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Is Storage Necessary For Renewable Energy? 442

Posted by samzenpus
from the on-the-fly dept.
mdsolar writes Physicist and energy expert Amory Lovins, chief scientist at The Rocky Mountain Institute, recently released a video in which he claims that renewable energy can meet all of our energy needs without the need for a fossil fuel or nuclear baseload generation. There's nothing unusual about that — many people have made that claim — but he also suggests that this can be done without a lot of grid-level storage. Instead, Lovins describes a "choreography" between supply and demand, using predictive computer models models to anticipate production and consumption, and intelligent routing to deliver power where it's needed. This "energy dance," combined with advances in energy efficiency, will allow us to meet all of our energy needs without sacrificing reliability.
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Is Storage Necessary For Renewable Energy?

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  • Expert?? (Score:4, Insightful)

    by Mr D from 63 (3395377) on Sunday August 17, 2014 @03:16PM (#47690169)
    This guy is clearly no energy expert. He should have consulted an electrical engineer familiar with grid behavior and transmission & distribution engineering before creating this over-simplified explanation. He completely ignores the importance of local load differences, and seems to assume there is a loss-less, instantaneous transfer of energy across the national grid, both transmission and distribution channels, with no limitations.

    He also doesn't get that even at a local level things like AC compressors are already averaged out and that delaying the timing of starts really makes almost no difference at the neighborhood level, much less a town level.

    Its nice to completely ignore realities like overall cost. Its nice to not realize that industrial areas have a significantly different profile than urban areas, and that rural areas are vastly different. Its nice to call yourself and energy expert and get submitted to slashdot by those that believe you just because they want to, or because you fall in line with their agenda.

    Credible experts are people who understand what they know, and what they don't know.
  • by XNormal (8617) on Sunday August 17, 2014 @03:19PM (#47690173) Homepage

    This is about as valid as the claim that "the wind always blows somewhere". Actual power generation data shows that weather is a very large scale phenomenon and the wind most definitely slows to a tiny fraction of its average power over an entire continent.

  • Re:Expert?? (Score:4, Insightful)

    by sycodon (149926) on Sunday August 17, 2014 @03:31PM (#47690231)

    I would suspect many people don't understand what it takes to get power from the power plant to your house. It's not just a case of power lines. It is a delicate balancing act between all manner of components that require constant monitoring and adjustment to prevent imbalances that can result in grid failures.

    Adding supplies that are unreliable/unpredictable would be quite some dance...like dancing on a 2x4...on edge, 100ft above the ground.

  • Re:Expert?? (Score:3, Insightful)

    by Mr D from 63 (3395377) on Sunday August 17, 2014 @03:37PM (#47690265)

    I would suspect many people don't understand what it takes to get power from the power plant to your house

    They don't, and we shouldn't expect them to. That's why these irresponsible articles tick me off, because they play to that ignorance. Even so called knowledgeable people consistently seem to not realize that the distribution part of the grid cannot handle the power transfers that the transmission portion can, and that power flow & management across the grid has a cost.

  • by ultranova (717540) on Sunday August 17, 2014 @04:02PM (#47690391)

    Demand is far easier to manipulate.

    No, it isn't. I need power for food storage, food preparation, Internet access and light. I also consume water, which takes power to prepare and pump. Trying to make any of these too expensive for me to afford - which is the reality behind talk of "incentives" - means it's time for torches & pitchforks.

    Turn a factory on full power when the wind is blowing and slow it down when the wind isn't.

    This means the factory is running at less than full speed on average, making it less profitable and thus more prone to be shut down. That's bad news for the employees and owners both. And that's assuming the factory can simply "slow down". Try reducing power to a chemical plant and it'll enter an emergency shutdown mode, hopefully only losing the raw materials under processing at the time (as opposed to, say, having them solidify in pipes or reactor vessels, or even outright exploding) but coincidentally creating work for hazardous waste disposal companies.

  • Re:Expert?? (Score:4, Insightful)

    by Kagato (116051) on Sunday August 17, 2014 @05:07PM (#47690677)

    To be fair the two largest HVAC providers in the US already offer predictive modeling services for regulating power consumption. Many times having complex interactions with market based supply/demand power pricing that's common in the commercial applications and buildings. We have models and systems already in the market place that take into account a number of these issues.

    Currently in the HVAC arena all the predictive models are predicated on still storing the energy in the form of chilled water. The systems figure out demand for the next day and determine the optimal time at night to chill down thousands of gallons of water based on the market (or predicted market) off peak power prices.

