Figure 6. Solar San Juan I pilot solar plant, a 1.2 MW test facility using different module and mounting technologies, including fixed and single axis orientation for crystalline, multicrystalline and amorphous silicon modules. Photograph courtesy of Estrada.

2.4. De-Centralized Solar Thermal Energy

Solar thermal energy in Argentina was already considered a potential key energy source in 1975 ^[2], when a national R&D program for the development of solar energy and other renewables was launched, leading to numerous research programs (see next section) and the elaboration of norms and certification criteria for ST collectors ^[22]. However, the deployment of this technology was hindered by the lack of long-term governmental promotion initiatives, as well as the sustained subsidies to conventional energy sources, which held until the present day ^[23][24]. Hence, ST persisted for decades as a solution serving only isolated communities and schools in rural areas with reduced access to a gas supply ^[25][26]. The 2001 economic crisis resulted in serious instability in the price structure, driven by frequent devaluations of the local currency. Through the Economic Emergency Law enacted on 6 January 2002, the Legislative Power temporarily delegated administrative powers to the Executive Power. In this framework, the rates of public services were frozen in the middle of the crisis in order to try to counteract the loss of the purchasing power of wages. However, after the crisis and with prices stabilized, the objective of economic policy was to maintain the new relative price structure based on a competitive (high) exchange rate and a scheme of low-cost tariffs, transport, and fuels. An explicit scheme of subsidies was established in order to maintain the low prices of public services (energy and passenger transport) ^[27]. During the period of 2002 to 2015, natural gas tariffs for final-use customers were subsidized to varying degrees by as much as 100% for social tariff users ^[28]. Such low prices in a growing economy did not encourage the use of ST technologies for heat generation. From 2015 to 2019, and with the aim to diminish the country’s fiscal deficit, tariff subsidies started to disappear, resulting in strong market growth for ST. As a result, local technology production was overrun by demand, international markets were open, and the importation of technology started to be a profitable option. In this period, ST equipment import grew each year ^[29]. Due to the sudden rise of the market, there was a boom of ST equipment import from Asia, with no regard to equipment quality. Given the low price of equipment imports, local manufacturers started to turn from local manufacturing to equipment importation, and the remaining manufacturing organizations started the chamber of ST manufacturers (CAFEEST), which nucleates most of the manufacturers and importers in the country. As is typical of other technologies, low-quality systems are cheaper than high-quality systems; in order to address this issue, CAFEEST helped define minimum technology requirements and quality standards. After discussion with solar thermal importers, and after 9 years of regulatory updates, mandatory national quality standards were implemented in 2019 by Resolution 520/2018 ^[30], stating that all solar thermal systems entering the country (whether imported or fabricated) must comply with the defined regulations. Because, in Argentina, there is no accredited laboratory for solar thermal devices, reports from international labs are accepted as a proof of compliance. In 2019, the new government implemented import and currency exchange restrictions, and implemented subsidies to natural gas one more time. Although the current natural gas tariffs are still very low, solar thermal energy is growing with the momentum gained during the 2015–2019 period. Equipment importation has become increasingly complicated due to exchange rate variability, importation permits, and recent equipment quality requisites (the Update of Resolution 520/2018). Local manufacturing has gained a renewed interest among entrepreneurs, and even importing companies. The main issue is that most of the materials needed for ST systems are either commodities or imported plastics (stainless steel, copper, thermoplastics, and polyurethane, etc.). Consequently, local manufacturing is affected by the same problems that affect equipment importation. Additionally, manufacturing activities are highly taxed. A regular solar thermal equipment sale must pay 21% VAT, 4% for gross income tax, and 30% over the profit and municipal taxes, which can take another 10% away. A further issue is that the sale is carried out in local currency, in what is essentially a by-monetary economy, and cannot be transformed into the foreign exchange needed to purchase the input materials and devices needed for local manufacturing without large financial risk. Solar thermal technology deployment is taking a different path from PV. Coincidentally with PV, Argentina has a huge potential for ST technologies, but in order to be competitive with imported equipment, technology transfer from academia and leveraged finance (both for manufacturers and end users) need to be in place. Currently, ST technology is mostly implemented at a household level, with very few examples in hotels and industries, with 2 m² collectors being the typical household average. The advance of the ST market should be coupled to a progressive elimination of fuel subsidies in all sectors. Furthermore, the correct deployment of local ST technology manufacturing needs clear investment conditions, which are not likely to happen in the short–medium term. Last but not least is the equipment quality issue, which should be monitored in order to provide a fair competition among manufacturers and importers.

