Saturday, September 01, 2007

Photovoltaic System Goes Live and First Test

On Thursday, August 30, 2007, our solar energy system went live. Yesterday I flipped the AC breakers off and we ran through the day on solar power. As a test, I left the breakers off last night forcing our energy to come from the batteries through the inverters. It is 7am as I type this and the inverters have turned off the AC power to the emergency circuits due to low voltage, 45 volts. The battery bank is 48 volts and the system keeps them over 50 volts during the day. The sun is coming up so the system should be waking up soon. Right now the inverters are showing ZZZZZZZZ since the sun is not up. They have turned AC voltage to the house off.

The important thing to point out is that for our test last night we made no attempt to change our habits. We watched the big tvs, left lights on, and acted as if nothing were unusual. That was our intent, to see how far we could go without trying to conserve. Now we have a base line. Everything ran through the night and the sun will be up soon. We will observe the wakeup cycle as the arrays start charging. For our next test we will use careful energy management as if a true emergency had occurred and the grid were really not available.

We know that the entertainment center is a big energy user so we would use our small tv to monitor local events. We also have our wind up radio which we would use. We would also use our LED night lighting instead of our big overhead lights. There are still some lights in the house that are big halogen bulbs and we will replace them with more conservative lighting. So, we now know that we can get through the night and possibly more if we are careful. Our refrigerators ran through the night with no connection to the grid. I consider this first test a success. Now we will monitor the wake up cycle as the sun rises.