9 ms·
Can validate. The problem with electricity is that there is no large scale storage like there is for other forms of energy like NG and Crude. Until someone come
by S_A_P 11y ago
Can validate. The problem with electricity is that there is no large scale storage like there is for other forms of energy like NG and Crude. Until someone comes along and figures out how to store electricity, this will continue to cause grief to power companies. Power plants are really just options, if the price per kWh is at a certain point then it makes sense to spin up or take down a plant and generate power. Adding a bunch of highly variant generation to the grid can make the market more volatile since there could be a lot of up and down with generation facilities.[0]
That said, there will be teething pains but this is a net positive thing that is happening. Growing up I lumped solar into the perpetual 10 years away category. It looks like I am going to see solar be competitive after all.
[0] I implement trading and risk management software in the energy sector, including Crude, NGL, NG, and electic.
- amenghra 11y agoSome countries store energy by pumping water up a dam. Seems efficient.
- coryfklein 11y agoWhoa! That sounds really cool so I looked it up. It's called "Pumped-storage hydroelectricity" https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...
- inovica 11y agoVery. One of the first was in Scotland. Great to visit as you drive into the mountain and I think one of the Bond files had a scene filmed in it https://en.wikipedia.org/wiki/Cruachan_Power_Station https://en.wikipedia.org/wiki/Cruachan_Power_Station
- Analemma_ 11y agoIt's very efficient and it's a great solution overall; the only problem is there are only so many dams we can build, since each one requires drowning a valley.
- jhallenworld 11y agoSolution: swimming pool on the roof. http://www.fastcodesign.com/1672202/you-deserve-a-house-with-a-pool-on-the-roof http://www.fastcodesign.com/1672202/you-deserve-a-house-with...
- richdougherty 11y agoThe more sun, the more water in the pool. Win-win!
- pbhjpbhj 11y agoSeriously though has anyone crunched the numbers on rainwater storage for microgeneration in a domestic setting. Could I efficiently use excess solar to pump water in to a house roof storage area and generate electric from that?
- jhallenworld 11y agoThe Tesla Powerwall has 6.5 kwh = 23.4 M joules. Gravity potential energy = mgh. Suppose pool is 10 meters up, then you need 239,000 kg of water = 63K gallons or 8400 cu ft. This is a huge pool: 29 ft. x 29 ft x 10 ft. You could use the city water supply: borrow water through a turbine at night, and return it during the day :-) Or have pool up very high, for example on a cliff overlooking the Mediterranean: http://inhabitat.com/crazy-home-carved-into-a-coastal-cliff-has-a-swimming-pool-roof/ http://inhabitat.com/crazy-home-carved-into-a-coastal-cliff-...
- cninja 11y agoThey crunch the numbers here: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/ http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor... The energy in one gallon of gasoline is equivalent to the potential energy stored in 13 tons of water one kilometer up
- mikereedell 11y agoI grew up by one of these in NJ: https://en.wikipedia.org/wiki/Yards_Creek_Generating_Station https://en.wikipedia.org/wiki/Yards_Creek_Generating_Station I remember parking at the lower reservoir and hiking to the upper one and being amazed at how big the water pipe is.
- ori_b 11y agoFlywheels are another option: https://en.wikipedia.org/wiki/Flywheel_energy_storage https://en.wikipedia.org/wiki/Flywheel_energy_storage
- cjensen 11y agoPumped storage is routinely used to store energy. It's not theoretical. Has Flywheel storage every been seriously used in large-scale commercial applications? Someone mentions it on every energy-storage thread, and I'd like to know if the people suggesting it are just spinning our wheels.
- cplease 11y agoIt's not even remotely on the same scale. There are three massive utility-level flywheel deployments according to Wikipedia that provide 15 minutes of output. Edit: Seems the purpose is purely frequency regulation, rather than storage per se.
- fanf2 11y agoThe JET fusion reactor in Oxfordshire uses flywheels to provide very large pulses of electricity for short periods of time (a minute or two iirc). The reactor requires too much energy to run directly off the National Grid.
- runholm 11y agoSounds like they use it for high output rather than efficiency though. Still interesting that it has real world applications though. Shows that the technology has potential as well.
