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Ted's Solar Installation

My Home Solar System - Roof Mounted Solar Panels & Inverter

Ted Doskaris

September 21, 2021 Rev GE-A Initial Release

Solar technology has been around for many years, and it has had plenty of time to reach a good degree of maturity and reliability. So I decided to go ahead and have a system installed, albeit without having the still very expensive back-up batteries.

Shown below are photovoltaic roof panels (aka modules) which include 11 on the west side of the house.

The west side favors the afternoon sun.

An additional 3 panels are on the east side of the house - shown below.

The east side favors the morning sunrise.

The Inverter that interfaces the panels with the utility company power is attached on the side of the house near the power mains behind the access door - shown below.

Contents:

Overview
The System
Monitoring Platform
Inverter & Safety Switch Internals
Videos

Overview

Because it has become routine for my utility company to increase electric rates (expected to be worse in the future owing to costs dealing with mitigating wild fires here in California), I decided the time has arrived to adopt solar. Also,beneficial is the 26% this year's (2021) Federal tax credit applicable to system ownership purchase, including loan long term interest if choosing finance.

Typically, a solar system purchase is promoted as no "out of pocket" cost on a per month bases. The reasoning is if you chose to borrow the money to pay for a roughly 25 year lifetime system, you will make monthly payments "frozen" at the rate of inception of the loan costing a lesser amount than you would pay the utility company because the solar system feeds back into the power grid that utility company will credit to you.

In my locale, this is done on a Net Energy Metering (NEM) basis, which, as I understand, costs you a minimal amount by the utility company (roughly $10 per month) over one year with an annual "true-up" bill (or credit) depending on your system's output vs. your energy use (in kilowatt hours) over that time.

Ideally, the system would be designed by the solar company with just the right amount of panels and Inverter capability so there would be a zero true-up bill. If you use more energy than supplied by the solar system, you would pay the utility company at their current retail rate predicated on "time of use". This could be a big bill if your use and/or system performance is out of whack. If you supplied more energy than used, the utility company would pay you at a lesser wholesale rate.

I chose to use the Better Earth Solar company to equip my house with a solar system.

My experience was excellent with Better Earth. They offer an optional loan not requiring a home lien that could also be paid off early without prepayment penalty. They also took care of permits, system installation, inspections, and activation via the utility company, and then a follow up phone call from them to check on how things are going.

All the Better Earth people, including the sales specialists and installers I dealt with, were knowledgeable, enthusiastic, motivated, and very outgoing and a pleasure to communicate with. The business card given to me by Better Earth's Specialist, Dylan, is shown below.

Looking at the card, the Better Earth trademark caught my attention when noticing the multi colored symbols with same pattern shown in the opening within the "b". It looks like the earth's tectonic plates at a time millions of years ago resembling a single land mass before it started to separate into continents we know today. Another way to think about it is them coming back together as the super continent - as if to express unity. In this regard, a Better Earth Solar company video will show a tree with leaves that look like the continents with them coming together for a better earth.

Their Better Earth Electric company did the system installation. They took the time to paint the electrical conduit to match the shingles and house paint. The utility company activated the system in about a week after the system passed the city inspection.

The System

My system includes 14 Hanwha 340 peak watt rated solar panels with SolarEdge power optimizers and a SolarEdge SE3800H Inverter which converts the panels' direct current to alternating current and synchronizes it when received by the utility.

Each of the panels include a dedicated "power optimizer". The panels with optimizers have their DC outputs connected in series, then connected to the Inverter as illustrated in the block diagram below with 18 example panels.

From what I read, the Inverter has bi-directional communication with the power optimizers over the DC lines, and during normal operation the Inverter is to receive a fixed 350 volts DC, so the optimizers which include a DC to DC converter, control the current & voltage for a given panel's developed power (E_Voltage = Power / I_current) to finally maintain a constant 350 VDC at the Inverter. The Inverter then converts the DC to AC and phase synchronizes it for delivery to the utility via an AC disconnect switch (if so required by code) and via dedicated mains circuit breaker (20 amp AC rated in my case) in the main power panel; thus back feeding to the utility.

The Better Earth installers placed a conduit (painted to match the house) on the wall from the roof to route the DC wires within to the inverter as shown below.

Red colored warning labels are everywhere to be seen. My main power panel and utility meter above it is located within a wall recess.

Shown below is the Inverter which includes two switches. The somewhat obscured red handled toggle switch can be better seen from the side of the Inverter.

The front of the Inverter is shown below where the large rotary switch is apparent.

For safety reasons, the prominent rotary switch could be switched off by Fire Department person should the need arise.

Illustrated below are the Inverter's LED status indicators and what they mean during normal operation.

Monitoring Platform

A SolarEdge application ("monitoring platform") is available for smart phone or for use with a computer browser so you can see what is happening in the system via SolarEdge's server (which communicates via Cellular in my case). The cellular antenna cable is routed from the bottom of the Inverter to where the antenna clips on the top, left side.

The large aluminum casting on the back of the Inverter where the antenna is clipped is finned, apparently for heat dissipation.

When the App is refreshed, it appears to update every 15 minutes on the hour for showing a plot with what had happened in the prior 15 minutes and before.

Illustrated below is a desk top PC browser linked to the SolarEdge server with depiction having added my insets, including the utility meter.

Shown below is the SolarEdge App as seen on an Android smart phone.

Inverter & Safety Switch Internals

The following illustrations show the Inverter's internal circuitry and connection points before the wiring had been connected. (I took the opportunity to take pictures whilst the installer had the covers off.)

The Inverter includes two housings; the upper area has the electronics; the lower area is where wiring connections are to be made.

The picture below includes the connection blocks for DC and AC wires. The installer pushes a screwdriver into the square openings, then places the stripped ends of the wires in the round openings, and then withdraws the screwdriver. Apparently, spring tension is sufficient to retain the wires. The wires can be pulled on to check for good attachment.

The following pictures shows selected areas of the Inverter electronics:

Shown below is where the DC wire connections are attached on the Inverter's upper housing.

Shown below is where the AC wire connections are attached on the Inverter's upper housing.

This model SE3800H SolarEdge Inverter includes several boxy shaped modules that are capacitors. Prior models were much bigger and heavier relying on more magnetics (transformers).

Shown below at the bottom left is where the toggle switch and LEDs are located.

The daughter circuit board below includes RF cellular and WiFi communication and connection ports for RJ45 Ethernet LAN and RS485. The RS485 port is for connecting and communication with additional Inverters (master & slave/s, if so equipped). My system made use of the Cellular antenna to communicate with the SolarEdge server.

Videos

Video of Installation:

Better Earth's Specialist, Dylan with his associate, Tyler, made a video of their installation that includes me with my garden "G" scale model train running. (I'm the one with the red shirt, eye squinting with the sun in my face.)