In Spain, as in the mediterranean basin, the development of herbaceous perennial energy crops in the extensive rainfed areas requires species that tolerate severe frequent droughts during summer. In a previous study (2011), it was shown that annual grasses like triticale or rye require annual biomass production about 8 odt/ha in order to achieve the GHG savings established for biofuels in the Renewable Energy Directive (RED) for 2018, when substituting natural gas in power plants under spanish conditions. In order to improve the results achieved with annual grasses, perennial grasses were evaluated as an alternative to supply sustainable biomass to power plants. Elytrigia elongata - called “Tall wheatgrass”- is a summer dormant perennial C3 grass native from Eurasia and has been tried in constraints environments all over the world. Its palatability for livestock is low at the same time that it could have acceptable characteristics to use for combustion in industrial boilers to produce electricity power. The aim of this report is to demonstrate and evaluate the potential of Elytrigia elongata to avoid GHG emissions and obtain lower economic costs in marginal areas of Spain and the Mediterranean region. Our research built scenarios based on experimental plots (2 years growth) in three locations of Spain with very different climate conditions The preliminary evaluation results suggest that the use of C3 drought tolerant perennial crops, like tall wheatgrass in marginal areas of Spain for electricity production might present a better performance in terms of energy yields, costs of the electricity and GHG savings, than utilizing annual grasses like triticale and C4 grasses like switchgrass than cannot be established because of spring and summer droughts.

1. Perennial energy crops for semiarid lands in the
Mediterranean: Elytrigia elongata, a C3 grass with summer
dormancy to produce electricity in constraint environments
Emiliano Maletta*1, Carlos Martin-Sastre2, Pilar Ciria1, Aránzazu del Val1, Annabel Salvado4, Laura Rovira4, Rebeca Díez3,
Joan Serra4, Yolanda González-Arechavala2 and Juan Carrasco1
1
CEDER-CIEMAT. Energy Department. Biomass Unit
2
IIT. Institute for Research in Technology - ICAI School of Engineering - Comillas Pontifical University
3
ITACyL. Biofuels and Bioproducts Resarch Centre
4
IRTA, Mas Badia (17134) Girona, Spain. Phone: +34- 972780275, Fax: +34-972780517
* Corresponding author: emiliano.maletta@ciemat.es

2. Introduction
INTRODUCTION
Semiarid environments and marginal areas usually
produce
•Low yields
•High economic costs
•Low GHG emissions savings
•Low energy balances
About 4M ha of arable lands available in Spain
Cereal-grains yield (national average): 1.8 t/ha

3. Perennial grasses background in Spain
• C4 perennial grasses require water for establishment and long droughts
are the rule in that moment => C4 grasses need irrigation support
• Traditional C3 perennial grasses limited to northern cold areas
•Farmers grow winter cereals (grains+straw) to feed power energy plants
•Drought tolerant AND productive species required for semiarid lands to
supply biomass for industry
Marginal yields, marginal benefits
Previous study on rye and triticale for electricity in a real 25MW
power energy plant (Northern Spain).
Need at least 8 odt/ha to reach 60% GHG emissions savings
compared to natural gas electricity

4. Background
Power energy plant (25MW) for biomass combustion.
Demonstration plot (2 ha)
160,000 ton per year. Straw price for farmers: 75-85€/odt
(mostly agricultural residues and rye/triticale/oats).

5. Tall wheatgrass:
Scientific names: Elytrigia elongata (Host),
Thinopyrum ponticum (Podp)
•Origin: Eurasia
•C3: three photosynthetic metabolism pathway (a
“cool season” grass)
•Perennial summer dormancy: resist long summer
US Tall wheatgrass trials (Salon
drought periods, through senescence and buds et al, 2009)
dormancy recommencing growth in autumn
•Deep root system / suited for alkaline soils
•From 50s in US, Argentina and Australia as
feedstock for livestock on marginal areas and for
re-vegetation (green covers)
•Biomass characteristics allow co-firing and 2nd
generation biofuels
•Breeding programs and commercial seeds are
available worldwide
•Productions in literature: 3-16 odt/ha.year
US Tall wheatgrass (Photo:
USDA-NRSC, 2008)

6. Objective
Objective
Tall wheatgrass performance regarding biomass
costs at the farm level and LCA for power energy
What we did?:
Tall wheatgrass (TW): using data from 3 sites with experimental
plots established in 2009 and 2010 to feed scenario building
LCA on 15 scenarios assuming future yields and lifetime (15
years) for three regions
Economic costs at the farm level for TW and cereals
Comparison: TW vs Rye/triticale/oats (GHG, energy balance and
mean costs)

7. Materials and Methods
Locations – soil – climate
Girona
Ombrothermic diagram for
the period September 2010- 70 140
60 120
Temperature (ºC)
August 2011 in all three
Precipitation (mm)
50 100
40 80
sites. 30 60
20 40
10 20
0 0
Girona Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Months
Rains: 400-700mm
Palencia
Palencia Soria 70 140
60 120
Precipitation (mm)
Temperature (ºC)
50 100
40 80
30 60
20 40
10 20
0 0
Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Months
Soil characteristics in 0-30 cm layer of the three Rains: 300-500mm
Soria
sites used for scenario building in this study
70 140
60 120
Temperature (ºC)
P K Organic 50 100
pH N (%) Texture 40 80
(mg/kg) (mg/kg) Matter (%) 30 60
20 40
Girona 8,2 0,11 28 192 1,65 loam 10 20
0 0
Palencia 8,5 0,09 50,4 0,22 1,37 Franc Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Months
Soria 6,8 0,03 6,6 61,2 0,6 sandy Rains: 300-600mm
Average Temperature (ºC) Precipitation (mm)

8. Tall wheatgrass
Mowed biomass let in the
ground in the first year
(Soria, 2010)
Wheatgrasses strips re-
Unfertile soil on a experimental parcel of growth (Palencia, March
wheatgrasses in Soria, (above: Jan 2009; 2012)
below: regrowth 2nd year, March 2010).

9. Tall wheatgrass trials
Establishment
year in
Palencia
(2009)
Small plots in Girona 2nd year in Soria,
(May 2011) (plots established
Second year harvest (Soria, Aug 2010)
in 2010)

10. Materials and Methods
Tall wheatgrass scenarios
Regions Soria Palencia Girona
Management and inputs 2009 2010 2009 2010 2009 2010
Experimental plot Strips Strips small plots Strips small plots small plots
Plot size (total in m2) 5000 4500 225 135 90 90
Tillage operations Chisel, harrowing, rotary tiller
Base (NPK in kg/ha) 350 500 none
Top fertilizers NAC27% (kg/ha)
1st year none none none
Succesive years 250 300 0 250
Sowing rate 40 20 30 20 20
Sowing date Nov.2009 Nov.2010 Oct.2009 Oct.2010 Oct.2009 Oct.2010
Herbicides
pre-emergence none Glifosate none
post-emergence none 2-4D 2-4D and MCPA
Weed control mowings 2010 2010 2009 and 2010 2010 and 2011
Cut numbers 1 1 1 1 2 (june - Oct) 1
Biomass yield range (odt/ha) 2.5 - 6 4 - 10 5 - 12 5 - 12 12 - 39 10 - 40
Yield scenarios (mean value for lifetime)
Regions Very low Low Middle High Very High
Palencia (odt/ha) 4,1 5,8 7,0 8,2 10,2
Girona (odt/ha) 6,2 8,1 9,5 10,9 12,8
Soria (odt/ha) 2,4 3,9 5,0 6,1 7,0

11. Tall wheatgrass scenarios
Evaluations:
•Economic costs data: Ministry of Agriculture and local
farmer costs. No subsidies taken into account.
•Energy balances and GWP: Simapro and Ecoinvent
•GHG emissions savings comparing biomass electricity to
replaced fossil reference (natural gas electricity in Spain)
•Winter grasses vs tall wheatgrass under rain fed conditions

