The sun provides free energy that can be used in a variety of ways. The most obvious is the light and heat it provides during the day. We can see outside, and with a properly designed house, much of the light we need indoors can be provided, as well. The sun can also be used to dry laundry and warm up the water in swimming pools. More importantly, the sun helps food grow and influences the weather.
Using the power of the sun in these ways is free, and doesn’t have any drawbacks. However, when harnessing the sun to create solar energy there are some disadvantages. The most obvious drawback is that isn’t available during the night, and it is much less powerful on cloudy days. In order for solar panels to collect the most energy possible, they have to face the sun directly. This is why large “solar farms” place the panels on rotating towers that track the sun’s movement throughout the day.
The problem is that even the most efficient solar cells can only convert a little more than 20% of the solar rays into electricity. Advances in solar cell technology is likely to increase the efficiency in the near future, but for now, that is all they can do.
Using solar energy is completely free, however the equipment used to harness, convert and store the power is quite expensive. Although government tax incentives help to off-set some of these costs, it is still an expensive project. It can take up to ten years for the system to pay for itself. This time can be reduced if the homeowner is able to sell excess electricity back to the grid.
Even a small, single family home requires a large surface area of solar panels for the system to be efficient enough to provide a reliable source of electricity. This can be a huge problem when space is limited. Most homeowners install the panels on the roof of the house because the space is usually large enough, and the panels have the greatest exposure to the sun.
In order for the system to work efficiently, the panels need lots of sunlight. The solar panels must be installed in a sunny area and in such a way as to receive the most sunshine as possible. For most homeowners, placing the panels on rotating towers isn’t an option, so they have to find an area on the roof with the most direct sunlight, and not in the shade of trees or other buildings.
Where in the world you live can also be a disadvantage of using solar panels. For example, high levels of pollution can reduce the efficiency of photovoltaic cells. Like heavy cloud cover, pollution can restrict the amount of solar energy the cells receive. This problem is being resolved with new designs that incorporate technologies to fight these effects. However, these technologies are still in the experimental stage and not yet ready for wide spread use.
Most residential solar energy systems are only useful on sunny days. To produce electricity at night or on cloudy days, some systems use batteries to store the energy, and draw on the batteries when sunlight isn’t available. The biggest disadvantage of this is that you need a lot of high capacity batteries to store enough energy for even a minimum amount of use. For example, you probably won’t be able to store enough energy for a load of laundry, but you may be able to use some lights and maybe a television for a few hours. And once the batteries are drained, it can take a full day or more of direct sunlight to recharge them. If you have several days in a row without enough sunlight to fully charge the batteries, you could be in big trouble.
Industrial solar power stations that use molten salt to power a generator are able to produce electricity throughout the night because the salt retains enough heat to keep the generator running.
Currently, these are the main disadvantages of changing over to a solar energy system to generate electricity for your home. As technology advances, more and more of these disadvantages will be overcome. The costs of purchasing and installing the systems will come down and new, better ways of storing the energy will be created. But even now, the advantages of using solar energy far outweigh the disadvantages.