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.
How Does Tidal Energy Work. Tidal energy is energy obtained from changing sea levels (the tide moving from high to low and vice versa.) This renewable energy source has great potential as tides are much more predictable than wind power and solar energy which are not at all consistent (seasons, bad weather, etc...).idal Barrages. Tidal barrages are very similar to the Dams in hydroelectric plants, except that they are much larger as they are built across an estuary or bay. The tidal range (difference between high and low tide) needs to be in excess of five metres for the barrage to be workable.