For most days over the first week we have not had ideal generation weather. Apart from one mainly rainy day we have had cloudy starts, lots of high fair weather cloud and a few short but intense periods of sunshine. Even so, performance seems to be getting better. Charging seems to be quicker and the battery is lasting longer. Maybe Lithium batteries need time to condition?Anyway, last evening the battery topped out at 96% and for the first time has continued to provide power until 0225 this morning. A somewhat odd (in my opinion) feature of this system is how it “defers” the generation. I expect many of you will be able to look at the weather conditions at any moment of time and make a good guess about how much your system is generating. From the very first day I noticed that when I would have thought the system would be generating, say, 1700w the SolaX system showed it to be about 700w. When the sun finally set I had clocked up a rather disappointing 8-9 Kwh when I might have previously expected 15-16Kwh. However, by the next morning my generation meter had caught up and all was well. This is because the “missing” generation is recorded later as the battery is discharged. If you have a look at the attached screenshot from today you will see on the top graph how the battery is finally exhausted about 0225 hours (2). Although the sun set many hour earlier you can see from the bottom graph how the Yield is still running high past midnight, tapering down to cease as the battery becomes exhausted. I have absolutely no idea why there appears to be a sudden demand as shown at (1).Kevin and others have previously asked if there is any facility to top up the batteries from off-peak power. I asked exactly the same question prior to purchase and was told well yes, but currently no in the UK. There is certainly a setting in the configuration that allows you to set 2 “charge from grid” periods. Both of these are shown enabled on my system but it doesn't actually do it. It was explained to me the reason is that SolaX think it would be frowned upon to buy power at off-peak (6p) and then effectively sell it back as generated power at your FIT rate as your battery discharges … because of the deferred generation feature. However, it seems that the same question is being asked by others, and it is not an unreasonable requirement in the winter when sun is in short supply. It is my understanding that they are “working on it”. While researching this prior to purchase I came across 2 documents, one from Parliament and another from OFGEM which seems to see the option to “time-shift” your use of power as being something to be encouraged in the future. I will upload those documents for others to see.
What I would like to see is some intelligence that is able to monitor and predict power requirements/weather so that during periods of poor generation, off peak (Eco 7) electricity is used to charge low batteries at night for use during peak times of the day.
So in the summer, the solar power runs the house during the peak times of the day, the excess being used to charge the batteries (and any excess to heat your water).
In the winter, the batteries power the house during peak hours and are recharged during the night on cheap off peak rate.
Any generation you're fortunate to get in the depth of winter can be used to heat your water.
That seems to me to be a win/win situation. Your batteries provide power during peak grid demand and are recharged in grid off-peak demand times. This saves money and helps keep the peak demands lower.