The solar industry is undergoing a seismic shift. Gone are the days when only premium brands like Sunpower dominated the solar panel efficiency charts. Budget Chinese brands are not only catching up but in some cases, surpassing their high-end counterparts.
Who are these emerging brands? How efficient are their panels, and does it matter? Will they knock off the industry stalwarts? All these questions answered and more! Read on.
Solar Panel Efficiency
Solar panel efficiency (also called solar module efficiency) refers to the percentage of sunlight a module can convert into usable electrical energy. The higher the efficiency, the smaller the panel needs to be to pump out the same power.
Don’t confuse solar panel efficiency with solar cell efficiency, as the former accounts for losses in the entire panel, including the frame and wiring, while the latter focuses solely on the silicon cells’ performance in converting sunlight into electricity.
A high-efficiency panel is a good choice for an installation with limited space, or to preserve the aesthetics of a property by having fewer modules on show.
Companies that make solar panels with the highest efficiency ratings are, quite rightly, perceived as having the highest quality control, and the most advanced cell technology, and are more likely to produce reliable products.
But is this the only metric marking a good solar panel? No! More on that later. First, let’s take a closer look at some conversion efficiencies.
Most Efficient Premium Vs Budget Solar Panels
Looking at 3 of the most efficient ‘premium’ panels on the SolarQuotes Solar Panel Comparison Table compared to the 3 of the most efficient ‘budget’ brand panels, extracting the efficiency ratings and cost per watt1 gives the following breakdown:
| Premium Panel | Efficiency | Cost per Watt |
|---|---|---|
| Sunpower Maxeon 6 (SPR-MAX6-440-E3-AC) | 23% | $1.74 |
| REC Alpha Pure-R (REC430AA) | 22.3% | $1.01 |
| QCells Q.PEAK DUO (ML-G10+ 415) | 21.1% | $0.90 |
| Budget Panel | Efficiency | Cost per Watt |
|---|---|---|
| Longi Hi-MO 6 Scientist (LR-54HTH 440~450M) | 23% | $0.53 |
| Jinko Solar Tiger Neo (JKM440N-54HL4-V) | 22.53% | $0.58 |
| Risen TOPCon (RSM108-9-4) | 22.5% | $0.60 |
Well, these sure are surprising results. When comparing efficiencies, the top budget panel (Longi) is equal to the top premium panel (Sunpower) at 23%. Not only that, when scrutinizing all panels, the budget models have a greater average efficiency than the premium ones at about half the price. How can that be?
How Do Budget Solar Panels Perform So Well?
Economies Of Scale
The three budget-branded panels in this graph are made by huge companies that dwarf the premium brands in volume. In fact, these three (Longi, Jinko, and Risen) are in the top ten Chinese companies that supplied 90% of the world’s PV modules in 2022.
Product shipped in 2022 (gigawatts) by 6 manufacturers in this comparison.
These guys have massive production capacities, benefitting from economies of scale, lower production costs, and ultimately cheaper prices for you and me. So, they are budget brands in terms of low cost to the consumer, but the connotations of budget being low quality don’t always ring true.
Budget Brands Have The Deepest Pockets
Top solar panel manufacturers invest significantly in research and development to improve solar cell and panel efficiency. None more than the giant Chinese manufacturers. They have access to the latest innovations and very deep pockets.
Longi is one of the largest solar panel manufacturers in the world and has held a number of efficiency records over the years. The new Hi-MO 6 series are manufactured using the high-efficiency P-type Hybrid Passivated Back Contact (HPBC) cell technology.
They have finally matched the efficiency of the world leading SunPower Maxeon Series which also uses back contact energy conversion in their interdigitated back contact (IBC) solar cells.
Premium Brands Survival Strategies
Have premium brands lost their competitive edge? The technology gap that has kept them at the forefront is narrowing, but that’s only part of the picture. They’re too small to compete on price, so must find ways to stay relevant. And they are doing that.
One example is the introduction of a 40-year warranty for the SunPower Maxeon product line. This far exceeds the benchmark industry norm of 25 years. Is a 40-year warranty of any value? It certainly gives a perception of a quality product, which may be enough for the company to stay in the game.
REC Group has earned a solid reputation for being one of the best in the industry across the board in quality, reliability, support, and sustainability. They have several strategies to highlight their points of difference such as a ‘Certified Solar Professional Program’, and claims to have the lowest warranty rate in the industry.
Datasheet comparison showing 23% efficiencies for top performing budget and premium solar panels. Top: Longi LR-54HTH 440~450M, Bottom: Sunpower Maxeon 6 SPR-MAX6-440-E3-AC.
Panel Efficiency Isn’t Everything!
