Solar power

[oil pan 4]

Where work if the electricity blinks off for a second, it's at least $70,000 down the sewer.
At 99.9% reliability the electric company is getting sued.

[redpoint5]

My previous job had several substations dedicated to the facility. I'm not sure if it was redundancy or simply to meet demand (#1 consumer of power, water, electricity, and gas in the county).

It takes up to several days to grow a silicon ingot, and losing power would scrap anything growing, causing contracts to miss their deadlines, not to mention backlogging other contracts on machines already near 100% utilization. Making up for lost production isn't as simple as having people work overtime for an operation that is already 24/7/365

The only way to make up for missed production is to maintain an inventory of product from surplus production capacity during periods where less than full production is required. I bet that inventory has been used up already given this chip shortage situation.

[ksa8907]

My example of 99.9% was to show that it seems good but in reality is crap. Also, that's measured at the output of the generating asset. Things like downed lines or failed transformers will further lower the uptime a consumer sees but is not included in generation asset reliability.

[RedDevil]

In the early 90's I used to work on the computer department of a large bank, where one of the favorite stories among operators was the Christmas Power Outage.

The bank had a centralized UPS for all the critical components of the mainframe. The CPUs, the hard disk units, the tape decks, the printers, even the invoice readers were all on the system. The whole system was in a separate building which was built almost like a bunker, with a double security zone and all the hardware in the inner zone with no windows.

What wasn't on the system were general lighting, the non-essential terminals and monitors (pre-PC), coffee machines, etc. But our grid was fairly reliable so it all worked for years without a hitch.

Then one day before Christmas the power went down.
And everything went pitch black, due to the bunker structure. All the lighting, all the screens, even the master consoles. The only light came from the power lights on the computer hardware which kept running and buzzing as usual, even without any control or monitoring.

And one tiny plastic Christmas tree, right next to the stricken Master Consoles...

It did not take my colleagues long to plug the Master Consoles into the correct power sockets. The Christmas tree saved the day!

It did not take too long for the main power to come back on so they could even use the powered doors again.
Some changes to the setup were made afterwards

[cRiPpLe_rOoStEr]

Originally Posted by RedDevil

In the early 90's I used to work on the computer department of a large bank, where one of the favorite stories among operators was the Christmas Power Outage.

For such a critical system, wasn't there any backup genset available?

[RedDevil]

You mean a backup for the UPS?
Really, that would be overkill.
We needed the UPS once in 10 years. And while total loss of electricity would be a problem (I was on duty when we had to shut down the system due to water shortage; it was water cooled and used 60 liters of tapwater per second) it could be all up and running again in an hour or so, even though setting the right restart parameters was sometimes a hassle. You needed to determine the exact transaction where the system shut down for every process running.

[cRiPpLe_rOoStEr]

Originally Posted by RedDevil

You mean a backup for the UPS?
Really, that would be overkill.

No, what I mean is a standby genset to provide power during the shortages.

[RedDevil]

I have no idea how the UPS worked, it may well have a genset.
The term we used was 'noodstroomaggregaat' which translates to emergency power aggregate. It could be anything, and in the late 80's it most likely was a combination of lead acid batteries and a generator.

Size matters, and although te mainframes at the time were very large power consumers the extra load of the whole department around it would make the system more expensive, while it was almost never needed. We have a small but densely populated country and the grid is also quite dense and almost 100% reliable; power outages are very rare.
The decision to only allow the critical components to the UPS was therefore logical, just not perfectly executed.

[cRiPpLe_rOoStEr]

Originally Posted by RedDevil

We have a small but densely populated country and the grid is also quite dense and almost 100% reliable; power outages are very rare.

Even though I have never been anywhere in Europe, I can relate to the time I spent in a city halfway between my hometown and the border with Uruguay. I don't remember experiencing any power outage in Pelotas, but the hospital almost beside the building where I rented an apartment still relied on a genset and at least once in a while there would be a test-run.

The decision to only allow the critical components to the UPS was therefore logical, just not perfectly executed.

Perfection is usually not easy to achieve anyway. And it's often easier to realise it when something fails or doesn't perform as it was supposed to do...

[JSH]

I just signed up for something called community solar. The company I work for has committed to using 100% renewable power and as part of that effort installed a 2.5 MW solar array. That is bigger than what they need so they are allowing 300 employees to use the excess 3251 KW of panels. So starting next month I will be paying a reduced solar electric rate. The more "my" part of the solar array produces the less I pay on my bill.

All of this is managed by the local utility (PGE) so nothing special to do except sign up and look for the credit on my bill.