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The "bufferedwrite" branch is the "low-write" version developed for SD card installs and the omission of the "power to kWh/d" is one of the steps taken to reduce the write rate.

Paul

Ok, that explains it. Thanks.

Would having kWh/d really add that much to SD card writing?

I would have though it would have only a few extra writes per day.

@craigfryer the method for calculating kwh/d using the buffered write version is to record an every accumulating kwh feed. This will also allow for kwh per week/month/year. The process you need is the power to kwh process and then you can use the method described at the bottom of the blog post here to create daily graphs: http://openenergymonitor.blogspot.co.uk/2014/08/monitoring-solarpv-heatp... "Creating a daily electricity consumption graph in a dashboard using watt hour feeds (instead of the old power_to_kwhd method)"
 

Thanks for the link.

It appears that I was saving the data correctly and had created a graph correctly except I had the value in the scale wrong. I was recording kWh, where as the example you have provided was recording Wh.

I do seem to have a problem with either the data source or the graphing system as there days when there is zero value, but the next day appears to have both days of data in it.

Then for a graph with kW/h, there are hours with data that has been added to the next hour.

Any suggestion on what would be causing this?

Yes there's a fix for the zero value on some days issue in the next version of the low-write bufferedwrite version of emoncms.

You can switch to that version now with:

    cd /var/www/emoncms
    git pull
    git checkout low-write-v8.5

The intention is to fully switch over to this soon with a new image and upgrade notes for existing systems but your welcome to go ahead and use it now.

Ok, thanks for the information.