LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 1B: TOWARDS LIFE CYCLE SUSTAINABILITY ASSESSMENT 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
3. Results and discussion: energy saving case study
3.1. Description
In 2010, in collaboration with Dairy Management Inc., Ensave performed an energy audit of a farm located
in New York state. The audit encompassed all sources of energy used for dairy activities, such as electricity,
fuel and propane. The recommendations of the audit were twofold:
Replace existing lighting fixtures with High Performance (HP) T8 fluorescent fixtures or T5 High-
Output (HO) fluorescent fixtures, both especially designed for agriculture applications. These fixtures
and bulbs are more energy efficient.
Replace existing barn ventilation fans with more energy efficient 36” circulation fans.
This case study assesses the differences in GHG impact and in costs for those installations compared to the
reference scenario. Table 1 lists the main data for the LCA computations.
Table 1. LCA data for the energy efficient equipment case study
Type of data Value Reference
Total herd 1,710 cows Ensave report
Annual milk production 21,233,225 kg/yr Ensave report- assumed FPCM
GHG impact of electricity 0.84 kg CO2e/kWh Asselin-Balençon et al., 2012
GHG impact of $1 lighting equipment 0.93 kg CO2e/$ produced US 1998 Input Output data for “lighting fixtures
and equipment” section
GHG impact of $1 ventilation equipment 0.60 kg CO2e/$ produced US 1998 Input Output data for “electrical”
section (SimaPro databases manual)
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The cost data used are listed in .
Table 2. Most of the specific data come from the Ensave report. Expected lifetime of equipment has been
assessed by expert judgement (farmer, Dec 2011). The discount rate has been set at the long-term interest
rate.
Table 2. Cost characteristics for the energy efficient equipment case study
Unit Lighting investment Ventilation investment
Cost of investment $ 39,219 21,700
Expected lifetime Year 10 7
Accounting lifetime Year 5 5
Estimated annual energy saving kWh/year 144,768 34,298
Total electricity consumed on farm in kWh/year 1,244,440
reference scenario
Initial price of electricity $/kWh $0.073 (Ensave, 2010)
Discount rate= Long term interest rate % 6
Annual inflation (2001-2011) % 2.5 (U.S. DoL, 2012)
Annual variation of electricity price
(2000-2010)
3.2. Cumulated results and Net Present Values
% 3.7 (U.S. EIA, 2012)
The cumulated costs and carbon footprint differentials are shown in Fig. 1. Year 0 represents the year of
investment. There is a positive carbon footprint differential due to the manufacturing of the new equipment,
and a positive cost differential due to the cost of the new equipment. Year after year, the new equipment
generates energy savings, which translates into both cost and carbon footprint savings; those savings are
cumulated. For the year equal to the lifetime of the investment, the final datapoint gives the total cumulated
cost and impact for the scenario.