- zeristor 11y agoAs I recall from a tour I went on of jet 30 years ago there are a large bank of flywheels which spin up over several minutes, these are then rapidly discharged to a bank of capacitors which are then used to power the experiment, I believe the duty cycle was 9 minutes. [1][2] I believe some electric cars used capacitors to store regenerated electricity from breaking. "More Ampères please Mister Woodbine." - Road to Welville [1] - http://pia.sagepub.com/content/200/2/95.abstract http://pia.sagepub.com/content/200/2/95.abstract [2] - http://www.euro-fusionscipub.org/wp-content/uploads/2014/11/JETC94082.pdf http://www.euro-fusionscipub.org/wp-content/uploads/2014/11/...
- hinkley 11y agoI thought I read that some water districts run their pumps at reduced volume during peak hours and top them off before or after. It's a smaller volume but it's already a solved problem. And it allows you to push some levers and dials as to whether it's cheaper this year to increase your water capacity or your power capacity. City planners love that kind of thing.
- taneq 11y agoWorks great if you have the right geography.
- dTal 10y agoBetter than nothing, but not that efficient. I took the tour of the somewhat mis-named Dinorwig Power Station (really a pumped storage facility) in Snowdonia, Wales. The figures they quoted there put it at about 75% efficiency. It's not really supposed to be for 24-hour power smoothing, more for rapid response to sudden demand; it's a lot faster to open a valve on a turbine than to stoke up a coal plant, and for some spikes (such as the example they quoted on the tour, when everyone puts the kettle on when Coronation Street finishes) you have a 30-second window or so. However, as demand has increased it's being used more and more, and the more it's used the more power we're wasting. Interestingly, it does not use a dam. There's a natural lake at the bottom of a mountain and a man-made reservoir at the top, and the entire pumping facility is completely inside the mountain; it's not at all obvious that there's anything there at all from the outside. I think about that whenever people moan about the environmental impact, or flooding valleys.
- mjevans 11y agoWe have a lot of good technologies already, the problem is they just don't scale well. I can envision older warehouses in an industrial district being converted in to vacuum flywheel storage sites where power fed in to the grid earlier is buffered and then released back to it. Changing our culture is another possible approach. Power is used in the evenings because that's when most people get off work/home/etc and they tend to have /that/ time to do cooking and cleaning (thermal cooling / heating are more solvable with changes in materials and building shape than culture change).
- pc2g4d 11y agoPrice electricity differently through the day according to its scarcity and people might eventually adjust their routines to reduce evening usage.
- derefr 11y agoThat seems backwards. The aggregate preferences and habits of humans should be seen as an incentivizing force for the creations of new technologies, not the other way around.
- msellout 11y agoYikes. Yes, of course technology is driven by human preferences. But, No, humans must occasionally accept that certain habits are not sustainable given current and near-future technologies.
- icanhackit 11y agoI generally agree with your position but in this particular scenario the people with the greatest capacity to adjust their behavior are the people who will be affected the least financially by a hike in peak prices and thus less likely to change or more likely to invest in solar at home, while those with the least flexibility in work arrangements and spending, e.g. lower income earners working in the services sector, will be affected negatively the most and unable to work around it.
- paulhart 11y agoOncor solicited a study that showed that a mass install of Tesla Powerwall devices would be an economic solution to this problem [1], at which point all the generators lost their minds and lobbied the PUCT to prevent Oncor from destroying their market [2] (because of their position as a Transmission & Distribution Service Provider in the market, it would require a change in law for Oncor to be able to implement the project). [0] Work for a multinational in their energy & utilities consulting practice; above comment is my own. [1] http://www.brattle.com/system/news/pdfs/000/000/749/original/The_Value_of_Distributed_Electricity_Storage_in_Texas.pdf http://www.brattle.com/system/news/pdfs/000/000/749/original... [2] https://www.texastribune.org/2014/12/15/state-law-could-short-circuit-battery-breakthrough/ https://www.texastribune.org/2014/12/15/state-law-could-shor...
- epistasis 11y agoIt's interesting to see the stark contrast between the naysayers that don't have information to back their claims (such as comments sibling to yours), and the people who have looked at current tech and made realistic assessments like Oncor and Brattle. A lot of people are willing to make confident, but very wrong, statements based on out of date information. It serves to protect entrenched interests and stop competition, but I have a feeling that disruption is far closer than anybody is publicly saying.
