The Kardashev Energy Scale Maximus Veritas
In a recent The Economic Times article, Elon Musk says “The World Isn't Using The Sun's Energy Enough Because Most People Don't Do The Math”. "Once you understand the Kardashev Scale, it becomes utterly obvious that essentially all energy generation will be solar," he insists.
The Kardashev scale is a method of measuring a civilization's level of technological advancement based on the amount of energy it is capable of harnessing and using.
Nikolai Kardashev was a Soviet and Russian astrophysicist, interested in the search for extraterrestrial intelligence who reasoned that such intelligence would have evolved long before ours and therefore would be much further advanced with respect to its ability to harness energy. A "Type I" type civilization, like ours, according to the Kardashev scale would be able to collect and use all the theoretical 1016 watts (1000 terawatts) of the planet’s energy potential.
Per the following projection of the Kardashev scale to 2040 based on data from the International Energy Agency World Energy Outlook (Brianpeiris), we are currently about 73% of the way towards being a Type I civilization.
According to Carl Sagan, the Earth will be a fully fledged Type I planet around 2100. And according to Kardashev we could be a Type II civilization capable of consuming the energy of the Sun, evaluated at 4,000,000,000,000 terawatts in about 3,200 years, and 2,600 years after that we could be a Type III planet able of consuming the energy of the Milky Way, or 10,000,000,000,000,000,000,000,000 terawatts.
Thomas Murphy however has a different take on the math. He estimates that the waste heat of current energy consumption is about four orders of magnitude smaller than the incident radiation of the Sun, but at a growth factor of ten per century (a modest growth rate of 2.3% per year) this waste heat would reach parity with the intensity of the Sun in roughly 400 years.
The current Earth's Energy Imbalance (EEI) associated with climate change is ~1 W m–2, but at a 2.3% energy growth rate, the waste heat of exothermic energy sources would equal the current EEI in 100 years, after which waste heat would become the dominating forcing.
Musk has previously highlighted the challenges of scaling renewable energy, particularly the lack of energy storage. He noted in August 2023 that the intermittent nature of wind and solar power makes stationary battery packs at utility scale increasingly important.
The lowest levelized cost of energy (LCOE) for solar photovoltaics is about $20 to $40 per MWh, for regions like the southwestern U.S., the Middle East, and parts of Asia. But for Anchorage, Alaska, the LCOE ranges between $100 to $150 per MWh (or possibly higher, depending on specific site conditions and energy storage needs).
The median latitude for the global population is around 27°N, so populations between 20°N and 20°S presumably can obtain in the $20 to $40 per MWh range and populations at higher or lower latitudes would have to pay upwards of $150.
But intermittent energy sources, like solar, requires storage, backup, and infrastructure upgrades that push the total cost of energy far higher. Lithium-ion batteries are the most common form of energy storage and are expensive. They can add between $100 to $300 per megawatt-hour (MWh) of energy stored. Hydropower or pumped storage is cheaper in the range of $50 to $100 per MWh. Peaker Plants which typically rely on fossil fuel power backup add between $70 to $200 per MWh to the total cost. Overbuilding renewable capacity is another approach to ensuring energy supply during low-output periods with solar energy, which increases the cost of energy by between 20-50%. And expanding transmission networks and integrating smart grid technologies to handle intermittent energy can add to the cost upwards of $50 per MWh.
But the 90% of the heat of global warming going into the ocean represents one of the planet's most significant (and growing) potential energy sources. It is a reasonably recoverable reserve accessible with existing technology and existing economic circumstances. The stratified heat of the ocean’s tropical surface invites work production in accordance with the second law of thermodynamics with minimal environmental disruption. This is an endothermic energy reserve that obtains energy from the environment, thereby negating the production of waste heat. Thereby reducing the cost of energy and everything that relies on its consumption.
The 2012 Assessment of Ocean Thermal Energy Conversion by Shylesh Muralidhara estimated the LCOE for conventional ocean thermal energy conversion (OTEC) at $122.24 per MWh for a 400 MW sized plant.
For a Thermodynamic Geoengineering plant which is 33% less expensive this cost would be $80.68/MWh. And since each doubling of the size of these plants reduces the cost by 22% a 1 GW plant would be about $56/MWh. The inflation rate between 2012-2024 is about 137% so the current LCOE would be about $77/MWh.
In 2022, Elon Musk expounded at the Cars of the Future event that hydrogen “is the stupidest way” he could imagine for energy storage. And he didn’t agree with fuel cells either.
Since offshore OTEC requires an energy carrier, of which there are many, but hydrogen derived from seawater by electrolysis, would be one of the best energy carriers.
According to hydrogeninsight, the cost of producing and installing electrolyzers for green hydrogen production in China, the US and Europe has risen by more than 50% compared to last year to about $2,500/kW for the US and Europe and $600/kW for China.
Using Chinese electrolyzers, the cost of Thermodynamic Geoengineering would be about 175% higher for a total of about $135/MWh.
Since Tesla manufactured 947,000 cars in Shanghai in 2023, it seems reasonable to compare hydrogen produced with Chinese electrolyzer rather the more expensive version. Therefore, Thermodynamic Geoengineering derived hydrogen would be at least as cheap as solar energy backed up by Tesla batteries in tropical regions and in higher latitudes potentially 135/450 or 30% cheaper than in the higher latitudes.
So, who is stupid or at least should be doing their math?