Solar Energy Beyond Photovoltaics






Sometimes we hear solar energy and quickly think of electric energy produced with photovoltaic panels. And it is that photovoltaic technology has become a boom in recent years.

The accelerated decrease in manufacturing prices of the panels, together with an increase in competition and adaptation of the technology, have driven an escalation in solar installations around the world.

In Mexico, in March alone, we broke the record for electric energy generated by photovoltaic solar panels. This reached 1.6 TWh of energy settled in the National Electric System operated by CENACE; which represented 6% of the electric energy generated in the country.

However, there are other forms of use of solar energy that we rarely talk about. On the one hand, thermal heat, that is, the use of solar irradiation to produce heat that can be used in industrial processes or for domestic or commercial consumption.

Heat consumption in homes can be divided into three large groups: space heating, cooking food and heating hygienic water. Together, cooking food and heating water represent 72% of heat in homes. For this purpose, electricity, LP gas and natural gas are used, but above all firewood. This represents 46% of the total primary energy used for heat in homes.

To address this part of the demand, various types of technology have been developed that collect solar irradiation to, for example, heat water or spaces both in homes and in businesses or offices, reaching temperatures from 30º to 90º Celsius.

Photovoltaic Solar Energy and Solar Thermal Heat

In a quieter revolution than the one photovoltaic solar energy has experienced, solar thermal heat has also had significant growth. In 2017, the total area covered by collectors was 675 million square meters and a total installed capacity of 472 GWth distributed in almost 120 million installations around the world.

According to data from the International Energy Agency, the mentioned installed capacity produced 1,404 PetaJoules in 2017. It represented a reduction of greenhouse gases of 135 million tons of CO2 equivalent worldwide, particularly in China.

In Mexico, according to data from the Ministry of Energy, CONUEE, IRENA and GIZ, there is an economically profitable potential in industry, businesses and homes that amounts to almost 33 Gigawatts. This could help reduce emissions not only from homes but also from industry.

Mexican industry represents close to 31% of heat demand at the country level and requires low heat cycles —less than 150ºC— for pasteurization, cleaning, cooking or bleaching; medium heat cycles —between 150 and 400ºC— for distillation, coloring and compression; and high heat cycles —more than 400ºC— for industrial transformation processes, which solar heat technology could provide with the correct incentives and with a policy oriented toward reducing greenhouse gas emissions.

This is not all, but space is running out, and next week we will address a very interesting technology: concentrated solar energy, which allows generating electric energy by conventional means but without using fuels, using a principle and a mechanism very different from that of photovoltaic panels. Until then.

This article was originally published by Business Insider México.
Date: April 20, 2021
Original Link: https://businessinsider.mx/energia-solar-opinion-paul-alejandro-sanchez/ [offline]
Archived Link: https://web.archive.org/web/20240723111757/https://businessinsider.mx/energia-solar-opinion-paul-alejandro-sanchez/ [Archived]

Diamonds with Recycled CO2






We have already talked about the possibility of capturing CO2 directly from the air and also about the energy requirements that this technology would have. But on this occasion I want to talk about one of the uses that captured carbon would have: becoming diamond. That is, competing with nature, which has taken years with high pressure and temperature to convert carbon into diamonds, to produce laboratory diamonds with captured carbon.

The idea of producing laboratory diamonds is not new; we could trace it back to the 19th century. In our times, for some years now, it is already an increasingly common reality; diamonds have been created in controlled environments, in laboratories that use cutting-edge technology to replicate natural processes such as high pressure and temperature that are involved in the transformation of graphite into diamond.

As is well known, since the end of the 18th century it was discovered that diamonds were, in reality, pure carbon. Then, multiple efforts began to develop them with a certain degree of economic viability. The first laboratory diamonds appeared in the 1950s and became popular from the 1970s and 1980s.

It should be noted that when we think of diamonds, those used for jewelry quickly come to mind, particularly in engagement rings and other high-end jewelry. However, diamonds, which do not necessarily have the aesthetic characteristics of the diamonds used in jewelry, are also used in other industries such as machinery and cutting equipment, thermal conductors, electronics, optical materials and even lasers.

