Maataloustieteen Päivät 2012 - Suomen Maataloustieteellinen ...

POSTERIT
Maa- ja puutarhatalouden energiansäästö
25 26
Energy input and output of Finnish Agriculture
Winfried Schäfer
MTT Agrifood Research Finland, Vakolantie 55, 03400 Vihti, winfried.schafer@mtt.fi
INTRODUCTION
There are many research results available how to
save energy within the production chain level of
agricultural products. Emphasis is mainly laid
upon consumption of fossil fuels and fertilisers.
However, holistic energy analysis results on
national level of the agricultural production sector
are rare. The objective of this paper is to identify
the most energy consuming input factors of
Finnish agriculture and to set priorities were to
start energy saving measures.
METHODOLOGY
To calculate the energy input and output the
following methods were employed: first law of
thermodynamics energy analysis and energy
intensity analysis. Based on data from Finnish
statistics direct and indirect energy input and
output within the agricultural production sector
were analysed. Indirect energy inputs like goods
and services are converted into energy units
using conversion factors available from literature.
This includes both mass to energy and money to
energy unit conversion factors. The different input
factors are grouped and after conversion into
energy units, their proportion within the overall
energy input is calculated. Thus, priorities for
energy saving measures can easily be set. Different
scenarios of energy saving measures are calculated
and the resulting consequences show alternatives
how and where to save most efficiently energy in
agricultural production.
RESULTS AND DISCUSSION
The calculation results of both methods lead to
the same outcome: energy input of the Finnish
agricultural production sector is about 28 GJ/ha
and the energy balance of Finnish agriculture
is negative. The reason is that energy gain of
crop production (neglecting sun energy input)
is overcompensated by energy input for animal
production. The proportion of energy input
factors depends on the employed analysis
method. First law analysis shows, that direct
energy input is the most important input factor
followed by fertilisers and machinery. However,
energy intensity analysis shows a completely
different ranking: most energy is used up by
purchased goods and other expenses, followed
by services and feed. This shows that direct
energy input, particularly fossil energy input,
is a minor factor for agricultural enterprises
with low priority in terms of economic value.
If energy crop fuels replace fossil energy input,
animal production must be reduced by more
than 72%, which is an unrealistic measure.
However, replacing fertilisers by manure and
nutrients of recycled organic material may
reduce the energy input by 19%.
CONCLUSION
The results show that developing an ecological
recycling agriculture may reduce considerably
the energy input of the agricultural production
sector. Reduction of indirect energy input is
as much important as replacement of fossil
energy by renewable energy sources. However,
energy crops are not very suitable to replace
fossil fuels because of their low entropy and the
low conversion efficiency of photosynthesis.
The energy conversion efficiency of wind,
geothermal, and solar techniques is much
higher. However, farmers act for the time being
soundly adopting presently common fossil
energy consumption practice because it is much
cheaper than use of renewable energy sources.
KEYWORDS
Energy saving, energy crop, energy conversion, energy efficiency, Finnish agriculture
Nurmikkoalueiden perustamisessa ja hoidossa
energiaa kuluu monessa eri vaiheessa
Oiva Niemeläinen 1 ja Frans Silvenius 2
1. MTT Kasvintuotanto, MTT Planta, 31600 Jokioinen, oiva.niemelainen@mtt.fi
2. MTT Biotekniikka ja elintarviketutkimus, Latokartanonkaari 9, 00790 Helsinki, frans.silvenius@mtt.fi
TIIVISTELMÄ
”LCA in landscaping” -hankkeessa kehitetään
elinkaarianalyysiä sovellettavaksi nurmikon perustamiseen
ja hoitoon. Elinkaarianalyysin tulosten
pohjalta voitaisiin perustettavat nurmikot suunnitella
erilaiset ympäristövaikutukset mahdollisimman
hyvin huomioon ottaviksi. Primäärienergian
kulutuksen määrän arviointi on yksi keskeinen
tehtävä analyysin tekemisessä. Hankkeessa tarkastellaan
erityisesti kuinka kierrätysmateriaaleja
hyödyntävien kasvualustojen ja/tai lannoitustuotteiden
käyttö vaikuttaa viherrakentamisen primäärienergian
tarpeeseen. Erilaisten kasvualustaratkaisujen
lisäksi käytetään siemenseoksia joiden
kasvuvoimakkuus ja siten leikkuutarve vaihtelevat.
Projekti pyrkii lisäämään kiinnostusta ja mahdollisuuksia
kierrätysmateriaalien hyödyntämiseen
viherrakentamisessa ja elinkaarianalyysin käyttöä
eri ratkaisujen ympäristövaikutuksia tarkasteltaessa.
Hankkeessa esitellään kierrätysmateriaalien
käyttöä nurmikkokohteissa eri paikkakunnilla
Suomessa. Hankkeessa on tähän mennessä tuotettu
pohjaa elinkaarimallinnukselle nurmikon
leikkuun polttoaineenkulutuksista ja pienikokoisten
nurmikkoalueiden perustamisesta. Hankkeesta
on lisätietoja saatavissa verkkosivuilla:
www.lcainlandscaping.fi.
ASIASANAT
Elinkaarimallinnus, energian kulutus, kasvualusta, LCA, niitto, nurmikko, puistot, viherrakennus.
164 Maataloustieteen Päivät 2012 Maataloustieteen Päivät 2012 165