CCRES AQUAPONICS CROATIA

 

  

HRVATSKI CENTAR OBNOVLJIVIH IZVORA ENERGIJE

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 Projekt

CCRES AQUAPONICS

Više informacija o Projektu CCRES AQUAPONICS na :

http://ccresaquaponics.yolasite.com/

 All the food CCRES produced during the year is given to poor families.

Za sve dodatne informacije slobodno nas kontaktirajte.

HRVATSKI CENTAR OBNOVLJIVIH IZVORA ENERGIJE (HCOIE)

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Indirect land use change ILUC

Indirect land-use change (ILUC) means that if you take a field of grain and switch the crop to biofuel, somebody somewhere will go hungry unless those missing tonnes of grain are grown elsewhere.

Economics often dictates that the crops to make up the shortfall come from tropical zones, and so encourage farmers to carve out new land from forests.

Burning forests to clear that land can pump vast quantities of climate-warming emissions into the atmosphere, enough in

theory to cancel out any of the benefits that biofuels were meant to bring.
The European Commission has run 15 studies on different biofuel crops, which on average conclude that over the next decade Europes biofuels policies might have an indirect impact equal to 4.5 million hectares of land – an area the size of Denmark.
Some in the biofuels industry argue that the Commissions science is flawed and that the issue could be tackled by a major overhaul of agricultural strategy to improve productivity or by pressing abandoned farmland back into action. Waste products from biofuels production can also be fed to animals, they say, so reducing the pressure on land resources.

Conventional biofuels like biodiesel increase carbon dioxide emissions and are too expensive to consider as a long-term alternative fuel, a draft EU report says.

The study ‘EU Transport GHG [greenhouse gases]: Routes to 2050’ estimates that before indirect effects are counted, the abatement cost of reducing Europe’s emissions with biofuels is between €100-€300 per tonne of carbon.

At current market prices, this would make their CO2 reduction potential up to 49 times more expensive than buying carbon credits on the open market at €6.14 a tonne.   

But the EU’s authors conclude that it “it is not possible (and useful) to determine cost effectiveness figures for [conventional] biofuels” because their indirect effect - measured in cleared forests and grasslands (‘ILUC’) - make it a CO2-emitting technology.

The latest report will feed a growing unease about the reasons for the EUs original biofuels policy - justified in environmental terms - and the way it has developed since.

“The truth is that policy makers inside and outside Europe are doing biofuels for other reasons than environmental ones,” said David Laborde, a leading agricultural scientist and author of key biofuels reports for the European Commission.

“It’s a new and easy way to give subsidies to farmers, and it’s also linked to industrial lobbies that produce these biodiesels, and also what they will call energy security,” he told EurActiv.

“They want to diversify the energy supply, and keep their foreign currencies instead of buying oil from the Middle East. They prefer to keep it for something even if it is not efficient or even green,” he added.

The 10% target

In 2007, the EU first set a 10% target for the use of blended biofuels in transport by 2020.

Although the target was re-sourced from ‘biofuels’ to ‘renewable energy’ in 2009, analysts say that 8.8% of the EU target will still be provided by biofuels, and up to 92% of that will come from conventional biofuels like biodiesel.

Industrial associations disagree, putting the EU’s ratio of sugar-based ethanol, one of the best-performing biofuels, to biodiesel, one of the worst, at 22%-78%.

But both the original announcement and the Renewable Energy Directive two years later conditioned biofuel use on subsequently neglected criteria of cost-efficiency, sustainability and, where available, the use of second generation fuels.  

“I don’t think we are there on cost-effectiveness,” said Géraldine Kutas, Brussels representative of the Brazilian Sugarcane Industry Association (UNICA).

“There are no monetary provisions to support this in the directive, and second generation biofuels are still a promise. They are not commercially available yet,” she said.

Even trying to address the issue of indirect sustainability criteria for biofuels had gummed up the EUs policy-making process, she acknowledged. 

French farmers

Research by EurActiv has uncovered evidence that the EU’s original biofuels target was set as much for industrial and political reasons, as environmental concerns.

