#1 June 16, 2016 12:32:50

Registered: 2011-12-08
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Instantaneous peak output

bhommels is right - I have a 2 string system either side of a dormer.

It's worth checking that the start up voltage of the inverter is not too high compared with the DC voltage of each string (calculated by multiplying the number of panels in the string by the maximum power voltage (Vpm) ). Vpm is usually around the 30V mark. Don't use Voc which is higher.

I had this problem with my first inverter (Eltek Theia S) but was fine when this was swapped for a SunnyBoy SMA 3600TL.

URN 215


#2 June 18, 2016 12:17:29

From: Staffordshire
Registered: 2016-06-02
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Instantaneous peak output

Well sunshine is in short supply at the moment but when it does does peek out between the clouds I have seen 3.3 kw instantaneous - this is clearly a big improvement on the 2.4 cap that led be to start this thread.
I understand the startup up voltage issue and will look that up, but perhaps that will be less obvious than the capped peak. I will have to see what happens in the winter. I guess there is a trade off here but hopefully the inverter folks understand that.


#3 Dec. 22, 2016 09:59:58

From: Southend
Registered: 2012-08-01
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Instantaneous peak output

Hmm, how interesting - thanks Steve. I now wish that I'd dug out my inverter manual and had a go at a special Winter setting for my start-up voltage. On some of these winter rainy mornings my East-West system takes a morning lie-in and struggles to start up at all before midday.

Economy 10 tariff provides 6.9p/kWh off-peak import between 12am-5am, 1pm-4pm and 8pm-10pm; http://www.pvoutput.org/aggregate.jsp?id=21047&sid=18934&v=2&t=m on approx. 63% off-peak usage, 22% solar usage, and 15% peak-rate usage.
1,900kWh annually is exported, mostly in summer, on approx. 3,200kWh generation. Approx. 4,500kWh/year is imported, mostly for (a) winter and springtime off-peak Storage Heaters, and (b) off-peak hot water Immersion heating (which is “dumb”, i.e. not linked to the solar PV).
PV array is split East-West. Income is from Phase II 21p/kWh Feed-in-Tariff plus smart metered 3.2p/kWh Export Tariff.


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