How Does The Weather Affect The Efficiency Of My Solar Panels?

It is obviously no secret that solar energy systems rely on sunlight to do their best work. However, many people wonder whether solar panels can still work in cloudy or less optimal conditions. We’re quite lucky in Australia to have good weather all year round, however, the amount of sunlight certainly fluctuates.

Let’s look at how your solar systems perform under different conditions.

The Best Conditions

Naturally, bright sunlight at the height of summer is the best time to for maximum power output from your solar power system. The days are longer during summer, so the number of hours per day that are considered ‘peak’ performance time is longer. The best times of day are usually 10 am – 4 pm, but in summer, you can probably add an hour or two on to either end of this.

Basically, clear, unaffected sunlight for prolonged periods will deliver you the best results.

Does Temperature Matter?

The outdoor temperature does affect solar panel energy production, but perhaps not in the way you’d think. The ideal temperature for solar energy production is around 25 degrees Celsius. Rather than producing more energy if the temperature rises, solar panel efficiency is actually negatively affected.

All solar panels have a coefficient listed on them, generally between 0.20 – 0.50 percent. Essentially, this is the percentage of efficiency your solar panel will lose for every degree Celsius over the optimal temperature.

For example, in high temperatures such as 35 degrees, you could lose around 5% efficiency in your panels.

The Impact Of Clouds

Clouds generally reduce the amount of direct sunlight that can reach your solar panels. As a result, this decreases the efficiency of your solar energy system. It’s difficult to accurately predict the difference in energy production on a cloudy day because the clouds vary so greatly. Thick, consistent cloud cover will certainly impact your system’s performance. However, on windy days where clouds move quickly, your panels may still receive bursts of direct sunlight.

Some panels work better than other panels on dull or cloudy days. Solar panels that use N-Type solar cells have much better performance in low light situations.

Ideally, a clear, cloud-free day is best for maximum efficiency. However, during winter, where clouds are prevalent, you may lose anywhere between 10% – 25% depending on the type of cloud cover. To keep an eye on this, you can use a solar energy monitoring app attached to your solar inverter (like the mySolarEdge app if you have a SolarEdge system) and monitor it in a range of other weather conditions.

What Other Factors Affect Solar Energy Production?

Naturally, the number of solar panels and the capacity of your solar inverter will affect how much energy you can produce. However, in terms of efficiency, there are a couple of other factors that can limit your energy production.


If your solar panels are affected by shade, it can reduce the amount of energy produced. Most importantly, with traditional string inverter solar systems, if one panel is affected by shade, all the panels on that string will suffer. The output of each panel will drop to the level of the lowest performing panel. So, always try to install panels on parts of the roof that aren’t obstructed by trees or other forms of shade.

If you have shade issues that cannot be avoided, a system that has power optimisers attached to the panels will help. The optimisers let every panel in the system work to its maximum output. So, if one panel is affected by shade, all the other panels will keep pumping out full power.

Position Of Solar Panels

The direction that panels point in relation to north can vastly affect the power production of the system. A professional solar retailer will use a specialised, satellite-based solar mapping tool. This is used to map the panels onto your roof. It considers the direction that panels face and the geographic location and can calculate the estimated power output of the system.

In every state around Australia, there are recommended angles that solar panels should be installed on for maximum efficiency. Most roofs are pitched to a certain angle, and many solar panels are installed to match the roof pitch. However, if you have a flat roof the panels can be mounted on tilted mounts to reach the recommended angle for best production.

Solar Panel Cleanliness

You need to keep your solar panels clean and preferably have them cleaned professionally once a year. This removes the build-up of grime, dust, dirt or even bird droppings that can affect solar energy production. If you do choose to clean solar panels yourself, make sure you’re safe on the roof and never use harsh cleaning products.

Professional Solar Panel Installation

SolarBright is your local expert for solar panels in Sydney. We partner with only the best solar panel, inverter and solar battery storage solutions, so you can be assured of high quality every time. You can even book a free consultation with our team, and we’ll analyse your current consumption to recommend the best system for your needs.

Read Also:
The MySolarEdge App Revolutionising The Future Of Home Solar
How To Choose The Best Solar Panels

A Look At Solar Finance

Solar Finance can be a good idea. The reason is the currently there is a Federal Government rebate helping with the solar purchase. These are called STC’s – Small Technology Certificates. This rebate reduces every year by around 7%. Currently in 2021 with a 6.6kW residential solar system consumers will get just over $3,300 in support.

So if you have not got the cash for solar today, and wait for example three years, you could have lost close to $1000 in rebate support.  Solar with finance, given the current low-interest environment, can still give you great savings.


*This graph is not an accurate reflection of the financial outcome for each customer. It is there to highlight the overall beneficial opportunities of solar finance.

