New world record for highest efficiency of monocrystalline PERC solar cell

The Chinese solar manufacturer known as LONGi Solar, recently held a press conference in Japan to announce that they had beaten their own world record for the highest ever recorded efficiency monocrystalline passivated emitter rear contact (PERC) solar cells. The new record is set at a 23.6% conversion efficiency, and is certified by China’s National Centre of Supervision and Inspection on Solar Photovoltaic Product Quality.

Monocrystalline PERC technology is known for its advantages when it comes to both performance and cost. It is unsurprising that these benefits have seen it increase in popularity right across the solar industry, particularly noticeable over the past two years. Due to the never-ending competition among solar providers and manufacturers to reduce costs all while improving efficiencies, more and more manufacturers are turning towards the cutting edge of monocrystalline PERC technology.

While this breaking of its own record is impressive, it is not an isolated event. In fact, determined to never be content, LONGi Solar has broken its own record three times since October 2017. After reaching an incredible 23.26%, it was only a couple of months later at the beginning of 2018 that LONGi Solar announced a new record of 23.6% conversion efficiency.
All this goes to show is that solar, and in particular, monocrystalline PERC technology, is a growing industry. We’re seeing conversion efficiencies that we’ve never before predicted, and it demonstrates that this is the best time for consumers to get on board and reap the rewards of these advancing technologies.

Perhaps predictably, LONGi Solar is expecting to continue this pattern of betterment of its own technology.

With ongoing significant investment expected in the coming years, LONGi Solar has announced that it will enter into a period of rapid expansion of production, with the goals of meeting the increased demand that they have helped to create.
We can expect a shift towards mass production of cells with a conversion efficiency exceeding 22%, so that the everyday consumer can enjoy the benefits of these high-efficiency cells.

Less-than-expected results for your 5kW solar panel system? Here’s why.

You’ve read the compelling arguments, seen the numbers and talked to the experts. It’s conclusive that solar panels are a smart move. But once the installers have left, how do you really know just how well your new panels are performing? How do you know if those numbers really add up to what you’ve been promised?

Take, for example, someone who’s just had their new 5kW system installed a couple of weeks ago. Everything seems to be going smoothly, until they get a reading of only 4kW of peak power for one day. What happened to the promised 5kW?
One factor is that most Australian solar systems will usually peak at 80% of their specified power peak. But before you get on the phone to complain, this isn’t uncommon in a number of industries. Your car’s advertised fuel efficiency is going to be an average, not an everyday reality.

For solar panels, you have to take into account something called system losses.
Temperature loss is a big one, which can actually account for almost 10% lower performance than advertised. When solar panels are too hot (ironic, considering their job is to be in the sun), they can actually lose some of their rated power. And we’re not necessarily talking about those awful 40 degree days that we get in a heatwave. Even a sunny 25 can be enough, wiht performance declining the hotter it gets.

Manufacturer’s power tolerance can contribute to around a percent of your total system loss. Dirt is another common culprit, blocking the sunlight from reaching the solar cells and ultimately reducing your power output. This can cost you anywhere rom 5–15% of your power.

Then you’ve got voltage drops due to electrical resistance in each wire that your electricity flows through, so that knocks off another 2%. And finally, take a look at your inverter. IF this isn’t as efficient as it could be, then your system won’t be either. After all, everything goes through your inverter, so it calls the shots when it comes to performance.

So what can you do to make the most of the panels you’ve got? Keep them clean, invest in a modern, efficient inverter if you haven’t already, and keep temperature in mind. You might not see 5kW of power being generated, but with good maintenance, your panels will serve you well for decades.

How to Measure Solar System Performance

In order to determine whether your solar system is working properly, it’s necessary to measure its performance.
Based on the Clean Energy Council Guidelines, systems in each capital around Australia should perform within at least 90% of these daily kWh outputs per kW installed, when averaged out over the course of a year:

Adelaide 4.2 kWh
Brisbane 4.2 kWh
Canberra 4.3 kWh
Darwin 4.4 kWh
Hobart 3.5 kWh
Melbourne 3.6 kWh
Perth 4.4 kWh
Sydney 3.9 kWh

That means if you’ve got a 4kW system in Adelaide, you multiply 4.2 x 4 to work out your performance standard. Once you’ve had your system for at least a year, your inverter will be able to report your daily average. If you have any issues finding this information, your installer will be able to direct you.

That might seem straight forward enough, but for most of us who are skeptical about the performance of our solar panels, we want to know whether we’ve got a bad system fairly soon after installation, rather than having to wait for a whole year.

Those figures are averages across the year, which takes into account different seasons and different temperatures. But for when you want to check performance for a specific month of the year, for example, you’ll have to be more scrutinising. What if you installed your panels in winter, and know that they’re not performing at their peak? What if your system is west-facing, rather than the optimal north? All these factors come into play, and need to be considered when you’re accurately assessing the performance of your system.

