How Long Does It Take for Solar Panels To Be Carbon Positive?

Craig Bailey
Craig Bailey
June 22, 2016

A common point raised in renewable energy discussions is that the environmental cost of producing items such as solar panels is high. After all they are made from non-renewable resources and fossil fuels.

Common objection: “The environmental costs to produce solar panels are more than you’ll ever save…”

We asked Markus Lambert, National Solar Manager for LG Energy for his response.

Disclaimer: LG has applied to sponsor the Solar Trust Centre site.

Craig Bailey (Solar Trust Centre): One of the common responses we see on Facebook when discussing solar and renewables, are people stating objections such as, “It costs more in fossil fuels to build the solar panels and systems than you’ll ever save over the life of the system.”

Markus Lambert (LG Energy): You’re raising the issue of the true carbon neutralness on the solar panel. Now, if a solar panel is of a very poor quality, and unfortunately in Australia, we have solar panels coming in attracting a rebate, which as it’s buy rule has that this panel has to achieve clean energy for 15 years. But unfortunately, in many cases, the very, very, cheap stuff fails within two or three years and the customers have a very poor experience.

Craig: How does the carbon footprint works for Solar Panels?

Markus: The solar product by the time it’s been made, shipped to Australia, put by the installer on the back of the car and installed on your roof – the solar system has caused a certain amount of CO2 to produce and for most panels in Australia it looks at about a two to two-and-a-half-year payback to actually get into a CO2-positive position. I’ll explain that in a second, how it works. But that means if the panel dies after year three, you’ve hardly made a difference in the CO2. So, buying very cheap solar is not going to help the CO2 abatement.

Craig: So how can one get the best CO2 abatement and true renewable energy outcome?

Markus: If you buy a high-quality high-efficient panel – eg if I can get out of the same panel 320 watt than the 250 watt, that means I use the same amount of aluminium, I use the same amount of glass, but I actually overall generate more electricity out of that panel. So the higher efficient the panel, the lower, what is called the CO2 footprint.

Craig: How does the CO2 calculation works?

Markus: Now, what you’ve got to do in your calculation, you’ve got to count what it costs to get the aluminium and have that generated, and then also the manufacturing of the panel, and the making of the glass, and certain calculations are available that you know what this manufacturing process normally will take in energy. So the less energy intensive your manufacturing process, the better the CO2 abatement. LG, actually have solar panels on the top of the solar factory. So if one is using renewable energy to make the panels, naturally that reduces the CO2 footprint of the panel in the first place.

Craig: So how long does it take for a panel to be truly carbon neutral ?

Markus: So, the calculation, for example, for the LG NeON2 is that you’re looking at about a 1.4-year payback in CO2 in a place like Perth or Brisbane in Australia. In Sydney, because it generates a little bit less electricity in Sydney than in Perth, you’re probably looking at 1.5 to 1.6 years. After that, the panel is generating genuine carbon-positive electricity. But you would look at most panels of the cheaper variety between around the two-year plus mark, of the high-efficient ones, about a year-and-a-half or a bit less.

Thank you to Markus for his responses.

Solar panels: Two years to carbon positive

Summary: If you install high quality, high-efficiency solar panels they have a 2 year CO2 payback (possibly less). ie electricity they produce after the 2 year mark is fully carbon positive.

Put another way: it takes around 2 years for you to pay back the environmental cost of all the materials and production and transport of the solar panels. After 2 years you are effectively generating electricity free from any environmental cost.

Featured image: Solar factory in Gumi with 3.5MW of solar panels (photo provided by LG)
Product mentioned: Markus referred to the LG NeON2 Solar panel

12 Responses

  1. While your calculations are most likely correct I think it is only fair to add into the calculations the amount of CO2 that you would have produced by NOT having solar panels during the payback period. You would still be using electrity from the grid produced from burning coal if you hadn’t fitted the solar panels which have already reduced your coal fired carbon footprint.

  2. That’s the point of this calculation, Michael. The point in time at which installing solar actually resulted in less GHG emissions. Take the situation after the first week of PV being installed. Sure you saved a few kWh of grid electricity which is likely to be ~85% FF in NSW/VIC/QLD, so you saved a few tonnes of CO₂-equivalent emissions but your panels resulted in a lot more CO₂ equivalent emissions. Make sense?

  3. Very interesting topic!

    “It costs more in fossil fuels to build the solar panels and systems than you’ll ever save over the life of the system.”

    “It takes around 2 years for you to pay back the environmental cost of all the materials and production and transport of the solar panels.”

    Thanks for putting up this article together! It seems with all the benefits solar panels have to offer, there is still some sort of offset to that.

  4. You state that its roughly a 2 year period to become carbon positive – does this include all materials for the install ? ie inverter, rail , feet, cable etc ?

  5. I wouldn’t be asking the seller of the panels to tell you when they become carbon positive, because they obviously take the extreme low side of the published modelling on this stuff. Noting the high side has the standard panel sold in Australia not lasting 10 years and saying it would take 10 to 20 years to pay back the total environmental damage of making them. E.g. Let’s not forget the silicone mining is destroying the ecology of the beach dunes, the factory making it consumed an enormous amount of carbon and other environmental damage to build, the damage of the cars from the workers driving to the factory . . .
    To surmise technology is getting us close to an environmentally sustainable energy production future, but we are certainly not there yet, and listening to sales people for your facts is ridiculous and dangerous to the environment. We need to keep investing significant support into trying to find the answers, work on reducing our own personal impact, and not give our money to sales pitches in the misguided believe this is helping the environment.

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