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Comment: Re:LibreOffice (Score 1) 190

by aaarrrgggh (#47747289) Attached to: Munich Council Say Talk of LiMux Demise Is Greatly Exaggerated

The GP is referring to the classic problem of collaborating with a single document. Party A provides base information, B edits information, A reviews changes and makes further updates. Collaborating with a PDF is called markup, and relies on a single party to be responsible for editing. Not sure if Google Docs does a good enough job on resumes yet to work.

Comment: Re:It is a public safety issue (Score 2) 149

by aaarrrgggh (#47747205) Attached to: Airbnb To Hand Over Data On 124 Hosts To New York Attorney General

Because transient residents are not intimately familiar with the fire escapes and layout of the building. Smoke compartments must be smaller, low-level exit signs are generally required (so someone can see them when crawling), and requirements for secondary exits are different. And... you must post a sign at the door indicating exit locations.

I am torn on the issue; in a place like San Francisco or NYC, the issue of taking units out of the rental pool is quite serious. This becomes worse where you have rent control. On the flip side, it is nice to have options when you stay in a place without sufficient traditional lodging offerings. Bed and breakfast establishments aren't really my cup of tea personally, but having a small apartment or house for a few days can put you more in the center of a community.

Comment: Re:Okay... and? (Score 1) 316

by aaarrrgggh (#47742597) Attached to: For Microsoft, $93B Abroad Means Avoiding $30B Tax Hit

While it has been 15 years since I had to deal with this, using your numbers you would owe no US taxes. You exclude the first roughly $100,000 in income, so the US would see your income as $100k, and you paid $68k in taxes already, and would have only owed about $25k in the US.

The only gotcha is that you need to spend less than 35 days in the US per year.

The capital gains is a bit of a bitch if you have anything meaningful, but that is a the price of entry into the US market.

Comment: Re:Welcome to the Information Age! (Score 1) 144

by aaarrrgggh (#47729825) Attached to: It's Easy To Hack Traffic Lights

I started to rebut your comment... but then actually came to agree. The cost of fixing this problem is huge; any traffic light pedestal could be an entry point from a "trusted" point on the system, and I have seen several in Los Angeles unlocked. Effectively the problem is reduced to if you have physical access to the machine there isn't much you can do for security.

Comment: Re:Some can be done - and is. Most is bull. (Score 1) 442

by aaarrrgggh (#47717955) Attached to: Is Storage Necessary For Renewable Energy?

The PV Watts gives ambient temperature and wind speed data in the hourly CSV output, and I just created a formula to calculate available wind energy for the given wind speed and turbine efficiency. The microhydro was just a basic reserve calculation on my elevation change, reservoir volumes, and average monthly rainfall; my intent was to try and use it as a dump load as well, but it wasn't effective.

The project included a greenhouse, desalinization system, and I was cooling a thermal mass during the afternoon when I had available power. The desalinization system could run for 3 hours and generate 24 hours of water consumption, not 3 hours at peak load.

How many days are you planning for a battery? I found I didn't have many discretionary loads that could be deferred for more than 3 days which drove storage substantially when I wanted to limit generator run time; I needed it 80+ days per year with a 3-day battery.

There are likely some math errors on demand side (especially looking at installed HP for some motors rather than going to the trouble to calculate BHP), but the general results seem rational.

Comment: Re:This is ridiculous. (Score 1) 146

by aaarrrgggh (#47716927) Attached to: Researchers Find Security Flaws In Backscatter X-ray Scanners

Nineteen people taking out 3500...

...out of some 5+ billion that have walked through US airport security checkpoints since. Out of (pessimistically) 50,000 people with the will or propensity to inflict ill will via items contained on their person or in their luggage on others. (And arguably 5 that could be successful on a given trip.) ...At a cost of countless millions of wasted hours, billions of wasted dollars, and fundamentally liberty lost.

Pretty good for the contractors though...

Comment: Re:Some can be done - and is. Most is bull. (Score 1) 442

by aaarrrgggh (#47709215) Attached to: Is Storage Necessary For Renewable Energy?

I modeled a quad-gen system with 4kW PV on 2-axis trackers, a 3kW wind turbine, 1kW micro-hydro, and a 2kW genset. Annual energy consumption was 7.5MWh. Batteries were sized at 25kWh; the micro-hydro could do 20kWh storage. I had some substantial demand-side flexibility due to a RO system that was sized to handle peak demand with 3 hours of operation per day, thermal storage, and a few other tricks. Peak demand was 5kW.

The PV System produced 86% of the needed power, and wind 12%. The micro-hydro was primarily backup, and was adequate for all but 6 hours per year when the generator was required. In practical use the generator would likely need to operate more when other components were out of service.

The point of this is that I needed 2x capacity vs peak demand, and 11x for average demand, even with tremendous flexibility in demand-side control. While the wind saves a few cycles on the battery per year, at least two thirds of the energy produced would be burnt up by the load dump. The microhydro was a waste and would never justify the cost; likely much more environmentally friendly to just get another generator.

The lowest capital cost solution for me would be a 6kW PV Tracker and a 65kWh battery, along with the 2kW genset, but I would be generating 30% more power than I could use most days. Running the numbers isn't that hard; even taking grid stability issues out of the equation it is clear that you are stuck with a substantial energy storage issue, either in the form of thermal or chemical.

Comment: Re:Some can be done - and is. Most is bull. (Score 1) 442

by aaarrrgggh (#47692843) Attached to: Is Storage Necessary For Renewable Energy?

I would suggest taking a look at the 8760-hour output of the NREL PV Watts program; it is enlightening. For me, if I sized a PV array at 150% capacity (best-day production vs average demand), I would need 80 hours of generator backup per year if my battery were sized for 3-days demand. If I have 7-days, I would only need a generator for 4 hours per year of generator.

The bottom line is that you need substantial excess capacity and a huge geographic diversity to be able to get by on renewables alone. Think 400% or so. That is incredibly inefficient.

Comment: Re:One of the most frustrating first-world problem (Score 1) 191

by aaarrrgggh (#47659951) Attached to: Reversible Type-C USB Connector Ready For Production

The cable connection at the lightning connector has failed on me several times, specifically because the connector stays connected to the device. The removal force exceeds the strength of the cable. Yes, I understand you shouldn't pull from the cable, but the connector body is sometimes too small to get a good hold on.

Comment: Re:One of the most frustrating first-world problem (Score 2) 191

by aaarrrgggh (#47659019) Attached to: Reversible Type-C USB Connector Ready For Production

As an Apple customer, I am quite happy they ditched the "30-pin" connector and went with the reversible lightning connector. One less thing to fiddle with when charging my phone. Nice to see USB picking up the feature, even if it is a couple years later with implementations still not available.

That said, the cable/connector interface on the lightning cables is not nearly strong enough for the insertion/removal force required. It will be interesting to see if the USB design will work better in that regard, as the shield does provide some mechanical latching.

Whenever a system becomes completely defined, some damn fool discovers something which either abolishes the system or expands it beyond recognition.