The world record for solar panel efficiency goes to SunPower‘s solar panels: 24% cell efficiency (sunlight  –> usable electricity in laboratory conditions) and 19.6% conversion efficiency (sunlight –> usable electricity in real-life conditions) with the SunPower E19 / 320W solar modules. SunPower prides itself in its hard-earned reputation for world-leading technology and excellent customer service. SunPower panels are commonly used in residential solar, building-integrated photovoltaics (BIPV), commercial solar, and utility-scale solar installations.

SunPower Solar Panels: World-leading 19-20% efficiency

-SunPower monocrystalline solar panels: E19 and E20 series-

Monocrystalline solar cells have a reputation as the most efficient kind of solar photovoltaic (PV) cell, and the first query from many Solar Choice and Solar Selections customers is, “Are monocrystalline solar panels better than polycrystalline solar panels?” In the Solar Choice blog we have previously discussed the issue of efficiency and solar technology, and pointed out that more important than efficiency or technology type is the quality of the brand of solar PV panel in questionThe question of durability, quality, and the credibility of the manufacturer trump nominal efficiency every time. (Solar Selections also has an excellent article about the importance of efficiency in choosing your solar panels.) The technology utilised in SunPower’s monocrystalline solar panels does indeed enable high efficiencies, but that doesn’t necessarily mean that all monocrystalline panels can reach such high efficiencies–in fact, the average is more in the range of 14-16%.

E19 and E20 are SunPower’s signature lines of solar panels use monocrystalline silicon technology. Their names stand for their nominal efficiencies–19% and 20%, respectively. These numbers are the highest that can be found on the solar panel market, and it is only with care and precision in design and engineering that SunPower was able to achieve these impressive figures. The company takes pride in its accomplishments, and has a reputation that is hard-won and well-earned.

-SunPower E19 and E20: Key Attributes and Points of Difference-

-SunPower E19 and E20 lines for solar and residential solar power-

SunPower e19 series Australia SunPower E19 series – Industry-leading 19% efficiency

SunPower’s E19 series solar panels 238 watt (W), 72-cell panels, while the E20 series is available in either a 327-W, 72-cell panel, or a 333W, 96-cell panel. The 72-cell panels are generally used in residential solar applications, while the 96-cell panels are more likely to be used in large-scale commercial applications.

-As noted above, SunPower panels have the highest efficiencies of any solar photovoltaic panels on the market. This means up to 50% more power per unit area than you would expect to get from conventional designs. This in turn means reduced installation costs because fewer panels are required to get the same amount of power.

Dependable, sturdy design means you can count on your panels continuing to operate over the years through all types of weather. Tempered front glass over the PV cells and an anodised alloy frame mean that the units will be slow to corrode or degrade.

Transformerless inverter compatibility means that SunPower panels can be used with the solar inverters with the highest efficiency: A winning combination.

Positive Power Tolerance of +5% for E20 modules: Some solar panels have a power tolerance of +3%/-3%, which means that the panels you install may actually have a lower output than their nameplate capacity. With SunPower’s E20 series, the nominal capacity is guaranteed to be met or exceeded. (E19 panels have a tolerance of +5%/-3%.)

10 year limited product warranty, 25 year limited performance warranty.

-Product Specifications/Electrical Characteristics-

SunPower E20 series solar panel datasheet (pdf)

SunPower E19 318W solar panel datasheet (pdf)

SunPower E19 238W solar panel datasheet (pdf)

You can see how SunPower panels compare to a number of other name brand panels on the Desert Knowledge Australia website, an invaluable resource for those shopping around for solar panels.

-SunPower Technology: What is Maxeon cell technology?-

SunPower maxeon solar cell technology diagram SunPower Maxeon solar cell technology. Unlike conventional cells (which use busbars), electricity is collected at the rear of each cell, thereby maximising surface area for sunlight collection.

