Alternative energy sources: solar electricity

Recommendation points

• Used types of solar panels
• Scope of solar power plants
• Service during operation
• Requirements for placement conditions
• Azimuth Angle Tracking
• System expansion potential

More than half a century has passed since the world saw the first solar panel. Today, these devices have gone far beyond the boundaries of the space industry: a tenth of the electricity on our planet is generated from sunlight. We will tell you about the use of solar panels in everyday life.

Used types of solar panels

There are two main types of panels used in modern solar energy: film and monocrystalline. The difference is that the latter are quite plastic, but have low efficiency compared to heavy rigid panels in metal frames..

Modern panels can convert 15 to 30% of the luminous flux into electricity. Higher efficiency products are presented in a specific market segment. It is noteworthy that as the efficiency of the panels increases, their service life also increases..

The latter is a very relative indicator. A service life of 30 years does not mean that after this period the panels will stop working. The manufacturer simply does not guarantee that over time the degradation of photovoltaic cells will not exceed 50% of the initial efficiency indicator..

Scope of solar power plants

Electricity from the sun is produced in various parts of the world: both at national solar energy stations and in small private complexes. The specificity of the use of panels is determined, rather, by a set of extreme restrictions for the object under construction..

For commercial buildings, this may be the need for an absolutely continuous power supply, which is typical for data centers, or, for example, climate control systems and refrigeration units. Any high-profile establishment (private beauty center, restaurant, parking) can also take care that the comfort of customers is not disturbed by a sudden power outage.

For private developers, solar energy is useful mainly when there is no other way to electrify the facility. Panels are currently the cheapest source of autonomous power supply for a small house. In any case, it is much cheaper than building and maintaining a wind turbine, and even more economical than a diesel power plant..

Service during operation

One of the main disadvantages of panels is that they can completely lose power if the surface is partially shaded. Panels that do not generate electricity, but remain in series with others, begin to work as consumers of electricity and reduce the generation of the entire circuit to zero. Therefore, the main work on the maintenance of the panels is to clean them from dust, streaks and small debris. It is better to simply blow off light dirt from the panels, stains like bird droppings can only be removed with a soft brush and a non-abrasive detergent. After washing, the panel must be manually wiped dry and polished.

It was mentioned that batteries can lose up to half of their original capacity during use. In fact, these figures are slightly less: 15-30%, depending on the quality of the panel and operating conditions. And this must be taken into account when designing a system: by calculating the power “end-to-end” you risk that in ten years the power system will not cope with your needs. At the same time, most modern solar energy complexes are easily expandable, you just need to provide sufficient throughput capacity of control and switching devices.

At the end of the operational life, the protective glass of the panels is re-polished, returning 3-5% of the lost power, and then another half of its composition is added to the panel park. After the next 30 years, everything repeats itself, but now new panels are replacing part of the old ones. Thus, the nominal efficiency during the entire service of the power plant remains stable, although this requires timely capital investments. This data will help the interested man in the street take a different look at the issue of payback of their installation..

Requirements for placement conditions

The location of solar panels should have a sufficiently high level of insolation – the amount of solar radiation in a specific area of ​​the area during the day, week, year. Cloudiness affects work efficiency to a lesser extent than nearby buildings, trees, and other objects that can cast shadows.

It is for these reasons that panels are traditionally placed on the roofs of buildings. It is believed that in order to power a home, the total area of ​​a solar farm should be roughly equivalent to living space. In addition, the panels on the roof are guaranteed not to be shaded, but such placement requires means for the approach and movement of people serving the farm. Roof panels are sometimes considered a substitute for roofing. But, firstly, not all panels are suitable for this, and secondly, it requires a thorough approach to installation..

When there is not enough space on the roof suitable for mounting panels, some of them are assembled on ground structures. Often the entire farm is lowered to the ground for more convenient maintenance, but this carries a number of negative factors:

• reduction of the exposure period by several tens of minutes;
• high risk of sudden shading;
• inability to use the occupied territory.

Often all of them are leveled by the increased efficiency of the panels as a result of their timely and regular cleaning. As for the insolation level, it can be calculated from panoramic photos with precise reference to azimuth and GPS coordinates..

Azimuth Angle Tracking

Another feature of modern solar systems. The technology designed for thermal concentrators has also taken root in photovoltaic installations. The essence of the system is that a small mechanism corrects the inclination of the panel plane relative to the radiation source. Thus, the light almost always falls on the panel at a right angle, which increases the daily generation by 15-25%.

There are two types of such systems. The first monitors the real position of the sun with a light sensor and turns the panel towards it. The other has a built-in program that contains accurate data on the location of the sun at every hour of daylight for the next 50-100 years. Systems of the second type are more reliable, although their setup and installation are not without difficulties..

System expansion potential

Usually, the construction of a solar farm begins when it is necessary to have an emergency source of at least a minimum power (for powering the boiler room, alarm, night lighting). Over time, everything changes, the system is being seriously improved to increase its performance.

Regardless of the number of solar panels, purchase special equipment, the power of which matches your total energy consumption. Even if the batteries generate ten times less energy, in this mode the equipment will last longer, and the system can be supplemented without interfering with the main circuits..

Also, remember that the common point in the distribution system is the battery fleet. Its capacity is always calculated in such a way that it remains possible to save excess electricity and prevent the system from depleting a charge in a few cloudy days..