Pros and cons of Daylight Saving Time: do we still want that?

Daylight Saving Time (DST) has a long and controversial history. After being introduced in an essay by Benjamin Franklin, the idea was adopted in 1916 by Britain and Germany. The goal was to reduce the domestic consumption of coal and to give factories daylight hours to work, in order to aid the war effort.

The functioning of the system is simple: clocks go forward one hour in the summer and back again in the winter. In this way, we can enjoy extra evening daylight in warmer months and extra morning daylight during the winter.

Nowadays, most areas in North America and Europe, and some areas in the Middle East, observe daylight saving time (DST), while most areas of Africa and Asia do not. In South America, most countries in the North of the continent near the equator do not observe DST, while Paraguay and southern parts of Brazil do.

How does DST affect people’s life?

The effects of this switch strongly vary depending on the geographical location of a country: the closer you are to the North Pole, the more noticeable they are. For example in Iceland, from mid-May to mid-August the sun only sets for around three hours a night and there are only around five hours of effective daylight during the winter months.

There are both positive and negative effects due to this practice. However, sometimes it is difficult to understand whether the positive ones prevail over the negative ones, or vice versa.

Thanks to DST during the winter time, people don’t have to go at work or school in the darkness and this strongly reduces the number of traffic accidents and makes streets a safer place. At the same time, people do not adapt so smoothly to changes and this can also raise the risk of health-related issues, mostly due to the disturbed sleep cycle. A 2016 study found that the overall rate for stroke was 8% higher in the two days after the change, while  the risk drops off in the following days because our bodies and circadian clocks gradually adapt. Moreover, the Monday and Tuesday after daylight saving time in the spring have also been associated with a 10% increase in heart attacks, according to a 2012 study at the University of Alabama Birmingham.

Are DST really effective for energy saving?

Originally, DST was aimed at reducing the energy consumption. However,  there is surprisingly little evidence that it actually helps to save energy. Matthew J. Kotchen and Laura E. Grant (2008) proved that DST increases residential electricity demand, approximately by 1% (also by 2-4% during the fall). That results in a higher cost both in terms of electricity, but also for the pollution emissions.

Disagreements among European countries

The relevance of the DST related effects gave rise to several doubts about the effectiveness of the system, mostly in the North of Europe. Last year, over 70 000 Finnish citizens signed a petition in order to press EU for end to daylight saving time. The issue has a strong relevance at the European level, since all EU members must follow the same timetable to keep trade and travel running smoothly between the internal market.

The European consultation: we can have a voice!

The European Commission has launched a consultation on the daylight saving time clock changes in order to evaluate whether or not the rules should be changed. Europeans and interested organizations have until August 16th to give their opinion (the consultation and more background information are available here).

The EC is assessing two main policy alternatives: keep the current summertime arrangement or discontinue the changes and ban periodic switches, leaving each state to choose between permanent summer, winter or a different time. Repealing the current directive would not automatically abolish summertime across the EU. It would just end EU-wide harmonization and allow individual states to decide the issue.

Morocco polishes up its energy sector

Just 200 kilometres away from Marrakech, between the sight of Atlas Mountains and the beginning of Sahara desert, Morocco’s greatest effort to introduce renewable energy takes shape.

The project to construct a thermosolar plant called Noor (“light” in Arabic) in Morocco got selected in 2011 as part of an investment package from Desertec, with the main objective of promoting the development of power plants in places where renewable resources were more abundant, such as North Africa, and then being able to provide energy to Europe through the Strait of Gibraltar.

Noor has been developed in different phases. Stage I started in May 2013, with the installation of half million mirrors covering an area of about 450 hectares and an installed capacity of 160MW. It was finally connected to Morocco’s power grid on 2016, and it’s estimated to deliver throughout the year about 370GW. Following stages of the project are expected to be up and running by 2018, according to the head of the Moroccan Agency for Sustainable Energy, Mustapha Bakkoury. When that happens, the total installed capacity will be of 580MW, enough to power over a million homes.

Interestingly enough, Noor planners have decided to combine different ways of energy storage in the different stages of the project. For instance, in Stage I and II, mirrors concentrate sun’s rays onto synthetic oil that runs through pipes, and through the heating of it a water vapour is created and gets a turbine-powered generator going. Stage III, however, will use the solar power plant system: all the mirrors will reflect the sun onto a receiver on this tower, and the heat from them will be passed and stored into molten salts, which experts affirm is a more efficient way of storing solar energy, reaching up to 8 hours of energy storage.

Water use is another of the issues to face in the implementation of a solar plant in the dessert, and again, planners have given different solutions to the different phases: while Stage I started with a wet cooling system, following stages went for a dry cooling one, in order to save water. However, mirrors still need to be cleaned up regularly in order to maintain an efficiency standard in the energy production, and that’s where the most intense use of water will happen.