12. Results & Discussion
Biomass economic cost comparison
Most frequent yields
in the study regions
Winter cereals in best areas produced biomass costs of about 80€/odt
Tall wheatgrass could be competitive with yields as low as 4 odt/ha.year

13. Energy inputs (TJ fossil per TJe)
0,002 0,002
Soria
0,011 0,011
5,0%
1,0%
4,4%
0,8%
Palencia
0,035
0,035 14,4%
16,5%
0,098
46,0%
0,051
20,7% 0,146
59,8%
0,067
31,5%
Seed and Pesticides Fertilizers Seed and Pesticides Fertilizers
Field Works Biomass transport Field Works Biomass transport
Power Plant Operation 0,001 Power Plant Operation
0,7%
Girona 0,011
6,4%
0,035
21,0%
0,085
50,7%
0,036
21,3%
Seed and Pesticides Fertilizers
Field Works Biomass transport
Power Plant Operation

14. Energy yields
Energy yields were higher in TW compared to winter cereals
In lower yields scenarios, TW can produce higher energy yields

15. Global warming potential (mg CO2eq/TJ)
Soria
0,6 0,2
2,3
0,6
1,8%
0,2
0,6%
2,3
5,2%
1,5% 0,4% Palencia
6,4%
3,5
8,0%
4,6
12,9%
14,5
40,8%
21,7
50,2%
15,0
34,7%
13,4
37,6%
Seed and Pesticides Fertilizers Seed and Pesticides Fertilizers
Nitrous Oxide Field Works Nitrous Oxide Field Works
Biomass transport Power Plant Operation Biomass transport Power Plant Operation
Girona
0,6 0,1
2,3% 0,4%
2,3
8,0%
2,4
8,6%
12,8
45,3%
10,0
35,4%
Seed and Pesticides Fertilizers
Nitrous Oxide Field Works
Biomass transport Power Plant Operation

16. Results & Discussion
Global Warning Potential (GWP)
Tall wheatgrass produce less GHG emissions (mg CO2eq/TJe) at similar biomass yields compared to
annual grasses when producing electricity

17. Results & Discussion
GHG emissions savings compared to
natural gas electricity
90%
Oat
80%
Lopsided Oat
70% Rye
60% Triticale
50% Tall wheatgrass
(Soria)
40% Tall wheatgrass
(Palencia)
30% Tall wheatgrass
(Gerona)
20% Tall wheatgrass
m
G
N
n
u
a
o
c
e
r
s
t
f
i
l
10%
%
m
H
G
C
B
d
p
n
S
y
o
g
v
a
c
e
r
s
t
)
(
l
i
0%
2000 4000 6000 8000 10000 12000 14000
Yield (kg d.m. ha-1)
Minimum GHG emissions savings for tall wheatgrass: 50% for lowest yields (average
above 70%) when replacing natural gas electricity

18. Conclusions
CONCLUSIONS
•According to the obtained results, the mean production
costs of TW at the farm level 40-60 €/odt for low and medium
yield scenarios (5-7 odt/ha.year). These costs are lower than
those of winter cereals. Under these conditions TW biomass
could be suitable to supply power energy plants in Spain
• Considering the explored range of crop yields and
management conditions, GHG emissions savings when using
TW biomass for producing electricity are significantly higher
(50-90%) of those of winter cereals (5-70%). Energy yields
ranged from 1.5-3 in winter cereals and 2.5-7.5 in TW.
•These results suggest that TW can have a significant
potential as energy crop in marginal lands in Spain.

19. Thank you for
your attention !
Acknowledgements:
This work has been developed in the framework of the Spanish National and Strategic Project “On Cultivos” co-funded by
the Spanish Ministry of Economy and Competitiviness and the European Funds for Regional Development under the dossier
PSE-120000-2009-15.