Electric News from Tucson Audubon's Mason Center

Kendall Kroesen, Urban Program Manager

I knew we were making gobs of electricity at the Mason Center with our new solar panels, but I didn't understand everything on the inverter readout. So here's my attempt at deciphering it via the user manual.

Mason Center energy production meter

Let's start with the graph in the upper left corner. This shows the energy made each hour for the last 16 hours. It can be changed to show the energy made over the last 16 days. The funny-looking symbol to the right that looks like a hand means that you can "tap" the display with your finger to change the readout.

To the right of the hand is the amount of power, in watts, being made at this instant (3:04 p.m. on January 10, 2014). At that moment we were making 2,886 watts. Below that is the amount of energy made so far on this day measured in kilowatt-hours (a kilowatt is 1000 watts and a kilowatt-hour is one kilowatt of energy expended, or created, for one hour's time). We were at 21.56 kilowatt-hours and we finished the day around 25.

Below that is the total amount of energy made by the system up to now in megawatt-hours (a megawatt is one million watts and a megawatt-hour is one megawatt of energy expended, or created, for one hour's time). We're getting close to having made one million watt-hours since the system was turned on in the last week of November!

At the bottom the graphic shows the solar panels on the left sending 4.6 Amperes of input current to the inverter, represented by the box with the equal sign and tilde. The inverter converts DC to AC, sending 124 volts output to the electrical grid.

One cool thing that the readout doesn't say is that this new inverter system allows the Mason Center to go on using electricity from the solar panels when the grid goes down (a blackout). Counter-intuitively, on older "grid-tied" systems even though the panels continued to make electricity, during a blackout that electricity wasn't available. This grid-tied system has a special circuit that switches off electricity to the grid and makes it available to the Mason Center in case of a blackout.

Cool, huh!


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