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Hello,

I assume that some, if not most of you own or like the idea of having an energy storage system to prevent unplanned and sudden shut down devices due to power failure from the grid. Personally I'm thinking of buying an UPS but with the rise of energy storage systems like the Tesla Powerwall that start at tens of kWh per unit, I'm starting to think it would be worth waiting and buying a cheap unit instead of an UPS that maybe stores half kWh and uses lead acid batteries that degrade in 5 years or less. Am I wrong? Have UPS systems become better in the last couple of years? What are your opinions on the matter? I'm thinking that by 2025 when the price per kWh is less than $100 I'm going to likely take the house off the electricity grid or if I keep the connection it will only be as a backup.

Where are you going to get the energy needed to charge your magical battery?

JustAnEngineer wrote:

Where are you going to get the energy needed to charge your magical battery?

From those future cheaper than coal solar panels.

Arclight wrote:

cheaper than coal

Tell that to the Chinese. For every ton of coal consumption that has been reduced in the U.S. and in Europe, China has burned several more tons.
http://www.indexmundi.com/energy//?prod ... onsumption

JustAnEngineer wrote:

Arclight wrote:

cheaper than coal

Tell that to the Chinese. For every ton of coal consumption that has been reduced in the U.S. and in Europe, China has burned several more tons.
http://www.indexmundi.com/energy//?prod ... onsumption
https://www.eia.gov/todayinenergy/detail.php?id=3350

I don't have to tell them, they know better than anyone as the world's largest users of solar power and producers of solar cells. It's nothing new though

http://fortune.com/2015/06/18/china-is- ... ar-panels/

China's coal use peaked in 2013 - 2014
https://www.carbonbrief.org/iea-china-m ... al-in-2013
https://www.theguardian.com/environment ... nge-battle

And it has began decoupling from economic growth
https://cleantechnica.com/2017/03/14/ch ... nsumption/

In case of your lack of knowledge, for your edification

https://www.bloomberg.com/news/articles ... s-to-solar

In 2016, countries from Chile to the United Arab Emirates broke records with deals to generate electricity from sunshine for less than 3 cents a kilowatt-hour, half the average global cost of coal power. Now, Saudi Arabia, Jordan and Mexico are planning auctions and tenders for this year, aiming to drop prices even further.

Assuming that the capital cost of the photovoltaic unit and the even larger cost of the storage system is of no consequence to you, UPS systems come in all sizes, up to those large enough to power a small city (e.g.: Fairbanks, AK) for as long as it takes to start up standby generators powered by diesel, propane or natural gas. If your energy needs are small, you could survive. I am certain that you and society would be better off to purchase your electricity from the commercial power grid and encourage greater efficiency at the commercial/industrial level. A large unit powering a whole neighborhood is more efficient than lots of tiny units. An even larger unit powering a small town is even more efficient... and so on.

If the total cost of solar were actually lower than coal, why would the Chinese be burning billions of tons of the stuff each year? Do they hate blue skies that much?

JustAnEngineer wrote:

Assuming that the capital cost of the photovoltaic unit and the even larger cost of the storage system is of no consequence to you, UPS systems come in all sizes, up to those large enough to power a small city (e.g.: Fairbanks, AK) for as long as it takes to start up standby generators powered by diesel, propane or natural gas. If your energy needs are small, you could survive. I am certain that you and society would be better off to purchase your electricity from the commercial power grid and encourage greater efficiency at the commercial/industrial level. A large unit powering a whole neighborhood is more efficient than lots of tiny units. An even larger unit powering a small town is even more efficient... and so on.

If the total cost of solar were actually lower than coal, why would the Chinese be burning billions of tons of the stuff each year? Do they hate blue skies that much?

When the solar panel from the grid has the same efficiency as the solar panel on the roof of a house, it's less efficient to use electricity from the grid due to loss from transmission. It could be cheaper to build due to utilities getting better deals on large orders but from an overall system perspective, it's more wasteful. The cost won't be that different, it will be of no importance for those living in cities though, as they can't exactly generate enough energy for a multi level building with the area on top of it. I'm not talking about an apartment I intend to take off the grid, but a house.

As for China, it has already started to shut down coal plants and invest hundreds of billions in solar with ambitious targets for the future. It can't happen over night (pun unintended) because it takes time to ramp up production and build the farms and more importantly, it's a slave to energy storage and the cost of said technology which is lagging a couple of years behind in terms of where it has to be to work well with solar, but it's getting there. That's why they haven't switched yet completely, but it's in progress.

