,” Saddler says.

” The combined share of wind and solar for the whole day (midnight to midnight) was 52 per cent.  The data also show the benefits of technology diversity in renewable generation.  Wind and solar generation  complement  each other when, as is very often the case in SA, there is more wind overnight than during the day.

“This demonstrates that, when Australia eventually gets serious about transforming its electricity industry towards a low emission future, both technologies should be important parts of the total generation mix.”

And, Saddler adds, the data shows the economic benefits for electricity consumers of interconnections between states.  For most of the day low cost brown coal electricity imported from Victoria displaced higher cost local coal and gas generation in SA, but on a couple of occasions surplus generation from wind in SA flowed east, helping to keep prices in Victoria slightly lower than they would otherwise have been.

There are several things to note about South Australia. It has the highest penetration of rooftop solar in the country,with more than 23 per cent of all customers having solar. It also has nearly 50 per cent of all wind capacity in the country, at around 1,500MW.

And as a result of all that, one of its two major coal generators is mothballed, and the other operators only part of the time. And its biggest gas plant, the Torrens facility owned by AGL Energy, will close half its capacity too because it is no longer needed.

Indeed, on an annualised basis, the state now meets around 40 per cent of total demand through wind and solar. That is expected to jump significantly in coming years.

The state government has a 50 per cent target by 2025, but in reality it could go much higher than that – even to 100 per cent - particularly if the national renewable energy target remains in place.

The prevalence of variable wind and solar underlines the importance of energy storage going forward. But battery storage is already proving to be economic, particularly in the role of avoiding costly upgrades and extensions to the network of poles and wires.

This in turn will encourage more renewables. The SA grid operator itself suggests that the future may lie in a series of renewables based micro grids based – it sees little future for conventional generators, or even conventional electricity retailers.

Batteries Not Included

Electrical banana is going to be a sudden craze

Electrical banana is bound to be the very next phase

  Donovan

The ghost of electricity 

Howls in the bones of her face

   Dyaln

Greetings

      In the drive to get off carbon, there is a lot of hope put onto renewables.  And the EROI for wind, especially, and solar to some extent, make it look like the transition would be relatively painless.  But,we can't just get by with a little bit of renewables.  We need to run carbon power down to zero, to have a chance of missing 2 degrees. see here

     Right now it is possible to use fossil plants as a battery to back up intermittent power - and perhaps built out these renewables to 20-30%  (Largest grid operator says 30% is no problem  ), But, this will obviously not work  for 100%.   What we need then, if we want to have non intermittent  power, is storage.

     Below is an interesting discussion on a paper evaluating the EROI of various power sources, including the energy costs associated with storage.  The study uses the cheapest of storage options - pumped storage, although, sites for such storage are not available everywhere.    

   (see here for a review of some of the possible battery technologies for the future)

   Adding the energy cost of storage makes a big difference to the EROI numbers..  Wind drops from 16 to 3.9; and solar CSP from 19 to 9,.   This is not to argue that we shouldn't pursue these technologies, but we should be cognizant of what the implications are.  A much less energetic future..

 

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http://bravenewclimate.com/2014/08/22/catch-22-of-energy-storage/#more-6460

The Catch-22 of Energy Storage

Pick up a research paper on battery technology, fuel cells, energy storage technologies or any of the advanced materials science used in these fields, and you will likely find somewhere in the introductory paragraphs a throwaway line about its application to the storage of renewable energy.  Energy storage makes sense for enabling a transition away from fossil fuels to more intermittent sources like wind and solar, and the storage problem presents a meaningful challenge for chemists and materials scientists… Or does it?

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Guest Post by John Morgan. John is Chief Scientist at a Sydney startup developing smart grid and grid scale energy storage technologies.  He is Adjunct Professor in the School of Electrical and Computer Engineering at RMIT, holds a PhD in Physical Chemistry, and is an experienced industrial R&D leader.  You can follow John on twitter at @JohnDPMorgan. First published in Chemistry in Australia.

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Several recent analyses of the inputs to our energy systems indicate that, against expectations, energy storage cannot solve the problem of intermittency of wind or solar power.  Not for reasons of technical performance, cost, or storage capacity, but for something more intractable: there is not enough surplus energy left over after construction of the generators and the storage system to power our present civilization.

