Getting energy from the vine

74 renewable energy focus November/December 2009

Feature article

Getting energy from the vineWHEN TEXANS TALK OF LIQUID GOLD,

THE CHANCES ARE THEY ARE REFERRING TO THE CRUDE OIL

THAT IS SYNONYMOUS WITH THE LONE STAR STATE. BUT IN ALUCIA,

SPAIN, ANY LOCAL USING THE SAME TERM WILL PROBABLY BE TALKING ABOUT

OLIVE OIL, WIDELY USED THROUGHOUT THE MEDITERRANEAN AND BEYOND

FOR COOKING. HOWEVER, AS ANDY ALLEN REPORTS FROM SPAIN,

OLIVE RESIDUES ARE ALSO AN

IMPORTANT ENERGY SOURCE.

Across mainland Spain’s southernmost region – the world’s most impor-

tant olive producing area – olive groves cover more than 1.4 million

hectares. The vast majority of these groves produce olives for oil.

Yet Spain’s own liquid gold has more than just gastronomic value. Energy

professionals point out that the olive crop generates biomass with a fuel

value of 1.3 million tonnes of crude oil per year as a by-product. It is an

eye-catching fi gure in a country that imports about 99.5% of its oil and

natural gas.

There is nothing new about olive power in these parts. Some rural homes

have traditionally used olive wood cuttings to fuel domestic fi res. The

energy-rich olive stones left once the pulp has been extracted have also

been used to power boilers. However over the last 15 years there has

been a move towards a much more comprehensive use of olive residue as

an energy source. In 1995 the fi rst plant powered by olive residue opened

in the province of Cordoba, in central Andalucia.

Now there are 15 power stations in Andalucia using olive biomass,

generating 164 MW per year, according to Maria José Colinet, director of

renewable resources and energy infrastructures at the Agencia Andaluza

de la Energía (Andalucian Energy Agency). And a further three are due to

come online this year with a combined power of 21 MW, Colinet says. And

despite the recession, which has struck Spain hard, she says that there are

still a “large amount of investment proposals coming through”.

Biomass yet to catch up to PV and wind

Given Spain’s renewable energy credentials it is unsurprising that a signifi -

cant industry has grown around this fuel source. The country has become

a market leader in the photovoltaic sector and wind power. Earlier in 2009

US President Obama named Spain as one of three world leaders in the

renewable energy fi eld.

Yet inside Spain there is a widespread sense that the biomass sector has

failed to develop as expected.

Heikki Willstedt, energy and climate change expert at the Spanish offi ce

of WWF, points out that Spain’s 2001 Renewable Energy Plan anticipated

that the country would be generating 3,000 MW per year by 2011. Even

though the target was considered outlandishly optimistic at the time, the

638 MW Spain generates annually from biomass still falls far short of even

realistic expectations.

As it stands there is a sense in Spain that the future of one of the olive

biomass industry is at a crossroads.

The reason lies in the complex nature of the biomass itself and the logis-

tics behind its collection, which has led to unequal development across

the sector. Willstedt explains, “quite simply people in this area were not

aware how much it was going to cost to collect the biomass and trans-

port it to the plants.”

Getting to the ‘low hanging fruit’

According to Marie Jose Colinet every hectare of olive grove generates

three tonnes of olives as well as around three tonnes of pruned wood

annually. In addition to this it generates two tonnes of what the Spanish

term orujillo – the energy-rich substance created after all oil has been

mechanically and chemically extracted from olive pulp.

Orujillo is eff ectively the low-hanging fruit of the sector. It is easy to

collect from its source – the 2000 or so processing centres across Anda-

lucia – and transport.

Using it as a fuel source also saves the farmer the labour of safely

disposing of a material that can cause pollution if it leaks into the soil.

Olive Oil is seen as the liquid

gold of Spain’s Andalucia region.

renewable energy focus November/December 2009 75

Bioenergy/Energy from waste

These advantages mean the bulk of power stations using olive biomass

in Andalucia as a source use orujillo.

To Jose La Cal, head of the Energy Agency in Jaen, which lies at the centre

of Andalucia’s main olive growing region, orujillo is “easy biomass”. This

makes it all the more regrettable that a more developed sector has not

grown up around it, he believes.

Nearly 800,000 tonnes annually have been exported in recent years

(though this has dropped to around 500,000 last year), mainly to EU coun-

tries like Italy and the UK. The reason is that these countries benefit from

Green Certificate schemes which allow them to pay orujillo producers

higher prices than Spanish firms. This however negates much of its value

as an environmentally friendly fuel.

