Archive for September 2008

A new type of vertical axis wind turbine for city spaces

September 25, 2008

A 5 Kw prototype of a new type of wind turbine with vertical axis and horizontal blades is ready to make its market debut.  It is a product developed by the company Indesmedia (IDM) EOL, based in Cantabria (Northern Spain). It is designed to be installed in urban spaces like buildings and industrial plants.

The installation of two prototypes was recently completed at the Besaya Business Park (Cantabria). Both devices are being tested by technicians from Indesmedia before being moved to Barcelona, where they will be reinstalled in a building for an R+D project headed by the engineering arm of the Spanish utility Endesa.

The current phase is testing the structural resistance, electronic controls and power electronics of the wind turbine, as well as the performance of different types of blades.

The product is the result of a project funded by the wind and solar energy program from the Spanish Ministry of Science and Innovation. Its main objectives are minimising the visual impact and noise of the wind turbines, simplifying their manufacturing process and installation and finding new spaces where to take advantage from wind energy, such as urban spaces, ships and marine platforms.

Another important factor considered in their design was reducing risks for birds and bats, hence they rotate at low speeds (under 10 rpm) and the towers are no more than 13 yards high. Two other key institutions collaborating in this project are INTA and Robotiker-Tecnalia. INTA, the Spanish Institute for Aerospace Technology, did the design of the blades and the rotor. Robotiker-Tecnalia, a technology center specialised in ITC technology and product development, assisted in the development of the power electronics.

New, more efficient solar cells patented in Spain

September 23, 2008


A team of researchers at the Spanish High Council for Scientific Research (CSIC) has patented a new type of solar cells whose efficiency is up to 30% higher than conventional solar cells. Their photonic crystal is composed of a nanostructured surface which increases the transmission of light inside the device.

CSIC researcher and project leader, Pablo Aitor Postigo, who works at the Institute of Microelectronics of Madrid (IMM-CSIC), points out the advantages of these cells: “They are more efficient in harnessing the sun’s rays. Current systems can only take advantage of 30% of solar energy to convert it into electricity. Our solar cells will enhance the effectiveness of these systems by up to 30%.”

The techniques used by these scientists to produce the crystal can be applied industrially.  The large-scale manufacture of these new solar cells would have the same cost as conventional ones.  In addition, they require less semiconductor material to get the same amount of energy.

Postigo has worked together with several researchers from the Institute of Microelectronics of Madrid (CSIC) and the Solar Energy Institute and the University of Pavia in Italy.

Spain to plant 45 million trees, set up a Climate Change Research Institute

September 13, 2008

Fulfilling an electoral promise, the Spanish Government has announced a drive to plant 45 million trees in the next four years as part of a $128 million program in the Spanish peninsula and in the Canary and Balearic Islands, which have been suffering from frequent forest fires causing major economic and ecologic losses.

Canarian landscapes - Ruiz ravine

Canarian landscapes - Ruiz ravine

Elena Espinosa, minister for the environment, said that reforestation will mainly target endemic tree species and will be carried out over a total area of 151,476 acres, mostly in National Parks and communal lands.

The trees will help to prevent desertification or land degradation by consolidating soils and preventing erosion. Other benefits will be improving the landscape and  consolidating ecological corridors.

The project will employ 2,997 people a year in rural areas, according to Espinosa.

The minister also announced the creation of a Climate Change Research Institute in Zaragoza, the same location where the International Expo 2008 for Water was held this year, discussing the challenges of water and sustainable development.

Nearly one-third of Spain’s roughly 200,000 square miles faces a “significant risk” of desertification, according to the Spanish environment ministry. The main goal of the institute will be to promote the analysis and research of climate change in Spain. It will also recommend measures which Spain could adopt to fight the phenomena.

FCC acquires two photovoltaic farms in Cordoba, Spain

September 9, 2008

Madrid-based Spanish Group FCC has bought from Sky Global Solar two photovoltaic farms located in Cortijo Viejo and Sierrasita, in the province of Cordoba, for $203 million USD. The farms are being connected to the grid this month and will therefore qualify for the current tariff of 0.435 euro/kWh. They have an installed capacity of 20 megawatts.

FCC originally built these two plants for Sky Global Solar, a solar  turnkey-project developer and module manufacturer and distributor with headquarters in Hong Kong and Spain.

This is FCC’s second investment in renewable energy in less than a month. In May, FCC said it would move into the energy sector to diversify its business, especially in the areas of cogeneration, energy efficiency, renewable energies and new waste-to-power technologies.

Its first move following that strategy was to acquire in August  Babcock & Brown´s 420 MW of wind energy assets in Spain (see FCC of Spain buys into wind energy).

Together, those acquisitions and future renewable energy deals are being grouped into a new business unit called FCC Energia, the company says.

New techniques to protect wind generators during voltage dips

September 9, 2008
Jesus López Taberna

Jesus López Taberna

An industrial engineer and member of the INGEPER Research Team at the Public University of Navarre (Spain), Jesús López Taberna, has put forward in his PhD two protection techniques  so that wind generators continue to be operative despite breaks in electricity supply.

The objective of Jesús López Taberna was to provide a solution to the problems caused by sudden dips in voltage in the electric grid. The fruit of his research is a rotor model which enables anticipating how the wind power unit will behave in these situations. This system allows the  generator to remain in operation during these voltage dips and thus prevent the wind energy converter from ceasing to function.

A voltage dip is a sudden reduction in potential in the electric grid, followed by a rapid return to its normal value. This, at times, can be caused by lightning or a tree falling on power cables, but also to a large company consuming a lot of energy in one go. This drop in voltage happens in a matter of milliseconds; “we are aware of it because the lights begin to flicker or because they go off and on for a moment– but, for a machine, this can be an eternity”, explains Mr López. In fact, an interruption of half a second in a productive process can cause the whole process to block.

With wind generators, in the case of a voltage dip, the electronic part of the unit can burn out or  be otherwise  destroyed, unless a protection system is installed. “The current system of protection, known as Crowbar, has the advantage of being able to protect the machine but its disadvantage is that it causes the machine to come to a halt”, points out Mr López.

Considering that, in Spain, for example, there are days when wind-powered energy can account for one third of electricity production, the problem can prove to be a serious one.

Jesús López Taberna specifically proposed in his PhD thesis two effective protection systems.  Both have been patented. The first, only requiring changing the control of the machine converter, has been transferred to a manufacturer for its introduction into wind farms worldwide; the other requires changing elements inside the machine, so it is still in study with the idea to apply it in the next generation of wind turbines.