So, a high conversion efficiency is a good sign that the module is a strong performer. However, it’s not the only metric used to identify a good-quality solar panel. A consumer should also be interested in temperature coefficient, degradation rate, and the aforementioned warranty. Let’s see how our budget panels stack up against the premium ones in those categories.
Temperature Coefficient
The temperature coefficient measures how much a solar panel’s electrical output decreases with each degree of temperature increase above 25 degrees C. In layman’s terms – the hotter the temperature, the less efficient the panels become. The smaller the negative percentage on the datasheet, the better. For a deeper understanding of this, the recommended reading is – How To Read A Solar Panel Specification: Part #1.
Here are the compared modules in order of temperature coefficient specification. The premium REC panel wins hands down, the rest is a mixed bag.
| Premium Panel | Temperature Coefficient |
|---|---|
| REC Alpha Pure-R (REC430AA) | -0.26%/°C |
| Sunpower Maxeon 6 (SPR-MAX6-440-E3-AC) | -0.29%/°C |
| QCells Q.PEAK DUO (ML-G10+ 415) | -0.34%/°C |
| Budget Panel | Temperature Coefficient |
|---|---|
| Longi Hi-MO 6 Scientist (LR-54HTH 440~450M) | -0.29%/°C |
| Jinko Solar Tiger Neo (JKM440N-54HL4-V) | -0.30%/°C |
| Risen TOPCon (RSM108-9-4) | -0.30%/°C |
Degradation Rate
The degradation rate indicates the annual percentage at which a solar panel’s efficiency decreases over time. The figure is typically measured from year two because, during the first year of a solar panel’s operation, it may experience a ‘settling-in’ period.
Once again, a smaller number is better, indicating less degradation annually over the specified period. In this comparison, two premium panels, Sunpower and REC, offer superior specs to all others.
| Premium Panel | Degradation Rate (from year 2) |
|---|---|
| Sunpower Maxeon 6 (SPR-MAX6-440-E3-AC) | 0.25% per year |
| REC Alpha Pure-R (REC430AA) | 0.25% per year |
| QCells Q.PEAK DUO (ML-G10+ 415) | 0.5% per year |
| Budget Panel | Degradation Rate (from year 2) |
|---|---|
| Longi Hi-MO 6 Scientist (LR-54HTH 440~450M) | 0.4% per year |
| Jinko Solar Tiger Neo (JKM440N-54HL4-V) | 0.4% per year |
| Risen TOPCon (RSM108-9-4) | 0.4% per year |
Product Warranty
The product warranty for solar panels covers defects in materials and workmanship for a specified period. An overwhelming amount of information is written about this on the SolarQuotes website.
In terms of product warranty periods for the compared panels, Sunpower Maxeon stands out a mile with a 40-years. Unfortunately that’s not the whole story with this particular module, as the microinverter, which is integrated as part of the panel, is only warranted for 25 years. And another minor detail – will the manufacturer be around in 40 years to honour a warranty?
Performance Warranty
The performance (or power) warranty assures that the solar panels will maintain a certain level of energy output over the warranted timeframe. Once again, the premium panels REC and Sunpower Maxeon reign supreme with a whopping 92%.
| Premium Panel | Product Warranty | Performance Warranty |
|---|---|---|
| Sunpower Maxeon 6 (SPR-MAX6-440-E3-AC) | 40 years | 92% |
| REC Alpha Pure-R (REC430AA) | 25 years | 92% |
| QCells Q.PEAK DUO (ML-G10+ 415) | 25 years | 86% |
| Budget Panel | Product Warranty | Performance Warranty |
|---|---|---|
| Longi Hi-MO 6 Scientist (LR-54HTH 440~450M) | 25 years | 88.9% |
| Jinko Solar Tiger Neo (JKM440N-54HL4-V) | 25 years | 87.4% |
| Risen TOPCon (RSM108-9-4) | 25 years | 87.4% |
Beyond Solar Panel Efficiency: It’s Your Choice
If your primary concern is getting the most efficient solar panel for the least amount of money, and you’re not too fussed about super-long-term warranties or a slight edge in performance then budget panels are a compelling option.
Otherwise, if you’re looking for a long-term, robust solution and are willing to invest upfront for lower degradation, more power on hot days and better warranties, then premium solar panels could be worth the extra cash.
Footnotes
- The cost-per-watt figures in the above comparison were used to distinguish the premium from the budget products, and that’s all. The actual dollar values are skewed because the most efficient panel in the premium category (Sunpower Maxeon 6) is an AC panel. Unlike all the others, which are DC, it has an integrated microinverter on each module, and so is more expensive. ↩
About Kim Wainwright
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Thanks for the article, in general competition will move the needle forward for the industry.
