During his first presidency, Donald Trump repeatedly promised to modernize America's outdated infrastructure. As it turned out, it was President Biden who worked with Congress to appropriate $1.2 trillion to repair and update the nation's power lines, pipes, bridges and highways.  Without a single Republican vote, Biden also managed to win the largest-ever investment in clean and renewable energy.   Nothing is more critical to the nation's future than its energy supplies and how we distribute and use them. Now, the ball will be passed again to Trump and a new Republican-controlled Congress.   Although the infrastructure and energy bills are on the books, incoming leaders will try to influence how the money is spent. Rather than allowing the nation's clean-energy transition to proceed, they could redirect the appropriations to far less essential purposes or spend them on last century's energy: fossil fuels. We can't let that happen. Meanwhile, the infrastructure bill will lay the foundation for clean and renewable energy in the United States by spending $65 billion — the largest such investment in American history — on a modern electric transmission and distribution system.  That system is often called the biggest machine ever built. It consists today of 11,000 generation plants, 5.5 million miles of transmission and distribution lines (enough to stretch to the moon and back 46 times), 180 million power poles, 3,000 electric utilities, 590 oil and gas rigs, 2.5 million miles of gas pipelines, 560 active coal mines and three separate regional electric grids that mainly transmit alternating current.  In 1982, energy visionaries Amory and Hunter Lovins published a study commissioned by the Defense Department to assess the system's security. The Lovins warned that America relied on a "continuous electrical supply (that) depends on many large and precise machines, rotating in exact synchrony across half a continent, and strung together by an easily severed network of aerial arteries whose failure is instantly disruptive."  They warned, "The size, complexity, pattern, and control structure of these electrical machines make them inherently vulnerable to large-scale failures: a vulnerability which government policies are systematically increasing. The same is true of the technologies that deliver oil, gas, and coal to run our vehicles, buildings, and industries. Our reliance on these delicately poised energy systems has unwittingly put at risk our whole way of life."  That assessment is still accurate. Fossil fuels have triggered economic recessions and brought the world to the brink of permanent environmental catastrophe. Power outages cost U.S. businesses $150 billion annually and households a similar amount. Extreme weather is responsible for more than 80 percent of blackouts. Because of global climate change, power interruptions have increased 67 percent in the U.S. since 2000. Millions of Americans have also found themselves without electricity because tree branches touched powerlines, squirrels chewed through system components, or vandals took potshots at transformers.  Now, the big machine faces modern challenges, including power-hungry electric vehicles, data farms, artificial intelligence, cryptocurrency mining, and a resurgence in domestic manufacturing.   During the last decade, energy-efficiency gains have kept America's electric demand relatively stable despite the growing population and economy. Now, a single query using ChatGPT uses nearly 10 times the electricity of a Google search. Analysts say data center power demands could triple in the U.S. over the next three years.  The good news is that nonpolluting, inexhaustible energy has become the least expensive and quickest way to generate electricity. Some 126 million solar panels on 4.3 million rooftops already contribute to the nation's power supply, along with 75,000 wind turbines, nearly 4,200 large solar farms and 2,100 hydroelectric dams. However, we need vastly more. We have the natural resources and technologies to provide it, but we must modernize and expand the grid to move clean energy to where it's needed.  As Amory Lovins says today, "We've got 21st-century technology and speed colliding head-on with 20th and 19th-century institutions, rules, and cultures."  "Our grid is at a make-or-break moment," according to Willie L. Phillips, chair of the Federal Energy Regulatory Commission. "(The grid) is being tested every single day in ways that we've never seen before. We're not talking about regular demand. We're talking about dramatic increases of demand on our system."  One idea gaining traction at the U.S. Department of Energy and Google is to locate power-hungry data operations where renewable resources are available and equip them with microgrids that can detach from the larger grid during outages. Several data operations could be served by the same assets if they are co-located in "energy parks."  Other experts point out that the transmission system could move electricity over long distances more economically by connecting renewable energy assets with load centers using high-voltage, direct current (HVDC) lines. They can be routed along existing rights of way and buried to keep them safe from weather and to minimize NIMBYism. The Energy Futures Initiative says the nation is underinvesting in HVDC today even though it's "the backbone grid that is important for economic growth, reliability, resiliency, and the proliferation of low-cost clean energy."  One challenge is the number of actors and stakeholders in America's electric system. They include three transmission regions, utilities, independent power producers, standards organizations, grid operators, government agencies, and consumer and environmental groups. Fortunately, under Biden's Energy secretary, Jennifer Granholm, the U.S. Department of Energy has issued a comprehensive grid modernization strategy, the coordinated product of nine DOE offices and 14 national laboratories.  For the sake of America's future, we should hope that Trump, Congress and decision-makers nationwide use the strategy to optimize the benefits of every dollar. After all, it was Thomas Edison, the inventor of the light bulb, DC power and America's first power plant, who said, "I'd put my money on the sun and solar energy. I hope we don't have to wait until oil and coal run out before we tackle that." He also said, "Good fortune is what happens when opportunity meets with planning."  William S. Becker is a former regional director at the U.S. Department of Energy and author of several books on climate change and national disaster policies, including the “100-Day Action Plan to Save the Planet” and “The Creeks Will Rise: People Co-Existing with Floods.”