Changes in the
Cumulative Energy Demand (CED) implementation in ecoinvent v3
The Cumulative Energy Demand (CED) method in ecoinvent v2.2 took into account the following 13 elementary flow entries :
• Energy, potential (in hydropower reservoir), converted [resource/in water] **
• Energy, geothermal, converted [resource/in ground] **
• Energy, gross calorific value, in biomass [resource/biotic]
• Energy, gross calorific value, in biomass, primary forest [resource/biotic]
• Energy, kinetic (in wind), converted [resource/in air] **
• Energy, solar, converted [resource/in air] **
• Coal, brown, in ground [resource/in ground]
• Coal, hard, unspecified, in ground [resource/in ground]
• Gas, mine, off-gas, process, coal mining [resource/in ground]
• Gas, natural, in ground [resource/in ground]
• Oil, crude, in ground [resource/in ground]
• Peat, in ground [resource/biotic]
• Uranium, in ground [resource/in ground]
and from their quantities as they appear input side in the Life Cycle inventory determined eight figures for the following categories:
• renewable energy resources, biomass
• non-renewable energy resources, fossil
• renewable energy resources, geothermal, converted
• non-renewable energy resources, nuclear
• non-renewable energy resources, primary forest
• renewable energy resources, solar, converted
• renewable energy resources, potential (in barrage water), converted
• renewable energy resources, kinetic (in wind), converted
For the renewable energy sources each category typically accounts for one specific energy, and has no characterization factor. In this sense they simply are used as inventory indicators.
Uranium extracted from ground is weighted with a coefficient of 560.000 MJ per kg.
Only the indicator "non-renewable energy resources, fossil" has an aggregation. It sums up the consumption of eight fossil fuels (oil, gas, coal and peat) and uses the energy content of each of them to calculate the total primary energy in MJ.
With the transition from ecoinvent v2.2 to ecoinvent v3 some of the elementary exchanges used have been adapted. The four flows marked with ** in the list above are affected, they don't exist anymore in ecoinvent v3. Only the following nine elementary flows used in the Cumulative Energy Demand (CED) calculation still exist:
• Energy, gross calorific value, in biomass [resource/biotic]
• Energy, gross calorific value, in biomass, primary forest [resource/biotic]
• Coal, brown, in ground [natural resource/in ground]
• Coal, hard, unspecified, in ground [natural resource/in ground]
• Gas, mine, off-gas, process, coal mining [natural resource/in ground]
• Gas, natural, in ground [natural resource/in ground]
• Oil, crude, in ground [natural resource/in ground]
• Peat, in ground [natural resource/in ground]
• Uranium, in ground [natural resource/in ground]
The renewable energy elementary flows have been abandoned and don't exist any longer in ecoinvent v3.
Hence only the following four "categories" remain:
• renewable energy resources, biomass
• non-renewable energy resources, fossil
• non-renewable energy resources, nuclear
• non-renewable energy resources, primary forest
As a consequence, use of CED results and their interpretation should be done carefully, as they deliver different results depending on whether activities from ecoinvent v 2.2 and ecoinvent v3 have been used.
ecoinvent also has a post in their forum that informs about this issue, see
http://www.ecoinvent.org/support/forum-for-ecoinvent-v3/?tx_mmforum_pi1[action]=list_post&tx_mmforum_pi1[tid]=64
The reasoning is described in the
'Documentation of changes implemented in ecoinvent database 3.0' on page 40, section 8.5 Renewable energy.