The project, known as the “Green Grids Initiative,” is being initiated by the International Solar Alliance, which was launched by India and France at the 2015 Paris climate conference to promote solar energy. The U.K. and India agreed to join forces in the initiative in May this year.

Although solar energy is becoming cheaper than dirtier alternatives, countries cannot rely on it at night and must fall back on fossil fuels that produce earth-warming greenhouse gases. This is especially the case in countries like India, where demand for power is soaring.

The new project is based on the idea that the sun is always shining in some part of the world, and the project aims to create a global grid that will transfer the sun’s power from one place to another, said Ajay Mathur, the director general of the International Solar Alliance.

“For example, when it is dark in east Asia, it’s still light in India… If there was a cable between India and east Asia, that solar electricity could be provided to east Asia,” he said.

The idea of a grid spanning regions is not new, but this is the first attempt to create a global network. Some experts view the project as India’s counter to China’s sweeping Belt and Road infrastructure initiative.

Mathur said estimates showed that in the next three years, solar power will become as cheap as power from fossil fuels, which will make it easier to build new solar power plants and storage facilities. But even then it will require countries with different priorities to reach complex agreements.

The project aims to start with a “coalition of the willing,” such as two countries that would mutually benefit from the transfer of solar electricity, he said. These countries would then have to decide how they want the interconnection to work and what rules would regulate it.

“The number of willing countries will keep on increasing over time, as costs lower and certainties become higher,” he said.

Mathur said investors need to be assured their investment is safe and that they can get a positive return, while also ensuring that the cost of the electricity generated will be affordable.

The International Solar Alliance hoped to enter into an agreement with a new group called the Global Energy Alliance, which includes philanthropy organizations and multi-laterals like the World Bank, to create a $10 billion fund for the project and help mitigate risks, he said.

“So we create the projects, we take it to them and they help…make those projects safe enough to draw in investments from international organizations,” he said.

Another potential challenge is if the path between two countries is impassable, for instance if the countries aren’t stable. In other cases, a longer cable or one that goes beneath the ocean would be required. Any of these factors could sharply increase costs.

Even with a “fairly aggressive” timeline, Mathur said the first projects connecting different regional grids would still “take a year,” since countries first need to be convinced of the concept and then work together to determine the best way to develop the interconnection.