Renewable Energy Storage -- What's Real?

[Skotty]

It has long been my position on renewable energy that the only way it will become a truly dominate energy form and not just a niche player is to have large scale energy storage solutions in place.

Personally, I stand behind Tesla, Gigafactories, and the Tesla Energy grid storage products (Powerpack and Powerwall). Those seem, though not off and running full speed yet, very real, and very important to the future of renewable energy.

That said, it has long been the renewable advocate position that renewable energy intermittency is not a serious problem. When this comes up, and it came up again in a recent Bill Nye Saves The World episode, the renewable energy spokesperson is quick to talk about things like pumped storage, geothermal solutions, and solar thermal. And sometimes batteries don't even come up at all (they were not mentioned on the Bill Nye episode).

Here's my problem. Those other solutions don't feel real. They seem like vaporware. The same vaporware the coal industry is peddling with clean coal and carbon sequestration.

Which of these energy storage concepts are real? How can the average person tell? Is carbon sequestration real? Who is actually going to build any of it? And by real, I mean a) it actually works, and b) it can be built on a large scale, and c) for a reasonable cost.

Right now, it looks to be like Tesla battery solutions are about the only energy storage solution that has crossed into the realm of reality. Everything else looks permanently stuck in concept, research, or demo phase, just like energy storing flywheels, fusion power, and fuel cell vehicles. Pumped storage seems viable, but how much space does it require, what is the impact on water resources, and why haven't I heard of even a single case of one being built?

I think there are already a couple of solar thermal plants, but how long into the night do they provide power, how efficient is that process, and is it really scalable?

 

[2012MS85]

Of all the solutions you mentioned above to solve the renewable energy intermittency problem (which is real and huge), Tesla Powerpacks for utilities and industrial/commercial clients, combined with Powerwalls for residential use, are the absolute best (most reliable and economic) real solution. Much of the rest that Bill Nye (an actor; not a real scientist) mentions are unicorns, beautiful and desired, but very hard to buy for my granddaughter who wants one to feed and pet.

And when I say Powerwalls are "economic," that is really only true when the "spread" of between your local utility's peak electricity rate (e.g., $0.30/kWh) and off-peak rate (e.g., $0.10/kWh) is about 20 cents, assuming you have Time-Of-Use (TOU) rates. I posted yesterday that most people nod off when I get too detailed with math, so I'm going to give the following break-even analysis only for those numbers geeks who understand and care (everyone else, just remember you need about a $0.20/kWh spread between your time-of-use rates before the Powerwall 2 (PW2) is cost justified for you, if saving money is your ONLY criteria). Let's assume the following:
1. Fully installed cost of PW2 is $8,000 (i.e., $5,500 PW2, $700 Gateway, $1,000 installation, $200 permit, $600 sales tax).
2. 11 kWh of energy are stored every day, on average, for the 10-year warranty life, then the PW2 dies. While you may benefit from a longer life, you also are going to have rainy, snowy, winter days where you can't charge much, so let's call that a wash. Also, Tesla's warranty is for 70% of the 13.2 kWh by year ten, so I'm using a simple linear average of 11 kWh [13.2 + (70% x 13.2)/2].
3. $8,000 full cost, divided by 10-yr useful life, means your cost (assuming you have cash and no better opportunity cost to invest your eight grand cause you're waiting for a stock market crash and your bank pays a lousy 0.1% interest) per year is $800. So you need to divide by 365 days to compute a $2.19 "daily cost" of your PW2. Now divide $2.19 by the average of 11 kWh that you'll charge each day (preferably with your solar, otherwise off-peak TOU cheap electricity) and discharge during peak time (offsetting the limited and expensive resource known as peak electricity). $2.19 / 11 = 19.9 cents.
4. For simplicity, I've ignored that you're going to have efficiency losses when you move all those electrons around (e.g., DC solar to AC PW2, etc.). Depending on your situation, this may average round-trip efficiency loss of 10% or so. So that would bump your 20 cent break even up to $0.22/kWh. So now open your next utility bill and see if you have a 20-22 cent spread on your time of use rates?

