Throwing Shade; When Great Solar Expectations Boil Over

solar power yield graph

Circled in red, hot water consumption should be under the solar curve

In this story, we’ll outline a great quality system, expertly installed and supported by an exceptional solar company, then a saga of customer complaints, despite the system performing better than promised.

Solar power systems are a modern marvel. They turn sunlight into savings, but they’re not magical. They’re subject to the laws of physics, the realities of weather, and the limitations of grid infrastructure.

Misaligned expectations and a communication breakdown can lead to frustration on all sides.

This isn’t just a tale of one disgruntled customer; it’s a word of caution for anyone engaging trades. Here’s why managing expectations and maintaining civility matters, and what you can learn from this scenario to avoid the same pitfalls.

A Solar Success Story—Or Is It?

The Sungrow system in question was an expertly designed and installed setup, including:

  • High-quality panels with modern split-cell technology for better shading tolerance.
  • Smart data gathering using native monitoring from Sungrow’s iSolar Cloud
  • A system design that, based on months of real world data, outperformed the quoted estimates.

Yet, despite this, the customer complained about the system’s performance, particularly in the morning when shade from tall trees on the median strip cast a shadow on the front of the house and parts of the array that faced East.

Why the System Starts Slow

The main complaint was about the system lacking morning output. The customer noted the inverter “wakes up” around 6:30 a.m. but takes time to generate significant energy.

This isn’t unusual. In the early morning, sunlight passes through more of the atmosphere, reducing its intensity. As the sun rises, the light becomes more direct, and energy production ramps up.

The morning shade was particularly bad in winter

Though it’s bleary-eyed in the morning sun, the output grows slowly but surely for an hour or more. When the sun clears the trees, this system gets its socks on and goes.

Shading: The Real Culprit

Split-cell solar panels are effectively two panels under the same piece of glass. However, shading losses are still a reality, and they are likely the root cause of this complaint.

When the installer explained, “Modern panels will work in the shade,” he meant they’ll cope. A saucer-sized patch of shade won’t triple ⅓ of your panel.

The customer misinterpreted “modern panels will work in the shade” to think they could magically create energy from nothing.

Analysing The Evidence

I sought a trial of Solar Analytics for this job in order to get unquestionably independent and unbiased advice. Even though it’s free for the first month, the complainant waxed and waned about enabling it.

Solar Analytics uses an algorithm to identify persistent shading patterns in the yield curve (e.g., trees) and estimate the percentage of energy lost.

Random curtailment events like export throttling won’t be picked up. However, there’s always a degree of approximation.

In this instance, shading was already accounted for in the system design, and moving panels to avoid it wouldn’t have improved performance, but it’s nice to have a number for it.

solar graph showing shading

Shading represents perhaps 4 or 5kWh lost each day, compared to an “ideal” system.

What’s Behind the “Flatline”?

The customer exclaimed the system was “flatlining” in the early morning.

Now, in the first instance, the yield was growing, just that it was slow. To confuse matters, SAPN’s flexible export throttling has kicked in later on some mornings. This grid-management policy designed to prevent overloading during peak solar generation times, puts a truly flat ceiling on solar export.

solar yield graph

What the customer called a flat line was a gentle slope

This throttling isn’t a fault in the system. It’s part of living in a region with high solar penetration. Still, it can be confusing for customers, especially when they are already suspicious about yield.

Graphs That Tell the Story

Shading is a common challenge for solar systems, especially in urban areas with trees, buildings, or other obstructions. The initial system design saw the bulk of the capacity facing North. While some faced West, there wasn’t an East-facing array to catch the morning light.

This quote was accepted, and the contract began with yields estimated in blue.

As this suburb is suffering some gentrification, the customer worried some panels may be overshadowed if the neighbours build a two storey house.

It was agreed that some East facing solar would be a good idea. Although some aesthetic concerns were ventilated, the installer assured it would be a better outcome, which is borne out in the yellow columns below.

solar yield graph

June hasn’t quite measured up to the estimates, but the actual measured yield is close otherwise.