    Be that as it may we have off peak facilities for a reason. As you pointed out getting the grid to handle this would be no easy task. The grid is made of 500 or so different companies, most of which are only obligated to serve in the interest of the community it serves. As such we have way more generation capability than we have transmission capability. Good luck getting a majority of the companies to agree. Previous attempts by the feds to use it's power (2005 during the Bush administration) was thwarted by congress. So, I guess my main point is it's not a technology issue, we already do a lot of the stuff he's proposing in the off-peak market. What we have a political problem with transmission.

  • Re:Expert?? (Score:4, Insightful)

    by geoskd (321194) on Sunday August 17, 2014 @05:09PM (#47690693)

    Does he? His only claim here is that both supply and demand can be predicted, and that these can be choreographed to optimize utilization. He mentions that current power generation technologies are not available 100% of the time and proposes that the predictable variability of renewable power would be functionally no different. Nowhere does his proposal require loss-less, instantaneous, unlimited transmission of power.

    The problem with this moron is two fold. First, he is not an electrical engineer, but a physicist which gives him absolutely zero qualification as an electrical grid engineer. The second and more direct problem with his hypothesis is that the system he describes is a classical control problem. In a normal control configuration, you have a demand for resources which you use your control of the supply to meet. It is a largely closed loop operation. With this guys setup, you have your usual, largely, uncontrollable demand, but now you are meeting that demand with uncontrollable supply. At best case, you have some limited ability to reduce the supply, but with renewable, there is a fixed upper limit to your supply, which could at any given moment amount to zero, or close to it. With base-load supply (such as coal or nuclear), there is a minimum supply you can count on, which is your fall back, and is 100% (or close to it) reliable. With renewable, you have only half of the controllability (no ability to increase production) which means you have to size the grid so that the odds of not producing enough power at any given moment is many standard deviations below capacity (probably at least 5 for reasonable reliability). That means making a power grid that produces several orders of magnitude more power than needed , on average, just so that the low point in the production scale is still above the high point in the demand scale. Its an idiotic solution from an engineering perspective, and is a perfect example of why scientists should not try to venture opinions outside their expertise.

  • Re:Funny (Score:3, Insightful)

    by Mr D from 63 (3395377) on Sunday August 17, 2014 @05:54PM (#47690945)
    So, that is your point? I am a climate change denier? I suppose you can back up, or is that what folks resort to when they don't really have a point.

    Its irrelevant. I want an energy future where we have clean air, supply when we want it, while balancing feasibility, reasonable cost and acceptable environmental impact. I actually believe solar can and should be part of that mix, I am just not a solar cultist who ignores the real challenges. Ignorance to the many challenges, and the unwillingness to admit they exist, do nothing for any 'side' of the debate.

    Spreading crap from agenda driven organizations that have little credibility is not my idea of how to achieve success. Discussing the real issues, including cost and practicality, and even basic engineering principles, is. Have a pleasant evening.
  • Re:Expert?? (Score:4, Insightful)

    by K. S. Kyosuke (729550) on Sunday August 17, 2014 @06:15PM (#47691057)

    So, once of the costs would be complete rebuilding of the entire power transmission system

    But that's a cost of *any* major technology shift, isn't it? When cars came, we had to build better roads. When trains came, we had to build railways. When airplanes came, we had to build airports. Now PV modules came and we'll have to build a better grid one day.

    Unless you are ready to cut AC off for hours on a hot day, this will not work

    Just an idea, couldn't you use some phase change materials to store the cold?

  • Re:Expert?? (Score:4, Insightful)

    by geoskd (321194) on Sunday August 17, 2014 @06:35PM (#47691179)

    No, that's not what he is proposing. He is suggesting that the demand can be controlled to some extent with smart appliances, some assistance from industry and small scale storage.

    On that score, he is just plain wrong. The demand side predictability is not the real problem. The problem is that with renewables, there are large periods (hours and days in length) when the supply does not meet the demand. No amount of jiggering with appliances is going to close that gap. Significantly oversizing the supply, or significant storage is the only way to solve the fundamental problem. This guy is assuming that the shortfalls in the supply side are on the order of minutes. The reality is that the shortfall is on the order of days. You cant put off running a refrigerator for two days because there is a two day period of low wind in your offshore wind farms, no matter how far in advance you predict the shortage...