The good news is that there’s a handy tool for this, called PVWatts, developed by then National Renewable Energy Laboratory in America. Go to rredc.nrel.gov/solar/calculators/PVWATTS/version1/ and type in your city location. Click the next arrow, and input the required figures based on your system.

DC Rating: size of your system in kW
Array tilt: if you don’t know, most Australian homes are between 18–22.
Array azimuth: north-facing is 0, east is 90, south is 180 and west is 270.

Then click ‘calculate’ and there you have a guide for what you should be seeing for every month of the year. If it’s been even less than a month, just divide your result by 30 and you’ll get a crude daily average.

Why Does Your Inverter Keep Tripping & How To Fix It

Have you noticed that your inverter seems to trip frequently, or that it’s reducing power on over-voltage. While it may seem like your inverter has a mind of its own, there’s actually a simple explanation.

According to Australian Standards, an inverter must immediately disconnect from the grid, or ‘trip’, if the AC voltage over any 10-minute period exceeds 255V, or the voltage at any time exceeds 258V. If you see an over-voltage error when your inverter trips, then your inverter has not complied with one or both of these standards.

Another common problem isn’t that the inverter disconnects, but that it goes into a power reduction mode. This happens when the voltage isn’t quite high enough to trip the inverter, i.e. you haven’t broken one of the rules outlined above, but the voltage is still at a concerning level. To cope, your inverter might reduce its power output, something that’s called ‘volt-watt response mode’.

It’s important to realise that your system isn’t doing this randomly, or just to annoy you. These are safety features that have been designed to maintain your grid and avoid any potentially dangerous situations that can result from excessive voltage.

If you’re seeing tripping or power reduction frequently, then it may be that your grid is not complying with Australian Standards. 230V should be the standard voltage with a +10%, -6% range, meaning it should not go above 253V. If it is tripping, then you’re seeing voltages of over 258V. Contact your local distribution network service provider, who should immediately come and fix the issue.

There is also another culprit, and that’s if your local grid sits just under the limit, and your system pushes it over. A voltage rise can occur at the point of common coupling, due to the electrically resistant nature of the cable. The maximum voltage rise allowed in Australia is 2%. This could be all it takes to push you over the edge and trip the inverter. The larger the cable running from your meter box to the connection of your inverter the lower risk you have of encountering this issue. The most common place for this to occur is typically when a customer request we install a solar system on their existing shed. More often than not, there is only a very small power feed supplying the shed with power for very small loads. A solar system can send back quite an amount of power at times and small power feeds really struggle with sustaining this and then that leads to Voltage Rise.

To diagnose your particular issue, ask an electrician to test your local grid voltage while the solar system is off. If the voltage is still high, when the system is off, on a sunny day mid-afternoon, then you might have an issue. You may need to get your electrician to record both the instantaneous reading, as well as the 10-minute average, and then take these findings to your local distribution network service provider for further support.

 

If you would like to learn more about this our team of trained professionals are always more than happy to assist. You can call our office on (08) 7127 0752 or email our team anytime at [email protected]

Tax Deductible Solar Panels

Did you know you can claim your solar panel system on tax? If you’re a small business or sole trader, with a turnover of less than $10 million per year, you’re able to instantly write off business-related purchases with a value of $20,000 or less.
Solar power can easily be categorised as a business-related expense. It’s the equipment necessary to efficiently and cost-effectively generate power to operate your business, from lighting to power points. Most systems for small businesses and sole traders will come in under this $20,000 limit.

To be eligible, you must be registered as a small business or sole trader. In Australia, that means having an Australian Business Number (ABN). That means anyone from freelancers to digital nomads are eligible, as long as your have that all-important ABN.

Of course, tax write-offs should be seen as s bonus, not an excuse for a spending free for all. $20,000 is a significant investment, although the potential for return and lifetime value is immense. This tax benefit is merely an added incentive for you to invest in a business expense that has long been on your radar.

As well as the instant tax write-off, you’ll see long term results from your smart decision to install solar for your business. Each quarter, you’ll be pleasantly surprised with your affordable power bill, and it will only take couple of years in most cases for the entire system to pay for itself in terms of money saved on electricity bills.

If your business is operated from your home, then determining the business portion of your purchase may be a little trickier. Nonetheless, it is certainly worth doing to save yourself at the next end of financial year. For the most reliable advice based on your individual situation, you should schedule some time to chat to your accountant about how to best work through this.

Businesses are in a prime position to get the most out of solar energy. Because most workplaces work from 9–5, your system will be producing power during the heat of the day. It will provide you with all the power you need, meaning you rarely if ever need to rely on drawing electricity from the main grid during those peak daytime hours (which mean peak daytime rates).

This tax incentive scheme isn’t guaranteed to carry into 2019, so the smartest move is for businesses to invest prior to 30 June, 2018.