Fix elastic slots

[wmeyers]

Just giving you an issue to mark off when done @antw !

See https://github.com/quintel/refinery/issues/21#issuecomment-22194114

[antw]

Implemented by quintel/refinery@49e0856b and quintel/atlas@79b88b3b.

The elastic slot must be a static attribute, even if the other conversions are specified as a query:

- output.electricity = 0.4
- output.loss = elastic

# - - - - - - - - - - - - - - - - - - - - - - - - - - - -

~ output.electricity = MAX(0.2 + 0.2, 0.3)
- output.loss = elastic

[wouterterlouw]

Works fine, however... some of the converters in industry does have the output.coupling_carrier. E.g. in energy_steel_blastfurnace_bat_transformation_cokes:

- use = energetic
- energy_balance_group = coal conversion
- output.coupling_carrier = 1.0
- co2_free = 0.0
- demand_expected_value = 0.0

~ input.coal = 0.391683437555641
~ input.cokes = 1 - 0.391683437555641
~ output.coal_gas = 0.400029027576197
~ output.loss = 1 - 0.400029027576197

Setting - output.loss = elastic does not work in this case!

[wouterterlouw]

When I define output.loss = elastic in the example above, I get the following message:

rake aborted!
nil can't be coerced into Float

However, if no output efficiencies are defined with a query, the problem does not occur. E.g.:

- use = energetic
- energy_balance_group = coal conversion
- output.coupling_carrier = 1.0
- output.loss = elastic
- output.steam_hot_water = 0.95
- co2_free = 0.0
- demand_expected_value = 0.0

~ input.coal = 1.0
~ input.torrified_biomass_pellets = 0.0
~ demand = 0.0

So it seems it is a problem of combining output.coupling_carrier, output.loss and a query specifying another efficiency.

[antw]

@wouterterlouw This should now be fixed. Please update Atlas with git up, and then bundle install to also update Refinery. Let me know if this causes you any more grief and I'll take another look. :smiley:

[wouterterlouw]

:+1: