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Page added on November 24, 2013

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Limitations of Unreliable Energy Sources, aka ‘Renewables’

Alternative Energy

As part of the discussions stimulated by their airing of Pandora’s Promise, CNN hosted a debate between Michael Shellenberger of the Breakthrough Institute and Dale Bryk of the Natural Resources Defense Council.

That debate included some commentary that I thought was worth promoting to the front page.

A commenter named Fred, a tech who has worked in the power generation industry on hydroelectric and diesel power systems, provided the following background information for Shellenberger and others that might engage in debates about energy sources in the future.

Shellenberger really missed the ball by not mentioning the inherent energy inefficiency of the main renewables: wind & solar.

  1. Induced cycling inefficiency in the shadowing fossil fuel power plants
  2. Necessity of long distance power transmission to get rid of surpluses and import shortages due to the vagaries of wind & solar, waste energy in transmission & the energy of construction & maintenance of the transmission lines
  3. Economics of heavily subsidized fluctuating renewables favors low capital cost, low efficiency generation to backup and shadow the Wind & Solar. That is mostly diesel generation, OCGT and archaic low efficiency coal burners. Utilities are now being forced to pay expensive capacity payments to keep these inefficient generators operational.
  4. The inevitable overbuild that comes with wind & solar generation. Even renewables advocates admit that. In order to supply peak energy, winter in the north, summer in the south you need to greatly overbuild the renewables. That inevitably means throwing energy away in the fall & spring. Compounded by the fact that hydro is max in the spring, when energy demand is minimum. That is the epitome of energy inefficiency.
  5. Need to heat & power wind turbines when they are not generating electricity, especially in the north.
  6. The inherent energy inefficiency of energy storage, very much needed by wind & solar. Typically batteries with about a 70% round trip energy efficiency. Pumped hydro about 80-90%. CAES about 65%. Hydrogen about 40%. Add to that the embodied energy in all that additional infrastructure.

In his response to my request for his permission to promote his comment to the front page, Fred added the following information:

One additional point on electricity transmission. The substations, transformers, switchgear and transmission lines must be sized to carry peak load, while only carrying an average ~15% of peak for solar & ~30% of peak for wind. The actual transmission conductors are made of aluminum. A high energy input material. Normally the conductor size & number of conductors is determined by economics, the marginal cost of increasing conductor size or number of parallel conductors to reduce line loss should equal the revenue gained by the increase in available power sold.

With solar & wind you are only transmitting a highly peaked power for an average of a few hours per day, so it is not economical to reduce line loss to a minimum by adding a lot of aluminum. Thus line losses are going to be considerable for long distance transmission. An absurd fantasy to send solar from the SW to match wind from the plains. A ridiculous waste of energy.

Like Fred, I am intimately aware of the limitations of wind, solar, geothermal, biomass, and hydro energy sources. Despite all of the attractive sales pitches that have been given for the past 40-50 years, I believe that continued pursuit of them as major contributors to our energy supply will impoverish our society, even if a few people at the top of the economic heap may be able to continue to live like nobility.

This is an area where I often part with other energy observers; building large scale wind and solar power systems is inherently a bad idea. It is not because the systems do not scale well; it is because they depend on diffuse, highly variable energy flows that cannot be controlled by humans or human-designed control systems.

Bright, observant people — starting with the first people who learned to control fire — have been struggling for millennia to develop machines and systems that enabled them to control their environments. As a species, we have worked hard to eliminate the limitations imposed by nature. Why are so many people enthralled with the idea of going back to a time when weather and climate tightly limited our daily routines? Do they really believe that life without controllable energy supplies is wonderfully utopian?

Atomic Insight



13 Comments on "Limitations of Unreliable Energy Sources, aka ‘Renewables’"

  1. J-Gav on Sun, 24th Nov 2013 1:48 pm 

    These limitations to ‘renewables’ are real. However, the other side of the argument is not presented in this article, i.e. “controllable energy supplies” sounds suspiciously like BAU concerning fossil fuels and nuclear … And when the coal, petroleum, uranium etc are gone, how ‘controllable’ are those sources going to be?

  2. Arthur on Sun, 24th Nov 2013 1:59 pm 

    building large scale wind and solar power systems is inherently a bad idea. It is not because the systems do not scale well; it is because they depend on diffuse, highly variable energy flows that cannot be controlled by humans or human-designed control systems.