The problem is analysed in an important paper by Weißbach et al.1 in terms of energy returned on energy invested, or EROEI – the ratio of the energy produced over the life of a power plant to the energy that was required to build it.  It takes energy to make a power plant – to manufacture its components, mine the fuel, and so on.  The power plant needs to make at least this much energy to break even.  A break-even powerplant has an EROEI of 1.  But such a plant would pointless, as there is no energy surplus to do the useful things we use energy for.

There is a minimum EROEI, greater than 1, that is required for an energy source to be able to run society.  An energy system must produce a surplus large enough to sustain things like food production, hospitals, and universities to train the engineers to build the plant, transport, construction, and all the elements of the civilization in which it is embedded.

For countries like the US and Germany, Weißbach et al. estimate this minimum viable EROEI to be about 7.  An energy source with lower EROEI cannot sustain a society at those levels of complexity, structured along similar lines.  If we are to transform our energy system, in particular to one without climate impacts, we need to pay close attention to the EROEI of the end result.

The EROEI values for various electrical power plants are summarized in the figure.  The fossil fuel power sources we’re most accustomed to have a high EROEI of about 30, well above the minimum requirement.  Wind power at 16, and concentrating solar power (CSP, or solar thermal power) at 19, are lower, but the energy surplus is still sufficient, in principle, to sustain a developed industrial society.  Biomass, and solar photovoltaic (at least in Germany), however, cannot.  With an EROEI of only 3.9 and 3.5 respectively, these power sources cannot support with their energy alone both their own fabrication and the societal services we use energy for in a first world country.

Energy Returned on Invested, from Weißbach et al.,1 with and without energy storage (buffering).  CCGT is closed-cycle gas turbine.  PWR is a Pressurized Water (conventional nuclear) Reactor.  Energy sources must exceed the “economic threshold”, of about 7, to yield the surplus energy required to support an OECD level society.

These EROEI values are for energy directly delivered (the “unbuffered” values in the figure).  But things change if we need to store energy.  If we were to store energy in, say, batteries, we must invest energy in mining the materials and manufacturing those batteries.  So a larger energy investment is required, and the EROEI consequently drops.

Weißbach et al. calculated the EROEIs assuming pumped hydroelectric energy storage.  This is the least energy intensive storage technology.  The energy input is mostly earthmoving and construction.  It’s a conservative basis for the calculation; chemical storage systems requiring large quantities of refined specialty materials would be much more energy intensive.  Carbajales-Dale et al.2 cite data asserting batteries are about ten times more energy intensive than pumped hydro storage.

Adding storage greatly reduces the EROEI (the “buffered” values in the figure).  Wind “firmed” with storage, with an EROEI of 3.9, joins solar PV and biomass as an unviable energy source.  CSP becomes marginal (EROEI ~9) with pumped storage, so is probably not viable with molten salt thermal storage.  The EROEI of solar PV with pumped hydro storage drops to 1.6, barely above breakeven, and with battery storage is likely in energy deficit.

This is a rather unsettling conclusion if we are looking to renewable energy for a transition to a low carbon energy system: we cannot use energy storage to overcome the variability of solar and wind power.

In particular, we can’t use batteries or chemical energy storage systems, as they would lead to much worse figures than those presented by Weißbach et al.  Hydroelectricity is the only renewable power source that is unambiguously viable.  However, hydroelectric capacity is not readily scaled up as it is restricted by suitable geography, a constraint that also applies to pumped hydro storage.

This particular study does not stand alone.  Closer to home, Springer have just published a monograph, Energy in Australia,3which contains an extended discussion of energy systems with a particular focus on EROEI analysis, and draws similar conclusions to Weißbach.  Another study by a group at Stanford2 is more optimistic, ruling out storage for most forms of solar, but suggesting it is viable for wind.  However, this viability is judged only on achieving an energy surplus (EROEI>1), not sustaining society (EROEI~7), and excludes the round trip energy losses in storage, finite cycle life, and the energetic cost of replacement of storage.  Were these included, wind would certainly fall below the sustainability threshold.

