Arizona is one of the sunniest states in the continental United States, which makes it a perfect location for solar energy production. There are two primary types of solar power systems: concentrated solar power (CSP) and photovoltaic (PV). Both of these systems have advantages and disadvantages that should be considered before installation in the deserts of Arizona.
Concentrated solar power
Concentrated solar power systems generate solar power by using lenses and curved mirrors to focus sunlight onto a small area of solar cells. Electricity is generated when the concentrated sunlight is converted to heat. The heat drives an engine, which is connected to a power generator. There are several types of CSP systems, including parabolic troughs, solar power towers, Fresnel reflectors, and dish sterling. CSP is almost exclusively used for large-scale commercial energy production.
One of the biggest advantages to CSP systems is that heat storage, often in molten salts, enables solar plants with this technology to continue to generate power after sunset, which adds reliability and value when compared to photovoltaic panel installations. CSP systems are also more efficient than their photovoltaic counterparts.
CSP solar power systems can have a significant environmental impact. In order to work properly, the mirrors or lenses must be cleaned regularly using water, a valuable resource in the desert. This water must then be held in storage ponds before treatment and released back into the local water system. These ponds often attract wildlife, which can be hazardous for the animals.
Insects and birds can also be attracted to the bright light caused by CSP systems. Due to the concentrated heat, insects can be killed and birds may suffer severe burns or death. CSP systems require a large environmental footprint for the mirrors, towers, heat storage, retaining ponds, and ancillary facilities required to convert and store electricity.
Photovoltaic solar power
Photovoltaic solar power has become one of the most popular types of solar energy production in Arizona. Typical PV systems consist of solar panels made up of solar cells, which generate electricity. These solar panels may be mounted on the ground, rooftops or walls.
The primary advantage of PV systems is a smaller environmental impact. The panels emit no greenhouse gases once installed and require infrequent washing. PV systems are also easily scalable, making them appropriate for large-scale commercial installations or for small, individual installations.
The major disadvantage of PV systems is that the power output is dependent on direct sunlight, so energy potential is lost if a tracking system is not used. Dust, clouds and particulates in the atmosphere also diminish power output. PV panels are also less efficient than their CSP counterparts. However, advances in technology and optimized manufacturing have increased efficiency and reliability.
The Arizona desert boasts an ideal combination of land area and resource potential for solar energy. Solar power will undoubtedly play a large part in helping Arizona achieve its goal of obtaining 15% of the state's energy from renewable energy by 2025. Both CSP and PV systems have their advantages and disadvantages. Weighing those pros and cons alongside natural resource considerations requires a delicate – but necessary – balance from businesses and members of the public alike.