For the record, I don't (have that large spread to cost justify the PW2). In Iowa, we have cheap (under 10 cents) electricity prices that still comes from relatively clean (fully scrubbed, low-sulfur Powder River Basin) coal that produces the majority of all electricity in the State of Iowa and surrounding Midwestern states. Yes, we all have about 33% of our electricity (mostly off-peak, at night) coming from wind...which happened ONLY because Warren Buffett is receiving $5 BILLION in federal and state Production Tax Credits for MidAmerican Energy's 6GW of wind turbines that have been installed over the past decade. Mr. Buffett has stated publicly that his wind investment exists ONLY because of the PTC (free govt cheese that he loves). So I was very happy to get my slice of the cheese (30% federal and 15% Iowa Investment Tax Credits for my ACPV solar). Since my electricity comes from the Rural Electric Cooperative (Eastern Iowa L&P), I have a $0.16 peak rate and $0.083 off-peak rate. So my 7.7-cent TOU spread doesn't cost justify the PW2. But I'll overproduce solar energy in the summer months, and my REC cashes out my excess solar MONTHLY, giving me only 3 cents per kWh. So that effectively raises my TOU spread to 13 cents, which cost justifies two-thirds of my PW2. So how does one cost justify the other third? Well, I don't think the world will end because of burning coal (sorry), but I do know I'm glad I made the investment in my own solar production and 3 EVs (for my business and self). So somewhere in there there's a "social cost justification" in each of us that we all have to figure out on our own. Sort of the same way we cost justify a Tesla vehicle; it's just worth the premium ;o) I'll enjoy explaining how the PW2 and solar work (my avatar is a slight modification of the new Tesla app for Powerwall). Together, we'll all do our little part to change the world for the better.

Skotty, you did mention one "storage" solution that has been done - by Ameren - with some success...until it failed. Ameren's Taum Sauk hydroelectric power station. Ameren used its excess nighttime (off-peak) electricity (mostly from its baseload coal-fueled plants) to its pumped storage sites up a mountaintop. When peak energy was needed the next day, they'd open up the flow of water and, voila, they sort of created more valuable "peak electricity." Here's the sad ending to their story: this 1960s operation had a catastrophic failure in 2005 when the upper dam gave out. It was rebuilt in 2010. So this was a good idea, just not properly inspected and maintained. A company with gobs of wind generation (that blows hardest at night, creating excess off-peak power that shuts down zero carbon nuclear plants) like MidAmerican could benefit from a similar pumped storage plant since the plethora of Iowa wind turbines push the wholesale power prices NEGATIVE in the Midwest ISO (that's what utilities pay each other for electric generation as wind, coal, gas, and nukes all compete for who produces what in real time).

Finally, carbon capture and sequestration (CCS) is, IMO, a really dumb idea for two reasons. President Bush created FutureGen 2.0, and President Obama killed it. FutureGen was going to be a real-world, industrial scale test of CCS, paid for through a joint venture of private money (coal companies) and public money (US Govt). It was to be built in Mattoon, IL. Long story short, it takes about 40% more energy (parasitic load) to sequester CO2, so that effectively makes it uneconomic to bury. But the second (real big) problem is that it's a really bad idea to bury CO2 because if you have an earthquake, and the buried CO2 is all-of-a-sudden released, every human above that area suffocates and dies. A similar issue (a "carbon burp") has occurred; google "Lake Nyos" and you'll see how 1,746 people died a horrible death in 1986. So it might have been good to know more through research like FutureGen 2.0, but those who claimed the sky was falling were the same folks who killed off the research needed to know more.

So, all things considered, I think Elon is onto something. And I also think it's Tesla's energy storage that will create the real value in Tesla's stock price going forward. For the record, I'm neither long nor short TSLA stock. Just a fan of TESLA and its products!

 

[Merrill]

2012MS85, thanks for the info I get what you are saying but not sure I understand all of it. You are lucky to have such cheap energy, our monopolies in California can charge what ever they want. I really hope the powerwall becomes affordable for residential use because for me without net metering I will need to go that route. Not sure how much longer NEM will last and the rates keep climbing, my off peak is 0.14 and peak is around 0.35.

