diff --git a/core/equations.gms b/core/equations.gms
index 310c89bd965601911427b71734538226be8e636a..a9647754c0bffa6573ca78bb749d4db0c48b69bc 100644
--- a/core/equations.gms
+++ b/core/equations.gms
@@ -467,12 +467,13 @@ q_costTeCapital(t,regi,teLearn) ..
 ***---------------------------------------------------------------------------
 *** this is to prevent that in the long term, all solids are supplied by biomass. Residential solids can be fully supplied by biomass (-> wood pellets), so the FE residential demand is subtracted
 *** vm_cesIO(t,regi,"fesob") will be 0 in the stationary realization
-q_limitBiotrmod(t,regi)$(t.val > 2050).. 
+q_limitBiotrmod(t,regi)$(t.val > 2020).. 
     vm_prodSe(t,regi,"pebiolc","sesobio","biotrmod") 
    - sum (in$sameAs("fesob",in), vm_cesIO(t,regi,in)) 
    - sum (fe2es(entyFe,esty,teEs)$buildMoBio(esty), vm_demFeForEs(t,regi,entyFe,esty,teEs) )
     =l=
-    3 * vm_prodSe(t,regi,"pecoal","sesofos","coaltr") 
+    (2 +  max(0,min(1,( 2100 - pm_ttot_val(t)) / ( 2100 - 2020 ))) * 3) !! 5 in 2020 and 2 in 2100
+    * vm_prodSe(t,regi,"pecoal","sesofos","coaltr") 
 ;
 
 ***-----------------------------------------------------------------------------