“The coexistence in the EU system of different incentives for the genera-

tion of electricity from renewable sources is distorting the situation in

Jaen and biomass across Spain,” he says. “This, in turn means that power

plants that use olive biomass are experiencing difficult times. Unless

remedied the situation could become irreversible.”

Not everyone is so pessimistic about the future of orujillo-powered plants.

Juan Luis Casimiro, production director at Valoriza Energia, the market

leader with three power stations partly dependent on orujillo, says: “Every

year orujillo exports are lower. This year we are expecting the exportation

figures to be much lower than in previous years.”

Olive wood cuttings

In any case complaints that the orujillo has failed to live up to expecta-

tions are dwarfed by the failure to exploit a much larger resource: the

pruned wood cuttings. Several times a year olive farmers prune their

trees to stimulate growth and ensure they remain disease free. Then, in

a traditional ritual which is marked by plumes of smoke across the coun-

tryside, cuttings are burned in the countryside to avoid wood building up

and contaminating healthy trees.

The process is labour intensive, causes the release of large amounts of

CO2 and particle emissions, and also presents a fire risk. Little wonder that

olive cuttings are seen as a natural biofuel.

A team at the University of Jaen’s department of chemical and environ-

mental engineering has been studying the viability of converting the

wood to bioethanol, a product with high added value that can be used

as fuel, in mixtures or replacing gasoline.

So far the team, under professor Eulogio Castro, has found that with

available technology the equivalent of 200,000 tonnes of oil could be

extracted from the available cuttings in Andalucia. At present his team is

engaged in a study to lay the groundwork for a biorefinery which obtains

a range by-products as well as ethanol from olive cuttings.

Olive cuttings (coming from plants like the one pictured) are relatively moisture free, making transport and collection economical compared to black poplar – a wood widely grown for use as biomass

in Spain. The wood grows, like black poplar, in demarcated rows, facilitating its collection mechanically.

Spain’s own liquid gold has more

than just gastronomic value. Energy

professionals point out that the olive crop

generates biomass with a fuel value of

1.3 million tonnes of crude oil per year

as a by-product



“One of the main features of this biomass, in addition to being renewable,

is that it is not competing with any other use as a foodstuff or animal

feed, unlike other renewable raw materials that are used today in the

production of biofuels such as corn,” said Professor Castro.

If extracting ethanol from cuttings is still at the research stage, there is

no novelty in using olive wood as a fuel for power stations. According to

Casimiro olive cuttings are relatively moisture free, making transport and

collection economical compared to black poplar – a wood widely grown

for use as biomass in Spain. The wood grows, like black poplar, in demar-

cated rows, facilitating its collection mechanically.

Yet at present only 14% of cuttings generated are used for energy

purposes. Using all the cuttings generated would provide 200 MW of

electrical power, according to the Andalucian Energy Agency.

Valoriza Energia is one of the few companies that has adapted its plants

to use cuttings as well as orujillo. According to Juan Luis Casimiro plants

now typically use 50% orujillo and 50% from other woods. Even so, only

a small part, perhaps four to five per cent of the total, is from olive wood.

There are several reasons why olive wood has not taken off as much as

hoped. According to Casimiro early technical setbacks within the sector

deterred investment.

“The process of controlled combustion in a closed environment for 365

days a year is, industrially speaking, highly complex,” he says. Now the

basic technological issues have largely been resolved, he says.

Yet it is only in the last two years that plants have started to use cuttings

as a fuel. There has been no time to allow for the development of a much-

needed service sector to aid in collection and transport and the costs

of collecting olive wood in the countryside are simply too great to be

economically viable given current electricity tariffs.

One solution to this problem lies in mechanising the collection of the

wood. Valoriza Energia itself has produced four prototypes of a self-

propelled automated pruning machine, which it has developed with the

Andalucian Energy Agency.

“Every year the prototypes go into the field at pruning time and we make

improvements based on their performance,” says Casimiro. He believes

such technology will at least partly improve the viability of the collection

of cuttings.

Paying the olive growers

More controversial is the question of what, if anything, olive growers

should receive in return for supplying their cuttings to biomass compa-

nies. This has proved a thorny issue among some growers who see

biomass companies profiting from their material and want a slice of the

action, according to Willstedt.

