Solar Power can be price competitive

Turnkey solar power systems are now available to Ontario homeowners at prices which, amortized over 25 or 30 years, can deliver electricity as cheaply as your local Hydro company!

There are of course provisos, principal of which is the efficiency of the site. When generous government incentives were available, solar was installed on many sub-optimal sites, facing east and west, even north.

To be as cheap as local distribution company, your solar roof needs to be south facing with a slope of 20-40 degrees so the annual production is the maximum (about 1200 kWh per kW per year).

To be cost effective, my preferred installer has focused on standardizing systems and reducing costs to the homeowner ever since the Ontario Government in 2018 removed all incentives for renewable technologies in the province.

Through me, you can sign an installation agreement directly with the installer who is an electrical contractor and will be responsible for the entire job.

A site assessment is mandatory: there first is a remote assessment, then after receiving a refundable deposit, the installer will visit the site in person to assess roof condition and electrical service panel in addition to the factors mentioned below.

The ideal roof for solar faces near south, has a slope of 20-40 degrees, and is unobstructed, not shaded, and large enough for at least 20 solar panels.

Asphalt shingles are the most common type of roofing and should be almost new to avoid the later expense of removing the solar panels in order to re-shingle.

To be cost effective, need to allow my installer to choose the equipment. Much work has gone into selecting components that are available in Ontario at negotiated prices. Insisting on the latest and greatest product you saw on the internet will in most cases add to the cost of the system. If you have strong preferences I suggest first getting the standard quote then upgrades can be considered.

There are 3 principal components to a rooftop solar power system: the inverter, the solar panels (also called modules) and the racking (also called mounting system).

At the present time, my preferred installer is using SMA inverters. Canadian Solar panels and Kinetic Solar racking. All tier 1 equipment.

My next post will provide examples with actual costs and return on investment for 5, 7.5 and 10 kW systems.

Shading of the Solar Array

Include a shade analysis when doing a site assessment.

Shadows reduce solar production

Passing shadows  reduce the productivity of a solar array. Shadows are cast by trees, buildings, passing clouds, falling leaves….but we love trees!

If there are shading concerns, we include in the site assessment an analysis using a “Sun Eye” or similar device. Its report will accurately forecast the monthly energy shortfall.

Nowadays most central inverters have 2 inputs so at worst half of the array would be affected until the shadow passes.

We recommend micro inverters or Optimizers to minimize loss when shading is an issue.

Both maximise the efficiency of individual panels by their MPPT technology. (Maximum Power Point Technology).

Optimizers are small devices attached to every solar panel in the array and have the effect of bi-passing the affected panel or panels so that the remainder of the array is not affected by the shadow. 

In some cases just a few optimizers can be placed on modules directly affected by shading.

Optimizers are usually  more cost effective than microinverters.

Central Inverters at ground level teamed with optimizers on the roof reduce the need for workmen to climb on the roof, saving wear on shingles.

Micro- inverters and optimizers both perform the additional function of maximizing production of the individual solar panel by their MPPT algorithms and can add 5% productivity to any array even without shading. They both  provide web based monitoring of individual panels and useful reports.

Its addictive to view either on line display to see how the show on your rooftop is displaying and to compare production between months or years.

We have had good results using Solar Edge Central Inverters with Optmizers. Here’s a link to their website:

www.solaredge.com/us/

The original microinverter is Enphase. Here’s that link: www.https://enphase.com/en-us/residential-solutions

Either solution brings more on line fun than plain vanilla reports from central inverters can provide as the homeowner can view on line how each solar panel is functioning.

 

Energy Storage

Energy Storage is a hot topic nowadays. In Europe and some USA States, where homeowners are charged time-of-use rates, it makes sense to invest in a battery to store solar electricity for  use at times when the rate charged per kilowatt hour is highest.

In Ontario, once the grid connection is changed to net-metered, the smart meter is removed and the customer is charged a flat rate so the rate charged  is no longer affected by time of use.

Ontario customers at this point in time do not need a battery for energy storage as a net-metered connection allows consumers to use the grid as their battery.

Back-Up power is an entirely different issue. I will discuss battery back-up in my next post.