Solar Panels

Solar Panels: Types of thermal installations

If someone tells us about an installation of thermal solar panels, the most normal thing is that the first thing that comes to mind is a house in which solar panels have been placed to generate hot water and use that water, especially forget a shower.

However, there are other facilities in which this renewable energy is used due to the level of savings and comfort it offers. Have you thought of any of the following examples ?:

  • Generation of hot water and heating of swimming pools (sports facilities, urbanizations …)
  • Generation of hot water and air conditioning of agricultural facilities (greenhouses, fish farms, animal farms …)
  • Generation of hot water and heating of fluids in industrial processes (clothes laundries, car washes, preparation of cooked food …)

Be it the case of the home in which the objective is to heat the shower water or that of the company that cooks food, the type of installation is based on the same principle: active solar panels energy. That is, energy is obtained by mechanical elements. These elements are the collector system (solar panels), the storage system (hot water accumulators), and the distribution system.

In addition, their common denominator is that low-temperature solar panels are used in the facilities . 

They are a type of solar panels that has the following characteristics:

  • They capture the sun directly.
  • They heat fluids up to about 100º C.
  • They take advantage of solar radiation in a more efficient way since the solar collector loses less heat and takes more advantage of the solar energy it receives.
  • They have greater durability since frequent high temperatures in thermal systems shorten the useful life of the installation and if these are excessively high they can cause problems in some elements.

All of the above allows these facilities to obtain good returns and therefore short payback periods. At the installation level, they are simple projects that at the legal level must comply with the provisions.

And finally, just as there are low-temperature collectors, there are medium and high-temperature collectors. These are not based on direct capture, but on the concentration of the sun to a lesser or greater degree. In this way, they can heat fluids at higher temperatures: those of medium up to 250º C and those of high temperatures reach up to 1,000º C.

Examples of applications? Industrial processes in which water has to be boiled: distillation or desalination. In addition, these collectors also allow the production of electricity. And it is along this line that progress has been made in recent years, betting on the development of thermoelectric panels.

And finally, always faithful to our quote: “For the cold and for the heat, renewable is the best.” 

How to size a solar panel installation

A question that we receive quite often is the size that thermal solar panels should have to cover the DHW needs of a home. Sizing solar panel installation is a task that should always be entrusted to accredited professionals in the sector.

What data appears in that table?

In the case of single-family homes, it is 30 liters/day per person, and if it is a multi-family building, 22 liters/day. That is, if there are 3 of us in a single-family home, we would multiply 3 x 30 liters/day and it would give us the necessary data to determine the size of the solar panel that we would need.

Although it may seem like a very simple calculation, knowing and applying this formula is essential to avoid future installation problems. If we choose solar panels that are too large for the needs of the home or building, the most probable is that “overheating problems” will occur in the collectors, in the accumulator, or in both. This malfunction of the installation can cause loss of heat carrier fluid and therefore damage the system.

Normally this overheating of the solar panels occurs when the sun radiates more energy, that is, in the summer months. In addition, we not only put the life of the equipment at risk, but with a poor dimensioning we waste the potential and energy efficiency that solar thermal energy is capable of providing us.