Monday, September 13, 2010

The Myers house goes solar photovoltaic-electric

My father was an electrical engineer who worked on satellites and space probes when I was in grade school. His crowning glory was Ranger mission, specifically Block 3, the first manned object to take photographs of and hit the moon, literally. He worked with the folks who did TIROS, the first US meteorological satellite. He brought me a quality-reject solar cell from TIROS and I treasured that bit of electronics as a grade school kid.

Nearly fifty years have passed and the technology has advanced enough that I now have solar cells on my roof. Akeena installed 32 panels two weeks ago and I turned it on last week. The meter does spin backwards now, at least during the day. I have enough to generate 5.6KWh DC, but probably only at the solstice; we are now approaching the equinox and the power is diminishing daily. You can see a layout of the solar arrays that I have in the image below (click on it for a full size version).

There are so many things that are neat here.

First, I have 32 panels for a theoretical max of 5.6KWh, DC. You do lose 15% in the DC-AC inversion process, which is why the power is never above 140W on a panel

Second, I am using the new Enphase Microinverter. There is one on each panel rather than having panels in series. This gives optimal performance: I get the best of each panel rather than sinking to the lowest common denominator. This is especially important as one gets shade from trees at various parts of the day.

Finally, these microinverters share their information over the power line to an EMU communications gateway in my house. This gateway then reports the information back to Enphase Enlighten. I can see access it on the web; this interface was built with Adobe Flex, so I can not only view information, but drill into a single panel, look at a time-lapse view, etc.

My next mission will be to analyze power usage in our house to eliminate waste such as vampire appliances. The trick will be to do this without irritating Ann.

If you're in the area, I can give you a tour and a referral to Akeena. They did a great job designing and installing this.


At 6:07 AM, Blogger Lee said...

Any plans to install batteries for local storage?


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