It was a big dumb cloud

Don't worry I'm not going to upload a graph like this every day. But I could, I mean it's my blog and all, but I won't. The mystery of that huge dip in the first day's graph has been solved. it was likely just a big dumb cloud. Today's graph is much more uniform and at a better 5 minute resolution.

I'm really happy with the data logger (an SMA webbox).

My First Solar Production Graph

Our system is still in testing mode, but now we've hooked up the webbox data logger and so I can get data out of it. I had knocked up a script to hit it every minute and get data but it crashed halfway through the day. Luckily the built in webserver and ftp server had all the data I needed for today's production and here's a graph.

That dip is interesting, I'll be interested to see if it's there in tomorrow's data too. It could be a tree shading the panels at that time of day, who knows. Looking at the data, the voltage of the panels is constant. I'll be looking into this more.

We made over 28kWh in one day!

Solar panels installed!

Well it only took two days to install the solar system. Everything turned out great and we're really happy with it.

The system got turned on for the first time today which was also the day the building inspector would sign off on our permit. While it was on for testing we generated 10kWh of power which is worth about $2 or $4 depending on which tier of power you are offsetting.

We're allowed to offset the power we use at night or on cloudy days but not sell back more than we end up using. There are no batteries, the electrical grid is effectively our battery. If there is a power outage, our inverter notices and refuses to output any power (to stop us electrocuting people working on restoring power).

Now we just need to wait for the utility company to come out and give us a fancy smart meter (for time of usage billing) and to bless the system and we'll be allowed to leave it on all the time.

From 20110607solarinstalled

The coolest thing was seeing our electric meter running backwards while the system was running!