 

[2012MS85]

2012MS85, thanks for the info I get what you are saying but not sure I understand all of it. You are lucky to have such cheap energy, our monopolies in California can charge what ever they want. I really hope the powerwall becomes affordable for residential use because for me without net metering I will need to go that route. Not sure how much longer NEM will last and the rates keep climbing, my off peak is 0.14 and peak is around 0.35.

My pleasure, Merrill. I need to follow my wife's advice and keep it simple. Long story short, you're a perfect candidate for the Powerwall 2 since you have a 21 cent spread between your peak and off peak rates. Your PW2 will pay for itself. And then when you add in the loss of net metering from the utility companies, that really makes it a no brainer. In Iowa we all have net metering (if you stay under 20kW of solar), but it's my REC cashing out my excess solar every month at below my lifetime cost of production that stinks. I wish I could roll my excess over for a full year period (which is how MidAmerican and Alliant do it). Oh well!

Cheap energy does great things for lots of people (especially lower income folks who can't afford a huge energy bill). That's a key reason I dislike Al Gore screaming that we're all going to die from CO2, or politicians who want a carbon tax (because everything, including our breath, produces CO2). The best path forward is a good DIVERSIFIED portfolio of ALL types of energy (i.e., baseload nuclear, low-cost PRB coal, plentiful clean natural gas, hydro where there's snowmelt, wind where it's windy, solar where it shines, geothermal, Tesla batteries now that the $/kWh is coming down, and lots of continuing research on whatever the future holds and nobody yet knows). When people scream the sky is falling, most folks stop listening and caring. It's a slow education of the masses, but it becomes much easier when Elon makes beautiful products that other people ASK YOU about

 

[Jeff N]

When this comes up, and it came up again in a recent Bill Nye Saves The World episode, the renewable energy spokesperson is quick to talk about things like pumped storage, geothermal solutions, and solar thermal. And sometimes batteries don't even come up at all (they were not mentioned on the Bill Nye episode).

Here's my problem. Those other solutions don't feel real. They seem like vaporware. The same vaporware the coal industry is peddling with clean coal and carbon sequestration.

Which of these energy storage concepts are real? How can the average person tell? Is carbon sequestration real? Who is actually going to build any of it? And by real, I mean a) it actually works, and b) it can be built on a large scale, and c) for a reasonable cost....

....I think there are already a couple of solar thermal plants, but how long into the night do they provide power, how efficient is that process, and is it really scalable?

Bill Nye (a former mechanical engineer at Boeing who contributed to the 747 design) is amusing and seems sincere. Thanks for the reminder to look up his new show.

I'm hardly an expert on these topics but here are my semi-informed impressions:

Pumped storage is real and has been in use for decades. It is useful not just for energy storage but also for load-following generation which can help balance variable solar and wind generation. The downside is that it only really works where the natural environment (local mountains etc) allows a dam to be built with sufficient elevation and storage size. Also, it turns out that large bodies of water promote significant climate warming gas emissions.

Solar thermal is real and is emerging as a cost-effective alternative for solar that can be stored and emitted for a few hours after dusk. The downside is that it may need large installations on rural land to be effective.

Geothermal is real but is limited to areas that have suitable underground thermal sources.

Solar PV and wind are both real, have been seeing quick and steady price drops, and are quickly becoming economical ways of generating power in addition to being ultra low-carbon and using no water during operation. However, their power is variable and solar PV is only available in daylight hours.

Carbon sequestration is not practical for a variety of reasons and is unlikely to be an important component of climate change mitigation in the next 20-30 years.

Stationary storage batteries are becoming practical due to large price drops. They can be used either to compensate for variable output from wind and solar PV. They can also be used to simply improve reliability and optimal operation of older generation sources. Batteries for storage are emerging for destination use in residences and businesses but utility scale storage (as opposed to reliability and stability) use may be less common at first except for special situations like islands (Tesla and Kauai) and remote locations.

 

[gavine]

All of that will still have compete with distributed energy. Once batteries and solar get cheap-enough, will the need for the grid go away? Pumped storage, etc. still relies on the grid and maintaining the grid is very expensive. I have read (on this forum) that, even if the fuel at power plants were free, electricity from the grid will still be more expensive than distributed battery with solar eventually.

So, that's a win for batteries and I'm a believer in distributed power being the norm in the future.

