Good news for NIPSCO electricity and natural gas customers. The utility has lowered its estimates of how much bills will go up under its seven-year modernization plans. Documents recently filed with the Indiana Utility Regulatory Commission estimate natural gas rates will go up by a total of just under 5 percent by 2020, compared with nearly 10 percent, which they first estimated. NIPSCO has reduced its estimated cumulative electric rate increase to just under 5 percent from about 6 percent.