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Random question re electrical networks


gertlush

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Professor Google has not given me a clear answer so I thought I'd ask the powerful minds on this forum. What I've always wondered, and never understood, is how an electrical generation company like BC Hydro balances supply & demand across their network?

 

So they're generating 100mw from a boiler/dam/flux capacitator. The load demand is also 100mw. I turn on my espresso machine and the load jumps to 110mw, how do they instantly match that demand? By the same token if somebody turns something off, and the load goes to 90mw, do they reduce their generation? What happens to that 'extra' electricity that isn't demanded?

 

Thank you geniuses :)

 

Edit (My understanding is that there are extra turbines in a hydro station/whatever. So you've got generation matching that first 90/100mw. The 'extra' turbines are turning slowly to match the 'extra' requirement. As the demand increases those turbines spool up to match it, which requires some kind of sophisticated load matching software or something???

Edited by gertlush
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The entire transmission system is 'balanced' and synchronized by power generation 'spinning reserves' which are reliable sources of power (dams up this way, nuke plants elsewhere). That is combined with operating engineers in all the regional transmission organizations (RTOs) trying to operate their grids under capacity by 10-15% to accommodate spikes and with standby gas generation plants which can be spun up fast in the case of sharp drops.

 

Unfortunately - since the days of Enron / deregulation (separating power generation from power transmission) - the operating engineers' transmission reserve capacity has been ogled by power marketers who think the operating engineers really only need 3-8% transmission line reserve capacity and that they should be free to use the rest to sell more power. CEOs tend to listen to the marketing and finance guys more than the engineers so sometimes they gamble and use the reserve capacity to sell more power.

 

This usually happens when they are incented by high demand / prices, but that's also when both power and transmission systems are stressed and operating close to the bone with everyone doing their best to keep the loads / system balanced. The practice often leads to 'brown outs' and the SW / California were particularly prone to them during the Enron days when traders would convince / pay power plant operators to fake outages and stand their plant down to drive prices up.

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what's even crazier to ponder is this machine we are discussing is the largest and most complex machine ever built. it takes a massive input of fossil fuels to maintain it. And solar power is almost useless without it.

Edited by Eric T
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And solar power is almost useless without it.

 

Wind and solar are problematic in that they generate when they generate and that's not necessarily when there's demand. Here on the Columbia the BPA simply dumps wind power when the water level is high because they can't use it.

 

What's needed is what are called utility-scale storage systems which could store wind and solar power in times of low demand and then access it when it's really needed as opposed to when generated. An example would be using wind power to pump water out of the Columbia and up to a lake at the top of the Gorge which could then be run back down to the river through a generator when needed. Another example would be using wind power to compress air in an underground cavern and use that to run a generator when needed. Big batteries of various kinds and ultracaps are also beginning to be used for such storage and some folks think using everyone's electric car batteries at night in their garages should be added as a form of distributed grid storage. Other ideas are things like using solar power to run heavy railroad trains up a long grade during the day and letting it roll back down at night to generate using what's called regenerative braking power (no really).

 

109d607b194c5cc205bf7ca9cf1c53e9.jpg

 

2016-05-0500-04-35ares2.jpg

 

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Huh, that's some cool shit, my former employer sold power to Hydro so it sparked my interest in the big picture of how it all ties together. And sometimes we did get paid to turn it off because the dams were full. Also been reading Daniel Yergin's 'The Quest' which touches on this stuff.

 

Back to spray...

 

 

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What's needed is what are called utility-scale storage systems which could store wind and solar power in times of low demand and then access it when it's really needed as opposed to when generated.

 

The pictures you show look like a lot of metal and effort form fossil fuels to set up and then we get electricity. I hear whoever said pump water up hill then run it down when you need it and the hydrogen solution but both are zero sum games.

 

That's the difference between power and energy, energy can be stored. You can fill a barrel with 55 gallons of oil, bury it in the ground for 10'000 years pull it out and use it. Same with coal or natural gas but not with electricity.

 

What seriously cracks me up or depresses me is that when we start talking about running out of fossil fuels the conversation ultimately goes to electricity.

