The intermittency of renewable sources of energy is emerging as the single biggest obstacle to decarbonizing the power grid. Fortunately, the problem does seem solvable.
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Energy storage is the key to deploying wind and solar energy on a vast scale, but exactly how much of it will be required remains to be seen
The intermittency of renewable sources of energy is emerging as the single biggest obstacle to decarbonizing the power grid. Fortunately, the problem does seem solvable.
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Add CommentCheck out this page. http://www.arpnjournals.com/jeas/research_papers/rp_2009/jeas_1209_278.pdf
Reply | Report Abuse | Link to thisThis is the best new idea I have seen and no one seems to be using it. I would think it could be scalable either by increasing its size or by adding additional units.
I like this article, but it could be improved by providing some quantitative information. What data are used to derive the ratings of scalability, cost-effectiveness, and energy efficiency?
Reply | Report Abuse | Link to thisScalability is the most difficult measure to quantify. Perhaps the availability of sites for energy storage projects or the availability of raw materials are input factors.
Cost-effectiveness is easier to quantify. It could be derived from cost per watt, cost per kilowatt-hour, and number of charge/ discharge cycles of the "battery" before it wears out or needs major maintenance.
Efficiency is the easiest to quantify. The five-point scale of efficiency could be equal to 5 times the ration of energy out divided by energy in.
Knowing these numbers would be very helpful in assessing the viability of technological proposals, such as hydrogen vehicles.
I think the baseload challenge for wind and solar power is somewhat exaggerated. Of course reliable and cheap storage technologies would facilitate the expansion of these renewables but a big enough array of turbines, especially off shore can likely can generate a baseload without the need to supplement it with separate storage systems, as two studies listed below have shown. Further, the expansion of a combined system of wind, photovoltaic’s, and concentrated solar power in deserts will generate a baseload simply because the wind is blowing and the sun is shining somewhere in the system linked to one grid. Meanwhile baseload would be backed up by petroleum, with coal phasing out first, on the way to a completely wind/solar global energy infrastructure, possible with robust investment starting very soon, as tipping points to climate catastrophe grow ever closer. This is modeled in our Report, “A Solar Transition is Possible”, available with much more at our website, www.solarUtopia.org.
Reply | Report Abuse | Link to thisArcher, C.L., and M.Z. Jacobson (2007) Supplying baseload power and reducing transmission requirements by interconnecting wind farms, J. Applied Meteorol. and Climatology, 46, 1701-1717, www.stanford.edu/group/efmh/winds/.
Kempton, W., F.M. Pimenta, D.E. Veron & B.A. Colle. (2010) Electric power from offshore wind via synoptic-scale interconnection. PNAS 107: 7240-7245.
Don't forget that methanol can store energy and can be generated according to the same principles as gravitational potential energy (water lifts).
Reply | Report Abuse | Link to thishttp://blogdredd.blogspot.com/2011/05/methanol-economy-way-out-of-here-4.html
If you build geothermal, hydro, ocean wave and river wave generators, and it doesn't take 100's of billions of dollars for each one neither like it does for nuclear, you would not need storage devices. Geothermal, ocean wave, river wave, and hydro generators give you a continues supply of never ending energy that can be put right into our existing grid just like coal, oil, nuclear, and natural gas is now and they are near zero and zero polluting and you do not need to find a place to store deadly radiation or destroy the Earth extracting them like you do extracting coal, oil and natural gas, and you do not need to use coal, oil, or natural gas as a backup, because the energy supply is never ending.
Reply | Report Abuse | Link to thisFor every geothermal (either above ground or below ground), hydro and wave generator you build, shut down a fossil fuel generator and put that energy straight into the current grid. It is really a no brainer, and since the republicans do not have a brain, it should be easy for them to implement and easy for them to remember.
Firstly I would like to thank all the contributors, finally some smart people.
Reply | Report Abuse | Link to thisWater to Ice is another possibility though i prefer resevoir pumping for its simplicity.
A system that converts salt water to fresh water is also a really useful solution for long-term man-kind occupation.
Why worry about building a giant battery to act as back-up for the whole country? What would be more practical would be a smaller battery in each home sufficient to run that home for 2-3 days. The batteries could recharge during those windy off-peak hours and keep the house going on calm, cloudy days or disruptions to the grid (storms, etc.).
Reply | Report Abuse | Link to thisThat would make too much sense, and each one of those batteries would probably cost about a billion dollars a piece. I know you read the denier's comments and you know that is what they are going to say. It is obvious that big oil, coal, nuclear, and natural gas companies and their utility companies are paying off these reporters and this rag to try and discourage clean energy production. Why else would this rag, and others like it, be so negative about clean energy research and production and say nothing about the real clean energy producers like geothermal and electric cars and how quickly they can replace dirty fossil fuel and clean up and restore our environment?
Reply | Report Abuse | Link to thisI wish someone would check out the idea I presented to see if it is feasible. The only time I have seen this storage facility working was to provide instant hot water.
