Dials and graphs

BritDownUnder · Post by **BritDownUnder** » 18 Mar 2014, 00:49

I would like to one for Germany too. I think that would be very interesting.

Pepperman · Post by **Pepperman** » 18 Mar 2014, 10:19

RenewableCandy wrote:Look at the number of countries they export/import with! With 6 countries, it's much easier to find a market for the pretty-well-constant nuclear output: we won't have that option.

We have some options though - interconnectors to Ireland, France and the Netherlands already exist and it would be feasible to connect to Belgium, Norway, Denmark, Iceland and even Spain. The longer stretches won't come cheap though.

biffvernon · Post by **biffvernon** » 18 Mar 2014, 11:31

BritDownUnder wrote:I would like to one for Germany too. I think that would be very interesting.

Can't find it just now but a few days ago I saw a graph that showed German wind and solar generation was so great that the base-load coal and lignite generation had been cut back on several occasions recently.

Pepperman · Post by **Pepperman** » 18 Mar 2014, 14:49

There's quite a nice live solar generation page here:

http://www.sma.de/unternehmen/pv-leistu ... hland.html

And Fraunhofer produce some nice (static) graphs of wind and solar production:

http://www.ise.fraunhofer.de/en/news/ne ... ny-in-2013

Pepperman · Post by **Pepperman** » 18 Mar 2014, 14:51

And when I say live I suspect it's modeled rather than actual generation data.

Post by **adam2** » 18 Mar 2014, 16:29

Pepperman wrote:And when I say live I suspect it's modeled rather than actual generation data.

Indeed, it cant be truly "live" as most small PV installations are not metered in real time.
By metering a percentage of installations, and then adjusting for installed capacity, time of day, and degree of sunshine one could of course derive a good approximation.

RenewableCandy · Post by **RenewableCandy** » 18 Mar 2014, 17:08

Yes, apparently there are 2 GW of PV here in the UK, but you couldn't put them on Gridwatch because their exports into the Grid are just registered as reduced demand. Which is a pity, because right now "Wind" is showing 5.52 GW, Nuclear is showing 6.01, and PV's probably at about 25% meaning that wind + solar are possibly out-producing nuclear at the moment. Bit of a Landmark

Pepperman · Post by **Pepperman** » 18 Mar 2014, 17:56

I was speaking to a guy from National Grid last week and he was saying that their forecasts during the middle of the day are starting to miss thanks to our installed solar capacity and cloud cover forecasts not being quite right. Nothing major at the moment but it's definitely there which is good to hear.

But yes domestic solar doesn't make it out past the substation in virtually every case. On some sunny early afternoons in May there might be some substations with a lot of solar installed which could see some export but generally there won't be much at the moment.

Post by **adam2** » 19 Mar 2014, 08:08

And if PV did make it past the substation and out into the wider network, that could cause problems with the grid configured as at present, in some locations.

Large substation transformers in urban areas are usually interconnected on the low voltage side with other similar transformers in the immediate area. This gives continuity of supply in case of a transformer failure, and also spreads the load a bit.
To localise the effects of a transformer fault it is usuall to provide "reverse power protection" This is a device that detects the direction of power flow and opens a circuit breaker if power flows in the "wrong" direction. This would trip if the local PV production exceeded the load on the same transformer.
This only normally applies to large transformers in urban areas, and I have never heard of the revere power relay tripping due to PV input, eventually though ?

The smaller transformers typicly found atop poles in rural areas have no such sophisication and are simply protected by fuses, that dont "know" the direction of power flow.

Blue Peter · Post by **Blue Peter** » 19 Mar 2014, 10:27

RenewableCandy wrote:Yes, apparently there are 2 GW of PV here in the UK, but you couldn't put them on Gridwatch because their exports into the Grid are just registered as reduced demand. Which is a pity, because right now "Wind" is showing 5.52 GW, Nuclear is showing 6.01, and PV's probably at about 25% meaning that wind + solar are possibly out-producing nuclear at the moment. Bit of a Landmark

Generally, domestic PV exports to the grid are not measured. The amount generated is measured. The amount exported is judged to be half the amount generated, but it is not metered. So, no one knows how much PV is actually put into the grid. On a good day, it is likely to be a lot more than half that generated. On a poor day, it could well be nothing (since the dwelling will consume all that is generated),

Peter.

RenewableCandy · Post by **RenewableCandy** » 20 Mar 2014, 20:06

Hey, what happened in France at 8 this morning?? Demand and nuke output down from the usual 50-ish GW to summat in the 'teens!!