- 16
- contrast
- contributed
- costly
- designs
- direct
- efficiencies
- emerging
- environment
- example
- extend
- forms
- gain
- geothermal
- global
- harsh
- heat
- hydropower
- installed
- just
- large_scale
- lifetimes
- limited
- mainly
- maintenance
- marine
- materials
- mature
- myriad
- ocean
- opportunities
- power
- procedures
- reliability
- remain
- renewable
- smaller
- stage
- testing
- upgrading
- widely
- worldwide
