Watt’s Happening: Solar Array Update

By Don Pettit

 

It’s time for a quick update on the performance of my new solar power system. After our long and unusually snowy winter, the sun is returning and the power is beginning to flow. Following is a description of the system, a rationale for the design, and a look at how much electricity it is beginning to produce.

HOW IT WORKS

This system was chosen for its simplicity and relatively low cost. All of the components were ordered through Dawson Creek’s very own Peace Energy Cooperative. In fact, having a local supplier and local expertise was the inspiration that got me off my butt to finally “solarize” my building, a dream I have had for some time. Of course, the fact that the price for solar panels has plummeted over the last few years sure helped!

The system consists of a solar array flush-mounted on the roof and an inverter that feeds power into the grid. Nothing else. When sunlight falls on the solar array, it generates direct current electricity, which the inverter changes to alternating current to be grid-compatible. The solar electricity powers the building first, and then any excess is fed into the grid. If the solar array is not generating enough power for the building’s lights and computers etc., power is drawn from the grid as usual. This is called a “grid-tie” system.

My existing BC Hydro Smart Meter automatically tracks how much power is used by the building as well as how much is generated by the solar array. I am billed only for the difference, and if at the end of the year a surplus has been generated, BC Hydro pays me (now that’s a refreshing change!) for that surplus at 10 cents per kilowatt hour, a bit more than the approximate 7 cents that I usually pay for power.

INSTALLATION

Everything was quickly and expertly installed by Moch Electric Ltd. with help from RJ Stam Construction Ltd. It took one day (two people and helper) to install the racking system on the roof, another day to attach the panels and wire them together, and part of a third day to wire in the inverter. It was electrically inspected and commissioned in November, and after filling out a simple one-page form, approved by BC Hydro for grid-tie almost immediately.

It was very reassuring to find that BC Hydro has greatly streamlined the approval process for grid-tie systems. I was impressed with how quick and simple it was!

SNOW COVER

Having commissioned the system in early winter, next thing I knew is was snowing, snowing and then snowing some more, covering the panels for weeks on end. When thick snow completely covered the panels, output dropped to zero, as expected, but it was good to see the panels clearing quickly with even the slightest warming of weather due to my fairly steep roof slope, the dark coloured panels and their slippery glass surface.

Our very low winter sun angle, short days plus snow cover means that ninety percent of my solar power will be generated in the spring, summer and fall, so any power generated in the winter I consider a bonus.

However, even in January the array would peak at about 2000 watts when clear of snow on a sunny day. Now, in late March, it is already putting out its rated maximum peak output of 5000 watts. Not bad at all.

CONSERVATION

Owning a solar-powered building has made me more aware of wasted electricity. LED lights are being added to the existing compact fluorescents and fluorescent tubes. A large and unnecessary outdoor yard light was eliminated. At the end of the work day, computers and all lights are turned off, except for a few LED security lights. Simple common sense conservation, and certainly no hardship.

By looking at previous electrical bills and estimating yearly solar output, Peace Energy and I calculated that this solar power system should supply all of the electrical needs of my commercial building and the electrical bills, averaged over the year, should add up to zero. Sweet. I will let you know how accurate our calculations turn out to be! Meanwhile . . . here comes summer, and here comes the sun!