Green Rhino Solar | Weather & Output

Resources

Weather vs Output

What is the effect?

Solar panels generate electricity from sunshine and, ideally, need constant and direct access to sunlight to maximise their power production. However, even in rainy weather, your panels will still receive photons and convert them into energy. On the most overcast day, your system could still produce 10% - 30% of the electricity it would on a perfectly blue-sky day.

What if it rains for 40 days? Weather affects output, but there’s more than enough sunshine in our area to keep you always on.

Sun Hours

How many is enough?

The number of sunlight hours required to generate adequate electricity, depends on your personal amount of electricity usage and storage capacity. It also depends on your roof angle and the available sunlight at your site.

On average, you’ll need four peak sun hours per day to make your solar system worthwhile. A peak sun hour is typically defined as an hour of sunlight that offers 1 000 watts of photovoltaic power per square meter. This would be when the sun is higher in the sky (generally between 10:00 and 15:00). More peak sun hours are available during summer and in drier (less overcast regions).

The Garden Route typically enjoys eight hours of sunshine per day, in mid-winter – and more during summer months. Solar installations in our area are definitely worthwhile – regardless of the weather forecast.

Shade

What about unavoidable shade?

A solar panel is composed of interconnected cells, which span across three sections – each with its own bypass diode. If a section is partially shaded, it affects that entire section of the solar panel, and the production of all the related cells. However, if the rest of the panel is still exposed to direct sunlight, the remaining sections will continue producing electricity. A little unavoidable shade on a panel (for example from a telephone pole) will thus not affect the entire solar panel – unless it stretches across all three sections.

Shade from neighbouring buildings, trees, or your own roof can dramatically reduce the amount of electricity produced by your system. But, shade levels can vary significantly throughout the day. Your panels might be shaded in the morning, but receive adequate sunlight in the afternoon – allowing for sufficient energy production.

We, therefore, do a thorough site investigation, prior to installation, to determine the ideal number and location of your solar panels. If optimal results cannot be achieved on your roof, because some partly shaded areas cannot be avoided, we can counter this by adding more panels or increasing your energy storage.

A solar installation makes only sense on a roof that is optimally exposed to sunshine.

Proper Evaluation

Determine Optimal Results

It is paramount to make use of credible solar installers, who would calculate your sun exposure correctly, to avoid overspending on a solar system that would be underperforming.

If you plan to install a grid-tied system, without batteries, you will need more panels to generate electricity than you would if you could also use from your stored battery power. It’s a fine calculation, which we do by investigating your current personal usage, appliances, and needs before quoting on a solar system.

The best way to avoid bad weather worries, is to invest in a hybrid solar system, which allows you to store electricity during sunny days for use when your panels are shaded.