Great was our surprise when we began to carry out the research work on El Salvador domestic solar thermal energy applications sector.

Considering that in country central region solar irradiation is high (5.3 kWh/m2/day), compared with other locations such as Germany or Tokyo (3.3 kWh/m2/day), the potential is enormous.

Given the almost non-existent information available (and official agencies lack of response), we decided to consult professionals and companies in the renewable energy sector of El Salvador.

The conclusions are:

1) There are very few companies that offer solar thermal equipment (some, including inventory they wish to liquidate due to low sales volume)

2) Unfortunately local mentality still focuses more on initial investment than on long-term savings from electricity consumption expenditure reduction

3) The use is practically limited to hotel and hospital sectors and is irrelevant in residential sector

4) There is no normative that regulates and promotes sector development.

This situation, which is repeated in many Latin American countries with solar resource great potential, raises the question of why solar thermal development is so inferior in relation to photovoltaics.

To answer this question we will make a brief comparison between both solar technologies:

– Domestic solar thermal applications

+ It is a simpler technology

+ It is more efficient respect to the space used

+ Higher yields are obtained (around 40% for solar collectors compared to maximum 20% of solar modules)

+ Solar fraction can easily exceed 70% in locations with medium-high radiation level

+ It is a technology with lower level of complexity in its installation

Aspects to consider:

* System performance is much lower in winter months, when hot water needs are higher

* If there is frost risk in system site, antifreeze use in heat transfer fluid is indispensable.

– Photovoltaic solar energy applications

+ Photovoltaic systems are more versatile

+ Photovoltaic modules have longer service life (30 years with a guarantee of 20 years by almost all manufacturers) than thermal solar collectors (10 years with between 1 to 5 years guarantee)

+ Frost does not affect them

Aspects to consider:

* Higher investment compared to solar thermal system of equivalent power

* Grid connected systems are subject to numerous bureaucratic procedures and taxes that lengthen its amortization time

* It is a newer technology that needs technical advances to improve its performance and efficiency.

We can conclude that the balance is slightly tilted in favor of solar thermal.

So, why photovoltaics development is bigger?

The answer is that solar thermal is developed almost exclusively in distributed energy generation way, while solar photovoltaic does it mainly from large central power plants.

Solar energy wherever you are with Sopelia.