3. Research and Development

Scientific research around solar energy is divided into three areas: radiation assessment, solar thermal power, and photovoltaic power. The ongoing radiation assessment efforts focus on the obtention of field data ^{[31][32][33][34][35][36][37]} and comparison with satellite estimations ^[38][39][40], whilst also combining efforts with photovoltaics for the design of photovoltaic radiometers. The first solar radiation map for Argentina was published in meteorological reports in 1972, while the more detailed, digitally available solar radiation maps based on a larger number of solar measurement stations across the country appeared only after 2005 ^[40][41]. Research on solar thermal is mainly oriented toward finding cost-effective solutions for communities deprived of access to conventional energy, mainly in solar greenhouse and distiller design ^[42][43][44], cooking ^[45], drying ^{[40][46][47][48][49][50][51]}, and pasteurization ^[52]. A few exceptions to this trend are larger-scale, industrial applications, where research efforts are directed towards the design of solar ponds to be applied to salt and metallurgical mining in Argentina‘s highest radiation region in the northwest ^[53][54]. More recently, at INENCO (the Institute for Non-Conventional Energy), the solar thermal research division developed medium-to-large-scale concentrating systems, which led to the construction and operation of several prototypes, including a 172 m² linear Fresnel concentrator ^[55][56][57]. Most of the research activities are oriented towards the use of locally available materials and tailored design, with some potential for technology transfer to the regional economy. Together with INENCO, an ONG called EcoAndina has worked—since 1989—on the transfer of solar cooking and water heating developments to rural villages near the Andes, both to grant access to better sanitary conditions and to help develop a local regional economy ^[58]. A key issue of research is that most of the ST research is not transferred to the market. Most national universities have little connection to the market and little experience in technology and knowledge transfer. As such, efficient mechanisms to build startups from research innovations are limited. An exception of public–private spinoff is the company Jujuy Solar, which manufactures solar thermal systems for the northwestern region of Argentina, oriented towards social housing in this high-insolation region of the country (see ^[59] for a manufacturing video). Another example is the company SOLARMATE, a spinoff from the University of San Martin. The company develops portable ST devices which incorporate compound parabolic concentrators and industrial design to allow users to experiment with solar heat at a personal level. Most of the local solar thermal manufacturers do not incorporate into their products well-known technological innovations such as selective surfaces (aerosol or sputtering deposited), or low-emissivity/textured/low-iron glass covers. This is due either to manufacturing costs or a lack of technical knowledge, with the latter being possibly due to poor know-how transfer from the academic sector. Some manufacturers have tried to import fin-tube-selective surface parts, joining them locally by means of conventional copper–silver welding, but eventually dropped the idea because market costs were lower for the imported collector than for the locally soldered collector. Others have tried to use aerosol selective coatings with very little result in the overall efficiency, and thus abandoned the original idea of using solar selective surfaces. Given the large range of the country’s insolation and climate conditions—above 6 kWh/day and 20 °C annual average in the north, and less than 3 kWh and 10 °C annual average in the south—the market needs a variety of technologies that respond adequately to each climate. Low-efficiency collectors do not work in the south of the country, and high-efficiency collectors produce overheating in the north. Given the different technology needs, transfer from the academic sector must play and important role in the development of the solar thermal market in Argentina. Research and development in photovoltaics followed a different path. PV research began in the early 1980s, as Argentine graduate students were trained in photovoltaics in technologically developed countries, where photovoltaics gained impulse during the 1970s and 1980s. The first published articles appeared in the early 80s, and were aimed at theoretical solar radiation assessment ^[38], solar concentration studies ^[60][61][62], and the optimization of silicon cell design ^[63]. Thin-film solar cell research began in the early 1990s with CdTe/Cds films prepared by the chemical vapor deposition of both CdTe and CdS ^[64][65][66]. These research lines were, however, isolated attempts which did not lead to long-term R&D projects, in part due to the lack of governmental policies aimed at the development of renewable energy technologies. Public funding eventually began in the mid-1090s for the development of space photovoltaic power systems for Argentine satellites. The applied research line included the design and fabrication of Si solar cells using commercial monocrystalline silicon wafers, the terrestrial testing of space radiation damage in local particle accelerators ^[67], and satellite mission testing ^[68][69]. SAC-A—the first Argentine satellite mission provided with a photovoltaic array—was launched in 1988, and could be regarded as the first practical application of photovoltaic devices fabricated in Argentina. The space photovoltaics group continued to produce solar arrays for subsequent commercial satellite missions ^[6770], eventually switching to commercial triple-junction solar cells from Emcore, USA (later SolAero Technologies Corp. ^[6871]). The long-term involvement in space applications derived in the development of EDRA, a facility dedicated to radiation damage in a simulated space environment and the in-situ characterization of solar cells and materials during irradiation ^[6972]. In the meantime, scientific research gained some governmental attention after the economic crisis of 2001. Though modest, the increase in public research funding produced new research groups in different regions of the country. These groups focused mainly on low cost, inorganic and organic thin-film solar cells, covering modeling ^{[70][71][72][73][74][75][76][77][78][79][80]}, characterization techniques ^{[7881][7982][8083][8184][8285][8386]}, and the preparation of solar cells ^{[7275][84][85][86][87][88][89][90][91][92][93][94]}. In the last decade, the research focus moved to alternative chalcopyrite and perovskite solar cells, covering modeling ^{[9295][9396][9497]}, preparation ^{[95][96][97][98][99][100][101][102][103][104][105][106]} and characterization ^{[9598][9699][104107][105108][106109]}.