Reply | Report Abuse | Link to thisI think it would be acceptable to rethink the idea of allowing the existing natural gas generators to act as backups and maybe continue to convert coal based plants to gas even if just to use as an occasional backup. This would greatly reduce the amount of totally new backup that needs to be built. Hopefully, we are wise enough to develop an intelligent mix of renewables and locate them optimally to rarely need the backups. The immediate need is to create lots of clean generation now and resources should be focused on that now.
Reply | Report Abuse | Link to thisThere already is a battery capable of load balancing the Grid. It's called the ZEBRA and uses sodium chloride and nickel for electrode materials and a ceramic electrolyte (much cheaper than Li).
Reply | Report Abuse | Link to thisYes, it would take more than one 'big one' to get the job done.
Made by MES-DEA sa - Switzerland.
http://www.mmmm.it/docaxu/fzd385.pdf
What about Shai Agassi's Better Place battery swap idea for electric cars? With his idea, service stations end up with stockpiles of batteries that sit on chargers most of the time. This can also be used as a storage place when not used in a car.
Reply | Report Abuse | Link to thisI have nothing to do with these folks. I saw Agassi's talk on Fora.tv a couple years ago and it seems he's got a reasonable idea.
"Experts, however, are increasingly skeptical that even supergrids or smart grids would suffice to cover the intermittency of wind and solar power..."
Reply | Report Abuse | Link to thisWho are these "experts" and what are they saying exactly? At least link to the paper or statement where this comes from! I suspect it was plucked out of thin air, or to be more specific, plucked from the conscience of a "scientist" that gets paid by the fossil fuel industry to spread doubt about a competing product!
Good idea! Nissan is re-designing the Leaf's battery pack to do exactly this in response to last year's tsunami. 24 kWhs can power your fridge and some emergency lighting for quite a while!
Reply | Report Abuse | Link to thisWhy not fly wheels? always batteries, batteries, batteries...
Reply | Report Abuse | Link to thisIt's actually easier to "store" demand than it is to store supply. Using "smart grid" technology, you can turn down thermostats a couple of degrees and delay many operations when electricity prices are high and then take advantage of lower prices at different times of the day. Solar power can be structured to handle most of the difference between nighttime and daytime demand while wind and gas can provide nighttime baseload. Wave, tidal, geothermal, biomass and a whole host of other energy sources can fill in the gaps where they make sense. Increasing our energy efficiency and minimizing wasteful consumption can meake this transition a whole lot easier. Millions of electric car batteries can provide a huge storage pool as well AND a secondary value stream for their owners via selling grid regulation services to the utility.
Reply | Report Abuse | Link to thisA good first step towards making this transition would be to stop subsidizing fossil fuels and make them pay SOME share of the cost that their pollution imposes on society. Channeling those subsidies to clean energy instead would speed up the transition, but it's not really necessary. We'll get cleaner air and water, our health will be better because of lower pollution and we'll get to tell OPEC where to shove their imported oil! The fact that we'll also lower the odds of severe climate change is a bonus.
Fortunately, every analysis that has examined the issue has concluded there is already sufficient capacity and flexibility built into the U.S. power system to accommodate wind and solar penetrations dozens of times higher than we currently have today. When wind and solar plants are distributed over large areas, variations in their output tend to cancel each other out. In addition, electricity demand already varies by a factor of three or more depending on the time of day and year, and many changes in wind and solar output simply cancel out opposite changes in electric demand. For any remaining variability, grid operators use the same flexible resources that they use to accommodate variations in electric demand and unexpected outages at conventional power plants, which tend to be larger and more rapid sources of variability. Energy storage technologies are one option for providing that needed power system flexibility. For more, see:
Reply | Report Abuse | Link to thishttp://www.awea.org/learnabout/publications/upload/Energy-Storage-Factsheet_WP11.pdf
Also, this joint statement between the Electricity Storage Association and the American Wind Energy Association does a good job of highlighting some of these common misconceptions about both of our technologies:
http://www.awea.org/newsroom/pressreleases/Joint-Statement-of-the-American-Wind-Energy-Association-and-Electricity-Storage-Association.cfm
Michael Goggin,
American Wind Energy Association
Didn't actually tell us much did it? It does point to the weak link in solar/wind/tidal power generation. Storage. There is power enough out there. A cheap high capacity storage method is where the future lies. Fossil fuels have the energy storage game beat at present.
Reply | Report Abuse | Link to thisThere are a couple other promising storage technologies on the horizon such as Isentropic's PHES, essentially a giant gravel battery using argon to move heat from a cold tank to a hot one.
Reply | Report Abuse | Link to thisSince you mentioned the ZEBRA, I'm reminded that Sumitomo expects to have a low-temp sodium-based battery by 2015, targeted for electric trucks and stationary applications.
Relatively cheap materials and great energy density.
