Featured Research

from universities, journals, and other organizations

Waste could generate up to 7 percent of electricity in Spain

Date:
March 5, 2010
Source:
FECYT - Spanish Foundation for Science and Technology
Summary:
Researchers have calculated the energy and economic potential of urban solid waste, sludge from water treatment plants and livestock slurry for generating electricity in Spain. These residues are alternative sources of renewable energy, which are more environmentally friendly and, in the case of solid urban waste, more cost effective.

This is a sewage treatment plant of Monfragüe (Cáceres, Spain).
Credit: Naturaleza Fragüe.

Researchers from the University of Zaragoza (UNIZAR) have calculated the energy and economic potential of urban solid waste, sludge from water treatment plants and livestock slurry for generating electricity in Spain. These residues are alternative sources of renewable energy, which are more environmentally friendly and, in the case of solid urban waste, more cost effective.

Using waste to generate electricity has economic and environmental advantages. "It gives added value to waste, because it can be seen as a type of fuel with zero cost, or even a negative cost if taxes are paid to collect it," says Norberto Fueyo, lead author of the study and a researcher at the Fluid Mechanics Group of the UNIZAR.

According to the researcher, generating electricity from waste avoids "pernicious" impacts. Waste in landfill sites releases methane and other polluting gases, so incinerating solid urban waste will reduce the volume of waste that reaches the landfill sites in the first places, as well as the implicit risks of landfills themselves (possible emission of methane into the atmosphere).

The study, published in the latest issue of the journal Renewable Energy, has shown that waste in Spain could generate between 8.13 and 20.95 TWh (terawatt hours). "This electricity generation was 7.2% of electricity demand in 2008," says Fueyo.

The researchers stress that the amount of methane generated from different kinds of residues is equivalent to 7.6% of gas consumption in 2008.

In terms of the economic cost, "solid urban waste is the most cost-effective," according to the researcher, because local authorities carry out the waste collection and local inhabitants pay for it. Since the waste is transported to large landfill sites or waste treatment plants, installing electricity generation systems "could take advantage of economies of scale due to the large volumes involved."

Cost depends on the heat generated

According to the study, incineration of waste and degasification of landfill sites are the electricity generation technologies with lowest financial cost. Producing electric energy through anaerobic digestion (a biological process in which organic matter decomposes into biogas in the absence of oxygen and through the action of a group of specific bacteria) is much more expensive.

"However, its profitability relies on being able to get value out of the heat generated during the process," explains Fueyo, who says this technique is "not competitive, but makes use of the heat to offset the costs of generation." However, the researchers point out that "directly applying this waste to agricultural land as fertiliser could contaminate groundwater with nitrates."

In order to evaluate the potential and the cost of generating electricity, the researchers applied the methodology in municipal areas (in the case of solid urban waste and sludge from water treatment plants) and regional areas (for livestock slurry) throughout the whole of Spain.

The work shows that the centre and south of the Iberian Peninsula, the Balearic and Canary Islands have the "greatest interest" in putting technologies into place to use solid urban waste.

In terms of using water treatment plant sludge, the coastal areas of Galicia. Valencia and Alicante, as well as central and southern Spain, were also areas of interest. The study also shows that certain areas of Aragon, Castilla-La-Mancha, Castilla-y-León, Extremadura, Galicia and Andalusia "would be effective" for using livestock slurry.

The EU 20-20-20 package

The research into electricity generation comes in response to the European Union (EU) objective to fulfil the 20-20-20 package for the year 2020, in other words to substitute 20% of the total energy consumed in Spain for energy from renewable resources, reduce CO2 emissions by 20% in comparison with 1990 figures, increase biofuels used in transport by 10%, and achieve energy savings of 20%. "For Spain, each one of these targets alone is a challenge, which becomes much bigger when they are all taken together," underscores the scientist.

Norberto Fueyo says the most problematic objective is that relating to increasing the amount of biofuels used in transport by 10%. "It is not achievable and is socially and environmentally questionable, because of the amount of land it requires and because it means using foodstuffs to produce fuel."

Even if the figure of 10% of biofuels in transport is achieved, "there will need to be an increase of around 45% in the contribution of renewables (including hydroelectric energy) to electricity generation in order to achieve a figure of 20% of renewable energy within total consumption," the expert says. The scientist adds that, in order to achieve the objective, it will be "essential" to promote energy saving and efficiency "and consider all possible sources of renewable energy, including waste."


Story Source:

The above story is based on materials provided by FECYT - Spanish Foundation for Science and Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Gómez, Antonio; Zubizarreta, Javier; Rodrígues, Marcos; Dopazo, César; Fueyo, Norberto. Potential and cost of electricity generation from human and animal waste in Spain. Renewable Energy, 2010; 35 (2): 498 DOI: 10.1016/j.renene.2009.07.027

Cite This Page:

FECYT - Spanish Foundation for Science and Technology. "Waste could generate up to 7 percent of electricity in Spain." ScienceDaily. ScienceDaily, 5 March 2010. <www.sciencedaily.com/releases/2010/02/100223100706.htm>.
FECYT - Spanish Foundation for Science and Technology. (2010, March 5). Waste could generate up to 7 percent of electricity in Spain. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2010/02/100223100706.htm
FECYT - Spanish Foundation for Science and Technology. "Waste could generate up to 7 percent of electricity in Spain." ScienceDaily. www.sciencedaily.com/releases/2010/02/100223100706.htm (accessed August 22, 2014).

Share This




More Earth & Climate News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California Drought Stings Honeybees, Beekeepers

California Drought Stings Honeybees, Beekeepers

AP (Aug. 21, 2014) — California's record drought is hurting honey supplies and raising prices for consumers. The lack of rainfall means fewer crops and wildflowers that provide the nectar bees need to make honey. (Aug. 21) Video provided by AP
Powered by NewsLook.com
Thousands Of Species Found In Lake Under Antarctic Ice

Thousands Of Species Found In Lake Under Antarctic Ice

Newsy (Aug. 20, 2014) — A U.S. team found nearly 4,000 species in a subglacial lake that hasn't seen sunlight in millennia, showing life can thrive even under the ice. Video provided by Newsy
Powered by NewsLook.com
Unsustainable Elephant Poaching Killed 100K In 3 Years

Unsustainable Elephant Poaching Killed 100K In 3 Years

Newsy (Aug. 20, 2014) — Poachers have killed 100,000 elephants between 2010 and 2012, as the booming ivory trade takes its toll on the animals in Africa. Video provided by Newsy
Powered by NewsLook.com
Charter Schools Alter Post-Katrina Landscape

Charter Schools Alter Post-Katrina Landscape

AP (Aug. 20, 2014) — Nine years after Hurricane Katrina, charter schools are the new reality of public education in New Orleans. The state of Louisiana took over most of the city's public schools after the killer storm in 2005. (Aug. 20) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins