New Solar Generator on DGEEU's Roof

Directorate General for Electricity and Energy Utilization (DGEEU) has just installed massive amount of solar panels on its main building roof. I personally do not know the intention of the installation. If it is just to reduce electricity bill then the investment will be able to cover the monthly bill up to approximately 270 months (let's say monthly electricity bill is IDR 5.000.000). I assume each watt peak costs US$ 5 and with exchange rate of IDR 10.000 per US$ then each watt peak will cost 50.000. When I try to look at the picture below (sorry it is not very clear, taken using Nokia 2360), each panel is 100 Wp and there are 27 panels in each row. There are 5 rows and that means the capacity is approximately 13.5 kW. That's just the under deck, the upper dect I assume they also install the same amount of capacity. Therefore in total there might be 27 kW installed. I only calculated for the solar panels. If I include the battery, I assume they use industrial 2 volts battery, there will be 110 battery (to reach 220 volts DC). Each battery can cost approximately IDR 90.000.000, and if there are 110 batteries then the cost of battery will be approximately IDR.9.900.000.000. The cost of battery can cover electricity cost approximately 1980 months (approximately 160 years with current electricity tariff). Oh...my God, is this the way the world should go or what? Don't they have more important things to do?

But maybe, it is a kind of renewable promotion. Indonesia is sun rich country. Solar power is easily deployed, but should we look for more "rational" source of energy? biomass for example. I believe there is huge amount of biomass potential in the country. The country is still agricultural and there are many options to reuse agriculture residues and generate energy from it. I don't know. I would rather do something more tangible to the people than just installing solar generator on my roof (maybe I will someday, if each watt peak cost less than 1 US$).