 

Here's the 411, electricity is a luxury compared to oil. Electricity is almost meaningless without oil. Would you like to hear the four truest words ever spoken?

 

WE RUN ON DIESEL.

 

Lets make a short list of what oil does and what electricity does.

 

Oil

Virtually every ship

plane

train

truck

tractor

mines

heats our homes

light cars and trucks

plastics (no current substitute)

pesticides (no current substitutes)

fertilizer (no current substitutes)

around 150 different petro chemicals that literally go into thousands of products and hundreds of manufacturing processes....(no current substitute)

 

Electricity

 

Pumps our water (that's the most important function of electricity)

lights

computers

some busses and cars....

 

 

Electricity, in the context of our modern way of life is almost meaningless.

Now, if you want to make a solar panel how do we do that? It involves three different high heat processes to make glass, metal and an integrated circuit. It all has to be mined (oil), transported (oil), manufactured (oil), transported again (oil), setup (oil) and finally it makes electricity.

 

EROEI or Energy Returned on Energy Invested is the only bar we should be looking at for "solutions". Solar is just now barely breaking even on EROEI (in the context of solar on roof and converting it to ac and putting it on the grid. Solar is way EROEI negative if you get batteries to store power.) and Nuclear never did.

 

That brings us to electric cars.

 

"In the face of imminent global chaos, from climate change, overpopulation and energy depletion, billions are being poured into development of alternative methods of transportation. Elon Musk, though producing a first class electric car, proposes it to be a vehicle for the ‘post oil’ age, which will inevitably mean a downsized environment. He ignores the basic reality that no road vehicle in the context of modern usage can function without an infrastructure that is itself a construct of hydrocarbon. The notion is that we can all get into electric cars and continue to drive from home to work and back, and our comfortable lifestyle can carry on much as before. In other words, it is the vehicle itself that creates and supports our prosperity. If we use an electric car, we can still somehow move a lump of metal and plastic around as an integral part of our employment and leisure.

 

But the electric car adds to the socio-economic complexity of our over-stressed life support system, it does not simplify it. In addition to the factory itself, an electric car needs sophisticated power hungry production systems, a living environment for its workers, housing, roads, schools and so on, as well as the Bolivian lithium mines and the socio-economic-industrial complexity needed in that country, all solely dependent on a vehicle concept that is ultimately a consumer of the hydrocarbon fuel it is promising to replace. All these systems are (hydrocarbon) energy intensive and expensive to produce. In a downsized society, that complexity will not exist, yet our focus on such dead ends as the electric car shows that humankind does not have the means to rid itself of dependence on the wheel. While the electric car might appear to be a bright shiny symbol of continuing wealth and prosperity, it is in fact a block of embodied energy, as subject to the laws of thermodynamics as any other construction. It demands constant energy input to maintain its viability, and serves no useful purpose in a downsized environment because the means to sustain will not be there. No industrialised nation can maintain its road transport system without the constant input of oil. Fossil fuelled vehicles, whether used on land, air or sea produce our food, sustain our infrastructure and maintain the cohesion of nations. And there are no alternatives."

 

I think Elon Musk is super cool and the fact he and JB are landing rockets is sick.

BUUUUTTTTTTT his whole electric car thing is a scam, the gov has given tesela billions to make a glorified golf-cart. There are 850 million light cars and trucks that have ICE. The resources don't exist to make 850 million of any type of vehicle let alone an electric one who's true EROEI is negative.

 

http://www.resilience.org/stories/2016-09-20/just-16-000-catenary-trucks-would-use-all-of-california-s-electricity-with-only-2400-to-8300-miles-of-overhead-wires

 

have a look at this recent artical about making trucks electric.

 

And I know I strayed way off the original topic but I truly believe that anyone talking and electric solutions is deeply in denial.

 

Here is a recent artical on better grid modeling to make better use of what we have.

 

http://www.resilience.org/stories/2016-10-12/better-grid-modeling

Edited by Eric T
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... An example would be using wind power to pump water out of the Columbia and up to a lake at the top of the Gorge which could then be run back down to the river through a generator when needed.

 

This is done in Northfield, Mass. I toured the facility about 20 years ago, quite interesting.

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