Claude Turmes, the European Parliament’s rapporteur responsible for steering the Renewable Energy Directive into law, said that business lobbies had influenced his negotiations with the then-French Presidency of the European Council.

“There were two lobbies, the sugar farmers lobby and the German car industry who tried to prevent the EU’s CO2 and cars legislation,” Turmes (Greens/Luxembourg) told EurActiv.

“The origin of the 10% renewables in transport target was the fact that these two lobbies joined forces to impose it on the Commission.”

EU insiders spoken to by EurActiv agreed, saying that biofuels had been a quid-pro-quo demanded for the imposition of ‘greener’ measures in the directive that would encourage wind and solar energy, and cut emissions. 

European sugar farmers had suffered in the 2006 Common Agricultural Policy reform which reduced the guaranteed sugar price by 36% and opened up the European sugar market to global competition.

A guaranteed market for agrifuel made from sugar-based ethanol held out some prospect of compensation. And the strength of the French farmers lobby made removing the 10% target “an absolute no go area” for Paris, Turmes said.

“The farm industry was obviously interested in biofuels, biochemicals and the bio-economy more generally,” Kutas added.

But Europe’s sugar farmers profited far less from the EU’s biofuels policy than growers of feedstocks for biodiesel, better suited to the continent’s diesel-based auto fleet.  

Car industry

EU officials say that the car industry was also instrumental in pushing for the biofuels target to be included as a compromise to bridge the gap between the 130g of CO2 per km that the EU wanted as a target for 2012 and the 140g that the car industry was prepared to offer.

“It was no secret,” a source told EurActiv. “It was very clear what they were lobbying for and it went all the way up the Commission”.

As a result, officials in the EU’s energy directorate responsible for biofuels did not treat research which questioned the fuel’s environmental credentials in the same light as that which supported it, multiple sources confirm.  

The EU’s biggest error was “that we started to make a policy without knowing the effect it would have,” Laborde said.

“We are now discussing the land use effect after saying for ten years that we need biofuels to reduce emissions,” he went on. “It was a serious mistake.”

Indirect emissions proposal

Brussels is due to publish a proposal measuring the indirect emissions caused by biofuels later this year, distinguishing between low-emitting biofuels such as ethanol and high-emitting ones like biodiesel.

But the EU’s decision-making process has been paralysed by the ongoing dispute between its energy directorate – which does not want ILUC factors considered – and its climate directorate, which does. And there are other problems too.    

Both the Renewable Energy and Fuel Quality directives contain ‘grandfathering’ clauses exempting all existing biofuels installations as of 2014 from further legislation until 2017.

As the biofuels industry’s existing capacity is already on the cusp of meeting the 10% target, according to a new report by the environmental consultants Ecofys, this would create massive overcapacity.  

The Institute for European Environmental Policy has calculated that on current trends, land conversion of between 4.7 million and 7.9 million hectares would be needed to accommodate the extra biofuels production, an area roughly the size of Ireland. 

But the introduction of any ILUC factor would probably rule out high-emitting conventional biodiesels, the majority of Europe’s biofuels production.

That would create a political backlash in EU states such as France and Germany, and potentially tear up the compromise which allowed the Renewable Energy Directive to be passed in the first place.  

For now, the proposal remains stuck in the corridors of an EU that appears equally frightened of the political consequences of admitting a policy mistake and the environmental consequences of denying it.

CCRES special thanks to 

Brussels Network Office:

International Press Centre

Boulevard Charlemagne, 1 b1

B-1041 Brussels

CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)

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Cultivation of Algae

Cultivation of microalgae can be done in open systems (lakes, ponds) and in controlled closed systems called photo-bioreactors (PBR).

Open cultivation systems use ponds or lakes with added mechanical equipment to grow microalgae. Open ponds were the first cultivation technology for mass cultivation of microalgae. In this system water levels are kept no less than 15 cm, and algae are cultured under conditions identical to their natural environment. The pond is designed in a raceway configuration, in which a paddlewheel circulates and mixes the algal cells and nutrients.

