Addressing the dark questions of solar energy.

Solar energy is a widely used power source in Canada despite (or, surprisingly, because of) our climate. It is understandable that some Canadians question the viability of solar panels due to concerns about the impact of weather (such as rain, clouds, and our long winter nights) on the solar modules.

As sunlight is a necessity of solar energy, weather raises questions for Canadians investing in renewable energy solutions. Contrary to common misconception, solar is widely used in Canada, especially Alberta and British Columbia, because we actually have the perfect climate.

Let us take a look at these concerns and how they actually impact solar photovoltaics.

cloudy skies over a roof mounted solar pv system installed by Empower Energy

Do solar panels function in cloudy weather?

In a nutshell, yes.

Some detractors of solar energy claim that solar panels do not generate electricity on overcast days. However, this statement is deceptive. Solar panels can generate power even when it is overcast outside. It is true that a solar panel does not yield as much energy on a cloudy day as it can on a sunny day, but it does produce electricity.

Solar PV panels will generate power from both direct and indirect sunlight, although they are more efficient with direct sunlight. Just as we still get enough sunlight to see when it’s overcast, enough solar radiation can pass through clouds for solar panels to function when clouds reflect or partially block sunlight.

To be fair, cloudy weather has a unfavourable impact on solar power output since it reduces the quantity of sunshine reaching your solar panels. Based on the cloudiness and the quality of the solar PV modules, efficiency might range from 10% to 25% of the energy production observed on a clear sunny day.

High-quality solar panels are much better at absorbing sunlight than others and comparatively perform better in overcast environments. Our solar designs take into consideration the location of the system and potential shading factors.

A solar panel is made up of many solar cells that absorb sunlight and convert it into direct current (DC) electricity. An inverter converts the generated direct current (DC) electricity of solar panels to alternating current (AC) energy. Alternating current is the standard electricity that we use to power everything in our Canadian homes.

On sunny days, your solar panels may generate more electricity than is required. What will happen to this surplus electrical energy?

If you have a grid tied system, the surplus energy will be sent out onto the grid.  In Alberta, the micro-gen regulation gives grid-tied solar system owners the ability to earn credit for surplus electricity generated. When the system pushes energy generated by your solar panels back onto the grid the meter will track the amount and the utility provider gives you credit for that. Keep in mind that the credit is only for the power and does not cover distribution and transmission charges.

On cloudy days, when solar systems produce less energy than demanded, the home draws power from the grid using that credit. Net metering rules vary from province to province.

If you have an off-grid solar system, excess energy generated by solar panels will be stored in a  battery. During cloudy weather, when there is a shortage of electricity, the home can draw power from the storage device.

Does the solar system make sense in western Canada?

Solar panels are less effective on overcast days, but that does not imply your property is not solar-ready. Our Northern climate is actually one of the better regions for solar electricity. The combination of long sunny days and cold temperatures works to Canadians’ advantage because excess heat is another element that limits solar production. Essentially, our cooler climate helps the panels regulate their temperature and allow them to perform better than in hot climates.

landscape view of a roof mounted solar system installed by Empower Energy  facing skies split between a storm front rolling in and clear skies

A common misunderstanding around solar is that it needs to be consistent year round. For grid-tied systems in Alberta and British Columbia, the entire yearly output of solar panels is more essential than the day-to-day production of  solar energy. The utility provider tracks your electricity generation and usage via a net metering system and adds it to your electricity bill. From month to month, this credit will be carried over. So, if your solar system produces more electricity than you need on a long sunny day, you may use that credit in cloudy weather or during our long winter nights.

In fact Alberta experiences an average of 330 sunny days a year! So although our winter days may be short, most are still sunny. Our long summer days make up for the winter with credit from a grid tied system.

Do solar panels function on rainy days?

Yes! Solar panels will function even if it rains. In fact, rain has certain advantages for solar panels mounted on a sloped roof. When water runs down through the solar panels, it washes away all dirt, dust, or debris. Thus, it improves the operation and efficiencies of solar panels.

an image of a rainbow, clouds, rain, sun, and mountains that was taken at a solar installation by Empower Energy

Although electricity production will be lowered to 10-25% (from the cloud coverage) compared to usual on a sunny day, you are still saving money since your solar system is still producing power.