  • Re:Expert?? (Score:5, Insightful)

    by angel'o'sphere (80593) on Sunday August 17, 2014 @07:34PM (#47691491) Homepage Journal

    Unfortunately Amory Lovins is right and you are wrong. I did not know that a guy who worked 40 years in the energy field and is a Physicist, does ot count as an expert.

    However as long as we are not even able to produce so much energy via renewables it does not matter if we reorganize the grid for it or introduce storage or both ...

    ... that delaying the timing of starts really makes almost no difference at the neighborhood level, much less a town level.

    It makes an immense difference if it is used to balance the grid. If I as a grid operator can activate an AC that would jump on in 5 mins anyway *right now* I can put my excess power to us, without the need to power down a conventional plant or without the need to store the excess power.

    Credible experts are people who understand what they know, and what they don't know.
    That is also true for a /. poster :D you seem not to know what you don't know.

  • Re:Expert?? (Score:4, Insightful)

    by angel'o'sphere (80593) on Sunday August 17, 2014 @08:12PM (#47691631) Homepage Journal

    Averaged-out appliances are what you want with baseload generation.
    That is nonsense.
    Baseload generates baseload, a flat line of constant power production which is roughly at 40% of peak load. That means of the course of a day the baseload production does not change. It only changes very slowly over the course of a year.

    The rest is correct.

  • Re:Expert?? (Score:5, Insightful)

    by Trogre (513942) on Sunday August 17, 2014 @08:47PM (#47691771) Homepage

    Gravitational potential energy cannot be used as an energy source.

    Several hundred million people who use hydroelectric dams as their primary power source disagree.

  • by raymorris (2726007) on Sunday August 17, 2014 @10:37PM (#47692273)

    > the minimum output of variable sources like wind. If you have enough turbines the wind is always blowing somewhere, and the overall output of the entire fleet never drops below some predictable level.

    Not at all true, but it doesn't need to be.
    The energy in a fluid , such as air / wind, is proportional to the velocity SQUARED. In other words, if a 10 MPH wind has 100 units of energy, a 30 MPH wind has 625 units. A light breeze of 5 MPH, just 25 units. 40 MPH, 1600 units.

    So suppose you build a turbine with a design speed of 25 MPH (625 units). You don't want it to fall apart in higher winds, so the blades, bearings etc need to be big and heavy enough to handle over 1,000 units. That means you'll have friction and other losses of about 25 units. Notice the loss is the same as 5 MPH of wind - you get zero energy production at 5 MPH. At 10 MPH, energy output is negligible. At much above the design speed, the force on the structure quickly becomes much higher than the 625 it's designed for, so the blades are rotated and such to work AGAINST the wind, to avoid having the turbine tower blown over or spin apart. These facts combine to mean turbines produce a useful amount of power only within a narrow range of wind speeds. Unfortunately, the rule power = velocity squared is a fundamental fact of physics. You can't change that by inventing a new type of battery chemistry or something.

    If you look at a radar map of the US, you'll see one or two weather systems covering nearly a million square miles moving across the country. Missouri may be on the north end of a system while the southern wind of the system is in central Texas. That's pretty typical that the radar will show one or two systems for the whole country. So it's simply not true that the country as a whole always has "average" weather, that the wind is always 25 over much of the country. The fact is, a windy system will move across the country one week, then the next week heat wave will tour the country.

    If you wanted to use wind as your "stable" primary energy source, you'd need a week of storage.

    Fortunately not all energy needs to be a stable primary supply. If wind produces good power 10% of the time, you can reduce the use of natural gas generators 10% of the time. That's a good thing! If solar heating heats just your hot water, just 30% of the time, that's a lot of natural gas that doesn't need to be burned.

    Since they are often idealists, it's not surprising that advocates of renewable energy always have their eye on renewables as a complete replacement for primary electrical generation, but it's sad because it means we've almost completely missed some great opportunities to make a big difference. Th syn is REALLY good at heating things up. If you've left water in your garden hose in the summer, you know making an effective solar water heater is dead simple - so simple most of us have done it on accident. Yet, most of us heat our water by burning fossil fuels. Why? Because we've ignored the obvious, simple, effective wins as we focus on the holy grail. We've spent tens of billions of dollars on solar electric and a workable solution is always five years and two billion dollars away. For half that money, we could have converted all homes to solar water heating AND mostly solved world hunger with the billions left over.

I never cheated an honest man, only rascals. They wanted something for nothing. I gave them nothing for something. -- Joseph "Yellow Kid" Weil

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