Indonesian power prices set to rise significantly, page-5

100% WRONG. You had better read the agreement.

https://www.asx.com.au/asxpdf/20180507/pdf/43ttmzb7x4db50.pdf

The agreement is for the quantity of power and no mention of a price contract. The agreement only sets out how much power PLN will supply and usage by GMC.
The agreement has nothing to do with pricing.
The coal pricing for PLN will run at US$70/tonne until the next election. Nobody knows what the price will be after that,but one thing is for certain it will go UP.

"Against a backdrop of rising coal prices, election-driven utility-price freezes"
https://www.bakermckenzie.com/en/insight/publications/2018/03/indonesia-new-coal-pricing

The power prices are being kept artificially low until the next election