Speaking of blue skies, the Chinese billionaire behind NIO has this to say "Blue sky coming".

https://youtu.be/c7RBK-xSAS0

If you're not familiar with the brand, it's a new-ish company that built the million dollar electric supercar called NIO EP9 which set an EV record at the Ring in Germany late last year of 7 minutes and 5 seconds and an autonomous record at COTA recently. It also unveiled plans for a concept called EVE, a 2020 project for a level 4 autonomous car but it should be known as a participant in FormulaE under the NextEV brand name.

The lap record short clip
https://www.youtube.com/watch?v=fcJd8wD9qeI
On board video
https://www.youtube.com/watch?v=UuW9qYVBLB8

I'm just saying, anecdotally Chinese people seem to yearn for a blue sky and their actions in the last couple of years reflect that desire. I mean, where exactly in the U.S. or Europe can you find this?

https://www.youtube.com/watch?v=sLo3Pn4KC3w

If your current electric service is unreliable enough that you feel a need for a UPS now, just get a UPS. I don't see why you need to tie that decision to whether you plan to eventually go with a PowerWall-type device and solar panels. An affordable single-house solar solution is still years down the road, and the batteries and inverters to power an entire house will probably never be cheap. Even assuming the price of solar panels and batteries comes down substantially in the future, the cost of a UPS to run a PC and a few peripherals will be lost in the noise.

Edit: It should also be noted that modern file systems are reasonably robust against unexpected power cuts. OTOH, there have also been reports that some consumer-grade SSDs may be susceptible to bricking if power is cut during a write.

just brew it! wrote:

If your current electric service is unreliable enough that you feel a need for a UPS now, just get a UPS. I don't see why you need to tie that decision to whether you plan to eventually go with a PowerWall-type device and solar panels. An affordable single-house solar solution is still years down the road, and the batteries and inverters to power an entire house will probably never be cheap. Even assuming the price of solar panels and batteries comes down substantially in the future, the cost of a UPS to run a PC and a few peripherals will be lost in the noise.

I get it but I'm also saying that between having the ability to keep the PC and a couple devices going for a couple of minutes or with the Powerwall, a couple of days, you can kind of guess why I'd want the latter even if financially they aren't exactly equivalent. I'm confident the prices will drop and it won't take 15 years either. Some predict less than $100 per kWh by 2022 for batteries and solar power to reach grid parity world wide by 2020. We're talking 5 years max. I guess it's a lot of time for me to find a permanent solution, but it's no small matter either considering what is happening, as in the end of the fossil fuel era AND the end of grid instability, hence why I made the thread.

I think the 5 year horizon is overly optimistic. It'll probably happen eventually, but these things rarely go as quickly as their proponents predict. Practical nuclear fusion has been "a decade away" for the past half century!

If you'd like a burger today but think there's a chance you'll get a big bonus next month that would mean you can afford to go out for a fancy steak dinner, go ahead and get the burger today anyway. (My apologies for the analogy if you're a vegetarian... )

Bigger is better. As energy storage and alternative power generation technologies improve, the place to apply those technologies is on the power grid. Transmission inefficiencies are much smaller than the inefficiencies of small isolated systems compared to large connected ones. If you need a UPS because your power utility is unreliable, get a UPS. If you want to make the world better by switching to less-polluting technology, you could accomplish more by doing it on an industrial scale. Just recognize that whatever reductions in coal usage are taking place in North America and Europe are more than offset by increases in pollution in China.

The significant decline in coal usage in the United States isn't because the electric utilities suddenly decided to give the Earth a break. Nor is it because consumers decided to conserve energy. It's because natural gas is so cheap in North America that coal is not economically attractive. Coal in China is still cheaper because they don't use the precipitators and scrubber systems that first-world countries require.

JustAnEngineer wrote:

Bigger is better. As energy storage and alternative power generation technologies improve, the place to apply those technologies is on the power grid. Transmission inefficiencies are much smaller than the inefficiencies of small isolated systems compared to large connected ones. If you need a UPS because your power utility is unreliable, get a UPS. If you want to make the world better by switching to less-polluting technology, you could accomplish more by doing it on an industrial scale.

