Thanks for a fantastically detailed and comprehensive article, Chuck! It stands to reason that the electricity grid will be wildly more efficient and economical when we have on-line storage within the distribution system. Just imagine how wasteful things would be if we did not have warehouses, stockrooms, and distribution centers for material goods, or reservoirs and tanks for water and petroleum storage. Even the use of capacitors within electronic circuits permit amazing systems to be designed.
This of course is not a new observation, but the technology required to realize efficient, large-scale electricity storage is new. Let's hope the promise of a new market with huge demand is enough to spur further development...
William, I want to second that. Actually, Chuck stole my thunder. Just last night at an IEEE Committee meeting we were discussing this as a topic for a future meeting.
I have implemented flywheels as a backup for a data center. They are smaller and more environmentally friendly (and safer) than standard batteries.
The biggest issues, beyond cost, are two fold. One is the conservative nature of the utility industry. The other is the investment model.
The utility industry makes their money by providing a reliable source. It is highly regulated and therefore conservative in its approach. Based on their incentives, that makes sense. That is why you have states having to pass laws requiring target percentages of renewables and, now, batteries.
The investment model has served us very well. Most utitilities are funded through long term bonds. The government role is to provide regulation, and sometimes support, but generally the investor owned utility is privately funded and provides a steady profit. Thus, there is a disincentive to take risks, since most infrastructure has to last a couple of decades to justify the investment.
The upshot is that battery technology, like renewables, has to be "proven" in long term operations before utilities will routinely install them. Since the technology is so new, this might make sense. Let's hope the investors in these technologies have a long term view as well.
Well stated, naperlou. I find it interesting that our heated discussions about solar, wind, hydro, biofuels, and fossil fuels are actually an argument over energy storage. Either collect the solar energy immediately, extract the energy from wind created by evaporating water, from condensed water, from short-term storage in living organisms, or extremely long-term storage in fossilized organisms in the form of petroleum and coal. So I guess our current debates have always been over our preferred energy capacitors...
We are on the brink of a cataclysmic change as the whole world shifts from Petroleum to Electricity. There is a great abundance of opportunities, and needs, for new energy technologies. It feels like an overfilled water-balloon ready to burst. Efficient and dense energy storage is way overdue. At the pace we are transitioning to Electrical Energy I believe our motivation will evolve from convenience to survival. Then many solutions will quickly surface.
The current technologies available for massive energy storage are not much better than a lake on a hill. With the growing needs for electricity, the limited capacities of these energy storage technologies are probably more suited for supplementing individual home alternative power systems. We need a major breakthrough in high density energy storage or an extremely efficient source of uninterrupted power. I don't think much will change until then.
Just where is the market? We already have $100/kwhr batteries in lead, molten salt/Zebra, etc, but none are used, why?
Fact is utilities are doing very well without batteries/storage for 120 yrs now and handling variable demand, same effect as variable supply, forever.
And now instead of spinning reserve the new NG generators are eff from 50 to 100% power so can be throttled, relieving the need for storage even more.
The need for storage for RE is another myth as it's not any more a problem as demand is.
In fact in many places A/C is the peak load and PV follows it prefectly. If a cloud comes over the A/C load also reduces. Since peak load following is 3-10x's the price/cost of electricity, then shouldn't PV get the most money?
Facts are only wind is that variable and only in big wind farms that start/stop at once. Far better is home/building size units spread out so their power averages to steady power.
And Solar CSP, biomass, hydro, tidal are steady or on demand and PV follows demand. So where is all this storage needed for RE? Or for the grid?
Thanks for the links, DaveWR. That illuminates the challenges behind pumped hydro. It sill seems to have some virtues, in that rain can offset some of the evaporation, and there is value in recreational use.
Good article of current state of things. I read between the lines of energy storage conference papers that grid storage is a perferred method, but I do not agree. Micro grid storage is more in line with the decentralization that will have to take place as fossil fuel costs rise. The recurring overhead of a large centralized solution alone would keep the true $/khw elevated. What I see coming sooner is a dense enough energy storage package that replaces the space in the house the hot water heater occupies. First customer would be home builders who are keen to build a sustainable home. IMHO, this is the way to go as it also means the solution would benefit a larger swath of the global population.
DanielJoseph, your comment is very well said. A well designed small home power source should replace the water heater, providing heat, and hot/purified water as well. A lot of energy in the form of heat goes up the chimney from my gas water heater.
I think that current battery grid storage solutions are very good to provide fast response to short term changes in load or demand and help to stabilize the grid in areas which are not very well connectet. But the batteries are still to expensive to provide hughe storage capacities needed for long term (days) storage.
I would like to point all hydro storage fans to the concept of pumped hydro without a lake. The company Gravity Power (http://www.gravitypower.net/index.aspx) has developed an underground storage with pumped hydro in a closed system which is modular and scales up to 600 MWh with 2400 MW peak power. Round trip efficiency is around 80%.
