Is Powerwall good for coal and nuclear?

No one seems to have spelt this point out, but there’s an obvious potential for Powerwall to be used in ways that benefit coal, nuclear and geothermal power, as well as renewables like wind and solar. Advocates of these technologies love to cite the fact that they are “baseload” supplies, but this is a misconception. Because they are costly to turn on and off (or even up and down), these technologies produce too much power at times of little demand (late night and early morning).

If owners of home solar systems, connected to grids with an off-peak excess supply, install battery storage on a large scale, it would make sense to run two cycles per day. The systems (most sensibly oriented west) would charge up from solar panels in the early afternoon, and supply power in the evening. Then they would recharge from the grid in the early morning, and supply power to meet the morning peak associated with getting ready for work, school etc.

What’s the net effect of this. First, obviously, it makes storage a more appealing economic choice for householders. Second, although it reduces costs for any kind of electricity that is not fully dispatchable, the benefits are bigger for renewables for two reasons. First, the variability of these sources is greater. Second, pricing systems, at least those in Australia, are already set up to encourage use of off-peak grid power, whereas current feed-in tariffs discourage solar PV.

From our current starting point, effect of adding more systems with a combination of solar PV and storage will be to reduce total demand for coal-fired power (and, where it exists, nuclear power), and to enable more efficient use of existing capital stock. So, it’s likely to discourage new investment in these sources. However, unless we have a carbon price, or other measures in place, it won’t necessarily accelerate the closure of existing coal-fired plants.

Update A note on the economics: Calculations I’ve seen on the web assumed that lithium batteries have a life of 1000 recharge-discharge cycles, but it appears this number can be improved drastically. These guys are claiming 20 000. More on this soon, I hope.

74 thoughts on “Is Powerwall good for coal and nuclear?

  1. @TerjeP

    I don’t think you understand the full effects of even a 2 degree C rise. Neither do I, but I think I am aware of a few more ramifications than you seem to be.

    1. An average global rise of 2 degrees C will not be a uniform rise in all regions. Modelling shows Australia for example will get hotter than the average increase. This will be especially the case in some regions. Overall, rainfall will drop but extreme rain events will be more serious. The drought-flood cycle will worsen in Australia. Average soil moisture readings will fall.

    2. Many other perturbations are caused by warming. Air is warmer and more moisture laden. There is more energy to drive cyclones, hurricanes, tornadoes, typhoons etc. Yes, I know some of these storm type names are semantic differences. I am alluding to the areas where they occur and are so named locally.

    3. The behaviours of the circumpolar vortexes are changing and taking on a larger waveform. This causes weather patterns to get “stuck” for months or even seasons. Extended drought in California, unseasonal warm weather in the Yukon in winter and extended and multiple blizzards on East Coast America are one result. Many other air and ocean currents could be affected.

    4. Some cool temperate zones may get warmer and more amenable to agriculture. Colder zones where the permafrost melts are likely to become tractless, impassable marshes, emitting methane for generations. They won’t be much use to us.

    5. During transition phases to new relatively stable climate states (if the new state is relatively stable) there are still likely to be long unstable phases. By long, I mean lasting for generations, even many generations in human terms. The instability and wider weahter variability (which is very likely to eventuate) is going to make agriculture and other activities much more difficult.

    6. There is no doubt that a (sixth) mass extinction event is going on right now and is likely faster and worse than any other extinction in the earth record. There is no doubt that climate change is driving part of this. Many other species are declining rapidly. So it is clear that what is happening even now is radically and catastrophically changing world ecology.

    The evidence is clear that these changes are extremely deleterious and inimical to human well-being. Humans did not biologically emerge or evolve in the holocene. However, we developed agriculture and civilization in the holocene. Some argue that the relatively benign and stable climate of the holocene played a role in and perhaps even enabled these developments of agriculture and civilization. Now we are trashing the benign, stable holocene climate our whole way of life depends on.

  2. @TerjeP
    Terje, a 2 degree rise is what we can expect if we are successful in getting global CO2 levels back down to 350 pmm, I.e. If we take all the emissions reduction actions you think are unnecessary. If we don’t we can expect substantially more warming than that. If you had even a dim idea of what you were talking about, you’d know that. This is why it’s impossible to take you seriously on this topic.

    Now you’ve done gone and made me break my own rule of not responding seriously to your comments on this thread. Ya got me, dammit. And you called me a troll! 😉

    It’s not some homoerotic fantasy.

    I didn’t actually think of the homoerotic angle. But you’re right – it is there. Glad you found it mildly amusing, anyway. 🙂

  3. TerjeP :
    p.s. There is also a risk that global warming will on balance be a good thing. In rushing to solve things you should not ignore that risk.