Every hectare of olive grove generates

two tonnes of orujillo – the energy-rich

substance created after all oil has been

mechanically and chemically extracted

from olive pulp



Biomass power producers are adamant that their margins are not high

enough to allow them to pay the olive producers, and say that in fact

saving the farmer the labour of burning the crop, leaves him better off

than under the traditional system.

“This (the biomass) is something that has traditionally been an expense

for the farmer,” says Casimiro. “Between it costing him money and it

becoming a source of income for him there is a very big leap.”

Casimiro says perhaps in the future it will cost the grower less to prune

and burn their cuttings but it is unrealistic to expect them to receive

income for their cuttings.

Meanwhile even increasing the mechanisation of biomass collection will

not rule out the need for what Casimiro terms “administrative help” in

the form of higher feed-in tariff s. This is the system used in Spain to

determine the premium which must be paid by law to renewable energy

producers who supply to the national grid.

Competing with PV

One touchy subject for advocates of biomass is the support given to the

thriving PV sector under Spain’s current Renewable Energy Plan 2005-2010.

“Right now feed-in tariff s for photovoltaic energy are around double

those for biomass but until September last year they were three times

as high,” says La Cal.

He also believes the lack of electrical infrastructure and shortage of points

where power plants can connect to the national grid is exacerbated by the

fact that many of the existing connection points are given to photovoltaic

sites. In his opinion the excess tariff s and support given to the photovoltaic

sector have unfairly skewed Spain’s renewable energy market in its favour.

This in turn has helped prejudice public opinion against renewable

energy in general, he says, pointing to complaints that feed-in tariff s put

an “unjust burden” on the taxpayer.

Click through

Interested in further information on bioenergy? Click on the following

links from the digital issue of the magazine:

Quality protocol introduced for biodiesel from waste cooking oil and rendered animal fats – http://tinyurl.com/yka4lem

Algae – an annoying growth, or green bioenergy gold? –

http://tinyurl.com/ygru6dv

Earlier this year Zapatero [the Spanish

President] argued in favour of a stimulus

package for the Spanish economy

arguing that “green spending”, particularly

that aff ecting renewable energy would

be a good investment for the future.

http://tinyurl.com/yka4lem

http://tinyurl.com/ygru6dv

renewable energy focus November/December 2009 79


In La Cal’s view favouring biomass generates more benefits in terms of

the employment it creates throughout the logistics chain. Willstedt at

the WWF is not convinced biomass is automatically superior in any social

sense to photovoltaic power. He says the rents paid by photovoltaic sites

have provided much needed income for many rural communities.

In any case the biomass sector strongly believes the Government should

grant it higher feed-in tariffs. In addition to this La Cal believes it needs to

be governed by a more sophisticated strategic approach than a simple tariff

can provide, considering the potential benefits it could bring to rural Spain.

“The problem here is not just one of energy, it is one of rural develop-

ment. I think in Switzerland or Austria biomass is treated as a strategic

issue rather than one to be regulated with a single degree.”

The Government stance

Help may be at hand from José Luis Rodríguez Zapatero’s Government.

Spain’s new Renewable Energy Plan, to run from 2011-2020, is currently

under consultation and will supersede the current renewable energy

plan. Earlier this year Zapatero argued in favour of a stimulus package

for the Spanish economy arguing that “green spending”, particularly that

affecting renewable energy would be a good investment for the future.

According to the Ministry for Industry, Tourism and Commerce details of the

new plan will not be released until mid-2010. But a spokesman added that

in questions concerning renewable energy, the ministry generally consid-

ered the more developed an industry was, the less state aid it required.

On the other hand, Zapatero’s own finance minister has publicly stated

that he does not think the country can afford any kind of stimulus. If his

view prevails there will be surely be less money on the table for renew-

able energy.

Yet Heikki Willstedt believes simply increasing the feed-in tariffs may

not be the answer. According to Willstedt this will simply lead to more

consternation from olive growers, and it may make more sense to give

money directly to the growers to collect the wood, and at very least there

should be a study into whether feed-in tariffs are the best way to help

the sector develop. Willstedt also cautions that steep rises in petrol prices

could make the costs of transporting the cuttings even higher.

It seems that while over the last decade or so olive oil has become the

gastronomic darling of the world, olive-based fuels have yet to win

quite such a hold in the marketplace. Yet if the logistic and regula-

tory challenges can be overcome, Andalucia’s liquid gold may yet win

another kind of lustre.

If the logistic and regulatory

challenges can be overcome,

Andalucia’s liquid gold [olive oil]

may yet win another kind of lustre.

Documents

Getting energy from the vine