Morocco has realized the importance of this strategic sector and is determined to make the best out of this comparative advantage. Until recently, the country imported 97% of its energy needs, something absolutely unreasonable when considering that Morocco has one of the world’s largest potential for solar power production, with up to 3,600 hours of sun in the desert. Now, a new trend of investment in renewable energy is dominant: 34% of the country’s electric power production comes from renewable sources, mainly hydro, wind, and solar. Its plan is continue on this path, estimating a generation of 42% from renewables by 2020, and 52% by 2030.



The implications of their approach to this opportunity are of great importance, not only for their own economy, but for the African continent as a whole. The fact that the country with the closest links to Europe takes the lead and develops diverse energy strategies, thinking on its own energetic needs but also on the European market, can produce drag effects on many other African countries, that potentially could become exporter of power supplies to Europe, as well as amongst themselves. Countries like Ghana, Rwanda and Congo are already investing in solar power projects. It could be the beginning of the new era of clean energy production in Africa, and Morocco is decided to spearhead the change.

Gorona Del Viento has the wind on its sails

The Island of El Hierro (Canary Islands, Spain) covered its whole electricity demand between the 25th of January and the 12th of February of this year on a 100% with renewable resources, avoiding the use of pollutant energy sources for over more than 560 hours in 2018, and a total of almost 2.000 hours since it started operating.

This major success comes mainly explained by the positive progress of El Hierro’s first wind and pumped hydro system, La Gorona del Viento, set up on 2014. The basic idea behind the functioning of this power plant is simple: an initial deposit of water is set on an adequate high ground area of the island, and another one is set on lower ground. The water running downwards produces energy, which, together with the input brought by a small wind farm, is used to pump the water up, back to the first deposit, while producing enough surplus to also feed the electricity demand of the island.



Since the moment it started normally operating, on summer 2015, Gorona del Viento has produced more than 20.250 MWh. Its progress is being remarkable: on the first half-year of performance, its share on the total demand of electricity was 19,2%. 2016 was the first whole year for the power plant, and it reached 40,7% of the total demand. On 2017, the share kept climbing up to 46,5%.

As the president of Gorona del Viento Belén Allende pointed out, one of the keys to explain the continuous improved performance of the plant is the close collaboration with Red Eléctrica de España (REE), the corporation that controls the national electricity grid in Spain and operates the power transmission system. In this regard, REE added that the recent operative updates introduced in the system will keep leading to efficiency improvements.

The positive effects that this initiative has brought and keeps bringing to the island of El Hierro are numerous: most obvious ones are directly connected with its environmental impact. Since Gorona started operating, it has been estimated than the emission of more than 30.000 tonnes of CO2 has been avoided, as well as saving the consumption of a great amount of diesel, which translates in lower energetic dependence, one of Canary’s biggest concerns.

Beyond that, Gorona del Viento has also helped re-launching the brand of El Hierro, promoting it as an environmentally friendly destination for regular tourists, while also becoming an interesting destination for scientific tourism, going from professionals in the energy field, to students, environmental engineers…  Besides, it has helped involving the inhabitants of the island into sustainability and increasing their awareness concerning these topics.

Overall, Gorona del Viento’s progress is slowly taking it from an experiment on how to switch to a 100% renewable energy context to a wider reality, becoming an example not only for the other Canary Islands but to anyone in the world interested on how to effectively perform this transition.

How far EnergieWende has come?

Since 2010 Germany has paved its road to be a clean and sustainable country. The transition is supported by the Energiewede project, German for Energy transition, an ambitious plan to switch to a low carbon and environmentally sustainable economy. The main goals are the reductions of GHG of 80% by 2050; increase the energy supply from renewables of 60% by 2050. Additionally, Germany is closing all its nuclear plants; the phase out should be completed by 2022.

What have been the major impact of the Energy transition?

So far Germany has made huge progress, firstly, reducing by 27% its GHG emissions. Moreover, renewables have reached a significant 30% share in the German Energy mix. However, energy coming from carbon sources still accounts for 42.2% and for 14.1% from nuclear sources.


Another important achievement is that thanks to 1.5 billion euro expenses on energy research, renewables have become competitive and the power generation cost in the country shows a constant downward trend. Although, we must remark that the index of household energy prices increased since 1991, but the cost of electricity has risen less than other Energy sources, because renewables generation is today the number one source for the electric supply of the country.



Among other thing, investing in green energy has helped Germany to reduce imports of energy significantly. The German Environmental Ministry estimated that renewable energy offset 9.1 billion euros in energy imports in 2013 alone.

However, the Energiewende has not been without critics.

