Efficiency

[Fnm]

I see that AICC , Emoncms and PVoutput gives a efficiency value. (kWh/kW)

The I also see that the size of the system does not dictate that value, for instance Aloe Ridge Farm with only 0.600kw plant have the highest efficiency of 4.535kWh/kW)

Myself with a 2790kw plant ended up with a 2.261kWh/kw efficiency.

What do I have to read in this value or what is a good value?

[Chris Hobson]

The efficiency value tells you what sort of day you have had. Most of us are between 2.5 - 4 kWh/kW. So for every kW of panels installed we are producing 2-4 kWh. So my 3kW system if it has an efficiency of 3.5 produces 10.5 kWh per day. GTIs and Aloe Ridge Farm are very efficient in that every potential Watt is used.GTIs have the grid for a load and with Mark's small PV array he can use nearly everything he produces.  If there is no demand the panel just does not produce the energy. Think of the energy produced by panels as being sucked out of the panels by the inverter rather than being pushed out like toothpaste. If you have little of no load you not going to have efficient panels no matter their positioning and the efficiency of your cabling. I have raised my efficiency over 5 kWh/kW by adding a geyser (1500W) so that I have a constant moderate load. Geyser still on manual but as things quieten down on the farm I will get back into the loft and run the final conduit and cabling.

[Fnm]

Thanks Chris, that means that you will have to control that geyser to not connect when on battery or when solar can't provide enough power.

[viper_za]

Yeah I'm planning to do the same Fnm, you can check this thread for how I'm going to try and do this

 

 

[Fnm]

I already have solar heating, can not use that to up the load.

[Guest]

I have  5kw system. My efficiency is very low at around 2 - 3, even with my wife at home. We do not use our system optimally. They say if you have 4 and up your system is performing to its optimal working capacity. That is why I am thinking of moving to the Infini as my panels will work all the time, not now and then. When we used the heat pump the panels worked more. Now with the solar water heater tubes the panels work even less. So if you think about it the solar water heater was actually a waste of money as now my solar power system sits and does nothing.

[cvzyl]

Jaco, since I installed my Infini last week Thursday my average is 4.65kWh/kW and on Friday I achieved 5.929. Unfortunately over the last couple of days we've had shitty PV weather here in the Cape but even so, on the Axpert it would have thrashed my battery bank.

[Fnm]

Jaco, I have the same problem, the geysers can not be used to up the load. I only have 1 inverter and 9 x 310W panels with 8 x 200ha battery bank.

By 10hoo in the morning the 100% soc is reached according to the axpert and then the system is floating.Will install the BMV 702 this week some time.

Will see what the real figures is then.

My 4.5 kw micro inverter system is working to its max as all the possible power is used by the workshop, if it is running.

On weekends if the shop is off I change it over to the house 2nd and 3rd phase where the washing machines ens is on the make use of the power , but that is only for 2 or 3 hours a day, so a lot of waste as there is no backup storage for them.

My average on the 2790W system is 7Kwh/day and the average on the 4.5Kw is 16Kwh/day. Taking in to account that on the 4.5 kw system 9 x 250Wpanels face east and 9 face west, not the best direction but that is how I could manage it.

Well it does feel good to know that I generate around 23kwh a day of my own power, still along way to get to my +-120kwh a day consumption.