    As J-Gav suggests, this is a crypto-BAU guy. He refuses to accept that the future of energy supply is NOT our wishes, but what about what is possible. Wind and solar are unpredictable? Too bad, simply turn on your washing machine when the wind blows. It is likely that for a long time to come energy will be rationed and consumption will have to be in sync with supply. Three weeks no wind? –> three weeks hibernating.

    However there are work-arounds for intermittent supply like mass scale hydro storage. But this will take decades to implement.

    Between 1980 (Apple-II/Commodore64/PC) and now (iPad) IT was all the rage, with internet, smart phones, dot-com bubbles, the lot. Expect for the coming decades attention to shift away from a taken-for-granted fully developed IT infrastructure, with tablets as an endpoint, towards energy problems and corresponding innovation.

  3. ghung on Sun, 24th Nov 2013 3:34 pm 

    One need only consider the source:

    About Atomic Insights-
    “Publisher: Rod Adams – Pro-nuclear advocate with extensive small nuclear plant operating experience. Former Engineer Officer, USS Von Steuben. Founder, Adams Atomic Engines, Inc. Host and producer, The Atomic Show Podcast…”

    In closing, he asks this: “Do they really believe that life without controllable energy supplies is wonderfully utopian?”

    This guy’s so threatened by folk’s re-discovered ability to live independently of his pet energy source he’s building strawmen. I had pretty much the same Navy training he had, but came to different conclusions, though he’s less likely to be stuck with the full cycle costs of my choices than I am with his.

  4. Jerry McManus on Sun, 24th Nov 2013 4:24 pm 

    Yes, it is ironic that it takes a shill for the nuclear industry to seize on the limitations of large scale “renewables”.

    Does that make those limitations any less real?

    The source of the comments by “Fred” is apparently an engineer with some experience, not a point of view that should so easily be dismissed.

    Rather than attacking the messenger a more productive conversation might take the time to address the detailed list of technical and thermodynamic limitations presented.

    Just a thought.

  5. Stilgar on Sun, 24th Nov 2013 6:29 pm 

    Maybe the criticism here is from the standpoint of how best to transmit electrical via a national grid for anytime energy. But I always took renewables, especially solar, as best on location with battery back up.

    This past Summer we had two utility bills over 350 a month. We need to get that down. So far my favorite are stand alone systems that continually reorient to face the Sun. We have room on the lower part of the property for about three (9′ x 12′ PV area). Not sure about battery back up. We may just start by using it to supplement grid energy, to reduce cost of AC for both buildings, house and artist studio.

  6. rollin on Sun, 24th Nov 2013 6:37 pm 

    Obstinacy and obstruction are adolescent characteristics. For the power companies to refuse to embrace new and important generation technologies is both embarrassing and dangerous. They will eventually cause their own demise as work-arounds are instituted, but will cause much harm and delay in the meantime.

  7. Gwynevere on Sun, 24th Nov 2013 7:19 pm 

    As far as I can tell the best way to get reliable information about energy companies these days is go to their opponents. If you want to find out about the eroei of renewables then go to the nuclear and oil lobbies and vice versa. It sounds mad but that probably means it’s pretty accurate in today’s world.

  8. surf on Sun, 24th Nov 2013 7:42 pm 

    “One additional point on electricity transmission. The substations, transformers, switchgear and transmission lines must be sized to carry peak load, while only carrying an average ~15% of peak for solar & ~30% of peak for wind. The actual transmission conductors are made of aluminum. A high energy input material. Normally the conductor size & number of conductors is determined by economics”

    The conductor size is determined by the voltage and current at peak load. The number of wires can very based on the circuit configuration and the need to avoid overloading power lines.

    Our current power grids are currently sized to carry peak load which may only happen a few days per year. If each home had it’s own solar PV system our current cities need to import less power meaning fewer and possibly smaller power lines would be needed.

    “Need to heat & power wind turbines when they are not generating electricity, especially in the north.”

    Most wind turbines are not heated. The only reason to heat a trbin is to prevent ice from building up on the blades. Most turnbins are not located in areas were that is needed. Furthermore it takes very little power to melt ice.

    If the turbin doesn’t need deicing equipment the only standby power needed would be used by the computer to monitor wind speed. Once the wind gets strong enough the power load would inecrease as the hydrolics and electric motors turn the turbin into the wind.

