There has been talk for some time now about photovoltaic solar energy, but there are still many doubts about the subject. Many questions still go around in people's heads: “Is it worth it? There are even kits being sold on the internet!” “Is that really it?” But, after all, What is it and how does it work?
Basically, photovoltaic solar energy is electricity produced from sunlight (photo=light). It is clean and renewable energy. But, you may be wondering: “Are those those black panels we see on the roofs of houses?” Not exactly…
Solar heating or solar energy?
Until very recently, we looked at the black signs on the roofs of some houses and knew it was solar energy, but for water heating from the shower or the pool. In a very simplistic way, they were black plates with water coils inside being heated by the heat of the sun.
But now, if you pay more attention, you will notice that they can be different. They can be photovoltaic panels, that is, plates that transform the sunlight into electrical energy. Yes, the one you use in the socket! 😉
A little history
This technology is quite old. The first photovoltaic solar cells were used in satellites, an excellent way to generate electricity up in space. Check out the chronology involving this type of energy below.
1990 – autonomous systems
In the 1990s, the technology became cheaper and became viable for use in isolated houses, street lamps and water pumping systems. In regions where electricity does not reach, It is cheaper to install a stand-alone solar photovoltaic energy system than taking the distribution network there. These are the so-called autonomous systems: a photovoltaic panel, a charge regulator and a battery. The battery allows the use of energy at times when there is no sun. We are talking about small systems, for a lamp, a TV and a refrigerator, for example.
In the late 1990s, with the falling cost of photovoltaic panels, grid-connected systems were encouraged in Japan by the “PV Roofs” program, and then by similar programs in Germany and the United States, followed by Spain, the Netherlands, Switzerland and Australia. In 1999, of the 200MWp installed, 60MWp were small grid-connected photovoltaic systems. Grid-connected systems do away with the need for batteries and send energy directly to the electrical grid, so, sometimes you are taking energy from the grid, sometimes you are putting energy into it.
2000 – advances in technology
Meanwhile, in Brazil, some institutions such as USP, COPPE, CHESF, among others, were already testing small systems connected to the grid, of up to 6.2kWp. By then, the technology was ready; all that was needed was to make it cheaper and have regulation so that it would be possible to officially feed electricity into the grid of the concessionaire and actually receive a discount on the bill.
2012 – grid-connected systems, distributed generation and energy credits
Finally, in 2012, came ANEEL Resolution REN 482/12, known as “Solar Energy Incentive Law”, which established the rules for access to microgeneration It is distributed minigeneration to the electricity distribution and compensation systems (net metering) known as “energy credits”. It is this resolution that regulates the exchange of energy with the electrical grid, that is, it was from then on that it became possible to generate energy on the roof, feed it into the utility grid and get a good discount on your bill!
The creation of this Resolution allowed the owner of a renewable source generator with a power of up to 5 MW to inject into the grid the energy that was not consumed at the time of generation, receiving credits (in kWh) on the electricity bill. The consumer, therefore, pays, each month, only the value of the difference between the energy consumed from the public grid and that generated by it.
2015/2016 – water crisis and the importance of energy efficiency
In 2015, Brazil experienced a severe water crisis, which led to an increase in energy prices. But what is the relationship between the water crisis and energy?
We have an abundance of rivers and our energy matrix is primarily hydroelectric. For this reason, a few years ago, Brazilians tended to think calmly about the hydroelectric issue. However, our lack of action regarding the impacts of climate change has led us to the current situation. Red tariffs level 3 and the possibility of levels 4 and 5. Thermoelectric plants being activated and generating dirtier and more expensive energy.
The equation is not easy to solve. We need to develop economically and, generally, this growth is linked to increased energy consumption. We have not been able to increase energy production to levels capable of keeping up with this demand and, on the other hand, the negative impacts of climate change make the situation even more complicated.
And how can we work to reverse this process?
The first action to be taken to solve this equation is called energy efficiency! It allows that, with the same amount of energy, it is possible to produce more or maintain the same levels of production or comfort. reducing consumption. The second action is inevitable and indisputable: we have to clear our matrix looking for more sources stable and renewable such as solar and wind.
