On 15/09/2021 00:08, Don Y wrote:
> On 9/14/2021 9:11 AM, Martin Brown wrote:
>> We can heat my home by oil, solid fuel or electricity as a last
>> resort. The first two can operate with or without a mains electricity
>> supply - we do sometimes lose power in the worst winter storms so it
>> pays to have multiple heat sources. Winter oil deliveries can get
>> disrupted too.
> How do you burn oil without power to run the blower and circulator?
> ("first two..")
Electric generator running a part of the house electrics off grid.
> We're gas-fired, here. And, have lost natural gas supply to the city
> on at least one occasion. It's even more disturbing than picking up
> your (landline) phone and finding it dead!
> [We didn't *lose* gas supply, just lost adequate pressure to create
> enough BTUs for "smart" furnaces to recognize that they were actually
> *lit* and deliberately shut down the gas supply to protect against
> unburned gas leaking into the residence!]
UK hasn't yet had this sort of failure other than at a local level. My
mother in laws garden took a roasting after the Gas Board dug a trench
to look for a leak and one of them was smoking. Think 20' high Bunsen
burner flame and you get the general idea. Fire brigade had to hose down
the house to keep it from burning until they managed to isolate the gas
main and stop the flame. Such incidents are rare but spectacular.
>> Most modern build are completely stuffed if they lose mains
>> electricity. Gas and oil boilers both require electricity for their
>> control systems to operate and also for the CH pump.
> Yes, but its a relatively small load to "backup". Two of my neighbors
> have "all electric" homes (roof mounted, air sourced heat pumps).
> They're screwed in summer *or* winter, if an outage.
> By contrast, we can keep the furnace running with a small genset -- and,
> power a portable ACbrrr (if we're in the humid Monsoon season; a fan
> for regular Summer).
>> UK has been so close to losing the grid in harsh winters that they had
>> to ask heavy industrial users to drop off non critical loads to keep
>> the lights on in domestic premises. The ageing nuclear plant is well
>> beyond its use by date now and still running on a wing and a prayer.
> During our gas shortage (*unusually* cold spell), the "fix" was to shut off
> the gas supply for parts of town to allow sufficient pressure in the
> remaining parts of town.
That sounds quite alien to me. I can't recall there ever being a gas
shortage in the UK beyond a little local difficulty caused by men with a
JCB hitting a gas main in the street. The change to plastic gas pipes
created a problem in that they have no way of detecting them reliably.
Modern ones have a metal tape on so that can be found again!
> I don't think we've ever had a city-wide electric outage. Most outages are
> very local and traced to some bit of equipment failure. E.g., the
> cables in our neighborhood tend to "blow" (best way to explain it, if
> ever seen one failed!) due to age. As ever circuit is fed from two
> the outage is usually small (a handful of houses) and short-lived (they
> send a crew out to isolate the faulted cable and "replug" the feed from the
> other direction to restore power to the isolated segment no longer being
> from the "original" direction).
We get little local ones fairly often (rural setting overhead lines). It
only takes a thunderstorm hit somewhere to cause a few seconds to few
hours outage depending on whether or not the surge damages something.
However, due to renewable energy a spectacular cascade failure occurred
when 1.8GW of plant dropped off grid at once. They found all sorts of
serious problems with stranded electric train controllers that assumed
power would never fail and required an engineering reset to restart.
Various safety systems interacted in a peculiar way causing a massive
outage that took down most of the East coast and London. It doesn't help
that most generation is done up north and consumption down south so the
supergrid lines affected were close to maximum load when they went down.
>> It was flat calm last week and they had to bring mothballed coal
>> generation back online because natural gas has suddenly become very
>> expensive. Problem is that the dash for gas in electricity generation
>> a while back means we are doubly dependent on the price of natural gas.
>> Several energy retailers went bust here last week due to gas and
>> electricity pricing fluctuations . Their business model was always
>> flawed to blazes in much the same way as Enron.
>> As an indication of just how crazy the energy retail market is here
>> our village hall gets its electricity (no gas available) from British
>> A harsh winter or even a normal one with no wind could get interesting.
> In the US, we tend to have bigger geographical regions and generating
> capacities to draw on for local shortages. "Big" outages are usually
> the fault of some weather event (e.g., ice taking down power lines)
> or "accident" (failure of a critical substation or distribution
> subsystem -- e.g., the chicago flood in the 90's)
There are interconnects to Europe that broaden the UK network. The snag
occurs when it is simultaneously very cold and becalmed in UK, France
and Germany. No one wants to export *their* power in that situation.