Monthly Archives: October 2012

What does your solar dream look like?

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Designed and developed using Google SketchUp Warehouse

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Does a solar system produce power in a snowy day?

Yes, it does. Although when fully covered in snow, the panels blackout. But once the snow stops, it will start melting very rapidly on the surface of a solar panel. When the panels are slightly covered with snow, they usually work at 30% of their rated power.

If the environment around the solar system is fully covered in snow, then that actually enhances the system performance as it increases the light reflected to solar panels.

Even if you do get continual heavy snows in your area, during daytime for very long periods of time in winter, that has very minimal effect on the overall performance of your system.

So the bottom line is, don’t be put off to if you live in a snowy area.

Read the academic research of the effect of snow on solar panels here:
Prediction of Energy Effects on Photovoltaic Systems due to Snowfall Events

Is it financially viable to install a solar system?

One of the main and most debatable subjects in this regard is that solar technology (in specific photovoltaic) is still at such a stage that the cost of producing electricity from solar energy comes out to be more expensive compared to other conventional methods of power production. This means that you have to pay more money for a unit of electricity that is produced from a solar power system.

For this reason many governments around the globe provide incentives and subsidies (known as feed-in-tariff) to promote solar power. The way it works is that the government buys the electricity you produce from your solar system at a higher rate. This is the only way it becomes financially viable to install solar systems on micro scales.

The government of Ontario introduced this program in 2009 and after a review, lowered the tariff rates in 2012. This doesn’t mean that new solar system owners make less profit, but because the cost of manufacturing various components of a solar system is decreasing as the technology advances, it will cheaper and cheaper to produce electricity from solar energy. This means that the solar power will be competitive with other modes of power production in the future and eventually there will be no requirement for government subsidies.

What does your solar dream look like?

Click on image to view larger size

3D model of a car wash equipped with solar panels both on its rooftop and the carports, designed and developed using Google SketchUp Warehouse

What does your solar dream look like?

Click on image to view larger size

Designed and developed using Google SketchUp Warehouse

I want solar panels on my roof, what should I do?

It is always hard to understand where to start from when you decide to invest capital on such a project. Depending on the size of the proposed system for the rooftop, there are various stages you need to take.

First of all, you should find out whether your roof is suitable for a solar system at all or not. Look at the orientation of the building, objects around your house, trees, buildings, are they shading your roof? Is there a possibility that within the next 20 years, there will be building built near your house that will cause shadings on the roof? And most important of all, will your building exist for at least the next 20 years? If the answer to these questions is a YES, then move on to the next stage.

Because of the weight of the solar array, your roof has to be examined whether it can bear the extra weight on it or not. At the beginning stages, this should be examined instinctively by yourself, or a general inspection by an expert. You could take the extra care and pay for a consultant to check the strength of your roof.

If you are going to install a large system, you must contact your LDC (local distribution company, or in other words, the utility) to check whether there is enough capacity available to add your system to the grid or not. This is usually known as pre-FIT application.

Once approved, you can move ahead to sign a contract with the OPA. The new rules set by the OPA require you to get a building permit before you become eligible to sign a contract with them.

It is recommended that from this stage on, you contact one of the many companies to handle the regulatory and design work to them. In order to find a company that can help you, submit the form here.

Do solar panels have to face south?

For maximum power production, YES.

But, if you have a house with tilted roof that has two sides facing east and west, you could still install a system on your roof. Of course compared to a system where the panels face south, your annual production decrease (just think of if as the east side will produce electricity before the noon, and the west kicks in the production after the noon). This means if you’re connected to a grid, the payback period of the system will extend. If you own a stand-alone system, you will just have less electricity to consume. Picture below shows the tilted rooftop of a house where two sides are perpendicular to east and west.

If your house itself is tilted a little bit (azimuth is not 0), so that no sides of the roof are facing perpendicular to any direction, then you have to be more considerate when aiming to install a system. Let’s consider the house below.

This house is tilted by 20 degrees (the east side is facing north by 20 degrees; the west side is facing south by 20 degrees). You will obviously consider the south side for installing solar panels. The east side is still suitable for solar panels (the azimuth of panels on the east side will be -20 degrees), but this azimuth angle should really be the limit for such situations. Therefore if your tilted roof, on any side, is facing north  by more than 20 degrees, then you should ignore that section.

On a flat roof, if the orientation of the building is not strictly N-S, then you have the option of making panels face south. This is a good action if you have enough space on the rooftop. Because if panels are not in the same direction as the orientation of the building, then they will take up more space on the roof. See image below for illustration.

 

If there’s not enough space on your roof, you could make the panels parallel to the edge of the building, if they will not be facing away from the south by more than 20 degrees (the azimuth should between -20 and 20 for optimum system production).