I was away last week, first at CSICON and then at a conference in Dubai. I was invited to give a 9 hour seminar on scientific skepticism for the Dubai Future Foundation. That sounds like a lot of time, but it isn’t. It was a good reminder of the vast body of knowledge that is relevant to skepticism, from neuroscience to psychology and philosophy. Just the study of pseudoscience and conspiracy thinking themselves could have filled the time. It was my first time visiting the Middle East and I always find it fascinating to see the differences and similarities between cultures.

What does all this have to do with alternating vs direct current? Nothing, really, except that I found myself in a conversation about the topic with someone deeply involved in the power industry in the UAE. My class was an eclectic and international group of business people – all very smart and accomplished, but also mostly entirely new to the concept of scientific skepticism and without a formal science background. It was a great opportunity to gauge my American perspective against an international group.

I was struck, among other things, by how similar it was. I could have been talking to a similar crowd in the US. Sure, there was a layer of Arabic and Muslim culture on top, but otherwise the thinking and attitudes felt very familiar. Likely this is a result of the fact that Dubai is a wealthy international city. It is a good reminder that the urban-rural divide may be the most deterministic one in the world, and if you get urban and wealthy enough you tend to align with global culture.

Back to my conversation with the power industry exec – the power mix in the UAE is not very different from the US. They have about 20% nuclear (same as the US), 8% solar, and the rest fossil fuel, mostly natural gas. They have almost no wind and no hydropower. Their strategy to shift to low carbon power is all in on solar. They are rapidly increasing their power demand, and solar is the cheapest new energy. I don’t think their plan for the future is aggressive enough, but they are moving in the right direction.

What I did not encounter was any defensiveness about fossil fuels, denial of global warming, or any conspiracy nonsense. The UAE is the world’s 8th biggest oil producer, so I would not have been surprised if I had. At the end of the day, the science and the tradeoffs are pretty much the same. There are regional differences in terms of how much wind, sunshine, and water there is locally, and that affects the calculus, but everyone is dealing with the same technologies. But I still found it fascinating to be in a conversation with someone half-way around the world, from an entirely different culture, and hit all the same talking points that I have been discussing for years. We even discussed net metering (he was in favor) and Germany’s poor decision to shut down their nuclear industry.

And, of course, the conversation turned to the question of AC vs DC (which he brought up). Most nerds and technology history buffs know that there was a big fight between Edison and Tesla about whether or not the electricity infrastructure in the US should be alternating or direct current. Edison favored direct current, while Tesla favored alternating current. AC won out largely because it is more efficient to transmit over long distances and to alter the voltage with transformers.

The question of AC vs DC is raising its head again, however, because technology has changed. I am not an expert in electrical engineering, and I have had enough conversations with experts to know that this topic is very technical and complex. So I am not going to try to explain the technical details, but just discuss some of the main issues. There are essentially two reasons to rethink the AC vs DC choice. The first is that as technology has improved, the advantage of AC over DC had diminished. The transformer advantage still exists, but transmission efficiency is not as big of an issue as it was. AC and DC are not very different over short and medium distance, but AC still has an increasing advantage over longer distances.

But the second reason has to do with solar power and electric vehicles. An increasing number of homes have both, and even battery backup to boot. And, in the opinion of many experts, with whom I agree, it is a reasonable goal to maximize the number of residential homes that have all three – solar, EVs, and battery backup. All three of these technologies are DC. So in such a home the solar panels convert their DC power to AC, which then gets converted back to DC to charge the EV. You can have either DC-coupled or AC-coupled battery systems – in the former the power remains DC, while in the latter it is converted to AC before being stored in the battery. DC-coupled systems are more efficient (97.5% vs 90%).

In a modern home, therefore, there could be an entirely DC system where the power from the panels to the battery to the EV (which is just another batter) is all DC. The car battery can then also more easily be used as additional storage without conversion. Every time you convert AC to DC and back you get about a 3% energy loss, and having an all DC system would avoid that loss.

In terms of appliances, it’s a mix. Many of the bigger appliances, like refrigerators and dishwashers, use AC. While most of the smaller appliances, like computers, light-bulbs, and microwaves, use DC power. In order to have a 100% DC home, therefore, all that is necessary is to convert a few large appliances to DC, or for them to have their own DC to AC converter. DC also makes sense for a distributed power system, rather than distant centralized power production. Microgrids could be all DC. All of this makes some experts advocate for a future with residential DC power grids and all DC homes. We would likely need a hybrid system where we will have AC for long distance transmission. There is also still the advantage that AC is easier to alter voltage, but that is not a deal-breaker for DC if the home system were all at the same voltage.

The largest barrier, of course, is technology inertia. It is difficult to change over entire industries and change standards. At this point it’s difficult to predict what will happen, and the default will be for no change. I suspect, however, that this conversation will increase as the penetration of solar power, home battery backup, and EVs increases. At some point “going DC” for the home may be a thing, with the advantage of knocking 10% or so off of electricity demand (by eliminating multiple conversions).

It may happen first in developing nations and those who are currently building a lot of new infrastructure, like the UAE, leaving older industrialized nations with their crusty technology.