OT? When Computer Controls Fail

Motors burned out? Went on strike, ignored the computer's commands?

This design is safer.

Michael

Bwahahahahaha! ROTFLMAO >:-} ...Jim Thompson

If it measured the sun's elevation wrong, it could aim all the mirrors low.

It concentrates on the tower so the mountains are safe... unless the software messes up again and focusses on a spot in the mountains! Even

Ivanpah is a fabulous boondoggle. Even when it's working, it has to burn a lot of natural gas every morning to get going.

In April 2015, "biologists working for the state estimated that 3,500 birds died at Ivanpah in the span of a year, many of them burned alive while flying through a part of the solar installment where air

the Wall Street Journal.[64]

If the mirrors simply stop moving at the same time, the moving sun is going to cause the focal point to move while staying pretty well focused.

The article states that this was in the morning. If the sun is moving mostly upwards, the focal point will move mostly downwards.

Measure the sun's elevation?? WTF? It would have to be an extremely dumb design when it derives the sun's elevation from measurement instead of calculation...

Of course if it has no sensors at all, a NTP error could be interesting....

Cheers

Phil Hobbs

Yes you need an accurate clock, but of course in an installation like that it would not be a PC only synced to pool.ntp.org.

And the accuracy requirements are not such that you could have problems from e.g. leap second insertion or latency variation on your link.

I would use one or a couple of GPS referenced clocks combined with some reliable NTP servers on the internet, and an oscillator stable enough that it can free-run for some time (the time required to troubleshoot network and GPS problems).

Won't it also move eastward missing the tower? A critical sensor broke somewhere, so now they discover the concept of single thread failure mechanisms.

Dumb designs happen. Something went wrong. Some news reports say that "some" of the mirrors aimed low; not clear how many.

What's dumb is the entire concept. It cost $2.2 billion, most with federal loan guarantees, and it doesn't work very well. The energy costs roughly 10x what a natural gas plant would, and this power is erratic and far from the loads. It roasts thousands of birds in mid-air every year.

Also use some of that readily available bug-free code and failure-free actuators.

Hey, a few failed actuators or power feeds could freeze some mirrors in position. Then wait an hour or two and see what they hit!

I guess you could send out a few hundred guys to tuck fitted sheets over the frozen mirrors. Maybe spraying them with black paint would be more cost-effective.

Yes, it will. But depending on how close you are to the equator, the lateral movement may be small enough that it would be possible to hit the mast enough to cause problems.

If you are located directly on the "solar equator", the sun will rise vertically in the east, move directly over your head and set vertically in the west. This site is quite close the equator. It is almost mid summer, so the sun should be fairly close to rising vertically around this time of year.

Let's play Devil's Advocate. It might not be cost effective today, but the technology will presumably develop, and maybe in the decades ahead it could become a viable and advantageous method of power generation. Is 10x so bad for a very early example of a technology?

NT

If the mirrors are frozen just right, it won't miss. There are 175,000 motorized dual mirrors and probably some zoned power distribution.

They should investigate and find the people who didn't think about that failure mode.

Better yet, find the people who conceived and approved this crazy machine.

It is very bad. Nobody competent seems to have done the math.

They will probably decommission the monster one of these years.

....not to mention inevitable...

Is it being operated as an operating prototype? If it is, and there's a good flow of suggested design improvements streaming out of it then it might be. If it's just a tire fire/Monument To Largesse/Simpson's Monorail, then no.

The sun moves enough that the the focal point should have been away from the tower:

Maybe the algorithms running the heliostats properly accounted for declin ation but got the right ascension wrong.

Mark L. Fergerson

Just cleaning the mirrors has to cost a fortune.

I think he meant the 'Tropic of Cancer' 23.??deg

This time of year the the sun illuminates the north side of our house, early in the morning and late in the evening. It does appear to rise vertically, and yes there is a southern movement.

Cheers