The Biden administration on Wednesday released a plan to produce almost half of the nation’s electricity from the sun by 2050 as part of its effort to combat climate change.

Solar energy provided less than 4 percent of the country’s electricity last year, and the administration’s target of 45 percent would represent a huge leap and will most likely take a fundamental reshaping of the energy industry. In a new report, the Energy Department said the country needed to double the amount of solar energy installed every year over the next four years compared with last year. And then it will need to double annual installations again by 2030.

Adding that many solar panels, on rooftops and on open ground, will not be easy. In February, a division of the Energy Department projected that the share of electricity produced by all renewable sources, including solar, wind and hydroelectric dams, would reach 42 percent by 2050 based on current trends and policies.

The new department blueprint is in line with what most climate scientists say is needed. Those experts say that reducing net emissions of greenhouse gases to zero by 2050 is essential to limiting the worst effects of global warming — and much greater use of renewable energy sources like solar panels and wind turbines will be needed to achieve that goal.

But administration officials have provided only a broad outline for how they hope to get there. Many of the details will ultimately be decided by lawmakers in Congress, which is working on a bipartisan infrastructure bill and a much larger Democratic measure that could authorize $3.5 trillion in federal spending.

One thing going for the administration is that the cost of solar panels has fallen substantially over the last decade, making them the cheapest source of energy in many parts of the country. The use of solar and wind energy has also grown much faster in recent years than most government and independent analysts had predicted.

“One of the things we’re hoping that people see and take from this report is that it is affordable to decarbonize the grid,” said Becca Jones-Albertus, director of the Solar Energy Technology Office in the Energy Department. “The grid will remain reliable. We just need to build.”

The administration is making the case that the United States needs to act quickly because not doing anything to reduce the country’s reliance on fossil fuels also has significant costs, particularly from extreme weather linked to climate change. In a Tuesday visit to inspect damage from the intense rainfall caused by the remnants of Hurricane Ida in New Jersey and New York, President Biden said, “The nation and the world are in peril.”

Some recent natural disasters have been compounded by weaknesses in the energy system. Ida, for example, dealt a huge blow to the electric grid in Louisiana, where hundreds of thousands of people have been without power for days. Last winter, a storm left much of Texas without electricity for days, too. And in California, utility equipment has ignited several large wildfires, killing scores and destroying thousands of homes and businesses.

Even so, many analysts and even some in the solar industry are skeptical that the administration can achieve its green targets. In addition to the 45 percent solar target, Mr. Biden has said he wants to bring net planet-warming emissions from the power sector to zero by 2035. He also wants to add hundreds of offshore wind turbines to the seven currently in the waters off the nation’s coasts and have as many as half of all new cars sold be electric by 2030.

While renewable energy has grown fast, it contributes about 20 percent of the country’s electricity. Natural gas and coal contribute about 60 percent.

“That kind of quick acceleration of deployment is only going to happen through smart policy decisions,” said Abigail Ross Hopper, the president of the Solar Energy Industries Association. “That’s the part where having a goal is important, but having clear steps on how to get there is the issue.”

Challenges like trade disputes could also complicate Mr. Biden’s push for more solar power. China dominates the global supply chain for solar panels, and the administration recently began blocking imports connected with China’s Xinjiang region over concerns about the use of forced labor. While many solar companies say they are working to shift away from materials made in Xinjiang, energy experts say the import ban could slow the construction of solar projects throughout the country in the short term.

Mr. Biden wants to use tax credits to encourage the use of solar power systems and batteries at homes, businesses and utilities. The administration also wants local governments to make it quicker to obtain permits and build new solar projects — in some places it can take months to put panels on a single-family house, for example. And officials want to offer various incentives to utility companies to encourage the use of solar.

Jennifer M. Granholm, Mr. Biden’s energy secretary, said part of the administration’s strategy would focus on its Clean Electricity Payment Program, which would reward utilities for adding more renewable energy to the electric grid, including rooftop solar. Many utility companies have fought against rooftop solar panels because they see a threat to their business and would rather build large solar farms that they own and control.

“Both have to happen, and the utilities will be incentivized to take down the barriers,” Ms. Granholm said. “We’ve got to do a series of things.”

In addition to its efforts, the administration pointed to changes being made by state and local officials. Regulators in California, for example, are changing the state’s building code to require solar and batteries in new buildings.

Another big area of focus for the administration is greater use of batteries to store energy generated by solar panels and wind turbines for use at night or when the wind is not blowing. The cost of batteries has been falling but remains too high for a rapid shift to renewables and electric cars, according to many analysts.

To some solar industry officials, the new solar target will help to focus people’s minds on the future.

“In essence the D.O.E. is saying America needs a ton more solar, not less, and we need it today, not tomorrow,” said Bernadette Del Chiaro, executive director of the California Solar and Storage Association, which represents solar developers in the state with by far the largest number of solar installations. “That simple call to action should guide every policymaking decision from city councils to legislatures and regulatory agencies across the country.”

Brad Plumer contributed reporting.