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01 Dec 2014

Research: Switching to energy efficient lighting : a bright idea!

Energy efficiency policies such as the EU ban on incandescent light bulbs (and on halogen ones in the near future) have been the subject of much discussion in the last few years. The majority of the academic community predicted that new emerging consumer behaviors would dilute the benefits of these regulations, as was observed in private transport with fuel-efficient cars.

This article by Joachim Schleich and  is the subject of the 10th GEM LAB Executive Summaries.

Based on a large representative survey of more than 6000 households in Germany, the research focuses on the « rebound effect », which causes fewer energy savings than first expected by the policy-makers.

The benefits of switching from incandescent lamps or halogen bulbs to more energy efficient compact fluorescent lamps (CFLs) or LEDs could potentially be reduced by two possible facts : as the effective cost of lighting services decreases, households may let light bulbs burn longer or increase their luminosity. The rebound effect was consequently split into two distinct causes : longer burn time and higher lamp luminosity (this particular factor had never before been separately quantified).

Calculating the rebound effect on over 4000 bulb replacements, the researchers found a tiny global rebound effect of 6 % only, which is even smaller (3 %) for the main bulb in the living room or dining room.

On average, more than half the rebound is due to a higher luminosity – an effect previous research had neglected. This unexpected finding could be accounted for by the following reasons: lighting needs that were not satisfied before; a « rather safe than sorry » attitude of consumers towards untried products; brighter bulbs used on the same fittings. While these hypotheses need to be assessed in future research, it seems that switching to more energy efficient lighting does improve households' welfare.

Key points

  • Electricity savings issuing from energy efficient lighting are only slightly affected by people using lighting in different ways like leaving the lights on for longer or opting for higher luminosity bulbs : regulations on lighting are extremely efficient.
  • The more intensive the bulb's use, the less significant, proportionately, the rebound effect: for bulbs that are used a lot, like the ones in the living room or in the dining room, it represents only 3 %.
  • In a third of transitions to CFLs and LEDs, electricity savings are even larger than expected. Inspiring

From the article

A brighter future ? Quantifying the rebound effect in energy efficient lighting
Joachim Schleich, Bradfort Mills, Elisabeth Dütschke, 2014
Energy Policy 72 (2014) 35 – 42

Mara Saviotti