 

[ecarfan]

@2012MS85 I appreciate the effort you put into the economic analysis you posted. My TOU spread is about $0.30 (on average over the year) and I am happy with my PW purchase. Plan on adding a PW2 in the future.

I deeply disagree with your simplistic description of the hazards of CO2 production from burning coal, and characterizing Al Gore as "screaming" trivializes your position. The best path forward is a goal of 100% sustainable energy and resource use.

We agree that Elon "makes beautiful products".

 

[RubberToe]

SB700 will incentivize solar plus storage to soak up the excess power supplied by Solar PV during the day. This should start reducing curtailment with the ever increasing PV being installed:

California Senate committee clears bill for new energy storage rebate program

 

[Jeff N]

That's a key reason I dislike Al Gore screaming that we're all going to die from CO2, or politicians who want a carbon tax (because everything, including our breath, produces CO2).

That's a bogus argument.

The issue is the relative timing of the carbon cycle. People and other animals eat carbon-based food and then poop and exhale the carbon back out within a matter of hours and with an overall lifetime of weeks or years. Plants do the same. That does not contribute meaningfully to climate change because the cycling happens over a short period of time.

Climate change is tied to carbon cycles that take massively longer. We are pumping or mining massive amounts of carbon stored underground over a period of hundreds of thousands or millions of years and emitting it into the air over the span of a few decades. That massive introduction of carbon into the air is the key problem.

Over the span of a few hundred years that carbon will largely be absorbed into the ocean thus dramatically acidifying the water in ways that life there has not evolved to live in. The relatively sudden PH changes will prevent many ocean species from forming protective shells (we've already started to see this in the NW coast) among other effects and will collapse major food chains among ocean life.

Aside from the air temperature change, which is most extreme at the poles thus melting land ice into the oceans, the big issue is the speed of the change we are causing. All of the atmospheric CO2 increase since at least 1950 is caused by humans and the rate of change is at least 10-20 times faster than the slow CO2 and temperature changes induced naturally due to cycles in the Sun's solar output and orbital variations of the Earth that have caused the periodic ice ages.

Few if any of the animals and plants on the planet today have evolved to handle such rapid carbon and temperature changes.

Some people think they can just move north or buy a bigger air conditioner but our lives and modern stable civilized economy are predicated on cheaply exploiting all of the life forms that sit under us on the food pyramid. Those plants, trees, birds, insects, and fish will see massive extinctions or reductions in their viable ranges and our food pyramid will collapse out from under us. That's an inescapable fact given the Trumpian carbon emission trajectory.

 

[transpondster]

solar thermal is dead, cheap PV killed it. And engineering problems on existing projects make them look terrible compared to PV. Most solar thermal are without storage and price is terrible, so for same money you can buy probably 30 hours worth of batteries and it will work, with CSP storage you get projected power which isn't likely be matched and if there is failure then it's output most likely 0, while PV can output partial output

 

[RubberToe]

solar thermal is dead, cheap PV killed it. And engineering problems on existing projects make them look terrible compared to PV. Most solar thermal are without storage and price is terrible, so for same money you can buy probably 30 hours worth of batteries and it will work, with CSP storage you get projected power which isn't likely be matched and if there is failure then it's output most likely 0, while PV can output partial output

Crescent Dunes has molten salt storage. Sells the power for $0.135 per kWh. What does raw PV with battery storage sell power for?

Crescent Dunes Solar Energy Project - Wikipedia

 

[transpondster]

well if you wanna know the terrible true numbers...
Crescent Dunes cost is $900M for 110 MW and theoretical 1100 MWh storage at first I thought that that can buy 110MW PV and Lithium for 3 hours storage (because there is no really need for 10h storage) for similar price and it will work unlike Crescent Dunes which is broken ATM, but then I realized that you can buy 1100MWh from Tesla for ~$300M and 200+MW from remaining $600M ...

 

[Ampster]

our monopolies in California can charge what ever they want.

Ever heard of Sonoma Clean Power? it is an alternative to PG&E. That monopoly model is being eroded by Community Choice Aggregation, ie entities like SCP.

 

[Ampster]

What does raw PV with battery storage sell power for?

Tesla did the Kauai project PPA for $0.14 per kWhr.