At SolarBright we offer several ways to finance solar through our partners with easy monthly instalments, which are often lower than the amount of electricity savings you will enjoy. So this means financially you will be ahead from day one.

Solar Finance – Some Options Available

Some of the major finance options we offer at SolarBright are:

Brighte Green Loan is a type of credit provided by Brighte to a customer on the condition that the money is used for something the lender deems eco-friendly such as solar PV systemshome batteriesMaxBreeze or solar hot water products.

A Brighter Green Loan is structured much the same as a personal loan. However, a green loan is used to finance energy-efficient products and benefits from a reduced rate compared to a personal loan.

Aside from the loan’s purpose, the eligibility criteria for the Brighte Green Loan is similar to those for other credit products.

When you apply, Brighte will consider your income, credit history (and credit score), whether you are an Australian citizen/resident, and whether you have filed for bankruptcy in the past.

You will be required to provide Brighte with your personal information, including your address and phone number, as well as proof of your income, employment status, assets etc.

Brighte offers a fast and easy payment platform and a quick and simple application process.

A Look At Solar Finance

The Brighte Green Loan has an easy to understand and complete application process and our friendly staff can assist you with some general questions you might have about this finance option about the details.

Brighte’s Green Loans offer a long loan term varying from 2 to 7 years, and they come with a fixed interest rate of 5.89% p.a. A range of $1,000 to $30,000 can be borrowed and there is an account keeping fee of $1.50 per week, and a loan establishment fee applies. The loan terms can go from 24 to 84 months.

The eligibility criteria include to be over 18 years old and an Australian resident or citizen; to own or purchasing a home; be employed, self-employed, a self-funded retiree; or receiving the Government Age Pension; have an Australian driver’s license or Passport or Medicare Card and provide the two most recent payslips or 90 days of bank statements. Another advantageous feature of Brighte’s finance options is that there are no early repayment fees.

Plenti previously known as RateSetter has financed many thousands of residential and commercial solar systems over many years.

They provide both variable and fixed unsecured personal loans. Their interest rate is linked with the length of the loan, the amount applied for and the information you provide in your application.

Plenti strives to build a ‘smarter, fairer and faster’ borrowing experience and SolarBright has been using them with a high customer satisfaction level for many years.

The lending platform is not only simple to navigate, but makes it quick and easy to check your rate, fill in the application, get the approval and finalise your loan

Plenti offers a personalised rate that rewards you for your good credit history. The interest rates can start from a low of 6.5% per annum.

A Plenti loan allows you to benefit from solar sooner and more easily than you would otherwise be able to. Paying for your solar energy system while enjoying the savings often results in money in your pocket right away with a good return when comparing your new energy bills to what you’re paying per month.

Our friendly SolarBright staff can run with you through your likely solar savings and the regular loan payments to show you how the loan for solar can be financed relatively easily.

The Plenti loan terms range from 3 to 7 years, and with many plans to choose from, it’s easy to find the one that’s just right for you. Making the switch to solar helps save the environment and helps you save big money in the long term.

Their green personal loan is flexible, allowing you to borrow an affordable amount between $2,001 to $50,000 that they feel confident is within your capability to repay, over the 3 to 7 years term.

They do not charge early repayment fees, so if you have an additional income and decide to pay back the loan earlier – no problem. One key condition for the loan is that you have an annual income greater than $20,000.


Energy Ease is an Australian payment option provider that specialises in commercial solar and energy efficiency projects. They boast no upfront payments and instant pre-approval on their competitive payment plans.

Energy Ease is geared towards businesses looking to finance their large-scale energy-saving projects to cut down their power bills, with payment plans that span from $3,000 to $5 million and repayment terms of up to 10 years.

Energy Ease offers a range of solar financing options as Power Purchase Agreements (PPA), Performance Guarantee Agreements (PGA) and Loan/Chattel Mortgage.

SolarBright’s Commercial Solar specialists have assisted our clients with guiding them through the Commercial Solar Finance process in many instances and can assist you anytime.

Power Purchase Agreements are ideal for companies that are committed to reducing their carbon footprint but do not have the substantial physical space to install their own renewable energy system or do not want the liability of maintenance upkeep.

Performance Guarantee Agreements are similar to a Power Purchase Agreement, but also comes with a performance guarantee on your system’s electricity generation, only available through select Energy Ease premium installers such as SolarBright.

Their Loan/Chattel Mortgage allows you to own the solar equipment from day one with no upfront costs, as well as claim depreciation on the equipment on your balance sheet.

The equipment itself serves as security for the loan, and often, the interest of the loan repayments are tax-deductible.

These finance products each have their own pros and cons that must be considered to choose a loan or financial product most suitable to your solar power installation needs and situation.

Talk to us about your commercial solar needs and finance options today.