The SPS is rated for 2000W, best-effort. That gets you probably one large window AC. It will run when the grid is down and the sun is shining on your panels, which depending on how your roof is angled and what trees etc there are might or might not be enough?
It will have times when it loses power due to clouds. I believe when that happens the SPS turns itself off and you need to manually re-enable it by flipping a switch in the basement. So might be a lot of hassle.
> Why propane? Because gasoline slowly degrades (polymerization) and needs to be drained, disposed of, and replaced with new (typically every year or so). Propane doesn't degrade over time.
If you have natural gas piped to your home then a natural gas generator is a solid option. Expensive, though.
> They do have models that can function off-grid, and even models with attached batteries to handle surge loads and night-time operation, but these models are not as widely installed.
Talking to solar salespeople, they say it's not code to run your house off-grid directly on the panels, without batteries. I'm not sure why; maybe they think handling brownouts is too much of a problem?
We're planning to install an SMA inverter [1] that has a "Secure Power Supply" outlet in the basement that gives best-effort power during a grid outage. This seems to be the only option on the market that gives you some power when the grid is out without needing the very large (quoted at $10k for the smallest size) expense of a battery system.
Right now we'd have no heat. I'm thinking of putting together a small general purpose battery backup that we can normally charge via the wall but can also charge via the SPS on the solar system we're installing. I'd use it for whatever was highest priority; depending on time of year that could be boiler, sump pump, fans, or unexpected things.
My understanding is that for anything big like a fridge (even a minifridge) the efficiency and reliability of standard well-optimized 120V AC appliances means it's worth it inverting to AC instead of sticking to DC. Lots of RVs use/used 12V DC systems so things are available, they're just not very good. Inverters are very efficient these days. Plus it's really helpful to have a way to run AC things you already have if you need to.
Though if you only want lights, I do see how DC could make more sense if you can either find or DIY the right electronics to handle the voltage issues.
1. This uses the Image Magick command "convert" so it will work on any system that has it installed. I've only used it on Mac and Linux.
2. It isn't lossless, no. I think jpegtran can do this, but you'll need to first read the correct orientation out of the EXIF data and then give the right arguments to jpegtran. Since the loss in quality is tiny, I just use -auto-orient.
Author here: I don't know very much about how swamp coolers are used in practice, so I could easily be missing something. I do know that they're basically never used up here in the Northeast (Boston) because they work by increasing humidity and in the summer we tend to have pretty high humidity already. We also tend to have daytime highs high enough that the air leaving a swamp cooler would be warmer than the temperature of a structure that's been cooled overnight with a whole-house fan, plus more humid, which means during the hotter parts of the day you don't want to bring in outside air. So, how could a swamp cooler be used without increasing the daytime humidity of the house?
What I'm imagining is running a swamp cooler overnight to cool the structure of the house as close to the wet bulb temperature as possible, then in the early morning run it a bit in fan-only mode to bring in drier outside air (accepting that this will warm the house up a bit), and then shut the house up and turn the cooler off for the day.
What we currently do is run a whole-house fan overnight, and shut the house up during the day, with no swamp cooler. I'm trying to figure out whether adding some evaporation to the system could make sense.
>patients are known to be highly inconsistent when reporting their own alcohol consumption. Answers patients provide depend on many factors, including the doctor-patient relationship. And patients’ spouses often disagree with their partners’ assessment of their drinking. The MACH15 trial had some sophistication built in to it, including the use of random smartphone-based check-ins for patients. But while some evidence suggests that smartphone-based self-reporting on alcohol consumption often contradicts patients hindsight reports, MACH15 had no ability to tease out which patients would adhere to the smartphone check-ins, and which were providing accurate accounts of their consumption. In essence, the NIH was making a $100 million gamble that volunteers would portray their alcohol consumption accurately.
This doesn't seem like a problem with the study design to me. You're effectively assessing the effect of telling people to drink "zero" vs "moderate" alcohol as opposed to the the effect of actually drinking those quantities, but since one major use for a study like this is to figure out what doctors should be telling people this still seems valuable.
Apache has dynamic modules too, and they're generally better designed. In nginx they were added later and a module compiled against one version of nginx won't work against any other. With Apache you could download a mod_brotli binary module and use it with any (2.4) Apache build.
Anyone can get an HTTPS cert, and with Let's Encrypt it's free. Restricting dangerous features to only websites that can demonstrate their traffic hasn't been man-in-the-middled is very different from giving established sites more expansive permissions.
(Disclosure: I work at Google, though not on browsers)
What would keep someone from getting an economically valuable degree, declaring bankruptcy on graduating, and then just waiting until that had expired from their credit record?
> Most of what Linus says would run foul of HN's guidelines
Keep in mind that you're much more likely to see it when he explodes at someone, because that's more entertaining to read. Most of what he writes in the ordinary work of building a kernel is unobjectionable.
The SPS is rated for 2000W, best-effort. That gets you probably one large window AC. It will run when the grid is down and the sun is shining on your panels, which depending on how your roof is angled and what trees etc there are might or might not be enough?
It will have times when it loses power due to clouds. I believe when that happens the SPS turns itself off and you need to manually re-enable it by flipping a switch in the basement. So might be a lot of hassle.