Regarding the data (in the article as it appears today 18th Sep) for some of the products, the “top efficiency” for the panel series are presented and for some of the products, a specific model.
This has the effect of comparing the 450W panel of one vendor with the 440W panel of another vendor.
It would be better to set the parameters at 440W for all the comparisions. A casual reader would not realise the 450W Longi is being compared with the 440W model of Risen and Jinko by this article.
For the exact product series compared, the Risen 440W, Jinko 440W and the Longi 440W have exactly the same efficiency being 22.5
Reading the article, the reader could mistakenly consider the Longi to have higher efficiency.
It is worth noting that some of the manufacturers are now standardising on the dimensions 1762 x 1134 x 30. Since efficiency relates to the area of the panel, we can expect a reduction an efficiency, but no negative change in performance for those panels
Hi Thomas. I understand your concerns, and if the comparison was a shootout between all 6 panels you’d be absolutely correct, however it’s not. The starting point for this particular comparison was to find the most efficient panel in the premium brands and also the budget brands to show how the playing field is being levelled with regard to efficiencies. To give my hypothesis some more weight I decided to throw in the next top 2 brands (re efficiency) for each category into the mix. You could think of Longi, Jinko, Risen as one team vs REC, Sunpower, QCells as the other team. If I had set 440W as the starting parameter there would be no premium panels to compare to. You’re right that a casual reader might construe that Longi is a better solar panel than Jinko from the data that I have presented, which is not a fair comparison in that regard. I will make amends though because you’ve given me another idea for a blog – “Budget Panels Shootout: Who Are The Real Winners”. Thankyou and watch this space!
Severely flawed article.
Several different types of technology is being compared e.g n type vs HPBC vs p type vs AC
You haven’t mentioned power density which is critical, such as a 475W panel would be lower power density vs 440W vs 430W vs 415W etc depending on physical characteristics as well
You would be better to compare oranges with oranges
Alternatively, we could simply compare solar panels with solar panels.
👍🏼😎
Power density is pretty much the same as efficiency.
In the Netherlands the solar price is imploding.
A jinko 435 Wp Tiger Neo N type panel cost 0.28 euro per Wp.
I am a certified installer in Haarlem
I think a focus on the levelized cost of produced energy over the relevant period (warranty, expected life, other?) would be the most useful comparison.
For instance I have a 7,650 w (DC) system (located on my home in Utah, USA) that is just over ten years old it has produced 129.46 MWh of energy to date. I expected to get a least 25 years and preferable 35 years of service out of it.
Assuming 30 years the total MWh of production should be close to 370 MWh. My after tax cost was about $14,500 (which at the time was a great deal). This gives a net present value levelized cost of around 3 cents a kWh.
Those “budget” panels might end up with a levelized cost approaching 1.5 cents. That sounds like a great deal.
That’s a great data point, John, with a long baseline.
Economics, power density, warranty & manufacturer longevity, and Pb-free status are my top criteria. Being off-grid, with only rainwater, the second and last criteria win out, as yield is important in winter and overcast. At age 70, a 25 yr warranty ought to suffice here.
I was wary of the budget panels, but learning that it is economy of scale which underpins the competitiveness, I’m now leaning toward the behemoths with greater long term prospects. I.e. a warranty which is more likely to be supported. I’ll have to look into whether any of their panels are Pb-free.
I’m disinclined to fret over the miniscule TempCo differences, not least because here in the temperate climate of SE Australia, PV yield will be ample in hot sun, and in more meagre winter, the panels will be cooler.
A large solar farm with low operating margins might be able to measure the economic effect, but for me, filling the roof is the quick fix, given power density is comparable.
Thanks, Kim, for a very useful article. I might just drift away from REC, after all.
Yes, this is the overriding analysis in my view – LCOE before installation plus LCOE of installation+repairs.
Other metrics of interest would be embedded carbon energy+emissions of manufacture (vs lifetime energy production) and ethical supply chain guarantees … for those interested in values as well as price …
This article is yet again great information we will share with our potential customers so that they have information from a credible third party such as Solar quotes. As we are all aware we are blessed to have such choices in panels and deciding on the right panel for each customer will depend on their individual needs taking into consideration, warranty, efficiency, size, wattage, availability and cost. Class A Energy Solutions https://classaenergysolutions.com.au/ like other quality solar companies want nothing but the best for our solar installations and by sticking with a great brand of panel we have confidence that they will last the test of time. Finn and his team at solar quotes is always a go to when customers want reassurance regarding quality of products.
