I have district heating from a combined heat and power plant, which should be 80+% efficient. A solar air to water heat pump could be more efficient at 29% * usually 200% but sometimes 400% (For reference, traditional gas boilers only go up to 94%.) = 58% to 116%, the latter might require ground instead of air. CO2 is a relatively safe refrigerant.
According to ChatGPT: The efficiency of a typical modern steam turbine in a power plant is around 30-40%. Fuel cells can achieve efficiencies in the range of 40% to 60% or even higher for solid oxide fuel cells (SOFCs). Those and molten carbonate fuel cells (MCFCs) are used in combined heat and power systems.
In 2016, Organic Electronics reported 1.3 microns (about 1/100th the width of a human hair) being on par with glass cells, efficiency-wise. I think organic (carbon-based) material degrades faster, though. I guess it's several spray-on coats, bottom up:
- Insulating layer.
- Positive (p-type) layer with connections. Boron has vacant electron spaces.
- Negative (n-type) layer with connections. Solar radiation excites the electrons in the neutral part of the p-type layer enough to move to the n-type layer and via the connection back to the p-type layer, according to ACS. Seems to me putting the part to be exited first in the path of the photons would be better, but more electrons would soak up more photons.
- Insulating layer.
Excess potential between the connections could be used to split water into oxygen and hydrogen:
In acidic or neutral solutions, H+ cations move to the cathode:
Anode (positive, electron stealing oxidator) reaction: 2 H2O -> O2 + 4 H+ + 4 e-
Cathode (negative, electron adding reducer - Who came up with these names?) reaction: 4 H+ + 4 e- -> 2 H2
In less corrosive alkaline solutions, OH- anions move to the anode:
Anode reaction: 4 OH- -> 2 O2 + 2 H2O + 4 e-
Cathode reaction: 4 H2O + 4 e- -> 2 H2 + 4 OH-
You could also simply use the sun to cook (even in a Michigan winter), cool, burn with 600 W, or grow algae (up to 98% efficient) and bamboo (up to 87% efficient?).
Liquid fuel wise, according to this and this, algae gets 10,000 gal/acre/year, bamboo 3,200, corn 600, and hemp only 200, on par with Jatropha:
Seaweed is also interesting. 19.4 metric tonnes of dry weight per hectare. By comparison, about 11 metric tonnes of maize can be harvested per hectare in the highly productive fields of the United States.
Hydrogen at 0.07 MPa is bulkier than lithium batteries, but Toyota's Mirai uses 70 MPa (700 bar) tanks which are safe to shoot assuming no ignition. Placement and design help. 300 to 1500 kWh H2 energy storage + 36 or 20 kWh battery for sale in Germany. A Tesla Powerwall is only 13.5 kWh for $10,500 or $8,500 times two. A 20 kWh BlauHoff Powerwall is 8,676 euro with a delivery time of 1 to 2 weeks, and the hydrogen house system cost $500,000. Metal hydride is also safe to shoot, but probably too heavy as this knowledge is from the 1960s.
Despite their storage density, hydrocarbons are only half as efficient as electrons. Neatly summarized here:
Characteristics of selected energy storage systems (source: The World Energy Council)
| Max Power | Rating (MW) | Discharge time | Max cycles or lifetime | Energy density (watt-hour per liter) | MJ/l | Efficiency |
|---|---|---|---|---|---|---|
| Pumped hydro | 3,000 | 4h – 16h | 30 – 60 years | 0.2 – 2 | 0.00072 - 0.0072 | 70 – 85% |
| Compressed air | 1,000 | 2h – 30h | 20 – 40 years | 2 – 6 | 0.0072 - 0.0216 | 40 – 70% |
| Molten salt (thermal) | 150 | hours | 30 years | 70 – 210 | 0.252 - 0.756 | 80 – 90% |
| Li-ion battery | 100 | 1 min – 8h | 1,000 – 10,000 | 200 – 400 | 0.72 - 1.44 | 85 – 95% |
| Lead-acid battery | 100 | 1 min – 8h | 6 – 40 years | 50 – 80 | 0.18 - 0.288 | 80 – 90% |
| Flow battery | 100 | hours | 12,000 – 14,000 | 20 – 70 | 0.072 - 0.252 | 60 – 85% |
| Hydrogen | 100 | mins – week | 5 – 30 years | 600 (at 200bar) | 2.16 (at 20 MPa) | 25 – 45% |
| Flywheel | 20 | secs - mins | 20,000 – 100,000 | 20 – 80 | 0.072 - 0.288 | 70 – 95% |
According to https://xkcd.com/1162/ uranium contains 76,000,000 MJ/kg, and coal 24 MJ/kg, so even using only 2% per fuel rod, fission is (0.02*76e6)/24= 63,333.33 times as efficient as coal. Fun fact: Coal ash contains more energy in the form of thorium than was gained by burning the coal. Some coal power plants pollute 100x more radioactive waste of fission power plants producing the same amount of energy, in addition to significant quantities of toxic arsenic, lead, thallium, mercury, uranium and thorium. That said, even on 100% coal power, EVs are cleaner than ICVs.
Solar is the cheapest source of energy right now, but car batteries still have a barrier to entry, so WW2 tech such as wood gas and NH3 is the most afforable short-term option to some, short of wind power, cycling, or walking:
For forward motion, we need energy. Regardless of the mode of transportation. Even on foot, a person weighing 70 kg has an energy consumption of around 0.075 kWh per kilometre. This makes walking the second-most efficient form of transport. Only cycling is a more energy-saving form of transport, with a peak value of 0.025 kWh. At the other end of the scale is the car (0.56 kWh), according to the Federal Environment Agency. According to the French energy and environmental agency ADEME, aeroplanes (0.52 kWh) and motorbikes (0.51 kWh) are similarly inefficient. The most energy-saving form of public transport is the tram or underground train, at just 0.05 and 0.08 kWh per kilometre travelled. - Efficiency Master – a Comparison of Different Modes of Transportation
Aptera is said to charge 100 Wh with 700 W solar power so 60 / (360000 / 700 / 60) = 7 miles per hour of sunshine, even while driving. 700W/250W/m2 = 2.8 m2 of solar panels, which appears accurate.
Remotes can run on solar or even piezo power.
Waste can be collected using protein amyloid fibrils from oilseed meal.
Batteries can be recycled and replaced for about the same cost as a new engine.
Methane (CH4) holds more infrared than CO2, and more OH helps cool the planet by OH + CH4 => H2O + CH3, so the culprit of climate change caused by global warming might be excess warm-era H atoms, which also explains why H2O is a bigger blanket that fortunately falls faster. So instead of recent hydrogen, excess electricity could also be used to calculate new materials, of which there could be number of stable nuclides to the power of the number of them in your molecule/alloy/lattice: Over 251**3 = 15,813,251, and 251**4 is already 3,969,126,001. That's not even considering ratios, but CrCoNi sounds like 1:1:1.
Concerning alarmist AI videos about climate change: The consumption of water in Panama has risen continuously in the past decade. In 2021, the Central American country consumed approximately 115e9 gallons of water, up from approximately 90.2e9 gallons recorded in 2011. - Statista, where 1 billion = 1e9. 115e9 US gallon * 0.00378541 = 435,322,150 m3 per year, so /365.25 = 1,191,847 m3 per day. Already achievable by a single desalination plant like those in Saudi Arabia.
See also my tech prefs.