Background
My wife and I have been looking at Solar for years, but I could never make it make financial sense. I had looked into both solar water heating with vacuum tubes and solar photoelectric. This past spring we decided to take another look.
As you may know Calgary is very sunny generally, and a large portion of our power generation is coal, so it certainly would have positive environmental impact. You can see an approximate solar energy production estimate at several sites like PVWatts from the US Government.
Through some research it seemed like it might now make at least some financial sense (i.e. an eventual payback).
System quotes
With some hope I reached out to about 4 solar installation companies in Calgary. A couple replied with a very high level quote using a satellite image of my house. Their quotes probably were good enough for my initial needs.
Two companies did come and visit my house to take a look and give me a more detailed quote with some explanations. Prices were fairly similar within about 15% or so.
The big difference I found between the companies was their ability to answer questions and explain why they recommended what they did. The one company was clearly a salesperson with no solar background and really couldn’t tell me why they were commending what they were.
Vendor Selection
We ended up selecting SolarYYC. They were very helpful in explaining things to us, and came back and did an electrical assessment to provide a firm quote.
One of the biggest reasons I chose SolarYYC was they use micro-inverters. The other providers seemed to a single larger inverter.
Solar Micro-inverters
Solar Micro-inverters as per Wikipedia “is a plug-and-play device used in photovoltaics, that converts direct current (DC) generated by a single solar module to alternating current (AC). Microinverters contrast with conventional string and central solar inverters, in which a single inverter is connected to multiple solar panels. The output from several microinverters can be combined and often fed to the electrical grid.
Microinverters have several advantages over conventional inverters. The main advantage is that they electrically isolate the panels from one another, so small amounts of shading, debris or snow lines on any one solar module, or even a complete module failure, do not disproportionately reduce the output of the entire array. Each microinverter harvests optimum power by performing maximum power point tracking (MPPT) for its connected module.[1] Simplicity in system design, lower amperage wires, simplified stock management, and added safety are other factors introduced with the microinverter solution.”
The primary disadvantage is micro-inverters cost more initially. My south roof has a large tree on the north east side, and a chimney in the middle I knew I would get a fair amount of shading. Given this micro-inverters became quite important to me, so this was a great benefit of the SolarYYC proposal.