The article discusses the importance of fossil fuels like coal, oil, and natural gas in powering the US economy. It states that over 85% of the country's energy comes from these fuels. Despite efforts to use more renewable energy, fossil fuels are projected to still supply over 88% of the nation's energy by 2015. The US has plenty of coal, natural gas, and oil reserves left for decades or even centuries. Three main factors affecting future energy use are environmental concerns, regulatory changes, and technological advancements in energy production. The article emphasizes that fossil fuels remain crucial for the US economy, and new technologies are key to accessing domestic energy resources.