Covering rooftops of Singapore with solar panels only provide 20%+ of the total electricity needed. How about indirect benefits?

Recently I read in the newspaper remarking that covering all Singapore roof-tops with solar panels will only provide 20%+ of the total electricity needed and that energy conservation is more viable. Petrol/Diesel is still the number one cause of pollution.

I do not disagree that energy conservation is important but based on a layman's perspective, I'm not sure if the author has taken into account the indirect benefits that solar panels can bring.

Some of the points which I can think of is

1. that most residential areas do not use much power during working hours and the unused energy can be tapped by the commercial areas during these periods. Likewise on weekends where commercial areas use less power, the energy can be fed back into the residential areas;
2. that we can build up our expertise by investing early into solar R&D. Solar efficiency and solar storage can only improve over time, provided R&D is done. Look at the first generation of motor cars and the F1 cars now. This also indirectly provide jobs for Singaporeans;
   
3. that solar parking lots or solar electricity stations can be built to encourage the use of electric cars in Singapore. I heard that in Google, these parking lots allow the electric cars to be charged by the solar panels when it is parked.

They are of course many other indirect benefits that such investments will bring. We should be more proactive in terms of energy efficiency and conservation instead of waiting for the big guys to do all the work first, and we pay through our noses for this technology when it is ready. How do you measure such savings from indirect benefits?