Real World Results Exceed The Quoted Design

It was put to me that all 8 panels on the front of the house should have gone on the south side. It’s not the first time I’ve had a customer try to make a technical argument over an aesthetic opinion…

As I’ve written before, south shouldn’t be discounted, but it’s almost always the last option.

To test the theory that south-facing solar in the sun was better than east-facing solar in some shade, I ran a separate design through the software.

As the green columns show, there’s no point in moving panels to the south side of the house, the best trick is simply add more.

The key takeaway: The system worked better than promised, proving that the design was accurate and the installation was electrically right.

aerial image of solar on a roof

The original design at the top and the executed system at the bottom, which performs better.

Data Revealed More Savings Going Begging

Being unable to fell trees or bend light, my advice for reducing electricity bills further included:

  1. Hot water diversion. Installing a Catch Control or sunshine circuit to divert excess solar energy into a hot water system, eliminating the need for off-peak grid power. (see the graph in the header image)
  2. Battery storage. Using tools like the SolarQuotes Battery Calculator or Solar Analytics to determine what size battery would deliver a good return on investment.
  3. Optimising the retail plan. Using Solar Analytics to identify better energy plans based on actual usage patterns.

With these steps, the customer could have significantly reduced their bills, but the advice was largely ignored.

Solar Is a Long-Term Asset

Solar power isn’t a one-and-done purchase. It’s a long-term asset that requires ongoing monitoring, periodic maintenance every 5 years at least, and occasional adjustments may be needed if you have a change in WiFi network or automation for things like hot water or battery. This case highlights a few key lessons:

  1. Manage expectations. Understand that solar performance varies with weather, grid conditions, and seasonal factors.
  2. Document your requirements. Ensure your installer designs the system to meet realistic goals, not idealised ones.
  3. Trust the experts. Installers and monitoring tools like Solar Analytics are there to help. If they tell you the system is working, it probably is.
  4. Maintain civility. A respectful relationship with your installer is essential for the long-term success of your solar investment.

The Importance of Solar People

Aside from having to bite my tongue, the most frustrating part of this case was the customer’s behaviour.

Despite the installer’s exhaustive efforts to explain the system, provide analysis, and offer solutions, the customer responded with impatience, suspicion, and even hostility.

Solar installers aren’t just service providers—they’re long-term partners and in my experience, they care about what they do.

Systems come with warranties that span 10–20 years, and maintaining a good relationship with your installer is essential for warranty support, maintenance, and upgrades. Keeping people onside just makes sense.

Final Thoughts: Don’t Be That Customer

This story isn’t just about one unhappy customer; it’s about the importance of education, communication, and mutual respect.

Solar is an incredible technology that can deliver decades of clean energy and financial savings, but only if you approach it with the right mindset.

By understanding your system, trusting your installer, and staying realistic about its limitations, you can avoid unnecessary angst and make the most of your investment.

About Anthony Bennett

Anthony joined the SolarQuotes team in 2022. He’s a licensed electrician, builder, roofer and solar installer who for 14 years did jobs all over SA - residential, commercial, on-grid and off-grid. A true enthusiast with a skillset the typical solar installer might not have, his blogs are typically deep dives that draw on his decades of experience in the industry to educate and entertain. Read Anthony's full bio.

Comments

  1. Thanks for an excellent article. Especially re the export curbing.

  2. I noticed, my energy provider switches on, off-peak electricity after the morning peak demand, which then heats my water with coal-fired energy before my evacuated tubes get a chance to heat my water with sunshine.

    Most people are blissfully unaware this is happening, but I have installed a little LED light which tells me when off-peak electricity is available, and I manually switch my off-peak hot water system off and save money. They do it again after the lunchtime peak. This action defeats your solar hot water system and forces you to buy more electricity you don’t need.

  3. Nice work. I work for local government, and I have people ring to complain when they reverse into stationary poles that are clearly visible, claiming it isn’t their fault.

    Society as a whole is more angry and intolerant and just plain nuts now. A very difficult time to keep anybody happy, let alone customers.

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