Second concept is developed in Germany by Eduard Heindl who proposed a pumped hydro storage which lift a huge rock mass with hydraulic pressure (200 bar) and potentially scales to 1 TWh capacity (http://lageenergiespeicher.de/en/hhs-storage.html)
Both concepts use existing pumped hydro technology and can be sited more easily than conventional hydro storage sites. Especially in Germany where some times more than 30% of electric energy is produced by PV and wind turbines, large scale storage will be required to keep the grid stable.
I'am pleased that I've pointed you to a new aspect of pumped hydro. There is a really good presentation of the Gravity Power concept on YouTube. If you want to learn more about this concept than you should give it a try. Takes 51 minutes and has some Q&A at the end.
Tom Mason, the CEO of Gravity Power has long experience in the energy sector and I've the feeling that he knows what he is talking about. Will be interesting what they learn from the planned small size pilot project.
Charles, renewal energy sources are common in universe and storage is a major concern, even from cell phones to smart grid technology. Most of the storage mechanisms can hold power for a shorter duration and forced us for a recharge. So there should be some new technologies which can hold more power and can sustain for a longer duration.
"..A recent study from Lux Research Inc. reinforces that position. "Grid Storage Under the Microscope: Using Local Knowledge to Forecast Global Demand" predicts the market for grid storage of electrical power will soar over the next five years, spiking from $2.8 billion in 2012 to, almost unbelievably, $113.5 billion in 2017..."
Which I'm sure has battery makers salivating. They *only* have a market because government mandates that power distribution companies buy from solar/wind/etc, regardless of cost, screw the economics.
Solar and wind generation is already much more expensive per unit power produced. This will only compound that cost difference. Who will be footing the $113Bn? Rate payers in increased costs, in a time when various technologies are making previously unavailable petroleum reserves feasible to develop, vastly increasing the estimated petroleum reserve in this country alone. Currently there is no oil shortage other than that engineered by regulation and lawsuit.
The only way this works is because governements are forcing electricity providers to buy power from "renewable sources" at rates far above what they pay for conventional sources, transfering those costs to me and non-power generation industry, making their products more expensive. Rent-seeking by an industry that's been struggling to field a feasible system and finally realized that all they really needed was the power of government to force folks to buy their product.
The lure of high volumes and possibly less price pressure could cause a focus on badly needed profits by some battery producers. This could cause higher tech cells to take a back seat in the area of manufacturing efficiency improvements and less focus by sales could hurt volumes. Not a big deal as the market sorts itself out - but it could come into play for EV manufacturers if the 'actual cost ramp' is much slower than the 'previously projected [and planned for] cost ramp.
Wind has proven to be an expensive mess when applied to a grid. Not good for Base Load or Peaking. You can't schedule the wind you can only guess when it will be available.
Batteries of scale are unrealistic in a multi-gigawatt system. Pumping is viable enviromentally but hard to site. I would suggest that Wind Energy be forced to crack water for it's elemental constituents. The hydrogen could be used to run mega-watt turbines and the other components of the cracking could be sold. This would allow wind to be used in a viable and eviromentally sensetive manner.
Yes, you can electrolyze water and then burn the hydrogen in an engine, but consider the round-trip efficiency. Electrolysis is only about 70% efficient, and the best binary cycle engines are close to 60% efficient. Multiplying these together gives you 42%. This doesn't include additional losses associated with compressing the hydrogen for storage. Thus for every 100 kWh of electricity you put in, you get back less than 42. Batteries and pumped storage, by comparison, have round-trip efficiencies of at least 80%.
The best observation I have seen on the subject of renewable energy sources such as wind, solar.
Renewable energy sources should be viewed as "negative loads"..
Not as power sources to replace or expand existing infrastructure. Simply put, they reduce power generation requirements from exiting sources.
This makes handling their capacity more akin to handling load variations (which are not all that predicable)
As renewables become a larger portion of the total, it will require very different methods for keeping the grid stable - from management and engineering. And has profound impact on the interconnections between areas. An area of infrastructure that is often thought of "after the fact".
Best to view storage of energy for the power grid in short term - as phrased earlier, "as shock absorbers".. to handled switching between sources. Not for it's ability to enable renewable sources to become dominate.
Is anyone working on using wind and solar to lift iron up a rachet belt to a tower. Hold it there as potential energy. Letting it compress air or liquid provides potential energy that can be converted to electrical energy as it's allowed to descend. Hmm, is any of the energy of a lowering elevator car saved for use in raising the car? Some hybrid automobiles save some of the braking energy in batteries.
It sounds like this article is suggesting new technologies for the batteries. Atlhough I may have missed it here, a few months ago I thought there was a rather large development being planned to use old batteries for these types of applications - specifically, those that still have life but could no longer be used in hybrids.
Design engineers need to prepare for a future in which their electronic products will use not just one or two, but possibly many user interfaces that involve touch, vision, gestures, and even eye movements.
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