Postings without closing dates are often positions that are difficult to fill or ones that come open frequently. An example of a position that is difficult to fill is a psychologist at a small-town state hospital. If the hospital left the job open for a month, it is unlikely to get a sufficient number of applicants.
The Disadvantages of Tidal Power Tidal power is growing rapidly in interest as countries look for ways to generate electricity without relying on fossil fuels. Tidal schemes have a number of advantages, including their lack of greenhouse gas emissions and 100% renewable nature.
There are also three main ways that tidal energy is harnessed: 1  Tidal Barrages-A tidal barrage works like a dam. 2  When the tide goes high, the reservoir fills up. 3  When the tide drops the dam lets the water out. 4  In both directions the moving water can spin the blades of turbines to create electricity.