Tag Archives: solar electric system toronto

How will shade affect the performance of my Solar Panels?

19 Jul

It’s common knowledge that vampires can’t stand garlic, that the Joker is Batman’s nemesis and that oil and water simply don’t mix. The same can be said about solar panels and shade. They simply don’t work well together.

Solar panels installed by Eco Alternative Energy at a house in Ontario

Solar System installed by Eco Alternative Energy

Solar modules are designed to convert solar radiation (otherwise known as sunlight) into electricity which will then either be sold to your local Hydro Company in a grid tie scenario or used to charge batteries in an off-grid system. When a panel is blocked by a shadow (either by a cloud, a chimney, or tree branch, etc), it can reduce the performance of your system dramatically.

Without getting too complicated, imagine a standard solar panel on its side, in a landscape position. Now divide the solar panel in two with a top half and a bottom half. Each half is a circuit interconnected together in series (30 cells in each half for a total of 60 cells). When you shadow any of the cells in either of these two half’s, the voltage of the solar panel will drop in order for the panel to protect itself. Even if only one of the 30 cells in that section of the panel is covered,  it will have a dramatic effect on that half of the panel and potentially on the system as a whole depending on whether you decide to go with a string or micro-inverter (future blog coming soon).

Some common shade considerations you will need to look out for include chimneys, hydro wires, dormers, TV antennas, snow, neighbouring houses and of course tree branches (doesn’t really matter if its winter or summer as the shadows of branches in the winter alone can still have a significant impact on your system). Do shadows from these obstructions mean that you can’t add solar to these areas of your roof? Not necessarily.

Solar Pathfinder: Eco Alternative Energy

Solar Pathfinder: Eco Alternative Energy

Your solar installer should have the knowledge and expertise in choosing the best areas of your roof to add your panels that will maximize your return on investment. He or she may avoid certain areas due to constant shade obstructions but it’s important to keep in mind that some shadows may affect a panel in the morning however may not affect the same panel the rest of the day – resulting in overall good performance. That’s  because shadows move throughout the day as the earth moves (but I know you already knew that).  Solar installers should have the tools, like a Solar Pathfinder, that will allow them to make educated decisions on the best places for you to add your panels. With the Solar Pathfinder tool, they should be able to predict your solar systems performance based on any obstructions you may have on your roof. It doesn’t matter what time of year they do the analysis – the tool is smart enough to give results for the entire year with surprising accuracy.

We hope you found this article on shade helpful. If you would like to have a shade analysis done on your roof, drop us a message here or call 1-888-907-5848. We have three locations to service you (Toronto GTA, Sharbot Lake and Peterborough) and we would be happy to help you out. You can also find out about other posts to many of your common questions here on our blog.

If you are in Ontario, Canada and would like a free online evaluation of your property for solar, feel free to fill out the short form below and one of our experts will get in touch with you in 1 business day.

Grid Tied vs Off Grid Solar Electric Systems: Which option is better for you?

19 Jun
Solar Electric System Installed by Eco Alternative Energy in Spring 2011

Grid – Tied Solar Installation Completed by Eco Alternative Energy in Spring 2011

If you’re wondering which of these two options are better for you, then you’re at the right blog!

Let’s face it, we would all like to be off the grid generating our own electricity and telling our local hydro company not to bother sending us another bill – ever! It’s also nice to take comfort that during a thunder-storm when the lights go out, you’ll be watching T.V with your lights on while your neighbours sit in the dark. It’s a pleasant thought however not always practical, economical or to your benefit.

First of all, just in case some readers are not sure about what Grid Tied or Off Grid Solar electric systems are, here’s the difference

Grid Tied Solar Electric System: In this case, your solar system generates power through your solar panels and you sell ALL of that power to your hydro company at a preferred rate (often guaranteed for 20 years). You will then buy electricity (including your clean solar electricity that you produce) as you normally would however you will buy this power at the standard lower rates for electricity that we all pay.

To take part in this Provincial Solar incentive program, (called the MicroFIT program in Ontario), you would be required to apply to the Ontario Power Authority for approval. To be eligible, you are required to own your home and your system cannot exceed 10 kW’s in total. Your Solar installation company can help you navigate through the approval process. ( In case you want to know if your home is fit for solar you can find out the requirements here)

Solar Electric System Ontario

One of our head installers installing a Grid Tied Solar Electric System

If you look at your hydro bill, you’ll see that here in Ontario, we all buy our electricity at a rate of 6.7-12.4 cents per kWh (depending on the time of day). Under the MicroFIT program, generating electricity with solar power and selling it to the grid will pay you a premium rate per kWh (current June 2013 MicroFIT rates are at 54.9 cents per kWh) and that rate is guaranteed for 20 years! Since the average Solar system costs between $25-$40,000 before taxes, you can expect your investment to pay for itself in about 8-10 years. As your OPA contract runs for 20 years, the remaining 10-12 years will be money in your pocket.

Off Grid Solar Electric System: For Off Grid systems, you are completely off the grid as your system generates power through your solar panels and that power is used for your own consumption. In this case, you will require batteries to store that power to be used in the evening or on cloudy and low producing days.

The trouble with Off Grid Solar systems is that you need to truly understand your electricity consumption and then you need to build the size of your array to the worst month of the year (let’s say January) so that it will still meet your minimum daily requirements. With Off Grid systems, you now need to purchase and hold a bank of batteries (amount and size of batteries to be determined by the size of the system) to store the electricity you generate. Batteries are not cheap and they typically only last about 10 years before they need to be replaced. Chances are, you will need a back-up generator for the times when your system is not be able to meet your requirements in the worst producing months of the year. These batteries can add at least a third of the cost of what a Grid Tie Solar system would be. Lastly, an off grid system is a lifestyle change as you need to conserve electricity wherever possible.

At the end of the day both systems have their merit. Off Grid systems work best in areas of the Province where you cannot connect to the grid in any other way, typically in rural settings. Grid Tie systems are better in an Urban environment where Hydro is readily available.

If you’re curious about your home and want to see how much a Solar system on your roof can generate, please feel free to drop us a line here or call us at 1-888-907-5848.