Polarity and Boiling Point: The polarity of the molecules determines the forces of attraction between the molecules in the liquid state. Polar molecules are attracted by the opposite charge effect (the positive end of one molecule is attracted to the negative end of another molecule.
The five disadvantages of solar power. It's intermittent. Solar energy is only available when the sun is shining. It's low efficiency. It requires large areas of land. It's not completely free of environmental impact. Ultrapure polysilicon is now scarce. It's high cost.
The advantages of solar power are no maintenance or running costs and silent operation, as well as âfreeâ (after the installation costs have been recouped) heating and electricity. A system should last for 30 years and can be uprated to provide more power in the future.ince the switch to a market economy, however, electricity prices have risen substantially, and you should allow around 300 lev (â¬150) per month to heat an average-size two-bedroom house in winter, compared with around 100 lev (â¬50) using an oil-fired system or just 50 lev (â¬25) using a wood-fired system.