Open cultivation system for growing algae

The raceways are typically made from poured concrete or they are simply dug into the earth and lined with a plastic liner to prevent the ground from soaking up the liquid. Baffles in the channel guide the flow around the bends in order to minimize space. The system is often operated in a continuous mode, where the fresh feed (containing nutrients including nitrogen phosphorus and inorganic salts) is added in front of the paddlewheel, and algal broth is harvested behind the paddlewheel after it has circulated through the loop. Depending on the nutrients required by algal species, several sources of wastewater can be used for algal culture. For some marine-type microalgae, seawater or water with high salinity can be used.

Outdoor algae farming

Although open ponds cost less to build and operate than closed systems using PBRs, this culture system has its disadvantages. The ponds can be built on any type of land but need large land areas for considerable biomass yield. Because they are in the open air, the water levels are affected from evaporation and rainfall. Natural CO₂ levels in the atmosphere (0.03%-0.06%) are not enough for continuous mass growth of microalgae. Biomass productivity is also limited by contamination with unwanted algal species, organisms that feed on algae or other poisonous particles. Only few species can be grown in normal conditions.
Other types of construction use: 1) circular ponds where circulation is provided by rotating arms; 2) inclined systems where mixing is achieved through pumping and gravity flow.

Closed cultivation systems use PBRs – containers made of transparent materials for optimised light exposure. Enclosed PBRs have been employed to overcome the contamination and evaporation problems encountered in open systems. These systems are generally placed outdoors for illumination by natural light. The cultivation vessels have a large surface area-to-volume ratio. The most widely used PBR is a tubular design, which has a number of clear transparent tubes, usually aligned with the sun’s rays. The tubes are generally less than 10 centimeters in diameter to maximize sunlight penetration. The medium broth is circulated through a pump to the tubes, where it is exposed to light for photosynthesis, and then back to a reservoir. A portion of the algae is usually harvested after it passes through the solar collection tubes, making continuous algal culture possible.

Tubular photobioreactor for growing algae

In some PBRs, the tubes are coiled spirals to form what is known as a helical-tubular PBR. These systems sometimes require artificial light for energy, which adds to production costs.  Either a mechanical pump or an airlift pump maintain a highly turbulent flow within the reactor, which prevents the algal biomass from settling. The photosynthesis process generates oxygen. In an open raceway system, this is not a problem as the oxygen is simply returned to the atmosphere. In closed PBRS, the oxygen levels will build up until they inhibit and poison the algae. The culture must periodically be returned to a degassing zone—an area where the algal broth is bubbled with air to remove the excess oxygen. Also, the algae use CO₂, which can cause carbon starvation and an increase in pH. Therefore, CO₂ must be fed into the system in order to successfully cultivate the microalgae on a large scale.
PBRs require cooling during daylight hours, and the temperature must be regulated at night as well. This may be done through heat exchangers located either in the tubes themselves or in the degassing column.
The advantages of enclosed PBRs are obvious. They can overcome the problems of contamination and evaporation encountered in open systems. The biomass productivity of PBRs can average 16 times more than that of a traditional raceway pond. Harvest of biomass from PBRs is less expensive than from raceway ponds, because the typical algal biomass is about 30 times as concentrated as the biomass found in raceways. Controlled conditions in closed systems are suitable for genetic modification of algae cells and enable cultivation of better quality species (e.g. microalgae with higher oil content).
However, closed systems also have disadvantages. Technological challenges with PBRs are: overheating, bio-fouling, oxygen accumulation, difficulty in scaling up, cell damage by shear stress & deterioration and expensive building & maintenance. Light limitation cannot be entirely overcome because light penetration is inversely proportional to the cell concentration. Attachment of cells to the tubes’ walls may also prevent light penetration. Although enclosed systems can enhance biomass concentration, the growth of microalgae is still suboptimal due to variations in temperature and light intensity.
R&D in algae biotechnologies focus on developing innovative PBR designs and materials. Different developed designs are: serpentine, manifold, helical and flat containers. From these elevated reactors can be oriented and tilted at different angles and can use diffuse and reflected (artificial) light for growth. More specific information is available in PBRs section.
After growing in open ponds or PBRs, the microalgae biomass needs to be harvested for further processing. The commonly used harvest method is through gravity settlement or centrifuge. The oil from the biomass is extracted through solvent and further processed into biodiesel.

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