 

[miimura]

Crescent Dunes has molten salt storage. Sells the power for $0.135 per kWh. What does raw PV with battery storage sell power for?

Crescent Dunes Solar Energy Project - Wikipedia

The Tesla Kauai solar + storage project reportedly sells energy for $0.139/kWh.

 

[2012MS85]

@ecarfan & @Jeff N I'll happily concede I oversimplified my CO2 comment, but I'll remain a non-fan of Al Gore mainly because I'm leery of prophets making profits and I don't like hypocrisy (e.g., politicians cashing in for hundreds of millions, while flying around on private jets, while mandating how others should live). Hopefully you won't hold that against me while I try to practice what I preach by educating others how they can personally improve our planet through conservation (the best solution that's rarely mentioned), switching to LED bulbs, adding DG solar, driving a Model 3 (or S/X if one can afford the luxury), installing a Powerwall 2, etc. I do appreciate your input

 

[RubberToe]

well if you wanna know the terrible true numbers...
Crescent Dunes cost is $900M for 110 MW and theoretical 1100 MWh storage at first I thought that that can buy 110MW PV and Lithium for 3 hours storage (because there is no really need for 10h storage) for similar price and it will work unlike Crescent Dunes which is broken ATM, but then I realized that you can buy 1100MWh from Tesla for ~$300M and 200+MW from remaining $600M ...

The blog post referenced in this post is an excellent source of information. I encourage all to check it out.

RT

 

[transpondster]

The blog post referenced in this post is an excellent source of information. I encourage all to check it out.

RT

but whole blog it's very pro carbon, but non the less CSP numbers are real and tragic

 

[RubberToe]

but whole blog it's very pro carbon, but non the less CSP numbers are real and tragic

Not sure that I would use the word "tragic"...

You have to consider: 1) when these CSP projects were started, 2) what the cost of PV was at that time, 3) whether or not one of the purposes of the projects was to see whether CSP as a technology could reduce costs by increasing the plant size, and 4) whether adding storage (molten salt) would make sense.

I followed the Ivanpah development pretty closely. Back when that was first planned, PV costs were much higher than today. There was a significant question whether PV prices could drop much, and how fast that might happen. CSP was a competing technology, which seemed at the time like another good option, even cost wise.

You were never going to find out whether a large CSP plant actually made economic sense until you built one (or several). The Ivanpah plant was a much bigger sibling to one that was constructed outside Yermo many years earlier:

The Solar Project - Wikipedia

Ok, so the cost of power from Crescent Dunes is $0.135 per kWh. And then the Tesla Kauai PV + battery is costing $0.14. One of the responders to the blog post mentioned earlier says that "The company behind the Crescent Dunes project now bids for PPAs as low as 6.3 US Cents per kWh"...

SolarReserve Bids 24-Hour Solar At 6.3 Cents In Chile

Unclear whether they are really able to get the cost down or not, especially given the problem that Crescent Dunes had that knocked them out for so long.

Anyway, I guess my main point WRT the "tragicness" of the CSP plant energy cost would be something like this: There are a lot of unknowns when dealing with new technology. Unless you have just arrived back from 50-100 years in the future, you likely don't have all the answers. I think it makes a lot of sense to go down multiple paths at the same time, and see whether each path gets you to where you want to go or not. In a world where, for whatever reason, PV prices hadn't fallen as far and as fast as they did, CSP might be a legitimate renewable energy contender.

So maybe we end up with several experimental power plants that produce power that costs more than burning natural gas, or burning coal, or even PV with battery. Outside of the fact that the government provided some of the funding as a test case for the technology, maybe the average power consumer ends up paying a few $ more per month. I wouldn't call that tragic.

If the only factor ever considered when deciding what kind of power plant to build is the current estimated cost, then no plants would ever be built other than natural gas. And if the only operational factor ever considered was the ongoing cost of running a plant, then you would probably end up burning the dirtiest possible coal until all the coal plants end their useful lives.

You have to consider the environmental effects, and also allow for some experimental projects that may or may not end up producing the lowest cost power per the above.

My $0.02

RT

 

[Jeff N]

CSP is certainly a lot less tragic than Chernobyl or Fukushima....