Next year, solar output at the power company in the chart rises by 60,000 MWh and every other source…

Explanation

1. 01

   Solar this year: $15\% \text{ of } 2{,}40{,}000 = 36{,}000$ MWh. Next year: $36{,}000 + 60{,}000 = 96{,}000$ MWh.

2. 02

   New total: $2{,}40{,}000 + 60{,}000 = 3{,}00{,}000$ MWh.

3. 03

   Solar's share: $\frac{96{,}000}{3{,}00{,}000} \times 100 = 32\%$.