Additional point I would like to make is that, a closed loop system with two resevoirs is perfect.... and no one said the fluid had to be water...infact I would use a thick oil! No rust, no cavitation!, slow moving parts that would have lifetimes so long as to make the plant a 1 price for it.
Reply | Report Abuse | Link to thisThe energy density can be made very very high, much higher than any battery, by making the resevoirs a massive distance in height, apart. Using archimedes screws in an always on position with pressure generating electricity as it goes down, this energy is reclaimed by powering bigger screws taking another load up, which is assisted by electrical generation from renewables like solar/wind, etc
This way it can generate a varying load output depending on input, lots of input, lots of input= lots of output, little input = lots of output.
There should be little or no load variation at all ever from the station if done right.
Endless running churning out electricity!!!
Energy demand and supply storage is now met, thank you and good night.
additional:
Reply | Report Abuse | Link to thisI would use a 80-20, system for it, 80% of electric generation from downward screw is always taken to grid, 20% back to up screw.
THis is a baseload system by the way, always on.
How big a battery? If you store the energy on the demand side at homes, it's quite small
Reply | Report Abuse | Link to this1 ft x 2 ft x 3 ft = 6 cubic feet of lead acid battery weighing 300 kg. That's enough to power your house for 8 hours at 1.33 kW (the ave. US residential power consumption)
But if you want to store energy on the supply side, I recommend magnetically levitated flywheel energy storage. A steel shaft 10 m diameter, 50 m long rotating 20,000 rpm has enough energy to produce 29,000 MW for 8 hours.
This energy is equivalent to pumping all the water in two million olympic-size swimming pools to a height of 50 ft.
The magnetic flywheel has minimal energy loss since it is practically frictionless and can be levitated by permanent magnets hence no electric power needed. Far better than the 30% heat loss in compressed air energy storage.
Great idea, but if this article represents the current state of knowledge, then it is even less developed than the ideas mentioned in the article. The researchers built a device that works, to some extent. But the paper doesn't even hint at whether the idea can be scaled to billions of MW-hs, and what the cost might be. But for me, the biggest issue is that it releases hot air, which is great for heating a house, but is very difficult to turn into electricity. If the thing could turn water into steam, then you can talk about turbine generators, but it operates at temperatures far too low for that.
Reply | Report Abuse | Link to thisA very considerable part of total energy consumption relates to heating/cooling near room-temperature, e.g. in buildings. For this, thermal storage by means of dynamic thermal energy storage (DTES) and of sets of boreholes in the ground, may provide required energy storage. It may also utilize day/night variation, sun/-overcast, and seasonal variation for increased energy efficiency.
Reply | Report Abuse | Link to thisPumping water uphill seems like a pretty straightforward way to store energy.... no "new and amazing" technology needs to be invented.
Reply | Report Abuse | Link to thisAdd into that the idea of moving heavy-objects like gravel or sand uphill.. and then dropping them back down through the equivalent of waterwheels might be a way to do so in freezing climates.
Inefficiency is no biggie.... so long as one knows how much one can harvest in the way of electricity with a given facility.
It is always all kinds of fin to dream up elaborate battery systems... except so few people actually think hard enough about the resources used to take cell-phone-battery ideas and dream up some vast array of them to power a nation.
Simple, plain vanilla..... rocks and water.... or some such thing is the way to go...... don't be in love with the Mr Wizard/Star Trek/Matrix Trilogy kind of ideas... if it is simple and cheap.. and uses already-nearly-perfected technology.. so much the better.
Nature and fate and Murphy's Law will throw us plenty of curves even with proven tech... never mind the drifty over-elaborate stuff.
I'm with @gmperkins, flywheels are an often overlooked type of battery storage that has the benefit of instant-on when it is needed instead of 15 minutes to ramp up other types of storage. I'd like one for my house, but the first 20 MW flywheel storage facility recently opened in NY:
Reply | Report Abuse | Link to thishttp://beaconpower.com/company/201107-gallery.asp
100 hours of storage? No technology can do it. Currently, one can count on a few hours of storage, max 10 hours. Pumped storage hydro power plants typically store 2 to 4 hours at max power. And batteries, from as low as 10 min. to max. 7 hours.
Reply | Report Abuse | Link to thisUnless a technical revolution that would merit the Nobel Price of the XXI century, there is no chance to be able to store 100 hours of energy at full capacity.
Therefore I do not understand what is the interest of such article, especially in Scientific American.
Pyrolyse biomass to generate hydrogen and biocharcoal. Store the hydrogen in gasometers as was done with town gas, and use it to generate electricity when solar or wind generators are not producing.
Reply | Report Abuse | Link to thisWhen will the public abandon its irational fears about nuclear power, the numbers of casualties due to nuclear power generation are tiny compared to any other form of power generation.
Reply | Report Abuse | Link to thisLet us not ignore Gemasolar, which also ran 24 hours from molten salt storage:
Reply | Report Abuse | Link to thishttp://www.gizmag.com/gemasolar-csp-solar-plant/19098/
Theirs uses a power-tower instead of troughs.