- andromeduck 11y agoX is realistic and smart because it agrees with my opinion You're amazing
- epistasis 11y agoThanks. But it's not realistic and smart because of that, it's realistic and smart because it examines the facts at hand and makes plans instead of handwaving. This is an important distinction.
- rms 11y agohttp://www.lightsail.com/ http://www.lightsail.com/ has been working on this for a while now
- eru 11y agoInstead (or rather in addition) to storing power, we can also get better at coordinating demand. There are already programs for industrial users to get electricity for much cheaper, if they can tolerate power cuts during peak demand. Those programs will become more and more rewarding to join and extend and automate as supply gets spikier.
- afarrell 11y agoIs there a way to coordinate demand without asking thousands of people to give Alice the ability to shut off their appliances?
- toomuchtodo 11y agoNo, although the current system is pretty tame. The electric company can turn your electric water heater or air conditioner (depending on geography and utility) off for 15 minutes at a time, and in return you get a credit on your electric bill. Its opt in.
- sjwright 11y agoSell electricity at spot prices, give consumers access to that spot price, and you'll see a lot of demand flatten simply through natural market forces. Where I live, I pay five times more for electricity between peak hours of 2pm and 8pm than I do between off-peak hours of 10pm-8am. (The remaining hours are priced at a medium level.) This has changed my behaviour, in that I now tend to wait until bedtime before switching on the clothes dryer and dishwasher.
- disposeofnick9 11y agoActually, there already is, it's called OpenADR. http://products.openadr.org/?posts_per_page=-1 http://products.openadr.org/?posts_per_page=-1 See also Ecobee vs. Nest: http://controltrends.org/controltrends-news/news-and-information/03/under-the-hood-of-an-wireless-ecosystem-stacey-higginbothams-a-tale-of-two-thermostats/ http://controltrends.org/controltrends-news/news-and-informa...
- pilom 11y ago
- bigger_cheese 11y agoI recall reading a while ago about using molten salt storage at large solar concentrators. Did this ever take off? The theory was you generate excess power during the day and you can use this excess to heat the salt solution which then release thermal energy during the night. Does anyone know more about this? Is this able to meet baseload demand?
- johnny99 11y agoSolana Generating Station, a 280MW solar concentrating plant, currently, uses molten salt, which allows for six hours of energy storage. https://en.wikipedia.org/wiki/Thermal_energy_storage#Molten_salt_technology https://en.wikipedia.org/wiki/Thermal_energy_storage#Molten_...
- adanto6840 11y agoThis one in Nevada came online not too long ago and is quite large -- apparently has 10 hours of storage and according to Wikipedia it generated 9.1GWh in February 2016 alone. https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Project https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Pr...
- usrusr 11y agoThermodispatchable solar, even if the word does not exist, has been a recurring theme. But installations seem to be one-offs that are rarely followed by a direct successor project with the ever dropping price of photovoltaic. In areas with cold weather, one of the most interesting (and underrated, due to only making fossil use more adaptable) developments is the installation of huge, insulated hot water tanks, to make the power generation and the great generation of combined cycle plants individually dispatchable.
- usrusr 11y agoSorry for the late correction: in the last sentence I meant cogeneration plants, not combined cycle. (which would typically not be combined cycle, because the heat not captured for electricity is not wasted in cogeneration)
- davedx 11y agoIt's a problem, but the nature of the problem varies a lot from country to country. In the Netherlands, we don't have enough renewables yet for this to be an issue (~10%). Once you start getting to Germany's penetration, you start to see some issues with balancing the grid and meeting peak demand. There are more options than just storage, though. Demand side response is already used in industry to regulate electricity demand and smooth peaks. Smart meter penetration will allow utilities to do this more and more in the residential sector too. Supergrids are also starting to emerge and indeed, some large grid companies are pushing hard for international interconnects. (China wants a supergrid). Countries are building out more and more HVDC interconnects, both across borders and within countries. Once you have a network of utility scale renewable sources across multiple countries, meeting peak demand becomes more a matter of coordination between grids. Europe for example, is looking like a very interesting area for this right now with planned interconnects between North Africa and Southern Europe. Since we're all citing employment, I work for a renewable energy company :)