Maxeon is SunPower’s patented solar cell technology that enables the company’s reputation for world-leading efficiency. Most crystalline solar cell technologies have metal busbars–strips of electronically conductive material–that sit on the face of each solar cell. Instead of having such busbars, electricity generated when SunPower panels capture photons from the sun is transferred to a conductive plate at the rear of each cell. This means that more of each cell’s surface area is used in the capture of sunlight, which in turn means higher efficiency.

Another feature which has enabled SunPower to make the headway that it has with its panel efficiency is the way that individual cells are shaped. They can be tiled closely within the solar module frames, which means a greater number in a smaller area. SunPower panels also employ an anti-reflective glass which helps to trap in sunlight and maximise power output.

-Other Information about SunPower Panels-

-Other products by SunPower-

SunPower also has an E18 series panel, which has efficiencies of around 18%.

Ford Motor Co and SunPower recently formed a strategic partnership to offer photovoltaic carport charging stations for electric vehicles.

-Component standards met/awards-

-All E19 series SunPower solar panels are certified by the Clean Energy Council (CEC) of Australia, and are on the list of CEC-approved components

PV Cycle– SunPower participates in PV Cycle’s voluntary take-back PV recycling program

CE mark– SunPower panels are compliant with European Union regulations

-TUV Certification means that claims made by SunPower about their solar panel specs have been independently verified by TUVRhineland


25 year solar cell performance warranty

10 year workmanship warranty

(Your installer may also offer additional warranties for the entire system.)

Read about solar panel and solar system warranties.

-About SunPower-

-Company Headquarters-

Global Head Office: San Jose, California, USA

Australian Head Office: Belmont, Western Australia

-Factory locations-

Malaysia and the Phillipines

-History in the Solar Industry-

SunPower is one of the oldest players in the solar power industry, starting around 25 years ago. Founder Dr Richard Swanson first conceived of the company during the 1970s oil crisis. Later, in the mid-1980s, when a professor of electrical engineering at Stanford University, SunPower was incorporated after Swanson won grants from the US Department of Energy to research solar power and secured financial backing from venture capitalists. By the mid-1990s, SunPower had installed 10 megawatts of capacity in various locations through the US and Europe. SunPower panels can now be found around the world.

© 2011 Solar Choice Pty Ltd

James Martin II

James Martin II

Communications Manager at Solar Choice
James has been Solar Choice's primary writer & researcher since 2010. He lives in Newcastle in a house with a weird solar system.
James Martin II

{ 6 comments… read them below or add one }

van der klugt john 5 July, 2016 at 3:41 pm

looking for photovoltaic panels to fit on a caravan we reside near Rockhampton qld

Solar Choice Staff 5 July, 2016 at 4:03 pm

Hi John,

We can’t help you source anything for a caravan directly (we are a brokerage & comparison service for resi & commercial installations, so don’t hold any stock), but we can recommend that you try getting in touch with RV Solar Supplies, who specialise in solar for camping & caravans.

Hope this helps!

Rich West 27 January, 2015 at 8:43 pm

I wish to buy one Sunpower E-20 solar panel to use on my yacht (currently in Surfer’s Paradise). Can you help me with that? Or recommend someone who can?


Rich West

Solar Choice Staff 28 January, 2015 at 12:12 pm

Hi Rich,

We’d recommend getting in touch with SunPower directly – they have a network of distributors/partners throughout the world. You might also be able to try shopping online on a site like

John 14 August, 2014 at 3:46 pm

I would like to see Australia get well ahead, And Build it’s own Solar Electric Car. We have plenty of sun, And it would save a load on the Grid. In the Cities people Travel about 20 to 50kms, I live further out, And we have to travel 30kms plus to the nearest Main town, it is nothing for us to travel 100 to 200kms in any day. Like i said Solar Electric NOT Hybrid, Get rid of the Fossal Fuel, Other Countries around the World are Leaving us way behind.

John 29 October, 2011 at 4:13 pm

Excellent! You have shared some very good facts and news about solar energy. Your work is no doubt appreciable. Keep sharing such information that would be a better approach.

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