A Photovoltaic solar energy has become a protagonist in Brazil and is already the second largest source of electrical energy production in the country, behind hydroelectric plants, with 30 GW in operation, including centralized (9 GW) and distributed (21 GW) generation.
Last week, the EPE (Energy Research Company) published the first edition of “Generation Technologies Notebook”, which shows the evolution of the technical characteristics of centralized generation projects ed in EPE energy auctions, including wind, solar photovoltaic, hydroelectric (CGH and PCH) and thermoelectric sources (biomass, natural gas, coal, etc.).
Since 2004, 89 auctions have been held. Between 2012 and 2022, more than 30 thousand projects were ed with EPE in energy auctions, as shown in Figure 1.
EPE warns that the accumulated values do not provide a clear view of the availability of projects for each source, since the same project can be ed in more than one auction.
In the following graph, it is possible to see the evolution in the number of ed and enabled projects, considering only the single participation of the project per year, in the period from 2012 to 2022.
EPE carried out an assessment of the enabled power of projects in this period, which shows an availability of more than 65 GW of new energy in the same year (2019). The water source has the smallest share, with wind and solar photovoltaic sources corresponding to more than 50% of the annual power supply, in all years evaluated.
How was the technical evolution of photovoltaic solar energy?
A first participation of solar energy in auctions was in 2014. Then the source gained space in the free market. Currently, there are 9,3 GW in operation and another 6 GW under construction and another 100 GW granted with construction not started, according to data ANEEL (National Electric Energy Agency).
Evolution of modules
According to EPE, until 2020, most photovoltaic projects ed for auctions used polycrystalline silicon technology. However, this share has been decreasing since 2016, until it was sured by monocrystalline silicon in 2021, which represented more than 90% of the sample in 2022.
“In of the number of cells for crystalline silicon modules, after the migration from 60-cell modules (1,66 m²) to 72 cells (2 m²) by 2016, there was significant growth in the use of 144-cell models, demonstrated in the graph below. The 144-cell modules have dimensions and powers similar to those of 72 cells, but use cells cut in half, which is why they are called half-cut cells”, says EPE
“These modules have lower currents than models that use the entire cell, reducing resistive losses. Another advantage is the greater tolerance to partial shading, as only 1/6 of the total power is affected when shading a cell, compared to 1/3 in common modules. More recently, we have noticed a large number of projects with modules of 156 cells, which reach 2,80 m² in area.”
Another evolution is the increase in the share of PERC technology and the growth in the share of bifacial modules from 2019 onwards, absent in previous years. In the 2021 auctions (A-5), 80% of projects used these two technologies.
Evolution of Inverters
Between 2016 and 2020, the use of inverters with power between 1 MW and 3 MW was predominant. “From then on, more projects started to consider equipment with power above 3 MW, reaching up to 5 MW. To a lesser extent, there was also an increase in the number of lower power inverters, between 60 kW and 500 kW, particularly those of the string type.”
Evolution of module
The market has given preference to the use of single-axis trackers, with shares above 95% since 2017, reaching 100% in the A-5/2021 auction. “The use of single-axis tracking has contributed to achieving higher capacity factors, with more constant energy production throughout the day, but requires a larger amount of area to install the plant.”
Evolution of the capacity factor
The capacity factor (FC) considered in the regulated market is defined as the ratio between the plant's expected energy generation, in MWmed, and its installed power, in MW. Since 2017, the FC has remained at an average of 30%, with some projects reaching 35%. Although the site's radiation influences the FC, factors such as the project's technical characteristics, such as inverter structure and sizing, interfere with the efficiency of the projects.
Evolution of the implementation period
Considering the implementation schedules of photovoltaic projects enabled between 2013 and 2022, it can be stated that the average deadlines remained between 12 and 15 months. Complexes undergoing expansion can reach lower values, reaching 5 months.
Evolution of investment cost
EPE calculates that photovoltaic modules represent 40% of the cost of a photovoltaic project, structures 15% and inverters 9% and other equipment, around 4%.
“Transmission and connection costs, in addition to civil works, also represent important portions, being around 11% and 8,5% respectively. The portion identified as “others” includes several costs, including: land, socio-environmental actions, indirect costs, logistics, assembly, testing and insurance, and represents around 11% of total costs”.
EPE explains that the focus was on the technical characteristics of the projects, leaving data and analysis on costs to the “Price and Generation Booklet”.
An answer
Good Morning!
There was missing information that I think is very important, the relationship between DC and AC power.
Because they talk about the 30% performance, the relationship between generated energy and installed AC power.
Most of the costs come from installed DC power, modules, tracker, cables, land, etc.
So it is not right to compare a plant with a DC/AC ratio of 1,2 with one that reaches 1,4.
This 1,4 will have a higher energy performance generated by installed AC power.