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I spent eleven hours today hooking up large generators (up to 2MW) for businesses. I'm a controls/PLC guy so it's not what I normally do but this was an all-ha

I spent eleven hours today hooking up large generators (up to 2MW) for businesses. I'm a controls/PLC guy so it's not what I normally do but this was an all-hands-on-deck situation. Two places had their fire alarms go off as soon as the power was restored (due to issues with fire pump controls too long to get into here) and they weren't able to disable the alarm in time to prevent a fire dispatch. Fire resources getting needlessly tied up plus a ton of hastily-connected generators seems like a recipe for a problem. Side note, I lost track of how many times I had to explain to people why their giant solar arrays wouldn't be able to power their facility when the grid is down.

mycall 7y ago
> I had to explain to people why their giant solar arrays wouldn't be able to power their facility when the grid is down Is there an actual size of solar array that could power their facility?
- ncmncm 7y ago
  Very few solar panel arrays provide power at night. Those that do have energy storage systems attached that were very expensive to add. When the purpose of the array is to save on expense of peak-usage power, storage is not essential and is often omitted. Even in the daytime, without grid access you need storage because the power produced does not rise and fall with your load. Turn on the microwave and the clothes dryer, and instantaneous load may exceed what the panels are producing right now. A cloud going by reduces generation, possibly below current load.
- gothroach 7y ago
  The main reason is that most solar arrays are set up in such a way that they require the grid to operate. If you want to run your array without the grid it's a different type of system and requires additional hardware (transfer switches) to ensure that you don't backfeed power to the grid, creating a safety hazard for people working on the lines. Storage is also a necessity if you're operating off-grid. Newer inverters also use a type of communication over the power line where the utility can among other things tell the system to curtail export power if there's too much of a surplus on the grid.

mycall 7y ago

> I had to explain to people why their giant solar arrays wouldn't be able to power their facility when the grid is down Is there an actual size of solar array that could power their facility?

ncmncm 7y ago
Very few solar panel arrays provide power at night. Those that do have energy storage systems attached that were very expensive to add. When the purpose of the array is to save on expense of peak-usage power, storage is not essential and is often omitted. Even in the daytime, without grid access you need storage because the power produced does not rise and fall with your load. Turn on the microwave and the clothes dryer, and instantaneous load may exceed what the panels are producing right now. A cloud going by reduces generation, possibly below current load.
gothroach 7y ago
The main reason is that most solar arrays are set up in such a way that they require the grid to operate. If you want to run your array without the grid it's a different type of system and requires additional hardware (transfer switches) to ensure that you don't backfeed power to the grid, creating a safety hazard for people working on the lines. Storage is also a necessity if you're operating off-grid. Newer inverters also use a type of communication over the power line where the utility can among other things tell the system to curtail export power if there's too much of a surplus on the grid.