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Comment by kencausey | Hacker News Reader

I'm curious about this consistent claim that electricity is at low demand at night. Perhaps this is less true of areas in the winter with electrically provided heat?

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In Calgary, the overnight temp is -27 F for tonight.

When the weather gets that cold, insulation and heating have a hard time keeping up.

Homes that have natural gas furnaces draw so much that utility companies have a hard time keeping the lines at full pressure.

People start using space heaters more and more, which moves the pressure to the electric grid.

The problem with the cold is that it is worse at night, so there's less spare capacity overnight than normal.

At least, this is what we went through in the upper Midwest a few years back. Right now it's -8 and things are running smooth as usual.

Do any houses use wood for heating, or at least as a backup for times like this? My brother had a wood stove with fireplace that is somehow installed in a way that it heats his ~2000 sqft, 2 story house. I think the system was expensive to install, but it's cheaper for him to use wood than the gas furnace. Granted it doesn't get nearly as cold here in Philly as it does in the midwest or Canada... lowest temp on the 10 day forecast is 14 degrees as a overnight low. Having a backup heat source that is completely independent of the grid is reassuring imo.

If I lived someplace where temperatures went that low I'd certainly want to have backup heat, regardless of what my primary heating system was. Either wood stove or at least a kerosene space heater and a supply of fuel.

Outdoor wood boilers are somewhat popular (don't help much without power though), but I'd hazard a guess that more homes than not just have a small backup generator rather than rely on any kind of wood heat.

Might be different elsewhere; propane is cheaper than the national average where I live, so my experience might be skewed.

Ottawa, ON, Canada: https://hydroottawa.com/en/accounts-services/accounts/rates-...

I can choose my rate plan.

  Regular:
  7PM-7AM+weekends = 8.7c/kWH
  11AM-5PM         = 12.2c/kWH
  7-11AM, 5-7PM.   = 18.2c/kWH

  UltraLow:
  11PM-7AM               = 2.8c/kWH
  W/end 7AM-11PM         = 8.7c/kWH
  W/day 7AM-4PM,9PM-11PM = 12.2c/kWH
  W/day 4PM-9PM          = 28.6c/kWH

  Tiered:
  First 1000kWH = 10.3c/kWH
  Over 1000kWH  = 12.5c/kWH

Here is the electricity production for the UK over the last week: https://electricityproduction.uk/total/?t=7d

Not sure how it is for other parts of the world. Maybe places with heat pumps like Norway are different? We have a lot of gas for heating.

The UK is heavy reliant on gas heating currently so only a small fraction of electrical energy on this graph is used for heating. With the switch to heat pumps and other forms of electrical heating the picture will change.

The switch to heat pumps will be glacially slow. I’ve had a look at doing it on my property and my mums and gave up due to the need to change the pipes and radiators. I suspect only new-builds will go that route for a long time.

Does it matter? If the utility can control EV charging times, then all that is necessary is that non-EV demand varies significantly. I haven't heard anyone claim that electric demand is anywhere near constant.

It's a consistent claim because it is consistently true.

The world does not generally operate 24/7 -- parts of it do, but most of it does not. And we (humans) tend to sleep at night.

While we're sleeping, we use less electrical power.

I mean: Think of all the things you (or any other person) might do in a normal day. Just list them out -- mentally, on paper, or whatever. Regular things, like work or school, or laundry, or eating food.

And now, you have a list of stuff that you generally do not do when you're sleeping.

So now, it should be intuitively obvious that energy consumption is reduced at night.

Here's some charts for different regions of the US that demonstrate that demand is lower at night, consistently, across all regions and all seasons: https://www.eia.gov/todayinenergy/detail.php?id=42915

And some data from Alberta (home of the frozen gas pumps being discussed here) that also shows this trend: https://www.aeso.ca/market/market-and-system-reporting/

And another link that shows it for the UK: https://electricityproduction.uk/total/?t=7d

How deep do you want to dig? https://www.eia.gov/electricity/gridmonitor/dashboard/electr...

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