Solar Energy Myth Buster #1: Solar cells take more energy to manufacture than they will ever generate

One of the myths that has floated around about Solar Energy is that it takes more energy to produce, transport and install solar panels then the amount the panels will ever be able to generate in their lifetime.

Quite simply, this is untrue.

Based on models and real data, the idea that PV cannot pay back its energy investment is simply a myth. In fact in Australia the energy payback time for Solar PV is generally under 2 years, meaning that your average PV system will provide 28 years of pollution and greenhouse gas free electricity.

To debunk this myth lets look at a fact sheet published by the US Department of Energy, What is the energy payback for PV:

Producing electricity with photovoltaics (PV) emits no pollution, produces no greenhouse gases, and uses no finite fossil-fuel resources. The environmental benefits of PV are great. But just as we say that it takes money to make money, it also takes energy to save energy. The term œenergy payback captures this idea. How long does a PV system have to operate to recover the energy – and associated generation of pollution and CO2 – that went into making the system, in the first place?

Energy payback estimates for both rooftop and ground-mounted PV systems are roughly the same, depending on the technology and type of framing used. Paybacks for multicrystalline modules are 4 years for systems using recent technology and 2 years for anticipated technology.

For thin-film modules, paybacks are 3 years using recent technology, and just 1 year for anticipated thin-film technology. With assumed life expectancies of 30 years, and taking into account the fossil-fuel-based energy used in manufacture, 87% to 97% of the energy that PV systems generate won’t be plagued by pollution, greenhouse gases, and depletion of resources.

Based on models and real data, the idea that PV cannot pay back its energy investment is simply a myth. Indeed, researchers Dones and Frischknecht found that PV-systems fabrication and fossil-fuel energy production have similar energy payback periods (including costs for mining, transportation, refining, and construction).

In Australia the energy payback time for Solar PV systems is actually even lower then in the US, due to our abundant sunshine. The International Energy Agency concluded in a 2006 study that in Australia the energy payback time for PV was under 2 years. And according to the Queensland Governments Energy Futures website on Photovoltaic Electricity a 1 kilowatt photovoltaic generating system will eliminate about 20 tonnes of carbon dioxide emissions over its lifetime.

So don’t be confused by misinformation, the fact is that solar panels are a clean, efficient way to generate electricity. What’s more, they are the way of the future.

Kobad Bhavnagri
Solar Energy Consultant
Solar Choice Pty Ltd

© 2010 Solar Choice Pty Ltd

Comments

  1. Can you point me to any published scientific papers that confirm the energy cost to produce solar panels ?

    Thanks.

    1. Hi James,

      We don’t delve into the academic aspects of these things too much, but you’re likely to find something if you have a search around Google Scholar. Best of luck!

  2. I am really curious about mining the materials used to produce solar panels. I find the news items about plastic films especially implauseable. If the solar panel can’t be recycled back into other solar panels at the end of their life, are we just leaving our children YET ANOTHER quandary to solve when we pass away?
    For me the cradle to grave solution to our energy needs (and I mean needs, not conveniences) is in serious need of addressing – What do you think?

    1. Hi Jenny,

      You bring up a very valid point. I think that what most people probably assume at the moment is that in 25 years’ time (the typical life span for a solar panel) that there will be a recycling system in place.

      In Europe that have the PV cycle program but unfortunately in Australia at the moment recycling programs are a bit more ad hoc and up to the manufacturer.

      Cradle-to-Cradle Certification is available for solar panels, but to date Sunpower is the only panel manufacturer to achieve it. (Incidentally, Aquion Energy is the only one to achieve it for battery storage.)

  3. Does the idea that it will pay back the energy in two years assume that all the energy that the panel produces is used? If it is are you including the batteries used to store the energy in the calculations? Thanks.

    1. Hi Jason,

      Yes, it assumes that all of the energy produced is used. This isn’t a far-out assumption – for grid-connected systems the energy produced is either self-consumed by the home or sent into the grid, where it becomes part of the ‘pool’ of energy on the network (intermingled with energy generated from other sources).