    Conventional foscil fuel power plants need standby power to provid lighting and heat for the workers. Also if it is a cold day with low power demand the plant might have to shut down and then electricity would be needed to to prevent its water lines from freezing. Nuclear power plants need to power cooling systems all the time even when they are not producing power. Otherwise the fuel may melt.

    Overall wind and solar need much less standby power than conventional power plants.

    Necessity of long distance power transmission to get rid of surpluses and import shortages due to the vagaries of wind & solar

    For solar sytems there is no need to get rid of execes power. if the power is not needed it can simply be left in the panel without any risk of damage. for wind power you can simply switch a turbine off if you have no need for the power. However if you do have excess power why not store it on sit for later sale. Excess power stored on the site of a power plant or in grid switching yards. In that case there is no need to build big power lines to ship it long distances.

    “The inevitable overbuild that comes with wind & solar generation. Even renewables advocates admit that. In order to supply peak energy, winter in the north, summer in the south you need to greatly overbuild the renewables.”

    Utilities have to overbuild fossil fuel power generation to handle the difference between night and day power demands and changes in seasonal power demands due to air conditioners and electric heat.

    “Induced cycling inefficiency in the shadowing fossil fuel power plants”

    Currently power plants have to cycle down at night when people are sleeping and then cycle up in the morning, cyclen up and down all day as demand changes, and finally cycle up even more as people go home and turn on there home lights.

    Renewables don’t cycle as much as people think. They don’t turn on and off hourly. Kind generally starts slow, builds up strength slowly, and then slowly dies. Solar power does cycle once per day due to night. Even clouds don’t necessarily cycle solar off. Most of the time clouds simply just reduce the amount of power generated. Solar PV doesn’t typically switch off due to clouds.

  9. surf on Sun, 24th Nov 2013 7:49 pm 

    “One additional point on electricity transmission. The substations, transformers, switchgear and transmission lines must be sized to carry peak load, while only carrying an average ~15% of peak for solar & ~30% of peak for wind. The actual transmission conductors are made of aluminum. A high energy input material. Normally the conductor size & number of conductors is determined by economics”

    The conductor size is determined by the voltage and current at peak load. The number of wires can very based on the circuit configuration and the need to avoid overloading power lines.

    Our current power grids are currently sized to carry peak load which may only happen a few days per year. If each home had it’s own solar PV system our current cities need to import less power meaning fewer and possibly smaller power lines would be needed.

    “Need to heat & power wind turbines when they are not generating electricity, especially in the north.”

    Most wind turbines are not heated. The only reason to heat a trbin is to prevent ice from building up on the blades. Most turnbins are not located in areas were that is needed. Furthermore it takes very little power to melt ice.

    If the turbin doesn’t need deicing equipment the only standby power needed would be used by the computer to monitor wind speed. Once the wind gets strong enough the power load would inecrease as the hydrolics and electric motors turn the turbin into the wind.

    Conventional foscil fuel power plants need standby power to provid lighting and heat for the workers. Also if it is a cold day with low power demand the plant might have to shut down and then electricity would be needed to to prevent its water lines from freezing. Nuclear power plants need to power cooling systems all the time even when they are not producing power. Otherwise the fuel may melt.

    Overall wind and solar need much less standby power than conventional power plants.

    Necessity of long distance power transmission to get rid of surpluses and import shortages due to the vagaries of wind & solar

    For solar sytems there is no need to get rid of execes power. if the power is not needed it can simply be left in the panel without any risk of damage. for wind power you can simply switch a turbine off if you have no need for the power. However if you do have excess power why not store it on sit for later sale? Excess power stored on the site of a power plant or in grid switching yards doesn’t require long distance power lines to ship it long distances.

    “The inevitable overbuild that comes with wind & solar generation. Even renewables advocates admit that. In order to supply peak energy, winter in the north, summer in the south you need to greatly overbuild the renewables.”

    Utilities have to overbuild fossil fuel power generation to handle the difference between night and day power demands and changes in seasonal power demands due to air conditioners and electric heat.

    “Induced cycling inefficiency in the shadowing fossil fuel power plants”

    Currently power plants have to cycle down at night when people are sleeping and then cycle up in the morning, cyclen up and down all day as demand changes, and finally cycle up even more as people go home and turn on there home lights.

    Renewables don’t cycle as much as people think. They don’t turn on and off hourly. wind generally starts slow, builds up strength slowly, and then slowly dies. Solar power does cycle once per day due to night. Even clouds don’t necessarily cycle solar off. Most of the time clouds simply just reduce the amount of power generated. Solar PV doesn’t typically switch off due to clouds.

