Domestic mains voltage and frequency

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#21
HVDC is there to store the energy produced by renewable sources.
You can't always satisfy load demand and it (cable) holds energy for some time, converted to AC with static converters it is implemented to the ordinary systems used by consumers.
 
#23
pitbul said:
...it (cable) holds energy for some time...
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Are you suggesting that the actual cable (wire) stores electricity? If so, that is quite incorrect. Unfortunately, cables don't store energy (it would make life much simpler for electric car engineers if they did!)

If we are being very pedantic, yes, thousands of kilometres of high-voltage DC cable will store a microscopic amount of energy, because of its capacitance. But this is such a tiny amount of energy that this is utterly irrelevant for the purposes for which such cables are used - transmitting hundreds of thousands, maybe millions, of watts.

Energy storage to compensate for erratic wind and solar power is done in several ways. One that's becoming more common recently is to build an enormous lithium battery, as Tesla recently did in Australia: Tesla's giant battery in Australia made around $1 million in just a few days - Electrek

An older system is to use excess energy to pump water uphill (up an existing dam where hydroelectric power is being generated), and later retrieve that energy from the falling water as usual.

Tesla's gigantic lithium batteries are now showing up in California as well: Tesla’s Megapack battery is big enough to help grids handle peak demand - The Verge


-Gnobuddy
 
#24
Gnobuddy said:
An older system is to use excess energy to pump water uphill (up an existing dam where hydroelectric power is being generated), and later retrieve that energy from the falling water as usual.
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One thing we are not short of in Scotland is water and I must give a plug (pun intended!) to the pumped-storage hydroelectric power station in Argyll and Bute which has been operating since 1965.

Cruachan Power Station - Wikipedia
 

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#27

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#31
nigelwright7557 said:
Its a compromise between efficiency, thickness of cables and safety.

In the UK it is 230VAC whcih is efficient and needs less thick cable but that voltage kills.
In the USA its 110VAC which is not quite so dangerous but you need thicker more expensive cable to carry the extra current.
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Isn't the higher Voltage statistically more likely to produce correctable fibrillation upon electrocution?
 
#33
Cables dont store energy nor power. `HVDC stabilize the power grid as they do not suffer from AC phase shifts when power demand is changing rapidly as is the case in AC grids. As soon as there is more than one AC power generator feeding the grid exact phase sync between all generators on the net is absolutely mandatory. They must run in exactely the same absolute 50/60 Hz phase. And in todays grids, there are hundreds to thousends of power generators on grids that span whole continents. If one is out of sync, all others will pump enormous amounts of power into this one creating a nice firework.
 
#34
pitbul said:
@mondogenerator
HVDC cable will stabilize a network against disturbances due to rapid changes in power, is my goal.
Also, HVDC cable stores energy, not power. You don't recognize power and enrgy meaning.
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Haha ok. That's what I said in correction of you post.
No power is stored

I work in the power transmission industry.

The energy stored isnt power, and doesnt contribute to anything much, except parasitic losses.

It certainly doesnt stabilise the network to transient load changes
 
#37
AllenB said:
In the home? Interesting.. We also have separate cooking circuits but just to support 15A. 10A is normal for outlets.
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Current UK practice is 30A circuit for Double Oven plus separate 30A circuit for Induction Hob. I know because I have replaced our gas hob with an induction hob. I thought the existing outlet would power both until I read the installation instructions. 15A is not much for cooking.
 
#40
Scotland's next Loch Ness monster could power 400,000 homes!

Plans for new pumped-storage hydroelectric schemes in Scotland have been submitted. Locations include Loch Ness and Coire Glas in the Scottish Highlands, and Glenmuckloch in Dumfries & Galloway.

Such schemes are highly efficient and improve grid reliability by balancing out fluctuations in output from wind farms and solar power schemes and promote maximum use of renewable energy.

Unfortunately such schemes are also highly expensive, running to billions of pounds. Somehow we could afford to build them in the 50s and 60s when most of the hydroelectric schemes were built, but now have to rely on investors who demand government support via changes to energy market rules in order to provide assurance about future returns.

The UK government is said to recognise storage as a way to reduce carbon emissions, but little has yet been done to remove barriers to investment.
 

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