This is a very exciting time of changes for off grid and alternative energy. The cost of established systems is coming way down and many new discoveries are in the pipeline. For sure, a lot of emerging off grid technology is highly theoretical and may never appear on the end user market, at least not in our lifetimes. Others show amazing promise and may soon be powering our ham shacks.
The “artificial leaf.”
It sounds like something from a science fiction movie, but it’s not. A microns-thin film of silicon, which basically acts as a conventional solar cell, is paired with catalyst made from ruthenium dioxide. The assembly is submerged in water and exposed to light. The electricity is used to decompose hydrogen out of the water. The hydrogen yield can then be used as fuel to power a generator. The artificial leaf does not directly produce useable power, it only converts light energy into stored chemical energy. Nonetheless, it needs only light and water to do its thing.
Right now this off grid technology exists only in a lab and still has a lot of hurdles to overcome, not the least of which is that water attenuates a lot of the sunlight and the serious safety issues with producing, processing, and storing large volumes of highly unstable and explosive hydrogen gas. It would also require devices/engines capable of using the fuel. Still, the promise of the artificial leaf is very real. I can see this process being implemented on an industrial scale and the gas being sold to off gridders the way propane is now.
Huge lithium battery farms feeding a hungry grid.
The Number One engineering problem with commercial renewable energy is that it is very difficult to coordinate the timing of supply with demand. No one can make the wind blow or the sun shine at the moment energy is required. Nature works on its own timetable, and that seldom matches up exactly with consumer need. Battery farms being developed by Tesla would be the bridge between these conflicting factors.
Lithium batteries have been around long enough that they are no longer considered “new” off grid technology. What is new is using them in huge multi-gigawatt banks to smooth out the power fluctuations inherent to renewable energy.
The indirect benefit to the off grid ham is that lithium battery technology –the cost of which has dropped considerably in only a few years– will soon go even lower and settle at price point very close to legacy batteries.
Imagine an inexpensive lithium battery that weighs less than half of whatever you are using now and produces twice as much energy, plus has a useful service life of eight or ten times more charge cycles. Yes, it’s going to happen soon. Adapting lithium batteries to the commercial power grid will drive retail prices down and make them easily affordable for amateur radio use.
The biggest downside to lithium battery off grid technology is that it requires specialty chargers capable of “cell balancing.” When you buy lithiums, you’ll also have to upgrade all of your chargers, including the charge controller on your solar power system. I hope someone comes up with an aftermarket converter or adapter that will let charge controllers work on lithium batteries because a lot of radio amateurs, including me, have invested many hundreds of dollars in controllers and we don’t want to replace them as part of the cost of going with lithium.
For more information about lithium batteries, check out this previous Off Grid Ham article.
Solid State Batteries.
Batteries don’t just mysteriously “die”. They go through a quantifiable degradation process that results in them no longer being able to perform the chemical reaction that creates electricity. The three big battery killers are electrolyte contamination, depletion, and plate decay/crystallization.
Either the battery gets contaminated with byproducts from the natural breakdown of the internal plates, or tiny crystals called dendrites form between the plates and short the cell out. In wet cell batteries, the electrolyte evaporates away. In gel batteries, the gel dries out over time. Wet cell battery electrolyte can be topped off with distilled water to stretch their lifespan, but ultimately all batteries will “die” from some combination of these three causes.
Solid state batteries (meaning, no liquid or semi-liquid electrolyte) being developed by scientists in Russia and Europe would be a huge leap forward in off grid technology. In addition to solid state batteries being even lighter and having a higher power density than current lithiums, many of the problems inherent to current electrolytes would be eliminated.
The main obstacle that needs to be worked out is that the plates in a battery naturally expand and contract as the battery cycles. When the electrolyte is a liquid or gel, there is enough “give” to allow for these changes. But if the entire battery is a solid mass, the expansion can crack the plate itself or the material around it and compromise the integrity of the battery. If you have ever seen a battery that is bloated and bulged in the outer case, then you are well aware of what can happen when guts of a battery have no room to move.
How well solid state batteries work and how long they last is a question mark at this point. Solid state batteries are still in the developmental stage so there isn’t any real-world data yet, but advances can happen quickly so don’t be surprised if this game-changing off grid technology suddenly does pop up on the shelf at your local hardware store.
Perovskite solar “panels” are coming soon!
Get used to the word perovskite because you’re going to be hearing a lot about this off grid technology.
The sun produces light all across the color spectrum but solar panels as they exist today can turn only a narrow band of that light into electricity. And the process for manufacturing solar panels, even with modern production efficiencies, is still complex and necessarily expensive.
Perovskite solves both of these issues, and more. The name perovskite comes from the chemical structure of the material used to make the panels (perovskite is also a mineral that naturally occurs in the earth, but that’s not what we’re talking about here). To call perovskite a solar “panel” is misleading because it can be applied like spray paint onto nearly any surface. It’s flexible and foldable and can be rolled up. There is no need to heat silicon, cut it into individual slices, and apply them to a firm substrate as it is done now with conventional panels.
Solar panel efficiency is defined as how much power the panel produces as a function of the total light energy shining on it. Perovskite is more efficient because it responds to a much wider bandwidth of colors than conventional panels. Present day panel efficiency tops out at 20-21% or so, and that’s a very generous ceiling. More realistically, most panels now on the market are in the 13-17% range.
Perovskite efficiency begins at 21% and can go to 27%. Light energy that is “invisible” to conventional solar is collected by perovskite and turned into wattage. For users of off grid technology, that translates into nearly double the output of anything out there now. And it may not even be in the form of a panel!
The main downside to perovskite is that the crystal structures at the heart of this off grid technology are very chemically delicate and will easily break apart. They are also water soluble. None of this is compatible with the harsh, wet environments to which solar panels are exposed. The good news is that scientists are close to a solving all these drawbacks. We may see perovskite solar available on the consumer market by 2018. It’s that close. Of all the up and coming off grid technology, perovskite solar is the most promising. I can’t wait to get my hands on one of these and write an evaluation for Off Grid Ham.
What you need to know.
New off grid technology is being introduced all the time and it’s often difficult to discern between theoretical dreaming and things with the potential to be genuinely practical and useful. Admittedly, the artificial leaf and solid state batteries are somewhere between these two points but I think both will eventually come to fruition. In the more near term, look for the cost of lithium batteries to drop dramatically and for the introduction of perovskite solar into the consumer market. These two advancements will make being an off grid ham a lot easier and offer more watts for the dollar.