      As for batteries – this article was written before battery storage started to hit the mainstream – most solar installations are just the panels (and inverter and other balance of system parts, of course). So no, battery energy payback is not included. Realistically, however, adding batteries could only increase the energy payback period, as they don’t produce energy but only store it. There is potential for efficiency gains in the network as a result of an increase in distributed solar + battery storage, however – but that’s an analysis quest for much bigger entities than Solar Choice!

  4. So the last electrical device I bought that lasted 30 years was ummm. Errr um. Does a Blackberry I had for 2 ye.. opps… sorry that got replaced when it got scrambled after 14mths…. Nope nobody I know has ever had an electrical device for anywhere close to 30 years. So of course a device that only started being manufactured a couple of years ago as referenced has been tested for 30 years and comes with a 30 year warranty. Seriously! Do people actually buy this bull?

    1. Hi David. Thanks for your comment.

      First of all, unlike a Blackberry, solar panels are fairly simple pieces of equipment, with no moving parts. Solar PV technology has been around since the ’60s, and there have been gradual improvements in both durability and efficiency during the intervening decades.

      There are actually plenty of solar panel arrays that have been in operation for more than 25 years already – you can’t say the same for any Blackberry (or other smartphones, for that matter) because most of these technologies they offer today haven’t been around for that long.

      Furthermore, smart phone warranties are never for periods as long as those of solar panels, mainly because we’re talking about apples and oranges – they’re not expected to last that long.

      The part of a solar panel system that does need regular replacing (every 5-15 years, depending on the unit) is the inverter. But this is a ‘known known’ and therefore not an issue if you understand what to expect.

    2. I would add to what the Solar Choice staff have said:
      Almost everyone has large electrical devices, such as fridges, clothes dryers, washing machines and dishwashers that last for decades. Newer versions usually improve on energy efficiency, though those gains seem to be marginal over the last five years.

      Those things are not comparable with complex electronic devices. The problem with such devices is not that they break, but that they’re very cheap and they become obsolete due to changes in consumer expectations driven marketing of technological innovation.

      Energy conversion systems (sunlight, wind, diesel, coal, etc. -> electrical energy) are at least an order of magnitude more expensive, represent an investment as opposed to an expenditure on a commodity, and are evolving slowly and steadily. No one is going to spend $25000 on a solar system and expect to throw it out and get the new model after two, five or ten years – any more than they would spend the same amount on a diesel generator and treat it as disposable in the short term.

      Regards,
      Stephen

  5. I have heard the claim made not about just the *manufacturing* of the solar cells, but of the transportation and installation. Do you have figures for that?

    1. Hi Lachlan,

      I’m afraid we don’t have the details on that, but I would assume it would be a similar situation to the energy associated with manufacturing. Indeed the manufacturing process today is more efficient than a few years ago, it’s likely that a quality solar panel will work off it’s carbon footprint in less than the two years we quoted when this article was written back in 2009!

      The energy needed at the point of installation is minimal, it’s more about man power than electrical power. The transport footprint of each component will vary depending on where it was manufactured, but it isn’t in the interest of the manufacturer or installer to add more milage to their product’s journey to your home. We’re also seeing more Australian and New Zealand manufacturers enter the market, although their products will make your system slightly more expensive, they are good quality and have a much lower carbon foot print. In addition to this you’ll also be supporting the Australian economy by buying ‘Australian Made’.

      At the end of the day solar panels are a good financial and environmental investment. Unless, of course, you go with a cheap solar deal which will cost you more per kWh in the long run as they’re not build to last, then you have the waste from a non-functioning panel leading to a larger carbon footprint.

      If you’re thinking of going solar please complete our Solar Quote Comparison to the right of the page, we can work through any questions you have and, ensure you’re getting a quality system that suits your needs – one that will pay for itself environmentally and financially.

    1. Hi Asci,

      Yes you may quote us in your blog, but please provide a references to this page stating it’s where you got your information from. And yes we do have a twitter account, it is: Solar_Choice

      Regards

      Kobad Bhavnagri
      Solar Energy Consultant
      Solar Choice Pty Ltd

Comments are closed.