When it comes to renewable energy, double-digit penetration in larger populations is more common than most might think. That was the gist of a recent Raymond James & Associates industry brief, which examined current uses of certain renewable energy sources in larger populations. The researchers’ conclusion was surprising: Within limits, 100% penetration in certain large markets can, and might, happen, although “significant” technological advances would have to be made for that level to occur.

The report compiled 2012 data on biofuels, natural gas and electric vehicles, wind, geothermal and solar power from regional populations of at least 5 million, with penetration taking place over a full calendar year to eliminate seasonal fluctuations. The researchers noted that for 2013, for which data was not yet available, the penetration was expected to be even higher.

The technologies with the best potential for the highest penetration rates were biofuels and natural gas vehicles, which are being used heavily in Brazil and Pakistan, according to the report.

In Brazil, the average blend rate for ethanol was 54%, the study said, contrasting that with the United States’ 10% blending ceiling. The Brazil rate is higher because of the government-mandated blending of fuels as well as the country’s flex-fuel vehicle-loving population. Flex-fuel vehicles can run on 85% ethanol blends.

Meanwhile, “the highest proportion in the world” of vehicles running on natural gas is in Pakistan, according to the study. Such high penetration levels were possible because of “historically abundant natural gas” and because the natural gas market in Pakistan serves more types of vehicle. “The market is not limited to trucks and other fleet-oriented vehicles,” the study said. This supply sharing is “in part due to strong government backing,” the study said.

Also pulling high rankings were wind and geothermal power. Denmark has a 30% penetration rate for wind power, with Germany, Ireland, Spain and Portugal close behind, hovering between 10% and 20%, respectively.

“Among U.S. states, Iowa is in the lead at 25%,” the study said of wind power exploitation in the U.S., also noting that Iowa doesn’t hit the 5 million population mark. “But if we abide by the 5-million population rule, Texas’ 9% is still quite lofty.”The Danish government’s goal is to have 50% penetration by 2020, according to the study.

Iceland outstrips the Philippines in thermal power penetration, but the Philippines is using its population size to its advantage in the storage