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David A's Solar Power

Since electric rates continue to rise and recent years have seen brownouts, many Californians have installed some solar panels to reduce our costs and to aid everyone by providing extra power when it's most needed: during hot sunny days.

See, below, a graph of recent electrical use and generation.

See also water use

Over 230,000 homes in California have solar panels generating electricity.

According to a February 2015 Washington Post, investment by individuals and companies in US Solar/Wind energy production was 389 billion dollars over the years 2007-2014.


Our Solar

SunRun installed our solar plant. Sunrun seemed a little...disorganized during 2015.

As of early 2019 SunRun noticed, via their tracking, a bank of panels was not working. They came out and discovered some small animals had gnawed the insulation off lots of wires. Hence a 1-amp trip-fuse blew and power generation stopped. Within a few days they had replaced all the damaged wires and also one panel the animals had damaged. At no charge to us.

We have Thirty panels installed. Twenty facing slightly south of directly west, Ten facing slightly east of directly south.

As of July 10,2019 one bank of panels ceased working (SunRun realized this on their own) and after some prodding from us a technician was scheduled to visit on July 31, 2019. That is poor service. And even an ironic failure (in a bad way) as we had multiple days in a row sunny in that period after weeks of hours of daytime cloudiness.

Each failure (5 between 2019-10-20 and 2020-01-21) is due to a fuse blowing. They are just 1A fuses but are industrial type and cost $6 each. I paid close attention to the service person and now know how to change that fuse myself. Sunrun gave us a couple and we bought some on Amazon.

We requested (late November 2019) SunRun replace that inverter so the problem stops. But that did not happen and we lost interest because the fuses (on the older unit) last 'long enough'. What is apparently the same industrial fuse is available in the UK under another name. Folks there think some of what has been sold there was fake, not made by the manufacturer on the label.

SolarMaid installed wire guards (2020-01-21) around the panels (at our expense) to keep birds, roof rats, and more from making nests under the panels. Since then the service interruptions at that inverter have stopped (that fuse blew 296 days later, 2020-11-14). So maybe we don't need a new inverter at all! We'll watch and wait and not do anything about the inverter.

Sunrun relies on cell/mobile phone signalling to determine if solar is working and how well. For many many months (as of 2020-11-25) they have not been able to get a signal so they have no idea if/how the system is working. They tried sprint meters and changed to (we think) verizon, but shows there is no data on our account. Fortunately our own sensors (TED Pro) tell us the systems are working. They supposedly have visited a couple of times to change out meters. No improvement. I phoned Sunrun and they realized nobody had updated the records with the new meter serial numbers. Sunrun updated the records and now we can see production numbers through sunrun as well as our own metering.


Tracking Generation

We watch our power use and generation using The Energy Detective TED Pro inductive couplers and the associated gateway device which provides a web server on our home network with all the power data.

We used to use TED5000 but it's discontinued so as of October 30, 2017 we switched to TED Pro..

TED can produce nice reports with just your browser on your home network, but I added my own software to make my own reports and to ensure the data is all captured on my systems (not relying on the wall-wart from TED to keep the historic data safe).

From examination of SunRun's historical data we were generating a maximum of about 20KwH per day in the summer of 2014 with the 18 panels installed then.

On a sunny day we generally generate 37 KwH. Here are some of the 5 highest recorded Kwh generation days so far. Five pine trees died in 2016 (two more died in 2017) and one eucalyptus was dangerously large. Getting rid of those trees has lead to generating over 40KwH in one day. Regrettably there has been lots of overcast (clouds) in 2019 so there have been no new highs in 2019.

Generation high
2017-06-10 42.513
2016-07-16 41.847
2017-06-28 41.206
2017-06-30 40.854
2017-05-24 40.699

For the month of July 2017
a total of 1157 KwH generated.

Here are some low recorded Kwh generation days.

Generation low
2014-12-11 0.588
2017-01-08 0.841
2014-12-02 1.361
2017-01-10 1.872
2017-01-18 1.948
2014-10-13 2.091

Most of the 2014-2015 winter was just above 500Kwh per month.

Global Warming is having a marked local effect in our microclimate. We installed a Rasberry Pi B+ computer and some DS18B20 temperature sensors August 30, 2017 (combined with some software I wrote) to track local temperatures. The DS18B20 sensor is remarkably easy to use when combined with the drivers provided in the Raspbian OS.


Tables and Graphs follow

outside highs(F) and lows(F) by day
04-25 04-26 04-27 04-28 04-29 04-30 05-01 05-02 05-03 05-04 05-05 
   60    64    72    86    78    69    64    69    83    84    84 
   47    46    45    48    50    49    50    48    49    55    52 

Electricity Use Graph

Electricity use. As recorded by TED Pro Home

Electricity Generation Hourly