Zombie image – dustinthewind
Just when you think it’s finally dead and buried, the myth of solar power system energy payback arises like a zombie from a B-grade horror movie.
The myth goes something like this:
“The energy that goes into making a solar panel is more than that panel will produce over its lifetime.”
Just because something is repeated time and again, it doesn’t make it true – and that certainly holds in this situation. The energy payback time of solar power has been very short for a very long time.
Solar Power System Energy Payback In Australia
For example, in the magazine ReNew: Technology for a Sustainable Future, issue No. 109 (October–December 2009), the results of a life cycle assessment (LCA) for a complete grid connected solar power system were published.
It looked at various issues including:
- mining of the raw materials
- processing
- production
- transport
- product use
.. of full systems manufactured in Germany and installed in each Australian capital city.
The study found it only takes between 1.7 years (Perth and Darwin) and 2.3 years (Hobart) for solar systems to pay back the energy consumed during their life cycle. 10 years have passed since that piece was published and since then, solar manufacturers have made further inroads in energy efficiency and material usage as it’s in their financial interests to do so.
Going back even further, the energy payback time for solar panels was still very short. A National Renewable Energy Laboratory (NREL) factsheet put energy payback estimates for rooftop PV systems at 1 – 4 years, and that was based on studies published between 1991 and 2000.
More recently, Germany’s Fraunhofer ISE stated the energy payback time of PV systems was around 2.5 years in Northern Europe and 1.5 years or less in Southern Europe, depending on the technology installed. It noted the material usage for solar cells had dropped from around 16 grams per watt to approximately 4 grams per watt as a result of increased efficiencies, thinner wafers and wires along with larger ingots.
Given a good quality solar power system should last 30 years and even with a solar inverter changeover during that period, the energy payback alone makes installing solar panels more than worthwhile. Add to that benefits including electricity bill savings providing rapid financial payback and it’s a truly wonderful way to approach electricity generation – and it’s a power you can take into your own hands.
