Out of the box thinking will be necessary in the coming years-- I'll be eager to see if this is WAY TOO out the box, or the kind of moonshot that can really change the landscape of how we do things. Where do you think it lies, Deepak?

Anyone considering battery capacity a substitute for dispatchable generation should have the number 8,760 hard-wired into their consciousness. It's a constant - the number of hours in a year. Dividing any country's annual energy consumption by it will yield the country's average rate of consumption (power). Singapore annually consumes 50,000 GWh of energy, so the country is consuming energy at a rate of 5.7 GW (billion watts), averaged over the year.

At that rate, Singapore will consume the entire capacity of Sun Cable's 22 GWh battery pack in 4 hours. So whenever the wind doesn't blow for more than 4 hours, its $30+ billion project will be useless. According to EIA, 22 gigawatthours (GWh) of battery storage will cost USD 26.4 billion. They'll need to be replaced every 10-12 years.

Is there an electrical engineer in the house? Tell him to go home, we've got a big renewables project to sell.

To call this "ambitious" is an understatement. The proposed undersea power cable would be 7x longer than the next-longest undersea power cable. That's the NorNed power cable linking Norway and the Netherlands. Per Wikipedia, the capacity of the NorNed cable is 700 MW -- less than a tenth of what's proposed in this project. 

Such a long, high capacity undersea power cable may be technically possible, but whether it would make economic sense is a different story. Singapore might do better building a cluster of nuclear plants, or importing floating nuclear plants from Russia.