The idea, then, is simple, at least in concept. Capture CO2 from the air, with the technology that we have already analyzed, to convert the captured CO2 into diamonds using laboratory processes. With this, it avoids the greenhouse effect that causes global warming and climate change, at the same time that it creates a desired product.

A company in the United States even already sells the idea of laboratory diamond jewelry that offsets your greenhouse gas emissions. The company is called Aether and maintains that each carat removes at least 20 tons of CO2 in the air; which is equivalent to offsetting 2 and a half years of emissions of an average person.

The process to convert the captured CO2 is that of high temperature and high pressure, which is the oldest and cheapest to date. The process requires an internal temperature of 1400º Celsius and high pressure to convert the captured CO2 into diamonds. The diamond produced is jewelry-grade because of its high market value, which competes with natural diamonds.

As we pointed out last week, to the high energy cost of capturing CO2 directly from the air is added the cost of the process of heating the CO2 to 1400º Celsius and subjecting it to high pressure. Therefore, if energy from conventional sources is used, the final CO2 balance would be negative. For this, the company uses renewable energy sources, with which it complements, at least in theory, the virtuous cycle of circular energy.

Without a doubt, recycled CO2 diamonds are not natural diamonds, but in practice they are identical and difficult to determine if they are from laboratories. In addition, they have an advantage by eliminating the problems of conflict, environment and monopolistic practices that have characterized the industry. And you, would you buy a recycled CO2 diamond?

This article was originally published by Business Insider México.
Date: April 14, 2021
Original Link: https://businessinsider.mx/diamantes-con-co2-reciclado/ [offline]
Archived Link: https://web.archive.org/web/20240223124233/https://businessinsider.mx/diamantes-con-co2-reciclado/ [Archived]

Circular Energy and Recycled CO2






The previous week we addressed the possibility of recycling CO2 captured directly from the air to give it other uses or, failing that, to store it. The advantage of this application is that it addresses emissions from mobile sources, mainly transport, and historical emissions, unlike the capture of emissions in fixed sources such as electricity generation plants or cement factories.

We concluded the circular effect that this measure would have in the energy sector, which generates almost 75% of global CO2 emissions. However, capturing the CO2 emitted by fixed and mobile sources related to the energy sector and transport also requires energy. And it is no small thing. Research published in the journal Nature indicates that, if massively implemented, direct air CO2 capture systems to capture all the remaining gas and gas in generation by 2100 would represent around 25% of total energy consumed.

In such a way that we have a circular energy problem; if the energy used to bring direct air CO2 capture machines to life comes from fossil sources, there would be a balance problem; more emissions would be produced while trying to control the existing ones.

What is the solution?

The expected answer comes in two ways. On the one hand, in the hope that technology advances and improves its energy efficiency per kilogram of captured CO2; on the other, in a world dominated by energy generation through renewable sources and storage.

In this way, solar and wind generation and thermal storage, in hydrogen cells or in gravity, could provide 100% decarbonized energy to turn on the CO2 capture machines. That would reduce the greenhouse effect caused by CO2 and other gases that cause global warming.

Consequently, the decrease of CO2 could lead to a lower effect of climate change and, in this way, to an energy and circular transition.

Of course, thinking about capturing CO2 directly from the air is a solution that allows a transition and management of historical and current emissions from fixed and mobile sources. In such a way that, accompanied by other transition efforts such as a revolution in renewables for generation and in mobility, both electric or through hydrogen, would allow thinking about a process of total decarbonization in this century.

Without a doubt, there is still much to think about developing this technology and adapting it throughout the world; however, this leads us to another situation: can we convert recycled CO2 and not only store it? We will talk about that next week.

This article was originally published by Business Insider México.
Date: April 6, 2021
Original Link: https://businessinsider.mx/energia-circular-y-co2-reciclado/ [offline]
Archived Link: https://web.archive.org/web/20240526060424/https://businessinsider.mx/energia-circular-y-co2-reciclado/ [Archived]