In a world anxious about issues from dwindling supplies of affordable oil to a human-abetted warming of the planet, the sun serves not only as the enabler of life on Earth but also as a tantalizing symbol of sunlight’s promise as a remedy for our energy woes. Or as Ernest Moniz, director of the MIT Energy Initiative (MITEI) puts it, “In terms of terawatts (trillions of watts) of potential energy use, sunlight is off-scale.”

That promise, moreover, isn’t necessarily a long-term proposition. “If we can get aggressive development all along the solar value chain, from basic research on materials to new manufacturing technologies to creative deployment policies,” says Moniz, “a robust solar future could be closer than many people think.”

The groups working under MITEI’s auspices are doing all they can to hasten that future’s arrival. Their efforts include not only improving on current technologies and inventing new ones but also shaping solar-related policies: an interdisciplinary group headed by Institute Professor John Deutch, whose numerous top government posts include director of energy research under President Jimmy Carter, is doing a major study to guide governments, companies, and other organizations in choosing potential solar energy pathways for timely deployment at a scale that materially cuts climate change risks.

Given the urgency of climate worries and other concerns, solar power in fact needs to emerge as a major player in energy. If the climate change threat is to be countered, for example, carbon emissions of all types must be reduced. Particularly imperative, says Moniz, is “working to decarbonize the electric power sector.” Since that sector is a huge part of the overall energy enterprise — it supplies about 40 percent of all the energy consumed in the U.S., for one — minimizing the role of fossil fuels in it is critical.

Solar, of course, can’t be the only answer to CO2 emissions in that sector. Major advances in energy efficiency, especially in residential and commercial buildings, are also key. Wind power and biomass already play a significant role in electricity generation and, along with other renewables such as deep geothermal and waves, may grow substantially. The emergence of clean coal technologies that capture carbon dioxide for underground storage, and the spread of safe, waste-minimizing nuclear power will also be essential.

But solar, says Moniz, needs to be “the long pole in the tent.” Here are snapshots of some of MIT’s efforts to make widespread and affordable solar energy a reality.