    That risk is miniscule. At this stage it can be safely ignored.

  4. > That risk is miniscule. At this stage it can be safely ignored.

    More appropriately at this point is to point out that “maybe good things can happen” can be safely ignored because if it does pan out you’re safe. Fails “safely”, as the jargon has it.

    [the basic problem here is a moral-hazard one; people die if we follow Terje’s plan and he’s wrong, but Terje doesn’t expect to be among them. I have an approach that will fix this problem.]

  5. @Ikonoclast

    1. Most warming will be at night and in winter.
    2. No evidence that there will be more cyclones etc.
    3. A hypothesis.
    4. You win some you lose some.
    5. Not concerned. You don’t know what will happen.
    6. Yes. I agree we are harming biological systems. But AGW isn’t the culprit. The main culprit is habitat destruction. Conventional pollution in some areas is also a problem. CO2 is not the issue.

  6. @Collin Street

    Collin – I’ll be dead before the end of this century. Most of my kids also unless there is some huge breakthrough in medical technology. You also I suspect.

  7. @TerjeP

    1. I am not aware that the climate scientists are saying most warming will be at night and in winter. Don’t know where you get that claim from. I am aware of several climate scientists and reports warning of a great increase in the number of daily maximums per year over a certain temperature. Usually 40 degrees C is mentioned for Australian regions.

    2. There is currently empirical evidence that storms (especially very large storms) and other severe weather events are getting more frequent and more severe. “Scientists caution that climate change has increased the chances for high impact events like the Texas drought.” – National Geographic. The reasons for this are climate physics. Global weather and storms etc. are essentially heat engine effects. Put more heat into a heat engine and you get more work. The work gos into winds, convection, movement of water, waves, rain etc. It only takes high school physics to understand this.

    3. This is not an hypothesis. The polar vortexes have already changed measureably. They are studying it right now. Don’t you read anything before you express an opinion?

    4. The science showa we will win a little and lose a lot when it comes to climate change.The net effect will be negative.

    5. It is generally understood that phase changes or state changes in complex systems are often chaotic events. Non-linear beahvious is observed.

    6. You agree that habitat destruction is the culprit. Well climate is part of the habitat. Change the climate and you change the habitat.

    Good grade 12 science students understand all of this. You have an extraordinarily simplistic view of what complex systems are and how they behave. I am not saying I am an expert; far from it. But I do have a healthy respect for what changing parameters in a complex system can do, especially when the changes induce non-linear change and phase or state changes. You seem to think everything remains simple and linear. But if a person does not have the mind and the training for understanding at least a little about complex systems, then it is quite hopeless trying to get them acknowledge complex system issues and and dangers.

    Finally, CO2 is the issue, not the only issue but certainly a major issue for climate change. The science is very clear on this.

  8. You have an extraordinarily simplistic view of what complex systems are and how they behave.

    You need to contextualise this, point out that it’s not just limited to the instant matter but pervasive through all of Terje’s behaviour and decisions, and that it’s had and will continue to have significant impact on Terje’s success in achieving his desired life goals.

  9. @zoot

    Assuming my youngest child has her youngest child at the age I did then by 2100 the grandkids will be approaching retirement age. I don’t expect climate change to be high on their list of concerns if it even rates a mention at all.

  10. Ikono,

    1. I thought it was well accepted that more warming occurred at night. That’s certainly what I read about ten years ago and media reports still make the assertion. If the idea has been overturned it’s news to me.

    2. The IPCC said cyclone frequency would decrease. Reference discussed here:

    3. Hypothesis.

    4. Who’s work are you reading? There are not many detailed attempts to add up all the costs and benefits. But Richard Tol had a crack at it and said the outcome was uncertain but could well be positive for the next half century or so. Could also be negative. Hard to say.

    5. Yes. Which is why it’s simplistic to suggest that if we just lower CO2 things will be all stable and wonderful. It doesn’t work like that.

    6. Climate change impact habitat. But other factors are vastly more significant. eg agriculture.

  11. @TerjeP

    I don’t expect climate change to be high on their list of concerns if it even rates a mention at all.

    And if you’re wrong? … I know, you won’t be here.
    My original statement stands.

  12. @TerjeP

    1. How does most global warming occur at night? Where does the accumulated heat energy go in the daytime? It is possible I suppose that by day the heat energy could go into evaporation and winds. I would need to see what the IPCC say about this.

