The United States ranks No. 8 among the world's most energy-efficient nations, while the clean-energy powerhouse Germany holds the top slot, a new report found.

Oil-rich Saudi Arabia, perhaps unsurprisingly, landed with a thud at the bottom of the list.

The American Council for an Energy-Efficient Economy (ACEEE) ranked 23 of the world’s top energy-consuming countries for its 2016 international scorecard, released Wednesday.

Energy-efficient steps include outfitting buildings with intelligent lighting systems, creating cars with gas-sipping engines, adding public buses and trains to cities, and designing factories to power themselves.

Here are the top 10 nations and their overall scores, out of 100 points:

Germany (73.5)

Italy & Japan (68.5)

France (67.5)

United Kingdom (65)

China (64)

Spain (62)

United States & South Korea (61.5)

Canada (59)

ACEEE, a nonprofit research group in Washington, evaluated each nation on the strength of their national energy policies and how efficiently their transportation, buildings and industrial sectors use energy.

2016 International Energy Efficiency Scorecard. Image: American Council for an energy-efficient economy

Down at the bottom, Saudi Arabia earned just 15.5 points. Brazil and South Africa, both battling severe economic crises, rounded out the final three with scores of 32.5 points and 33 points, respectively.

Energy experts consider efficient technologies and systems as among the easiest, least-expensive ways to reduce electricity and fuel consumption — and thus reduce emissions of harmful greenhouse gases.

Yet it often garners less global attention than other clean energy sectors like solar and wind power or electric vehicles. The average score on ACEEE's scorecard was just 51 points.

“Energy efficiency remains massively underutilized globally,” Steve Nadel, ACEEE’s executive director, said during a Wednesday press call.

2016 International Energy Efficiency Scorecard. Image: American Council for an energy-efficient economy

But efficiency may provide one of the best ways to meet the planet's energy demand in the future, even more than building new power plants or pumping more oil and gas, Nadel said.

The International Energy Agency forecast that global energy demand will rise 37 percent by 2040 as economies expand and populations soar, an amount that, if met by burning fossil fuels, would significantly boost global warming emissions.

“We consider energy efficiency as maybe the most important energy resource... for achieving the reduction of greenhouse gas emissions,” George Maue, a senior energy adviser for the German Ministry for Economic Affairs, said during the call.