Because of the renewable energy levy to finance green power investment, households have experienced an increase in the electricity unit price; the surcharge in 2016 was 22.1%. Moreover, the quick phase out of nuclear generated power has increase the coal generated electricity up to 45% in 2013, consequently boosting CO2 emissions.

Although the increment in coal and lignite demand has not been caused by the energy transition. Indeed, the progressive desertion from carbon sources has played a very little role here. The explosion of coal demand must be related to the fact that since 2002 the German export of energy increased steadily. The coal binge must be related to an overall increase in power generation and exports.
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To conclude, is hard to fit everything in one article and there are many aspects we have not given voice today. Surely what has emerged is that the ambitious German plan is effective and a real energy transition is happening, without creating poverty or GDP losses for the country. The Energiewende is a coherent government policy to transform a country economically and socially, and should be replicated in other countries that are ready to take such an important step.

Solar Flying

This Sunday the Green Column is celebrating an inspiring and good event.

This Thursday, the 23rd of June, Solar Impulse, an aircraft solely powered by solar energy, completed its first transatlantic flight: 71 hours zero emission cruising from New York to Seville!

Solar Impulse flying over Hawaii
Solar Impulse flying over Hawaii

What is Solar Impulse?

It is an innovation-driven project, whose founders are the two Swiss  Mr Bertrand + Mr Borschberg, a medical doctor and an engineer,  who proclaimed themselves ambassadors of clean energy.
In fact they achieved it and showed it  up in the air as a symbolic political message:  an inspirational push to implement a strong  clean energy transition on the soil.
After all, if it is successful in the air, why shouldn’t it be on the ground?
They are actually at their 15th solar flight after beginning in 1999, after 12 years of ongoing R&D, achieving 8 world records and conquering the financial support of important investors such as Omega and Google.
Solar Impulse is actually not the first solar plane, but it is the first to fly day and night, without any fuel, only using energy stored in its batteries, weighting as much as a car, covered with 17,248 solar cells.

Here is their history: http://

Look at the stars… Whoops we can’t!

You may find yourself looking at the sky during these summer nights, but where are the stars at?

Light pollution in our cities is a serious issue. In a recent study conducted by an Italian and American research team, it has been found out that more than 83% of the world’s population experiences light-polluted night skies, including more than 99% of all Europeans and Americans. The countries with the worst skies are Italy (yes you are reading right) and South Korea.

      Most and Least light polluted countries by population’s size

You can see this horrifying data looking at the following link of the NASA Blue Marble project, showing light pollution around the globe (the most recent image however is from 2012)

But what are the real hazards of light polluted skies?

According to various researches the main negative impacts are the following:

  • Increasing energy consumption: in an average year in the U.S. alone, outdoor lighting uses about 120 terawatt-hours of energy, mostly to illuminate streets and parking lots. That’s enough energy to meet New York City’s total electricity needs for two years!
  • Disrupting the ecosystem and wildlife: light pollution disrupt natural cycles of many species of birds, insects, plants and night animals, interfering with their reproduction, hunting activities and migration patterns!
  • Harming human health: increasing risks for obesity, depression, sleep disorders, diabetes, breast cancer and anxiety are related to bad night luminosity! It also alters the circadian rhythm having severe consequence on our sleep-wake timing.
  • Effecting crime and safety: More light does make us feel safer but it does not make us safer. Different studies in English or American cities concluded that more outdoor lightening does not deter crimes!
Levels of light pollution

Moreover, the lack of darkness is causing a huge loss in terms of cultural heritage for current and future generations. Since ancient times stars have inspired science, religion, philosophy, art and literature. Just  looking at them we have been able to navigate and to explore seas, we learned about our expanding universe, not to recall the beautiful Van Gogh’s painting “Starry Night” or the infinite numbers of songs, poems and sonnets “written” under the stars.

Thinking that the majority of us will never experience a brimming night and appreciate the vastness of the universe is just as sad as terrible.

Once Stephen Hawking said: “Remember to look up at the stars and not down at your feet. Try to make sense of what you see and wonder about what makes universe exist. Be curious”

Well Dr. Hawking we all would like to follow your advice, but now how can we do that?

Exotic Renewable Energy Plants: Tidal Energy

Tidal Energy power plants are definitely some kind of an exotic form for energy production. That’s because most tidal power plants are just pilot projects that are only build for research purposes and do not create a very big amount of energy in their lifetime. Tidal energy is one form of hydropower energy that gets obtained from tides and is then converted in useful electricity. In ancient times and in the middle ages tide mills have been used to mill grain, and nowadays axial or cross flow turbines are used to produce the electrical energy that is needed in modern times. As the gravitational attraction of the moon moves huge amounts of ocean water on certain coastlines or trough lagoons, tidal power plants were build in this strategic positions, there are 4 main types of tidal power generators: Tidal stream generatorstidal barragesdynamic tidal power and a tidal lagoon.