If you are residing in an area (like British Columbia) that has a strong net metering policy, the extra energy generated by your solar panels during the day can offset the energy used on rainy days when your solar system is not running at full capacity.

But what about the hail? Can hail damage solar panels?

A common concern is whether solar panels can withstand hail throughout their 25+ year lifetime.  A correctly mounted and oriented solar module or panel should never be damaged by hail. In fact, many car dealerships who are in hail prone areas actually install solar carports to protect their inventory. In Alberta’s hail alley, a notable large solar installation is over a Calgary dealership.

Solar panel researchers have recognized the necessity for solar panels that can endure harsh weather conditions such as hail. Solar panels are now manufactured to endure even the most extreme weather conditions. Many manufacturers use aluminum and tempered glass casing to hold solar panels. As a result, solar modules are very waterproof, even in the event of heavy rain and hail.

Solar panels from most manufacturers are tested and certified to survive the hail of up to one inch in diameter, dropping at 50 miles per hour. Check out our solar facts page to watch a video demonstrating hail testing.

That means, regardless of whether you are planning to install rooftop solar or ground-mounted  solar, your solar panels will continue to generate electricity from clean, renewable solar energy for decades.

Your property insurance coverage should, in any event, cover damage to solar equipment when solar panels are mounted on the roof. However, different insurance providers may have different policies. If you need to add any specific endorsement, it is a good idea to check your policy’s coverage with your insurance provider.

Won’t snow block the sun unless you clean the panels?

This is a common concern and misunderstanding that turns many Canadians away from solar unnecisarily. The reality is that the slope of solar panel installations typically allows the bulk of snow to fall off, rather than stick to solar panels.

The other great thing is that, since solar panels are soaking up the sun, the panel itself is warmer than the surrounding air. This means that snow will often melt off on the occasions when it does stick.

Snow melting and clearing itself from ground mount solar pv system installed by Empower Energy

That being said, there is some loss of productivity due to snow. A study on the impact of snow on solar performance in Alberta (including Grande Prairie) showed that snow reduces annual energy production by less than 5%. With this research in mind, we calculate for that when designing solar systems so there is no need to clean the snow from your solar panels.

Are shady areas an issue?

Shaded areas are not ideal for solar systems. It’s not recommended to mount the solar system on a shadow-prone location of the roof or ground. If you have trees around your home, an above-water tank, or high-rise buildings nearby, your roof may be a shadow-prone area.

It is important to find a location that experiences the least amount of shade for your solar panels. If you do not have an appropriate location on your roof, you can consider ground-mounted solar. By using ground mounted solar, you can easily avoid shading coming from the nearest buildings, or trees. We can recommend whether ground or roof mount is the best option for your property.

Do solar panels function at night?

Unfortunately, the answer is no. Although there is new research into generating voltage in existing solar systems at night from the temperature gradient between the modules and air, this technology is not available yet.

the last light from a sunset reflecting off a roof mounted solar system installed by Empower Energy to represent solar pv at night

Since the solar system becomes inactive at night, what supplies electricity to the home at night?

Solar panels do not generate electricity at night, but they do provide additional power throughout the day when the sun is shining. Solar users can balance things out and keep the electricity going after dark by using net metering with a grid-tied system.

What can we do to help you?

When you request a solar system quote from Empower Energy we ask for your power bill and location so we can analyze all aspects of your needs and the space available. We tailor every design to our customers’ unique situation. To design the best system we need to asses the best placement, space available, usage, potential future changes, roof angles and direction to name a few.

We can also assist you in submitting applications for different solar incentives available in Alberta and British Columbia to reduce your installation cost. Our solar solution services are available to all residential, commercial, institutional, indigenous, and municipal buildings in Northeast B.C. and all of A.B.  We would love to assist you in increasing your property value by installing solar panels with top-notch equipment!

Conclusion:

Although solar panel technology prefers direct sunlight for power generation, it will still operate when it is raining or the sky is cloudy, just at a lower efficiency. Besides, solar panels are designed to endure harsh weather, such as hail. Even though electricity generation by solar panels turns down at night, you have the option of having power available. All of this suggests that solar energy is one of the most cost-effective solutions available to Canadians for building a sustainable future.

For further queries, you can email us at sales@empowerenergy.ca.