It’s important to understand the nature of this EROEI limit.  This is not a question of inadequate storage capacity – we can’t just buy or make more storage to make it work.  It’s not a question of energy losses during charge and discharge, or the number of cycles a battery can deliver.  We can’t look to new materials or technological advances, because the limits at the leading edge are those of earthmoving and civil engineering.  The problem can’t be addressed through market support mechanisms, carbon pricing, or cost reductions.  This is a fundamental energetic limit that will likely only shift if we find less materially intensive methods for dam construction.

This is not to say wind and solar have no role to play.  They can expand within a fossil fuel system, reducing overall emissions.  But without storage the amount we can integrate in the grid is greatly limited by the stochastically variable output.  We could, perhaps, build out a generation of solar and wind and storage at high penetration.  But we would be doing so on an endowment of fossil fuel net energy, which is not sustainable.  Without storage, we could smooth out variability by building redundant generator capacity over large distances.  But the additional infrastructure also forces the EROEI down to unviable levels.  The best way to think about wind and solar is that they can reduce the emissions of fossil fuels, but they cannot eliminate them.  They offer mitigation, but not replacement.

Nor is this to say there is no value in energy storage.  Battery systems in electric vehicles clearly offer potential to reduce dependency on, and emissions from, oil (provided the energy is sourced from clean power).  Rooftop solar power combined with four hours of battery storage can usefully timeshift peak electricity demand,3 reducing the need for peaking power plants and grid expansion.  And battery technology advances make possible many of our recently indispensable consumer electronics.  But what storage can’t do is enable significant replacement of fossil fuels by renewable energy.

If we want to cut emissions and replace fossil fuels, it can be done, and the solution is to be found in the upper right of the figure.  France and Ontario, two modern, advanced societies, have all but eliminated fossil fuels from their electricity grids, which they have built from the high EROEI sources of hydroelectricity and nuclear power.  Ontario in particular recently burnt its last tonne of coal, and each jurisdiction uses just a few percent of gas fired power.  This is a proven path to a decarbonized electricity grid.

But the idea that advances in energy storage will enable renewable energy is a chimera – the Catch-22 is that in overcoming intermittency by adding storage, the net energy is reduced below the level required to sustain our present civilization.

BNC Postscript

When this article was published in CiA some readers had difficulty with the idea of a minimum societal EROI.  Why can’t we make do with any positive energy surplus, if we just build more plant?  Hall4 breaks it down with the example of oil:

Think of a society dependent upon one resource: its domestic oil. If the EROI for this oil was 1.1:1 then one could pump the oil out of the ground and look at it. If it were 1.2:1 you could also refine it and look at it, 1.3:1 also distribute it to where you want to use it but all you could do is look at it. Hall et al. 2008 examined the EROI required to actually run a truck and found that if the energy included was enough to build and maintain the truck and the roads and bridges required to use it, one would need at least a 3:1 EROI at the wellhead.

Now if you wanted to put something in the truck, say some grain, and deliver it, that would require an EROI of, say, 5:1 to grow the grain. If you wanted to include depreciation on the oil field worker, the refinery worker, the truck driver and the farmer you would need an EROI of say 7 or 8:1 to support their families. If the children were to be educated you would need perhaps 9 or 10:1, have health care 12:1, have arts in their life maybe 14:1, and so on. Obviously to have a modern civilization one needs not simply surplus energy but lots of it, and that requires either a high EROI or a massive source of moderate EROI fuels.

The point is illustrated in the EROI pyramid.4 (The blue values are published values: the yellow values are increasingly speculative.)

Finally, if you are interested in pumped hydro storage, a previous Brave New Climate article by Peter Lang covers the topic in detail, and the comment stream is an amazing resource on the operational characteristics and limits of this means of energy storage.

References

1. Weißbach et al., Energy 52 (2013) 210. Preprint available here.
2. Carbajales-Dale et al., Energy Environ. Sci. DOI: 10.1039/c3ee42125b
3. Graham Palmer, Energy in Australia: Peak Oil, Solar Power, and Asia’s Economic Growth; Springer 2014.
4. Pedro Prieto and Charles Hall, Spain’s Photovoltaic Revolution, Springer 2013.