codecogs equations
tisdag 12 juli 2022
fredag 17 september 2021
The first privately funded Fusion Plant
Suppose you are a future entrepreneur in the emerging fusion market. In this scenario, the technology risk is substantially lower (i.e. we know fusion works), but there is still the matter of bringing fusion to mass use. Hopefully as quickly as possible, since 1) Early actors can make a lot of money, and 2) Also we are in a hurry to save the Earth. Your job is to convince investors that they will get a better return on investment than from other entrepreneurs. Your job is also to convince government bureaucrats that they should let you build your plant.
Where to put the first plant? It depends on which of these factors dominates.
1. Fusion experts are hard to come by
Everyone who has worked with fusion until now are concentrated in a few clusters around major projects. Only a few of them will be willing to uproot for your cause, and only for a hefty pay raise/equity. If this makes your option much less likely to succeed than the government projects, then you will have to put the first plant near Boston or Oxford. Unfortunately, this can reduce the comparative advantage of a private option. The comparative advantage of a private option is that it often accepts higher risks, and is therefore able to iterate faster. Fusion researchers presumably want to advance fusion technology as fast as possible. Maybe the key challenge will be to attract some of the most respectable fusion researchers, and if some of those are on board then getting others to move will be mostly a matter of making it convenient.
2. Governments are reluctant to let private enterprises build fusion plants
This could be due to safety concerns or wanting to retain control for national energy security purposes. It could also be a matter of just demanding a high tax, or requiring a list of security measures that is essentially a security theater, in order to avoid blame for potential accidents. Luckily, unless all of the US federal government, the UK, and the EU (and also all other locations where experts live/could be convinced to move) put in place a moratorium on private fusion, then there is a way to make it economically viable. That is to say, you only have to find one defector. Not being dependent on a particular location is also good for negotiation.
The problem is: if you put down a fusion plant next to no particular location (i.e. where the best tax deal is), then chances are there will not be a demand for an extra 500 MW of utility power nearby [1]. So the local price will go down. However, you can just mine bitcoin with the surplus power. The fact that bitcoin mining is possible makes fulfilling the following wish list more promising:
- A bit away from a population center, for safety.
- Permissive regulations for industrial development.
- Low tax.
- Cooling available.
- Large capacity for power transmission.
- Announce the building of plant in a location that fulfills above.
- When it seems likely that the plant will actually be operational soon, bitcoin miners will start to move in close to the location.
- From day one, the plant has a guaranteed selling price for its electricity that is limited by the price of energy in other bitcoin mining locales.
- The miners make a neat profit, but since their market has low barriers to entry, the plant owners get most of the surplus.
- From the perspective of the nearby population center, the plant acts as a reservoir of energy: it means that their local energy price will not be significantly higher than the energy price in other bitcoin mining locales. This is less of a social benefit than having electricity that is basically free, but it is still a significant social benefit, especially if the current power sources are unreliable or relatively expensive (such as in Germany).
- Over time, industries that produce more value per unit of energy than bitcoin mining may establish near the site.
- When the above steps have been carried out, there will be an established trust in the economic viability of fusion plants, and the energy revolution will be a matter of fact. Your company has hopefully already attracted more capital and started building next generation sites, attracting more actors to the market, which indirectly increases the viability of new industries that can leverage cheap electricity, further increasing demand for fusion power, and so on.
fredag 10 september 2021
The value of more options
I took a course on Statistical Modeling of Extreme Values in university. The following results may have been covered elsewhere, but it was missing from the course I took. I think that's a shame because they lend themselves more easily to quick estimations than the GEV. When valuating insurance it may of course be important to use the formal tools, but for most cases in extreme value analysis we just want to know whether something has the chance to be Really Bad.
Suppose we pick N samples from a stochastic variable X that are independent and identically distributed. What is the expected value of the Max of these samples? In particular, how does it grow with respect to N?
1. X ~ U(0, 1)
Another way to see this is that the expected value of 1 - Max(X) shrinks with the speed of O(1/N). So with N=10, the max will be about 0.9, with N=100, the max will be about 0.99, and so on...
2. X ~ Exp(1)
At this point, I had to take help from Wolfram Alpha [1]. The expression evaluates to the Digamma function of N, plus a constant [2]. The constant is about 0.58. The Digamma function grows as ln(N) - 1/(2N). Calculating some values:
N | E(Max({X})) |
---|---|
10 | 2.8 |
100 | 5.2 |
1000 | 7.5 |
1,000,000 | 14.4 |
Basically, the expected max grows logarithmically. Every extra order of magnitude adds about 2.3 (ln(10)) to the expected max value.
3. X ~ Pow(a), a > 1
N | E(Max({X})), a=2 | E(Max({X})), a=3 |
---|---|---|
10 | 3.16 | 2.15 |
100 | 10 | 4.64 |
1000 | 31.6 | 10 |
1,000,000 | 1000 | 100 |
References
[1] Wolfram Alpha input
[2] Digamma function (wikipedia)
[3] Wolfram Alpha input
[4] Why, do you ask, did I not just use WA on the original expression? Actually, computation time in the free version times out then.
lördag 4 september 2021
Back of the Envelope: Carbon Capture
How difficult will carbon capture be? The principle is that a fan blows air through some process that captures the CO2 out of it. I am assuming some things:
- The fan operates 24/7
- The wind speed through the fan is constant at 5 m/s
- The process captures 100% of the CO2
fredag 14 maj 2021
Hexagon Mint
- Num Rings 4
- Grid Rows 9
- Grid Columns 6
- Randomize
- Checkpoints
- Remove all checked tiles.
- The puzzle is guaranteed to be solvable with the available rings.
söndag 9 maj 2021
Hexagon Jazz
- Num Rings 4
- Grid Rows 9
- Grid Columns 10
- Randomize
- Checkpoints
- Remove all checked tiles.
- The puzzle is guaranteed to be solvable with the available rings.
torsdag 6 maj 2021
Hexagon Blues
- Num Rings 5
- Grid Rows 5
- Grid Columns 5
- Randomize
- Checkpoints
- Remove all checked tiles.
- The puzzle is guaranteed to be solvable with the available rings.