More than 5.5 million Mexican families already use energy-saving lamps that consume only 20 percent of the energy and last 10 times longer than a traditional light bulb, thanks to the Mexican government's Sustainable Light program launched in July 2011.

Having replaced 23 million incandescent light bulbs with compact fluorescent or "energy-saving" ones, the program entered the Guinness Book of Records.

In the first stage of the program, partially financed by the World Bank, there were more than 1,110 points of exchange in the whole country. To obtain four energy-saving lamps for free, it was only necessary to present four incandescent light bulbs, an electricity bill and an ID.

With the already replaced light bulbs, the saving is calculated to be 1,400 gigawatt hours (GWh), in other words the energy that is consumed in a year in Nayarit (population 1 million) or Colima (popolation 0.7 million) states.

According to calculations by the Energy Ministry, the program also has an impact on the budget at home, as a family can save up to 18 percent of the electric bill.

Less consumption of electricity also favors the environment, as an emission of about 700,000 tons of CO2 is being avoided with the light bulbs that have been replaced until now, the equivalent of more than 130,000 cars.

In its second stage, the program hopes to replace other almost 23 millions of incandescent bulbs with energy-saving lamps.

This time, families that have not yet participated will receive eight energy-saving light bulbs in exchange of four normal ones. Those who already have participated in the first stage will receive four additional energy-saving light bulbs.

When the second stage ends, it is estimated that the saving will be of 2,800 GWh per year, more than double the electricity consumption of the State of Campeche (population 0.8 million) in 2011.