There's a difference, though: QuickCheck randomly tries a large-ish number of possible inputs to try and disprove a postcondition, whereas formal methods prove the postcondition for all inputs. Practically, if the number of possible inputs is huge compared to the number of failure cases, it's unlikely that QuickCheck will find it. I strongly suspect - and this would be an interesting experiment - that QuickCheck wouldn't have found this particular bug, since Timsort has been in use for years without anyone noticing it.
American Fuzzy Lop (http://lcamtuf.coredump.cx/afl/), a fuzzer which instruments programs at compile-time to help find interesting inputs faster than brute-force fuzzing.
It may have indeed found a bug in TimSort, since it's more apt at exercising branches, but I think AFL is C/C++ only.
Utilities should be happy about this. One of their biggest problems is uneven load on the grid - low at night, too high during a heatwave - and this has the potential to make that problem a lot easier.
They should be, but they won't be. Because it makes people less dependent upon them.
If you bought one of these and enough solar panels you could go completely off-grid. Which the power companies desperately don't want. It's to the point where they're charging people for being hooked up at all, lest everyone think about putting in solar and only buying power when the sun isn't shining.
The utilities would be happy about this if they controlled it, but they won't because the capital expense would be way too high. They'll only be happy about it if they somehow are the only ones who have control and get to use it for free. Somehow I doubt that'll happen.
Hey, utilities are often run by public-spirited folk with no greedy agenda. They make decisions that are aimed to balance the needs of the many, which can appear to be against the wants of the few.
You're absolutely right! Some are. But some aren't, and some power companies are very scared and lashing out. There was an attempt in Arizona to get monthly connection fees of up to $100/mo if you have solar at all. Hawaii has blocked people from getting solar hooked up to the grid.
The problem is obvious, of course. At some point the only people left paying any kind of substantial monthly fees are those who can't afford solar, and those are likely the poorest. And then what happens is that there's a regressive tax. I get that you can't have that kind of bad outcome.
But at the same time, grid maintenance is fairly cheap and peak power generation is very expensive, which is why utilities will pay people to be able to turn off their A/C at peak times. This is quite literally where solar shines: the more A/C load there is the more likely you're getting good power out of solar.
If the utilities need to prevent a regressive tax situation then they need to change incentives to be more transparent rather than just flailing about. If peak power is expensive, make it easier for people to put solar up and get paid for it. If nighttime power is cheap, make it cheaper on the bill.
Power companies are basically complaining that arbitrage is hard. They're the ones who are in charge of their own business models, though, not me. So if they fail to adapt to the world as it stands, you'll forgive me for not feeling sympathy.
For the most part, 'they' is 'us'. We have to live with the results. My power company is the REC, and I could run for the board but I don't. Anyway its my neighbors trying their best to keep the power on for everybody.
You didn't mention issues of connecting to the local grid. There may be issues adding solar to your house, relative to the transformer and neighborhood substation. That $100 may be what it cost them to adapt. Likely its a tiny fraction of the cost of dealing with customers with unusual requirements.
> There may be issues adding solar to your house, relative to the transformer and neighborhood substation. That $100 may be what it cost them to adapt.
Almost assuredly no. There are laws in place and inspections which get done that prohibit anyone's inverters from being on when the power is off, this is to protect workers from getting shocked when a line SHOULD be down, but isn't. The inspection is simple and it's been done for many years for people who choose to install backup generators. Obviously those don't feed power back, but that leads into my next point.
If they can run 100 or 200 amp service to my house, surely they can afford a few dozen amps of power in the other direction. 100 amps * 220V = 22kW Many houses are wired for 200 amps so that's 44kW of power. Who is putting in 20kW to 40kW solar plants on their roof? A normal panel is between 200 and 400 watts. Which houses have 100 solar panels on them?
Further $100/mo times forever isn't reasonable if they only have a fixed capital cost to adapt. Again, they almost certainly don't unless everyone in the neighborhood is developing truly commercial amounts of solar and wind power. And if someone is breaking that threshold, fine I have no problems with them having to jump through hoops. They can afford it.
> For the most part, 'they' is 'us'.
It GREATLY depends on where you live. In rural areas it's a power co-op or whatever and I'm inclined to agree with just about everything you've said. But there are a lot of places where it's not a co-op and it's about someone turning a profit; for shareholders and everything.
> It's to the point where they're charging people for being hooked up at all
That's a completely reasonable thing to do... You're saying you would expect them to be ready to provide electrical service at a moment's notice, 24/7, but you should only pay for the actual power you use, but not for the standby capacity?
Yes, of course I agree it's reasonable. But it does serve to illustrate the point that utilities aren't necessarily happy about people being able to generate and store their own power. I'm refuting the idea that utilities will be happy about this, not trying to prove that they're evil bastards.
I'd also be happy to sign a contract whereby I'm only allowed X watts of draw and no more than Y watts of feed-in such that they don't need to have much standby capacity for me. But if I do that I want to get real-time pricing on power so that when it gets cheap or negative that I can charge batteries or make ice or whatever.
To me it kind-of feels like the utilities are pushing for a heads-they-win-tails-we-lose kind of situation where you get paid "base load" wholesale for your solar even if it's at peak times, but then have to pay retail for everything.
I know a guy who used to run a power company here in Houston (we've got a utility owned grid with many retailers making use of the "last mile" to sell power) and he said that $50/MWh ($0.05/kWh) was the normal rate but on very hot days it might go as high as $1500/MWh ($1.50/kWh) as everyone scrambles to buy enough wholesale power to meet the demand of their customers.
I'm not necessarily saying that I should get the $1.50/kWh that the utility is paying the marginal producer. But it doesn't feel exactly fair that someone who is peak-shaving their load and saving the utility company from buying power at $1.50/kWh and selling it at $0.08/kWh should also have to pay a connection fee for even having solar at all.
Utilities won't be happy about thus. They are already upset about having people with rooftop solar selling to the grid (taking their revenue); this will only make it worse.
It's not just maintenance. The system as a whole was architected to take advantage of the economies of scale you get when you assume that your customers remain consumers and you control the production. Nobody foresaw back then that each house could be a potential power plant. When you start to change that, you're still having to maintain the current infrastructure, which is steadily becoming obsolete, while also building new infrastructure to handle random power spikes and draws in arbitrary locations. You have to do this across the whole grid, everywhere in the country. This has the utilities very very nervous.
Using Paul Graham's disagreement hierarchy (http://www.paulgraham.com/disagree.html), your first paragraph is DH2 (responding to tone), and the rest is DH1 (ad hominem). Do you have any arguments relating to the points being made?
The first paragraph correctly points out that the "seven previous studies" are not applicable to the general public, despite the fact that the article attempts to do so. That is not responding to tone, that is responding to content.
The second paragraph rightfully questions the integrity of the author based on past deceptive statements made in a similar capacity. It also points out a legitimate conflict of interest. Neither of these are ad hominem.
If a police officer is found to commit perjury or otherwise tamper with evidence on one case, We the people find just cause with all of their cases.
The same goes for powerful people whom sit on drug panels in a company whilst holding a federal position requiring drugs. Because he held a dire conflict of interest, I do not see how we can trust him.
Not seeing the tonal disagreement in P1 - that looks like a fairly legit dissection of the assumptions in an argument to me. What phrasing made you feel it was tonal?