Shared generation
In this scenario, in 2015, ANEEL improved Distributed Generation with the REN Resolution 687/2015, which conferred more rights for those who generate their energy, in addition to creating new energy compensation models, increasing the possibilities for those who want to adopt solar energy. Among the changes, which came into effect in 2016, are the increases in the maximum power of energy generators (from 1 MW to 5 MW) and the validity period of credits on the electricity bill (from 36 to 60 months).
Furthermore, a great novelty was the possibility of shared generation. But what does this mean? It means that it became possible to build a large power plant in a remote location, where land is cheaper and the sun is abundant, free from the shadow of large cities and form consortia, associations or cooperatives. In this way, it is possible offer clean energy to many different consumers. If the biggest problems for small consumers, whether individuals or legal entities, were the lack of space and money for installation of a photovoltaic system, at home or in the office, you no longer need to worry.
This means that, through consortium or cooperative models, we can have access to a certain amount of renewable energy according to our needs. For example, if the property consumes, on average, 300kWh/month, it is possible to choose to buy between 150 and 250 kWh/month, or up to the equivalent of the total, since the surplus is not lost, but turns into credit, which can be used for up to 60 months.
There are still small bottlenecks, such as administrative difficulties with distributors, but we can say that Brazilian energy regulations already allow anyone has access to renewable energy.
This modality brings advantages that go beyond environmental ones, since Conventional market rates tend to grow increasingly and can fluctuate suddenly depending, for example, on rainfall.
In practice, how are things happening?
Five years after the regulation of micro and mini distributed energy generation by ANEEL, Brazil reached the milestone of 17 thousand connections. Most connections are in the residential segment, around 13 thousand installations. As can be seen in the graph below, Minas Gerais is the leading state in the country, followed by São Paulo, Rio Grande do Sul and Rio de Janeiro.
These are some of the results identified by the research “The Brazilian Distributed Photovoltaic Generation Market”, which reached its fourth edition in 2017. This research is an integral part of the America of the Sun Program, developed by the Institute for the Development of Renewable Energy in Latin America (IDEAL) together with the Brazil-Germany Chamber of Commerce and Industry of Rio de Janeiro (AHK-RJ).
Companies participating in the Study were asked which the average time to complete all steps of the installation of a grid-connected photovoltaic system – from the signing of the contract between the company and the customer to the approval by the distributor and the effective connection of the system to the grid. In the 154 companies that carried out some project in 2016, the average installation and connection time was two months and 15 days.
In the first edition of the Study, in 2013, this number was even higher: companies took about six months to complete the design, installation and connection. Recent data shows that the time spent on the entire process has been optimized and that, with each new year, the installation and connection happen in less time, which is a very positive point for the end consumer.
In addition to the installation time having decreased over the years, another crucial point is the average installation price, which has also been falling. In the power range up to 5 kWp, the installation companies reported an average of R$ 7.51/kWp. Depending on the region, a 5kWp kit can generate 500 to 700kWh in a month, more than enough to meet the demands of a large family or two medium-sized families. Since the beginning of the research, this price has fallen by around 15% in the power range up to 5 kWp. In the graph below, it can be seen that in the other installed power ranges the average price also suffered a fall since 2013, the first edition of the survey.
Next steps!
Now that you know more about photovoltaic solar energy and understand the advantages that adopting this system can bring to your installation, be sure to consult a specialist before purchasing any kit online!
Are you interested in the topic? Would you like to know more? Simulate the characteristics of a solar system and/or find an installer? All this and much more can be found on the website http://americadosol.org/, a program for the dissemination of photovoltaic solar energy in Brazil and across the continent. Access it, find out more!
* Post written by Gisele Benedetto, Ipiranga; Rosana Corrêa, House of the Future; Taynara Mighelão, IDEAL and AHK-RJ; and Tatiana Araujo, CEBDS.
** This post is part of the partnership with Secovi Rio with the Energy Efficiency in Buildings Project (EEB Lab), of Brazilian Business Council for Sustainable Development (CEBDS).
*** Text originally published in Green Condominiums Blog.
