Hello??? Did anyone catch this?
Elon FINALLY talked about desalination in public on tonight’s interview with Bill Maher. He didn’t say much about it, but he shut down Bill Maher’s claim that we will run out of water and insisted that desalination is “absurdly cheap” and will solve it.
I was disappointed to see desal totally omitted from Master Plan Part 3, because 1) we will need it and 2) it will be a BIG driver of total global demand for electricity in the coming decades. This increases my conviction that MPP3 is a base case for the transition to sustainable energy that’s massively underselling the actual total addressable market for energy consumption.
If you don’t believe me, search my post history for “desalination” for some math on this topic. Because desal is already done at industrial scale, we already know the order of magnitude of energy required to desalinate water via methods like reverse osmosis and multistage flash distillation and the physics are well understood. In a future world of cheap, abundant clean energy I expect the much more energy-intensive flash distillation option to become dominant, because it’s really cheap and simple except for the energy cost, which is why almost all desal today is performed via reverse osmosis instead. Multistage flash distillation is basically just boiling water and condensing it repeatedly in a series of staged tanks until it’s pure enough.
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Freshwater scarcity is a huge problem we’re facing in many regions around the globe, and droughts are hitting the Middle East, North Africa, Australia, and the North American Southwest especially hard. This is going to continue getting worse and worse over time. Relying on increasingly unreliable precipitation and wishful thinking is not a viable strategy, and neither is sucking our aquifers dry until nothing’s left. Luckily, almost all of those countries facing the worst drought and heat stress also have have excellent solar resources, lots of barren and deserted land, and their own saltwater shorelines on oceans and seas which are also conveniently located near the biggest population centers. The H20 molecules are there in abundance but they’re mixed with impurities and downhill from where they’re needed. Both of these problems can be solved in brute force fashion with copious supply of energy. Right now, this is why only countries with extremely scarce freshwater and extremely abundant energy, such as the UAE, do substantial amounts of desalination. With where the cost of electricity from solar and batteries is headed, soon everywhere will have even cheaper energy than Emirati oil and gas is today.
MPP3 presented a path for replacing existing energy uses with renewables. It estimates that total human energy consumption maybe actually be cut in half due to the efficiency gains from electrification. For what MPP3 looks at, this is probably more or less correct, but again I assert that MPP3 is totally neglecting new future use cases for energy that will come from low-cost, guilt-free renewables. Depending on exactly how you want to estimate it, it’s plausible that desalination
by itself would consume more energy than everything else in MPP3 combined, possibly even by a factor of 2-10x. It’s really hard to estimate precisely without making big assumptions but no matter what parameters I use the numbers are gigantic. Water just has a high specific heat, a high latent heat of vaporization, and is used in staggeringly large quantities by humans.