Science and technology are constantly growing and expanding in every field. One particular area of interest is finding uses for the oceans/saltwater, one of the most readily available resources on the planet. Unfortunately, some of the most hyped technology involving saltwater does not live up to its press, yet.
History of Ocean Technology
Using the oceans’ bevy of resources has been done since civilization began. It started with finding better ways to harvest food from the ocean, then ways to travel and navigate. Then people started looking for ways to purify the water so it could actually be consumed and used. Some of the first efforts at desalination were recorded by Aristotle, and crude evaporation systems were used on sailing ship as early as the 16th Century. While desalination plants have been built using different technologies, there is still not a truly cost-effective method.
In the modern era, we also use the ocean for play and exploration. Technology for these pursuits has grown over the years. Dive suits and submarines were first employed in the 1700s. Since then, we have developed wetsuits with advancements to keep us warm and dry in various water conditions; scuba gear to breathe underwater without a tether; and small maneuverable submersibles to explore the depths, down to 3.7 miles. The one area of technology we have been unable to conquer is using saltwater for energy.
Current Technology in the News
The closest we have come is using saltwater in batteries to store energy. For one company, this is enough; for others, they would prefer you believe they are generating energy with saltwater. Upon examination of their claims, they aren’t. They are just storing it. Let’s look at the battery first.
- Aqueous Hybrid Ion Battery
This battery uses saltwater to store excess energy. It is the first battery to be cradle-to-cradle certified so it is the most environmentally-friendly option currently available. The Hybrid Ion battery from Aquion Energy is cheap, clean, safe, and lasts longer than other lithium-ion batteries. Because the main material is saltwater, they won’t explode or catch fire like lithium versions.
In addition to the safety aspect of the battery, it has a long list of other positives. Because there is no corrosion, maintenance is low, and there is no need for backup fire suppression or secondary containment in case of leaks. They are abuse tolerant, operate without loss of performance in a wide-variety of temperatures, and can handle 100 percent discharge or staying in a partial state of charge for long periods, all of which will negatively impact lithium-ion batteries.
The biggest drawback of this battery is its size. They are larger than the Tesla Powerwall, but not enough to make them impractical for home or business use. Mass production of this battery started in 2014. So far, it is living up to its hype.
Next, let’s talk about a couple of hyped saltwater technologies that aren’t exactly what they seem.
- SALt LED Lamp
The SALt lamp was created by engineer Aisa Mijeno when she saw how dependent native Filipino tribes were on kerosene lamps for light. While kerosene lamps are inexpensive to run, they are fire hazards and bad for the environment and human health. The SALt lamp runs on salt water, producing light for eight hours. If you are near the ocean, like the Philippines, you can use ocean water. If not, you can use a cup of fresh water and 2 teaspoons of salt, making it an environmentally friendly product anywhere water is available.
Unless you are conversant in the science of batteries, this all sounds amazing, and it does have potential, but there are a couple of points that need to be clarified.
First, it is not the saltwater that is creating the energy. The lamp uses a galvanic battery, technology that has been around since the 1780s. Saltwater is simply the catalyst. It dissolves a piece of metal - called an anode electrode - that is immersed in the water. It is this dissolution of the metal that creates the electricity, meaning without this anode, the lamp will not work, and it will need to be replaced.The frequency of replacement becomes an issue of supply and additional operating cost.
The second, and potentially bigger problem is the production of this anode. What kind of carbon footprint does the production facility have? Does it outweigh the carbon-savings of the lamp versus the kerosene the target market is currently using? It is a metal, so presumably it will have to be mined, refined, and then formed into this anode. Also, the remains of a used anode should be recycled to be truly an environmentally safe product. What are the costs associated with this process?
This has the potential to be a great backcountry product for places with plentiful water, but it isn’t a truly renewable energy product like a solar powered lamp.
- nanoFlowcell Saltwater Car
While Tesla is ramping up its Gigafactory in Nevada to produce cheaper lithium batteries for its electric cars, another company is working on a flow battery-based car, using saltwater. The technology behind the nanoFlowcell car is based on old NASA studies that were discarded due to low energy output. The nanoFlowcell battery uses two tanks, one with positive liquid electrolytes and one with negative liquid electrolytes. They are separated by a membrane and when they interact, the reaction creates the power to move the car.
The positives of the nanoFlowcell vehicle over an electric car, like the Tesla, are two-fold, according to the parent company. First, rather than hours in a charging station, you can fill your tank in about the same time as you can fill up your gas powered car. Second, current gas stations could easily be retrofitted to dispense the electrolyte fluids, thus allowing for the quick creation of a network for powering the cars, versus the slowly developing network of charging stations.
Despite the positives, there are two major sticking points. The biggest is that the company has only shown prototypes at the Geneva car show and no one has been allowed to test drive it for more than a couple of hours. Plus, they have been in the Geneva show since 2009, widely reported on since 2014, and still, there is no definitive word on when you will be able to purchase one.
The second problem is that the saltwater is not an energy source; it is a storage medium. So, just like the electric car has to be charged with electricity generated elsewhere, likely from burning coal, the electrolyte solution (saltwater) of the nanoFlowcell car needs to be charged. How the two liquids are charged has not been made clear. Presumably, it will be from another true energy source - maybe even a coal-burning plant.
From the perspective of operating the car, it looks great. There will be no negative environmental output from running the car. The fuel is stable, non-flammable and has no shelf life. There are no precious or rare-earth minerals used in the cell or the bi-ION solution. However, creating the charged bi-ION is probably as environmentally damaging as other technologies.
The jury is out on this new car. If it really lives up to all the claims of nanoFlowcell, this will be an environmental step forward.
Saltwater covers 70 percent of our planet. While we have succeeded in developing technologies to effectively play in and explore the ocean, we have yet to fully succeed in harnessing all the power of the ocean. The Aqueous battery is proof that saltwater is an effective way to store energy. However, the lamp and car do not hold up under scrutiny to the hype that has been built up around them by the media or their creators.