Solar PV 3 year performance

 After three years of operation, I have a summary of the system generation.  The data is collected from the SMA inverter that has an Ethernet cable connected to the internet and is pushed to a cloud database that is accessible to customers.  

The three year average equals 5294 kWh (although I know I had a few data losses that should make it more like 5400 kWh).  Not bad from a ~4800W nominal panel power system.  

Here is my home metering net summary over the past 3 years. Negative numbers on top are solar generation surplus and positive numbers below are consumption.  There are some data holes from faulty connections a few times but it gives the picture.  Summer generation generally exceeds winter consumption.  Hopefully I get a full data set this year and can get an accurate reading beyond the flawed meter data from the utility.  

This is currently far exceeding our consumption but will change with our future purchase of either an electric or PHEV car along with a planned transition to a heat pump space and water heating system.  I would like to make these transitions sooner rather than later but am stuck with poor product choices that are currently on the market.  We hope that this opens up in the next 2 years.  

PV System Performance

SMA SunnyPortal Solar generation report

New EKM power meter will also soon connect to water meter and gas meter.

Hourly History

DIY Solar PV Electric System

After having salvaged an old solar PV system from a house that was getting demolished two years go and putting the panels on last summer to see what they were capable of doing, I decided to go all in and build a new system on our house.  The old system was 13 years old and 3x less efficient and outdated than what could be purchased now.  The urgency was due to the ending of the subsidies and tax breaks.  They will all be disappearing over the next few years including the 30% tax refund on installation cost.  Now was the time to do it.  I got a bid for a company to do the job and it was $18,000 - 30% ( which would never pay for itself with our annual use of $300 of electricity.  I estimated about $7500 in materials and fees and then you subtract 30% so that worked out to $5200 in the end before generation credits.  I would take on the job to see if I could pay myself $7500 for about a month of part-time work. 

Photos are backwards of course.

First kWh generated September 1st after waiting nearly a month for the electric utility to install the meter.

One by one, every nice night after work I would pull up another panel or two.

Installing the racking was straightforward of course it took a few tries to figure out what straight meant since the roof has is not flat or square in any direction.  Some setscrew clamps were used to attach the rails to the roof standing seams.  This was another reason I decided I could handle this as a DIY project.  

 I would hand carry each panel up to the roof myself up the scaffolding.  I borrowed my dad's roof fall arrest harness for safety. 

SMA Sunny Boy inverter and rapid shutdown from Germany looked like top quality assembly and construction on the inside.

Bathroom Finally Finished

Here are some images of the finished bathroom.  Final finishing always takes too long.


Glass pocket door 

Subway tile vertical on wall in 1/3 offset.  Wood texture porcelain tile in herringbone pattern on floor.  

Salvaged shoji screens.

Heated towel rack. Glass pivot shower door.  

Paper lamp shade.

Round Ikea Mirror.  Floating shelf. Red frames cover abandoned sconce boxes.

Floating cedar valance.

Salvaged cedar fence turned into vanity facing.  

Cedar trim.

Someday we will do something with the panel doors (paint, paper, stencil, cloth).

Steps Update

We had temporary basement steps for years and it was finally time to finish them.  Wanted clear Douglas fir to match the rest of the house and it ened up costing $50 per step.  Good thing there were only five.  

Super tricky secret drawers in three of the risers.  

Applied full trim boards on outside of stringers to avoid scribing, but made each tread need to be custom fit to the 1/32" with 2 degree off perpendicular cross cuts.

Raya helped with the screws