Water battery

Future is wet for grid power storage

Sometimes technology advance has a very simple goal.  It may not be to do things faster or longer, it may be just to do them as cheaply as possible.

 Current changes the colour of Prussian blue dye          

In the arena of grid power storage, cost control is paramount.  Traditionally we don't store generated electricity because it is too expensive to be cost effective.  However, if we had a large capacity battery that was a cheap as chips to make and run, power storage could become viable.

Take solar or wind or any other renewable source where the generator is at the mercy of the weather elements.  During the day solar panels can harness all that sunshine to turn into electricity but at night when the sun disappears over the horizon that power generation capability is lost.  Day time sunshine yields far more power than we could use locally but come night time, when the lights go on and the power consumption goes up, demand cries out for the power we didn't need before.

One Stanford PhD student surveyed this landscape for his thesis and set out to design and build a battery that is so cheap, it could be viable for power storage.  (Have you noticed how it's US based university boffins that seem to be having most of the good ideas in the battery technology field recently?)

Colin Wessels formed a start-up, Alveo Energy to pursue this dream.  His technology uses copper, iron, water and some electrochromic prussian blue dye to create a simple battery.  It's a large unit, the size of about four car batteries and it's heavy too.  Size and weight are not such an issue when a battery is intended for fixed rather than portable usage.  This prototype one is a 50 kg 1 kWh battery.

On the face of it, not a particularly exciting project but cost-wise, this is very exciting indeed.  Wessels reckons his battery can be constructed for less than $100 per kilowatt hour.  Lead batteries are $150 to $200 per kWh and lithium is way more expensive and cost-wise, not really even in the running for use in power storage.

Clearly the US government sees great promise in the Alveo Energy project as they have invested $4 million via an ARPA-E grant (one of the larger grants so far allocated to battery projects).

The ARPA-E project description summarises the goal of the venture:

Open Framework Electrode Batteries for Cost-Effective Energy Storage
Alveo Energy will develop a grid-scale storage battery using Prussian Blue dye as the basis for active material within the battery. Prussian Blue is inexpensive, readily available, and most commonly known for its application in blueprint documents. Alveo will repurpose this inexpensive dye for a new battery that can endure more charges under more extreme circumstances without suffering internal damage, helping to facilitate the adoption and deployment of renewable energy technology.


It will be 2016 before Alveo has a demonstrable prototype but this will certainly be one to watch.

The bottleneck of battery storage for renewable energy (Wired)

$4 million ARPA-E grant for Alveo water based battery