  10. surf on Sun, 24th Nov 2013 8:00 pm 

    “One additional point on electricity transmission. The substations, transformers, switchgear and transmission lines must be sized to carry peak load, while only carrying an average ~15% of peak for solar & ~30% of peak for wind. The actual transmission conductors are made of aluminum. A high energy input material. Normally the conductor size & number of conductors is determined by economics”

    The conductor size is determined by the voltage and current at peak load. The number of wires can very based on the circuit configuration and the need to avoid overloading power lines.

    Our current power grids are currently sized to carry peak load which may only happen a few days per year. If each home had it’s own solar PV system our current cities need to import less power meaning fewer and possibly smaller power lines would be needed.

    “Need to heat & power wind turbines when they are not generating electricity, especially in the north.”

    Most wind turbines are not heated. The only reason to heat a trbin is to prevent ice from building up on the blades. Most turnbines are not located in areas were that is needed. Furthermore it takes very little power to melt ice and the power to melt it is only needed just before the turbine starts producing power.

    If the turbine doesn’t need deicing equipment the only standby power needed would be used by the computer to monitor wind speed. Once the wind gets strong enough the power load would increase as the hydraulics and electric motors turn the turbine into the wind.

    Solar PV doesn’t need standby power at all.

    Conventional foscil fuel power plants need standby power to provide lighting and heat for the workers. Also if it is a cold day with low power demand the plant might have to shut down and then electricity would be needed to to prevent its water lines from freezing. Nuclear power plants need to power cooling systems all the time even when they are not producing power. Otherwise the fuel may melt.

    Overall wind and solar need much less standby power than conventional power plants.

    “Necessity of long distance power transmission to get rid of surpluses and import shortages due to the vagaries of wind & solar”

    For solar systems there is no need to get rid of excess power. if the power is not needed it can simply be left in the panel without any risk of damage. for wind power you can simply switch a turbine off if you have no need for the power. However if you do have excess power why not store it on sit for later sale? Excess power stored on the site of a power plant or in grid switching yards doesn’t require long distance power lines to ship it long distances.

    “The inevitable overbuild that comes with wind & solar generation. Even renewables advocates admit that.In order to supply peak energy, winter in the north, summer in the south you need to greatly overbuild the renewables.”

    Utilities have to overbuild fossil fuel power generation to handle the difference between night and day power demands and changes in seasonal power demands due to air conditioners and electric heat.

    “Induced cycling inefficiency in the shadowing fossil fuel power plants”

    Currently power plants have to cycle down at night when people are sleeping and then cycle up in the morning, cycle up and down all day as demand changes, and finally cycle up even more as people go home and turn on there home lights.

    Renewables don’t cycle as much as people think. They don’t turn on and off hourly. wind generally starts slow, builds up strength slowly, and then slowly dies. Solar power does cycle once per day due to night. Even clouds don’t necessarily cycle solar off. Most of the time clouds simply just reduce the amount of power generated. Solar PV doesn’t typically switch off due to clouds.

  11. Kenz300 on Sun, 24th Nov 2013 8:57 pm 

    Sounds like a shill for the nuclear industry bashing any competition……. nuclear energy is too costly and too dangerous…… we will see how much it costs to clean up Fukishima….. the current time frame is 30 – 40 years and I do not believe that it will ever be completely cleaned up. The cost to store nuclear waste forever is too high a price to pay.

    Fukushima is collapsing – the worst is coming… – YouTube

    http://www.youtube.com/watch?v=me1ov9YoA1g

  12. banjo on Sun, 24th Nov 2013 10:28 pm 

    pumped storage is 80-90% efficient then just build it out. No need to worry about fossil fuel anymore.

    Of course the real proof is in the pudding.

    the difference between theory and reality is that in theory they are the same but in reality they are different.

  13. Bob Owens on Tue, 26th Nov 2013 3:51 pm 

    At the end of the day we will be left with only renewable energy sources. Although there are problems with these systems we are certainly able to figure out ways to deal with them. Molten salt storage works and is available today. Is it perfect? No, but it works and we know how to use it. Other storage systems are available now and work. In the future we will know more about our problems and how to solve them. This path is certainly less difficult than the work that went into designing our current nuke plants. At the end of the day we will only have renewables; we need to get used to that idea and deal with it.

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