Tips08.21.2019

How solar panels work on cloudy days, low light, rain, night.

If you’re looking to invest in a solar power system or even if you already have one, you may have plenty of questions around how solar works and, in particular, how solar panels operate under different conditions.

Some of the more common questions around solar panel production include:

How do solar panels work?

Do solar panels work in the shade?

Do solar panels work in low light?

Do solar panels work on cloudy days?

Do solar panels work on rainy days?

Do solar panels work at night?

There are all really valid questions!

To fully understand the answers it’s useful to first have some basic knowledge of the two main systems that solar panels work under: DC and AC systems.

This may seem complex at first, but rest assured an experienced One Power advisor can step you through these options and ensure that the system you choose is the best solar power system for your situation.

Solar panel systems: DC and AC

Not to be confused with the iconic Aussie rock band, AC and DC refer to the two main systems that solar panels are grouped under for home or business use.

#1 String or DC System

The DC or String System is historically the most installed method of solar throughout the world and continues to be the most common.

A String System usually comprises one main solar inverter that is installed at the ground level of a home or business.

The inverter usually has a screen displaying the system’s readings and can also be connected via WiFi to an app that you can access on your tablet, phone or laptop from remote locations.

#2 Micro or AC System

The AC or Micro System is a newer method of installation whereby a smaller individual inverter is installed under each panel, and in some cases, one for every two panels.

These inverters don’t have a screen display. The information on the system is only available via WiFi connection.

A Micro System requires more components to operate than that of a String System and therefore can have more points of failure.

Which is the best solar system?

If you’re assessing each system based on its potential to save you money, then the short answer is that a DC string system will suit 97% on properties installing solar.

Some would argue that an AC system is a better choice as the panels can work independently of one another in the case of shade or orientation restrictions.

While that was once true, the development of DC Optimisers allows panels in a String System to have multiple orientations and to be positioned in shade without reducing the efficiency of the other panels.

The main core difference between the two systems today is that the AC system has multiple inverters and the DC system has one main inverter.

What is a DC Optimiser?

A DC Optimiser is DC to DC converter technology and is used to connect one, some or all panels in a system and enable them to operate as independent panels.

These optimisers can increase energy output, reduce string losses from shade, and allow system expansion into areas of a roof that have different orientation or pitch.

What is a Micro Inverter?

A Micro Inverter is a small, individual DC to AC converter which is connected to one or two solar panels.

These are located on a rooftop and do not have a display for the customer, instead readings are available via WiFi connection to your phone or device.

A Micro Inverter offers the same benefits as a DC Optimiser, however using a Micro Inverter means all panels in the system must have a micro inverter incorporated, unlike a DC Optimiser which can be connected to as little as one panel.

Let’s take stock for a moment and consider these stats…

Now that you’ve got a basic understanding of the main systems and how they work, let’s look at some of the more common questions concerning solar power production under various light conditions.

Will my solar panels work in the shade?

The short and simple answer is yes — solar panels do work in the shade.

That being said, production levels can be greatly affected depending on the density of the shade, time of day, direction of the sun, time of the year and the duration of the shaded period.

A system designed by One Power will always aim to mitigate shading issues by avoiding or removing them.

This could mean trimming or removing a tree, relocating or replacing a TV antenna, utilising extra roof spaces or reducing shade losses on the system by incorporating DC Optimisers on selected panels.

We are able to calculate production projections on each house individually and accurately predict the savings your system will make, even when shade is involved.

This means you can anticipate what impact, if any, shade will have on your solar savings and make an informed decision.

Will solar panels work in low light?

The short and simple answer is yes — solar panels will work in low light.

Solar panels work by allowing particles of light — known as photons — to knock electrons free from atoms, generating a flow of electricity in the panel.

Panels only require a minimal amount of photons to generate an electricity flow and supply power to the home.

In most cases, a solar power system will be productive before the sun can be seen in the sky.

The system continues to work on cloudy days (as the sun’s rays is still pushing through the cloud) and will remain on after the sun has set (and as long as photons are still available).

While solar power production will be less in the early morning, late evening and on cloudy days due to lower light, any power generated by your system is still saving you money that you would have handed to your electricity retailer.

An important note here: the optimum flow of electricity from your solar panels will vary across the day depending on the orientation of the panels.

For example, if your panels are facing due east then your optimum flow time is 10am; facing west, you’ll get peak power production at 2pm; and north facing systems power best at midday.

Will solar panels work on cloudy and rainy days?

Short and simple answer… Yes! Solar power panels will work when it rains and on cloudy days.

Solar power production is less on these days as there are less particles of light available to create a high flow of electricity.

While the power output is reduced, you are still saving money whenever power is still being generated by your solar system.

Rain also provides some benefit to solar panels that are installed on a pitched roof. As the water runs down the panel, it washes them clean thereby helping to maintain their effectiveness.

Do solar panels work at night?

The short and simple answer is no, solar panels do not work at night.

As we’ve already discovered, solar power production relies on light particles to generate a flow of electricity in the panels.

The higher or quicker the flow of that electricity, the more power your system puts out.

So while the sun provides particles of light that generate a flow of electricity, light from the moon does not have the same power producing qualities.

Having said that, you can incorporate a battery into your solar system to store excess power generated during the day. Your solar inverter can then draw on the battery at night when power is needed.

In this scenario, the panels would remain off at night and the battery provides power that was generated off the panels during the day.

Interest in solar batteries in Australia is increasing and in our next blog we’ll consider batteries to help you to understand if that’s the right investment for you.

Book in a free in-home assessment with One Power Solar to find out which system is right for your home or business. Call 1300 568 589 or book online.

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