Unfortunately the issues that come with tidal energy are fairly big, from environmental concerns on marine life (also given the danger of blade strikes and the acoustic output). From a technical and maintenance point of view corrosion in salt water and fouling have a big impact on the plants and make them hardly economically efficient.

Even tough there are some massive problems to face when it comes to significant tidal power generation, there are some steps in the right direction, like a 3,4 MW tidal power generator in the East China Sea.

Check out for more news on the argument!


Paris Summit 2015 – Each country’s pledge

Carbon Brief has been following each country’s pledge towards the Paris 2015 summit. Here on this post you will find more details on how each country pledged in the upcoming summit. While for some countries, the pledges seem a big task however it will be interesting to see if they manage to achieve the target.

For instance, Mexico – the first developing country to come forward – includes a section on adaptation, while the EU is silent on the topic. Switzerland’s pledge of a 50% reduction in greenhouse gas emissions looks high compared to the EU’s “at least 40%”, until you realise they plan to use international carbon credits where the EU will make all reductions on home soil.

These pledges are also known as “intended nationally determined contributions”, or INDCs. You can find more details of each country’s INPC on UNFCCC. If the INDCs fall short – as they are widely expected to do – there is no official mechanism in place to ratchet them up before Paris. This is where they will be incorporated into the agreement, and likely take on some element of legal force.

I have my skepticism too but let’s wait for this event to happen!

Source: Carbon Brief

Wind Hybrid Power System

Few days ago my colleague and a friend Max wrote a piece about Wind to hydrogen possibility. It was an interesting article.
It got me thinking about other possibility so in this post, I am going to write some different ways of creating energy and storing through Wind/Solar.

Hybrid power describes the combination of a power producer and the means to store that power in an energy storage medium. In power engineering, the term ‘hybrid’ describes a combined power and energy storage system.Hybrid systems, as the name implies, combine two or more modes of electricity generation together, usually using renewable technologies such as Solar Photovoltaic (PV) and wind turbines. Hybrid systems provide a high level of energy security through the mix of generation methods, and often will incorporate a storage system (battery, fuel cell) or small fossil fueled generator to ensure maximum supply reliability and security. As you can see it from the image above.

From coal usage we generate almost 50% pf pollution so using Wind energy is very very sustainable.

Let’s look at various like of Hybrid Power Systems.There are five kinds of Hybrid Power system. We will see a brief overview of each hybrid system.

1) Wind-Hydro system
2) Wind- Hydrogen System
3) Wind-Diesel System
4) Wind Compressed air system
5) Wind – Solar System

1) Wind-Hydro System – It generates electric energy combining wind turbines and pumped storage. Wind-hydro stations dedicate all, or a significant portion, of their wind power resources to pumping water into pumped storage reservoirs. These reservoirs are an implementation of grid energy storage.

2) Wind-Hydrogen System – One method of storing wind energy is the production of hydrogen through the electrolysis of water. This hydrogen is subsequently used to generate electricity during periods when demand can not be matched by wind alone. The energy in the stored hydrogen can be converted into electrical power through fuel cell technology or a combustion engine linked to an electrical generator.

3) Wind-Diesel System – A wind-diesel hybrid power system combines diesel generators and wind turbines, usually alongside ancillary equipment such as energy storage, power converters, and various control components, to generate electricity. They are designed to increase capacity and reduce the cost and environmental impact of electrical generation in remote communities and facilities that are not linked to a power grid. Wind-diesel hybrid systems reduce reliance on diesel fuel, which creates pollution and is costly to transport.

4) Wind-compressed air systems – At power stations that use compressed air energy storage (CAES), electrical energy is used to compress air and store it in underground facilities such as caverns or abandoned mines. During later periods of high electrical demand, the air is released to power turbines, generally using supplemental natural gas.Power stations that make significant use of CAES are operational in McIntosh, Alabama, Germany, and Japan. System disadvantages include some energy losses in the CAES process; also, the need for supplemental use of fossil fuels such as natural gas means that these systems do not completely make use of renewable energy.

5) Wind-solar systems –

5.1) Wind-solar building – The Pearl River Tower in Guangzhou, China, will mix solar panel on its windows and several wind turbines at different stories of its structure, allowing this tower to be energy positive.

5.2) Wind-solar lighting – In several parts of China, there are lighting pylons with combinations of solar panels and wind-turbines at their top. This allows space already used for lighting to be used more efficiently with two complementary energy productions units. Most common models use horizontal axis wind-turbines, but now models are appearing with vertical axis wind-turbines, using a helicoidal shaped, twisted-Savonius system.

solar wnd turbine

If I missed some kind of Hybrid Power system, you are welcome to comment or suggest further.

Source: Wikipedia