Having observed my export output parameters I never get to 16 amps because the voltage where I am is around 248/9 volts during the day and is about that regardless of whether there I am exporting or not. Then at tea time drops to about 240V to rise again at night to about 245V so could get away with exporting at close to 4kW rather than 3.68kW and would still be well under the 253 V max. So if inverter controlled to A rather than W then we could see an 10% increase in PV output to grid, a decent contribution to being a bit greener. Presume the 3.68kW is because 230V is the mid point but have never seen it that low in recent times. So could one controll to 16 amps and still be ok with DNO?
Solar PV Export, 3.68kW or 16 Amps
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The DNO limit is 16Amps. Sod all to do with the voltage
So I could set my export limit so as to export 4kW or a bit less as long don't exceed 16 amps? I suppose the issue might be if the voltage drops so amps exceed 16.
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Exporting it is the very worst thing you can do and should be your last resort. Re think and see how much you can self use instead. I only export about 100kWh per year.
Have you got battery storage?
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Nope. I keep looking at it, and for a small array it does not make sense.
I self use almost all of it, by using the big appliances in the day one at a time, timing the DHW to start heating at 11AM (air source heat pump), and a PV diverter to send anything else left to the immersion heater.
The small amount I do export is when there is nothing else on in the house and the PV generates more than the 3kW immersion can absorb. In the shoulder seasons my PV diverter also turns on a 700 panel heater, but in the summer I disable that (though out of spite to avoid unpaid export I have thought about putting that 700W heater outside)
If I had more than 4kW PV then batteries might start making sense.
I’m thinking about them …. not run any numbers as yet, but with the cost of electricity going up and up, batteries may make sense
when I bought the panels, it was more about saving a bit of money, reducing our emissions and reducing the import of power to the uk
when I bought the panels, it was more about saving a bit of money, reducing our emissions and reducing the import of power to the uk
Your inverter should have this built in, whether the voltage on the grid is 253v or 230v. You maybe able to change the settings but strictly speaking that is illegal, and be careful what you tweak.
If this helps I have a growatt battery 5kw and another aray which I connect 4 110 amp caravan leasure battery's to to make 48v. They last 3 times longer .so you don't have to pay thousands. I am in the process of adding another 4 to my system which should run the home all night. It depends on what loads you use as well mine are based on an average 600 w. Like everyone I am trying to cut my bills but don't want to spend thousands on power walls or other expensive battery's and equipment as the payback would take years. For me it would not be financially sensible paying out £10k so my 8 battery's will work but at a massive saving on outlay to achieve similar results.
I forgot I have had 3 battery's replaced under growatt warranty in 5 years the next failure for me would be out of warranty and I will be looking at fiddling with my control unit to try and get a 48v battery to work as the growats are 52v so the equipment is set up for this as well as the onboard BMS. Knowing what I know now I would not have spent £3k 6 years ago on a 5kw battery I would have purchased more stays and paid my dno for the pleasure to have more specifically for winter use. My theroy is more surface area of solar for winter months is what I need.summer is fantastic . Free ev charging as I have an 9kw solar system.
surface area is as good as effiiciency if you have the space for the panels. I've crunched numbers on the 'best' panels numerous times, for the extra money they cost, you don't get that much extra output, ergo, a watse of money. Angle of panels to the sum nakes a difference too, if you are loking for winter output, then you want the panels at a steeper pitch ie more upright to catch the winter sun better.
you also need to factor in charge cycles, can't remember how many you get from lead acid, but lithium is now around 6000 cycles (that's full charge cycles not part charge, although I suspect 2 half charge equals one full charge cycle)
You can get around 10kW of lithium batteries and a 5 kW inverter (AC coupled so independent of the solar panel inverter) for roughly £5k if you shop around enough. Or a smaller 5kW battery and 2.6kW inveter for around £2.5k. If your energy useage is already low, then it will take a fair while to pay for itself, I'm a much bigger fan of heating a water tank. Customers of mine who still have hot water tanks reckon they get nearly all their hot water from excess energy on 4kW arrays for about 2/3rds of the year.
