Flow Battery, Flow!

Brent Cullimore

The field of positive psychology is devoted to making so-called “normal people” happier. A key observation is that people tend to be happiest when they are in a state called Flow. (As much as I would like to live the State of Flow, Colorado comes close!)

In this state of relaxed concentration, people are performing an activity (knitting, fly fishing, solving crossword puzzles etc.) to which they can devote themselves exclusively ... at least for a little while, and which they do well.

So is a flow battery a happy battery because it is doing just one thing, and doing it well?

Or was I just experiencing flow while building math models of flow batteries? After all, just adding the word “flow” to anything gets my attention, living as I do on the Wet Side of Mechanical Engineering Boulevard.

So why should a battery flow? Other than the American Declaration of Independence asserting that pursuing happiness is everyone’s unalienable right, of course.

Perhaps the biggest advantage of a flow battery is that there is no design constraint between the maximum rate of energy that you can put in or take out of one, and the amount of energy that you can store inside. You can design a flow battery that accepts a mere 1MW charge or discharge rate, yet holds 5GWh of energy. Or you can design one that can charge at an astounding 5GW rate but which only holds 1MJ of energy. Why you do either of those extremes is beyond me, but the point is: you could.

If that isn’t impressive, then please learn to be disturbed when some press release says “a 50 MW battery” but doesn’t say how big it is. Or if it says “a 50 MWh battery” but doesn’t say how fast you can discharge it. C’mon people, we’re engineers. We have full right to get upset when a journalist can’t tell amps from amp-hours!

Do a search on “flow battery” maybe sprinkling in keywords like vanadium (VRFB) or iron-chromium (ICFB) or zinc-bromine (ZNBR). You’ll be amazed at what is already available and has been life-tested for decades, and what is being developed for the next generation. You might start with a little overview, such as this:

As I have mentioned in a prior blog, we need grid-scale batteries, and most technologies struggle to reach that scale and yet stay cost-effective.

There is an incredible amount of research and investment happening in the energy storage world, and flow batteries are but one recipient. A majority of the attention (and R&D money) is still flowing into dry cells, especially that stalwart: the lithium-ion battery. The press is full of stories of advances in that technology.

In fact, it is darn hard to wax effusive about flow batteries in the same week that Tesla and Panasonic showcase their Nevada-based lithium-ion battery Gigafactory.

That’s OK, CRTech software can model lithium-ion batteries too, at least in regard to thermal management and investigations of runaway. In fact, here’s a model derived from a Panasonic battery that happens to be a lot like the ones that Tesla uses:

Modeling a dry cell may not bring the same joy, but if I were a betting man (meaning: "if I were not an engineer") I would bet on some variation of a lithium-ion battery winning the Charge Wars, especially for vehicles.

Still, I’d hedge with a side bet on flow batteries, since it really is too soon to tell which one will win the race for utility-scale batteries. Both types have already been deployed for that application. I personally think that extra research money should flow toward flow batteries for grid-scale electrical energy storage because of scalability, longevity, and safety. Yes, you read that right: I’m OK betting someone else’s money on flow batteries!

May you find happiness in whatever you enjoy and excel. And may both you and your batteries flow.

Advanced Pipes in FloCAD
Thursday November 14, 9-10am MT (8-9am PT, 11am-noon ET)
This webinar introduces advanced features for FloCAD pipes in addition to working with complex geometry. Complex geometry includes interior fins and surfaces for heat transfer, flow around enclosed objects, annular flow, concentric pipes, and more. FK Locators and TEEs as modeling objects will also be introduced.
Custom Heat Transfer and Pressure Drops
Tuesday November 19, 2-3pm MT (1-2pm PT, 4-5pm ET)
Do you know what the default assumptions are in FloCAD, and whether or not they apply in your situation? Do you know how far you can go past that starting point? The answer: pretty far. There are numerous mechanisms in FloCAD for adjusting factors, scaling uncertainties, and applying different or supplemental correlations. This webinar summarizes the options available to you to customize your flow models to make sure that they apply to each new situation you encounter.
Heat Exchangers: Detailed and System-level
Thursday November 21, 2-3pm MT (1-2pm PT, 4-5pm ET)
This is two webinars in one. The first explains the use and assumptions behind the FloCAD HX system-level modeling object. The second webinar describes detailed-level modeling of complex heat exchanger passages, including application of Compact Heat Exchanger (CHX) methods.
Starting in 2020, we will begin offering Introduction to Thermal Desktop and Introduction to RadCAD as either in-person training or online training, alternating between online and in-person every three months. The training uses lectures and demonstrations to introduce you to basic Thermal Desktop and RadCAD usage. Hands-on tutorials provide practice building models and interpreting results (tutorials are completed by students outside of the online class time).
The next training class will be an online format in January 2020:
  • Introduction to Thermal Desktop (and SINDA) - A three-part series on January 14, 16, and 21 from 9am to 12pm, Mountain time
  • Introduction to RadCAD - January 23 from 9am to 12pm, Mountain time
For up-to-date schedules, fees, and policies, visit our Product Training page. To register for the class above, complete our registration form and select "Online" for the Training Format.
If you are interested in product training for your company based on your schedule, please contact us to obtain a quote for training between 8-12 attendees. We can come to your facility or the lectures can be presented online. Descriptions of the available classes can be found in our course catalog.
To keep up with our training opportunities, take a look at our new Events and Training Calendar.