As individuals, there's very little we can do to move the commercial power generation industry though. Our only leverage is through our elected officials and the laws they pass, and we do not have anywhere near the lobbying power of the incumbent electric utilities and fossil fuel producers. This latest election cycle was even a step backward.

Even if the industry has a change of heart (most likely a coerced one...), reworking our power grid infrastructure to accommodate a large-scale shift to solar and wind will take many decades. The current grid simply isn't suited to the geographic patterns of generation and usage which would result.

Once the price of the tech becomes more affordable, I expect the shift will actually happen first at the individual and local (municipality) level. I just don't agree with the OP on the timescale of it becoming affordable enough to be widely adopted. He says 5 years; I'm thinking more like 10-20.

JustAnEngineer wrote:

Just recognize that whatever reductions in coal usage are taking place in North America and Europe are more than offset by increases in pollution in China.

Recent indications are that they are slowing or even reversing their ramp-up of coal use. India may be another matter.

Unless you live in Hawaii I don't think solar will be reliable enough to take your house off the grid. You would need a massive amount of panels just to get close to break even, then throw in inclement weather, your location, latitude, and the changing angle of the sun throughout the year (drops efficiency unless you have movable panels) the average panel won't be enough.

A powerwall would be fun, but it will degrade like any other lithium-ion battery pack over time, so you don't really gain much over a lead-acid UPS there.

just brew it! wrote:

Once the price of the tech becomes more affordable, I expect the shift will actually happen first at the individual and local (municipality) level. I just don't agree with the OP on the timescale of it becoming affordable enough to be widely adopted. He says 5 years; I'm thinking more like 10-20.

Aye, they still need to find a ready, efficient means of storing energy to equalize the power flow. Kinetic-based storage mechanisms only go so far and few places have the geography to make hydro-electric storage possible.

There's also the issue of battery tech, I think we need that next-gen replacement to lithium-ion before home-based storage becomes viable. Thankfully there are some very promising options on the horizon, if anyone saw the PBS documentary "Search for the super battery" the solid battery that the host sliced and diced with a pair of scissors is getting a lot of attention since the episode aired. A week or two after the airing, on a follow up NPR interview the host joked why wasn't Samsung interested in his tech, and the inventor replied that they had actually just paid him a visit to investigate and look into scaling it up.

At the risk of going further down the R&P rabbit hole, I have difficulty taking much of the alt-energy community seriously given that they seem to hate solutions that actually work, i.e. nuclear, almost as much as they do fossil fuels. In CA the rabid environmentalists have even blocked wind and solar farms for various stupid reasons. And don't even get me started on the shameless cronyism associated with energy research programs, both public and private. Cost wise, it'll probably get cheaper but it will be a long time if ever before solar/wind capex costs drop far enough that Joe Sixpack who does not have a cushy Silicon Valley marketing job and barely has enough money to cover emergency expenses will be able to afford it. You're probably better off hoping that a clever engineer comes up with a superior method of power generation sometime between now and then, which isn't unreasonable given that the current state of the art isn't great to begin with.

As far as the original question, as noted UPSes come in many sizes and shapes. Datacenter size UPSes aren't cheap though...what makes the Powerwall so interesting is that it *is* cheap for what you get, though we don't really know yet whether that cost can be maintained, what the long term total cost of ownership will be like, or even if it can pass the various regulatory and logistic hurdles on the path to widespread use. Hopefully it will; I like Elon Musk, he's one of the few involved in the energy discussion that's actually doing something useful. Usually what you do if you're serious business is have a diesel generator configured to automatically turn on at power loss, and enough UPS to carry everything through until the generator is warmed up. That doesn't sound like the kind of thing that OP wants, though.

Kougar wrote:

Aye, they still need to find a ready, efficient means of storing energy to equalize the power flow. Kinetic-based storage mechanisms only go so far and few places have the geography to make hydro-electric storage possible.

CAES is viable in some of the flatter states that lack a handy mountain on which to build a lake.

Hmm. Shoving 1,000 PSI air into an underground hole. There will be failures, and they will be spectacular.

Captain Ned wrote:

Hmm. Shoving 1,000 PSI air into an underground hole. There will be failures, and they will be spectacular.

Also sounds like it is rather inefficient unless you're willing to deal with the added complexity of a secondary system to store the heat produced during compression.

just brew it! wrote:

Captain Ned wrote:

Hmm. Shoving 1,000 PSI air into an underground hole. There will be failures, and they will be spectacular.