    2. I stand corrected on this. Latest modelling on how the climate system (and storms) act as a heat engine shows a decreased frequency but an increased severity of storms. This especially applies to precipitation but probably also to wind speeds. There is more ocean water being evaporated by the extra heat energy. This increased evaporated moisture will be dropped in less storms. So more rain than present but dumped in less storm events. That equates to a very significant rise in major flood events and greater extremes of dry spells and droughts.

  13. Terfe P,

    1. You are miss understanding how warming occurs.

    Glodal warming effect is most “visible” at night. The Warming occurs during the day, but the atmosphere continues to be heated at night with energy and moisture being released from both land and oceans. The CO2 aids in the heating by capturing the back scatter IR radiation heating the atmospere marginally more and holding up the night time air temperature longer than it otherwise would, thereby making the warming more “visible”.

    So the energy is captured during the day and continues to be disbursed during the night detectable as the increasing in the average night time temperature. Atmosphereic CO2 concentration oscillates wildly at the surface between night and day also.

    3. Not hypothesis at all, accepted and visible fact.

    4. Grasping Richard Toll’s conclusions as an argument for inaction is a dangerous choice. There definitely is more “greening” goinvg on in some areas. But there is also drying and browning going on in others. Whereas thd IPCC says that there may be fewer cyclones, it also says that they will be more intense and more damaging, as will other climate activity. So being able to grow greater bulk with increased CO2 but then having that crop production demolished by wind fire and rain, is not a worthwhile gain.

    6. Terje you are just not understanding what is going on. Human activity, habitat destruction, AGW, Climate Change and species destruction are all integrally linked. Habitat destruction dud to human activity is just one cause of species loss. There are so many other causes that are related to Global Warming induced habitat change. You are flatout wrong on your conclusion, Terje.

  14. @TerjeP

    You’ve made up your mind to ignore empirical evidence and science in general. There is nothing I can say that will change your mind so I won’t waste my time further.

  15. Apologies for the typoes. The Android keypad is just a disaster for accurate typing. I correct as many as I notice but still miss many.

  16. @BilB

    I agree, TerjeP has not the slightest idea of what is going on. He gets his information from crank, science-denying sites. His climate “models” just like his economic, social and political models are defined and linked by their simplism. Crime? Simple, let everyone own guns. Climate Change? Simple, ignore it. Economics and maldistrubution and inefficiency? Simple. Free markets will solve everything. It must be kind of comforting to live in such a simple world. I have no doubt he derives great psychic comfort from believing everything is so simple.

  17. Ikonoclast :
    There is nothing I can say that will change your mind so I won’t waste my time further.

    I’m pretty sure we will both waste further time trying to persuade the other to shift their outlook. But maybe not today.

  18. Ikonoclast :
    There is nothing I can say that will change your mind so I won’t waste my time further.

    I’m pretty sure we will both waste further time trying to persuade the other to shift their outlook. But maybe not today.

  19. Saying things twice won’t make you more correct, Terje, it just makes you look nervous and uncertain, as someone with your views should be.

  20. “Powerwall” is a new entrant into this market, similar systems (identical?) are marketed to consumers in Japan and many other countries -including Australia.
    The round trip efficiency of Powerwall is given as 92% for the batteries alone. I calculate the round trip efficiency – using standard inverters – as about 83%. It is possible to build inverters with 99% efficiency over a wide power range. In this case the round trip efficiency could be > 90%.
    The future of Point of Consumption Energy Storage clearly rests on round trip efficiency. No-one will want a system that throws away 17% of the generated energy; or even more as some of the systems on the market do.

  21. @Huggybunny

    The upper theoretical efficiency for IC engines is about 50%. In practical applications (automobiles are a major example) the primary efficiency is about 25% to 35%. So the statement nobody will want a system that throws away 17% of the generated energy does not hold true at least in the sphere of IC engines.

    The efficiency of thermal coal power stations is about 33% to 48%. So, depending on the generation system and application, people and “economics” are often prepared to throw away a lot more than 17% of generated energy.

    So far I am comparing apples and oranges: primary generation efficiency versus round-trip storage efficiency. However, I think the principle still holds. Systems can be very viable at these loss rates.

    To compare apples to apples: “Typically, the round-trip energy efficiency of PSH (pumped storage hydro) varies in practice between 70% and 80% with some claiming up to 87%.” – Wikipedia.

    It is interesting to note: “The molten salt energy storage system (MSES) is extremely efficient, with a round trip efficiency calculated to be 99%.” – Wikipedia.

    I wonder, will MSES systems the size and safety level of a standard hot water system ever be viable? Could a home concentrating solar thermal and MSES system ever become viable and safe. I would not rule it out. Such a system could conceivably achieve 95% or better round-trip efficiency at this micro scale. Small scale MSES just might supersede batteries.

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