Articles
COMBINED HEAT AND POWER (CHP) AS A POSSIBLE METHOD FOR REDUCTION OF THE CO2 FOOTPRINT OF ORGANIC GREENHOUSE HORTICULTURE
Article number
915_7
Pages
61 – 68
Language
English
Abstract
In recent years, the horticultural sector has been confronted with questions about the carbon footprint of its products.
However, the global standards used to calculate the greenhouse gas (GHG) emissions have some gaps that do not address the sector-specific issues for horticulture, such as crop rotation, land use of soil organic matter and the use of combined heat and power (CHP). The need for a sector-specific standard which addresses these interpretation gaps was identified.
In response to this need, the Carbon footprinting of horticulture products protocol (DNCF2009) was developed by the Dutch horticultural sector.
The protocol is intended to follow the guidelines of PAS 2050 for the life cycle analysis of horticultural products; a lot of situations in greenhouse horticulture have to be described in so-called Best Practices. In greenhouse cultures, energy consumption is the main component of the CO2 emission.
To save energy, many Dutch greenhouse companies use CHP to heat their greenhouses.
These growers may sell the superfluous electricity produced by the CHP to the national grid, thereby generating two products; the horticultural product, e.g., a tomato and the electricity.
The CO2 emission of the electricity production should be deducted from the total CO2 production of the CHP, in order to calculate the CO2 emission that should be assigned to the production of the crop.
To investigate the carbon footprint of organic crop production, an organic crop production system and a conventional crop production system are compared, and the effect on carbon emissions of a CHP system is studied for both production methods.
An example for organically grown tomatoes is worked out.
It shows the specific organic input factors and their impact on the CO2 footprint.
The functional unit used is kg CO2 per 1000 kg product, and the system boundary is from seedling production until the delivery of product at the distribution center of wholesalers or supermarkets.
The CO2 footprint of the organic tomato crop grown without cogeneration is 10% higher than that of the conventional crop grown without cogeneration and more than double that of the conventional crop grown with CHP. The higher footprint compared with the footprint of conventional growing without CHP can be mainly explained by the lower yield of the organic crops.
With CHP, the organic and conventional tomato crops have an equal CO2 footprint.
The use of CHP is a way to reduce the CO2 footprint for both organic and conventional tomato growers.
However, the global standards used to calculate the greenhouse gas (GHG) emissions have some gaps that do not address the sector-specific issues for horticulture, such as crop rotation, land use of soil organic matter and the use of combined heat and power (CHP). The need for a sector-specific standard which addresses these interpretation gaps was identified.
In response to this need, the Carbon footprinting of horticulture products protocol (DNCF2009) was developed by the Dutch horticultural sector.
The protocol is intended to follow the guidelines of PAS 2050 for the life cycle analysis of horticultural products; a lot of situations in greenhouse horticulture have to be described in so-called Best Practices. In greenhouse cultures, energy consumption is the main component of the CO2 emission.
To save energy, many Dutch greenhouse companies use CHP to heat their greenhouses.
These growers may sell the superfluous electricity produced by the CHP to the national grid, thereby generating two products; the horticultural product, e.g., a tomato and the electricity.
The CO2 emission of the electricity production should be deducted from the total CO2 production of the CHP, in order to calculate the CO2 emission that should be assigned to the production of the crop.
To investigate the carbon footprint of organic crop production, an organic crop production system and a conventional crop production system are compared, and the effect on carbon emissions of a CHP system is studied for both production methods.
An example for organically grown tomatoes is worked out.
It shows the specific organic input factors and their impact on the CO2 footprint.
The functional unit used is kg CO2 per 1000 kg product, and the system boundary is from seedling production until the delivery of product at the distribution center of wholesalers or supermarkets.
The CO2 footprint of the organic tomato crop grown without cogeneration is 10% higher than that of the conventional crop grown without cogeneration and more than double that of the conventional crop grown with CHP. The higher footprint compared with the footprint of conventional growing without CHP can be mainly explained by the lower yield of the organic crops.
With CHP, the organic and conventional tomato crops have an equal CO2 footprint.
The use of CHP is a way to reduce the CO2 footprint for both organic and conventional tomato growers.
Authors
P.C.M. Vermeulen, C.J.M. van der Lans
Keywords
Life Cycle Assessment (LCA), co-generation, electricity production, natural gas, sustainable greenhouse, organic horticulture
Online Articles (23)