Keep up the good work team…
These large reductions in the cost of converting free sunshine into electricity should make us re-evaluate our preconceived ideas of the benefit of spending large sums on energy efficient heat pump water heaters, instead of installing simple and cheap and very reliable resistive water heating.
Of course if we cannot fit more cheap PV on our roof, (and we use a lot of hot water) then the huge increased price of grid power might favour energy efficient heat pumps in some circumstances.
Never waste an opportunity to catch more free sunshine, and use it with timers or diverters before export, and if you cannot (due to Network rules) then run it direct and offgrid, with mains backup, or batteries.
Could be a very interesting decade with all sorts of tipping points able to really disrupt the landscape:
A crowd like Sundrive with HJT+QuantumDot enhancement could deliver nearly 30% efficiency without silver contacts. Perovskites could get up. Tandems could get up.
Once battery LCOS drops below Regular- FeedIn tariff it’ll be open season on duck curves …
I’ve seen some clever inventors working on super-simple-cheap-reliable-HP designs and one wonders when modular HP systems might start integrating hot and chilled water reservoirs (thermal batteries) for water, space heating/cooling, refrigeration, drying (I’ve got 6 HPs in my house …).
I often thought it would be good to have a fridge to be cooled by the residue of heating the water through the heat pump, but the practicallities unfortunatley dont stack up unless we have a side by side in the kitchen. The biggest challenge is the capital cost of fitting, and repairs and lack of choice.
In larger commercial situations it clearly works, but with fickleness of people as to the size or shape or brand or colour of appliances it would get real messy.
If we used wasted airconditioning then when we wanted it most (to cool on very hot days) we have efficiency losses if trying to dispose of the heat into a 55 degree water tank instead of into a 40 degree air,… and who wants hot water then anyway? and in the winter we are struggling to make heat for the house on the very cold nights, and what good is the surplus cold then?
Maybe someone can figure a way around this,… but at this stage i like the option of bulk electricty to turn into whatever I want at the push of a button or timer, with huge flexibility of use.
I always wonder Tindo can survive in long term?
“We live in interesting times”. The whole game is moving fast.
Great article!
Is a 40 year warranty worth the paper it’s printed on? (I would say no, and that ignores the fact I won’t be here in 40 years).
How many solar manufacturers have come and gone over just the last TEN years?
How hard is it to claim warranty on even say a five year old panel? (There are always lots of “out clauses”.)
And then you most likely can’t get something compatible with the rest of the string anyway, so the only answer is replace the lot.)
My (very expensive) and tired old system (partly 12 and part 13 years old) is hobbling along, and I’ve replaced four or five panels with second hand. Output is way down, but I’m not too concerned as I still get around 4kW peak at midday from 6.6kW of panels. I don’t think ANY of the three companies that made the panels exist any more, so warranty is academic. Despite being very expensive at the time, it’s paid for itself a very LONG time ago.
When I finally bite the bullet to replace it, I won’t be spending top dollar- just something reasonable and mid range.
Something that does not appear to be addressed when evaluating/comparing
panels is the quality of the glass on the top.
Quite a few years ago there was a massive hail storm in Canberra where I live. Post the storm it was really interesting to observe that most brands were trashed. Those houses/businesses with Sunpower panels did not sustain damage. This was confirmed by several installers. Upon hearing about the effects of hail,
I put Sunpower 425W panels on my roof 21 months ago. No hail since but I’m confident it will never be an issue,
Hi, thank you for a great post and looking forward to the next “Budget Panels Shootout: Who Are The Real Winners”.
I just wanted to clarify/flag one issue.
“The temperature coefficient measures how much a solar panel’s electrical output decreases with each degree of temperature increase above the NOCT”
– if that’s correct panels with higher NOCT would perform better in hotter temperature which is directly contradicting Ronald Brakel’s post which concludes: “The lower {NOCT] it is the better because it means the panel will be cooler when sitting in the sun.
https://www.solarquotes.com.au/blog/solar-panels-temperature/#:~:text=NOCT%20stands%20for%20Nominal%20Operating,or%20Nominal%20Module%20Operating%20Temperature.
So what is the more important parameter: NOCT or temp coefficient and where does NOCT come into the equation with regards to efficiency loss against rise in temp?
Hi Jacek. Thanks for pointing that out. I made blunder! The NOCT reference was wrong. My text should have read
“The temperature coefficient measures how much a solar panel’s electrical output decreases with each degree of temperature increase above 25 degrees C.”
I’ve now corrected the article. Ronald’s post that you quoted is 100% correct.
So which is the more important parameter NOCT or temperature coefficient? Drilling down to the nth degree (pun intended) they both come in to play. See Ronald’s article for a very good explanation.
Thanks for keeping me on my toes!