OT: BEIS announce closure of solar panel export tariff

[Roger Hayter]

This used to happen regularly, but might prove a little harder now. We are certainly getting covered with wind turbines for the benefit of someone or other.

[harry]

It is being generated when wanted.

[harry]

Brain dead as usual. Trains don't go up significant hills so there is no significant stored energy to be recovered by regeneration.

[Chris Hogg]

[Chris J Dixon]

Still lots of KE to be recovered, especially on rapid transit systems.

Chris

[charles]

what have hills got to do with it?

[tim...]

you don't need to go up a hill to recover energy from regenerative braking

tim

[John Rumm]

I should introduce you to my mate Physics... and acquaintance you could find quite beneficial!

[Dave Plowman (News)]

I'd guess harry has never been on a train.

[The Natural Philosopher]

God harry is thicbk.

1/2 mv^2 harry.

there's 100 tonnes in the loco alone. Typical train might be 1000 tonnes

so a million kg at 20 meters per second = about 45mph =

1,000,000 x 400 joules - 400MJ = 400,000,000 watt seconds or 111 KWh

Thats what makes the brakes hot. Bringing that lot to a halt in a minute is a peak power of 6MW...

That's why MOST locos push that back into the grid.

saves on leccy, saves on brakes

[The Natural Philosopher]

Is there a distinction somewhere that I have missed?

[Marland]

This article is now about 10 years old , more trains that can regenerate have been introduced since then.

The 1930?s designed but because of WW2 not commissioned till early 50?s DC line between and Manchester and Sheffield made extensive use of the principle as it carried heavy coal trains . At that time it was not practical to reconvert DC back into the grid so if there were no trains in the area that could use it it was sent to trackside resistance banks. It still saved mechanical wear on brakes.

?Wath_electric_railway Modern electronics have solved the return togrid problem so even the DC Network of the Southern lines and the Tube are now doing it , the latter for some time as an important benefit for them is keeping heat from friction braking from building up in the tunnels which after a hundred years of friction braking and other heat sources are now much hotter than when opened.

For someone who has claimed to have held several engineering based positions Harry seems to show little awareness of what goes on, even people working in one field tend to read a journal or two which mentions another.

GH

[Dave Plowman (News)]

Quite. Now explain how it is impractical to push power back into the grid from solar?

Do trains only brake during peak demand for electricity? Or when the sun isn't shining?

[John Rumm]

There are not enough of them to represent a significant imbalance even though they are not dispatchable.

[The Natural Philosopher]

Its a bit more cunning than that. The underground uses - or is beginning to use - regen braking and it works really well because as many trains are accelerating as are braking and they have wahat amounts to a private mini grid. Dvelopment fof substations that can possibly push power back to te grid are underway.

In the case of the deep Tube, regen braking also removes a HUGE amount of heat from the tubes that would otherwise have to be ventilated or airconned away.

Geeks read more:

Regen braking has been in use on some locomotives and trains since forever

Of course this is all beyond the Dennises and Harrys of this world who can't understand that what works well in one case because of technical details is a pain in the arse in another case.

Pint of water good. Tsunami bad.

[Bob Martin]

Does anyone here need reminding of that fact?

[bert]

It's generated when the sun shines or the wind blows and there is no direct correlation to when the power is needed.

[bert]

In article [e-mail]>, Bob Martin [e-mail] writes

Well it would seem some people still continue to follow his links.

[bert]

In article <pvl2ou$fue$ [e-mail], tim... <tims_new [e-mail] writes

Nor down one either.

[Andrew]

Dinorwig ?