The initial investment of a thermal solar energy system will be greater compared to a conventional energy supply system.

On the other hand, the cost of operation during the more than 25 years of life of the solar thermal installation will be irrelevant compared to that of the purchase of fuel or electrical energy, repairs, maintenance, etc. associated with the conventional energy system.
One of the advantages of solar energy is on the economic side. All the energy obtained from the Sun is energy that will not need to be produced by another fuel. Solar radiation is free. On the other hand, the fuel of the other conventional energies has a cost.
A solar thermal energy installation ends up profiting over the years. Energy saving becomes economic savings. Over the years, the economic savings will allow us to amortize the cost of the installation.
This amortization can range between 5 and 12 years. This variation depends on:
Installation size.
Aid obtained from lost funds.
Place where it is installed. The amount of solar radiation received depends on it.
Greater or lesser needs of the user.
In the case of placing these solar thermal installations in new construction or rehabilitation homes, the amortization can be considered instantaneous.
The increase it represents in the total price of housing is very small. The amount paid for this higher cost in a mortgage loan each year is less than the amount in euros that represents the lowest cost of gas or diesel.
Advantages of Solar Thermal Energy
We highlight the main advantages of solar thermal energy:
Economic Advantages
For the same needs, the conventional system will need to consume less fuel ( non-renewable energy sources). This reduction will represent a lower annual expense.
Solar energy is independent of conventional fuel. It is compatible with any conventional system and independent of the variation in the purchase price of fuel.
Environmental Benefits
The generation of energy with conventional systems has very important environmental costs that solar energy does not have. For example:
CO2 emissions
Climate change.
Greenhouse effect.
Nuclear waste
Acid rain, etc.
On average, a m2 of solar thermal collector is able to prevent the emission of one ton of CO2 into the atmosphere every year.
Easy Maintenance
The useful life of solar thermal installations is over 25 years. The maintenance required is much less important than in the case of conventional systems.
Disadvantages of Solar Thermal Energy
One of the drawbacks of solar thermal is that it requires the same conventional system as that which would result if solar collectors were not installed.
Sometimes mounting them in existing buildings is problematic as a result of their lack of foresight at the project level.
Summary
A solar thermal installation is profitable after 5 years of its installation. For this, the dimensioning must be calculated correctly.
The main factors to consider are:
Expected consumption.
Solar availability. Winter, summer, daylight hours, weather, etc.
Electricity cost through conventional systems.