Also sounds like it is rather inefficient unless you're willing to deal with the added complexity of a secondary system to store the heat produced during compression.

Reading the article, the compression heat is part of the process.

just brew it! wrote:

Captain Ned wrote:

Hmm. Shoving 1,000 PSI air into an underground hole. There will be failures, and they will be spectacular.

Also sounds like it is rather inefficient unless you're willing to deal with the added complexity of a secondary system to store the heat produced during compression.

Yeah, but the nearest alternative -- which is being installed in various California locations right now to help meet the state's regulatory requirements for renewables -- is essentially a shipping container stuffed end-to-end with batteries, power electronics, and HVAC. These units are sized in terms of 1-2MVA storage per container and are being intalled in groups of 5-20 units per site.

The losses for shoving air into the ground is probably break-even compared to the environmental, manufacturing, and maintenance costs for those containers.

Captain Ned wrote:

just brew it! wrote:

Captain Ned wrote:

Hmm. Shoving 1,000 PSI air into an underground hole. There will be failures, and they will be spectacular.

Also sounds like it is rather inefficient unless you're willing to deal with the added complexity of a secondary system to store the heat produced during compression.

Reading the article, the compression heat is part of the process.

Looked to me like it is an optional part. Fully capturing and re-using the heat is the difference between ~40% overall efficiency and ~70%.

ludi wrote:

Yeah, but the nearest alternative -- which is being installed in various California locations right now to help meet the state's regulatory requirements for renewables

The day that one of those Li-Ion containers self-destructs will make for some epic filmage.

Captain Ned wrote:

ludi wrote:

Yeah, but the nearest alternative -- which is being installed in various California locations right now to help meet the state's regulatory requirements for renewables

The day that one of those Li-Ion containers self-destructs will make for some epic filmage.

These are lead-acid IIRC, and they have internal halon fire supression along with all the other support systems. A large failure probably wouldn't be catastrophic, but it would be expensive.

ludi wrote:

These are lead-acid IIRC, and they have internal halon fire supression along with all the other support systems. A large failure probably wouldn't be catastrophic, but it would be expensive.

And here you go to take all of the fun out of it,

Could still have some fun fireworks if the systems responsible for venting the hydrogen from charging the batteries malfunctions. Not nearly as fun as a lithium battery fire though.

Grid energy storage is likely to diverge away from lithium ion batteries, though it could be a small percentage at lower sub TWh scale. The most likely approach to grid storage will be to use what makes sense for each region and scale of energy produced. It doesn't make sense to use pumped hydro near a city, likewise it's impractical to deploy TWh scale energy storage with lithium ion batteries. There is research into compressed air energy storage beyond using underground emptied gas wells, like for example:
https://arstechnica.com/science/2017/03 ... ge-sphere/

Personally I'm more interested in liquid metal battery for the part of the grid that needs to cycle daily.
https://www.youtube.com/watch?v=pDxegcZqx_8

For home energy storage there is no near term alternative to lithium ion batteries as the best in class. They cost less now than lead acid per kWh, they last more than double the time with thermal management. For those interested in future improvements:
https://youtu.be/xMnTOpJScpg

The simplest, close to home analogy would be to say that liquid metal batteries or compressed air storage is like RAM, pumped hydro is like a HDD and lithium ion is like CPU cache memory.

Captain Ned wrote:

Hmm. Shoving 1,000 PSI air into an underground hole. There will be failures, and they will be spectacular.

http://www.apexcaes.com/bethel-energy-center
https://www.greentechmedia.com/articles ... y-storage2
http://www.emergingenergyinsights.com/2 ... ination-3/
http://www.ercot.com/gridinfo/etts/comp ... -a_drm.pdf
This unit actually will be on-line in 2020. The OP's battery system wouldn't still be making hundreds of megawatts with 95% reliability after decades on-line.

Pretty cool, hadn't heard of CAES before.

Captain Ned wrote:

Hmm. Shoving 1,000 PSI air into an underground hole. There will be failures, and they will be spectacular.

It's not really a new concept though... the oil and gas industry uses underground storage for natural gas in old wells all the time. And there's that crazy practice of pumping CO2 underground as well.

For comparison purposes if you remember the Aliso Canyon gas leak, the rest of the Aliso Canyon natural gas storage field goes up to 3,000 PSI with a "minimum" PSI of 1,000 allowed by state regs. The company itself estimates it could safely go up to 3,500 PSI.