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.
Tidal and wave resources have great potential to become important renewable energy sources in years to come. These two sources are predictable and this gives them an important advantage over solar and wind. However, before widely deploying wave and tidal energy technologies it is important to study their environmental impact.