Index: civ2/effects.ruleset
===================================================================
--- civ2/effects.ruleset	(revision 12530)
+++ civ2/effects.ruleset	(working copy)
@@ -1412,6 +1412,44 @@
       "Building", "Sewer System", "City"
     }
 
+[effect_solar_plant]
+name	= "Output_Bonus"
+value	= 25
+reqs	=
+    { "type", "name", "range"
+      "Building", "Factory", "City"
+      "Building", "Solar Plant", "City"
+      "OutputType", "Shield", "Local"
+    }
+
+[effect_solar_plant_1]
+name	= "Output_Bonus"
+value	= 25
+reqs	=
+    { "type", "name", "range"
+      "Building", "Mfg. Plant", "City"
+      "Building", "Solar Plant", "City"
+      "OutputType", "Shield", "Local"
+    }
+
+[effect_solar_plant_2]
+name	= "Pollu_Prod_Pct"
+value	= -100
+reqs	=
+    { "type", "name", "range"
+      "Building", "Factory", "City"
+      "Building", "Solar Plant", "City"
+    }
+
+[effect_solar_plant_3]
+name	= "Pollu_Prod_Pct"
+value	= -100
+reqs	=
+    { "type", "name", "range"
+      "Building", "Mfg. Plant", "City"
+      "Building", "Solar Plant", "City"
+    }
+
 [effect_space_component]
 name	= "SS_Component"
 value	= 1
Index: civ2/buildings.ruleset
===================================================================
--- civ2/buildings.ruleset	(revision 12530)
+++ civ2/buildings.ruleset	(working copy)
@@ -362,12 +362,10 @@
  bonus, and a Factory, Mfg. Plant and Hydro Plant together give\
  a 150% production bonus.\
 \n\n\
-A city can only have one Hydro Plant, Power Plant, or\
- Nuclear Plant.  A city can only build a Hydro Plant if it is next\
+A city can only have one Power Plant, Hydro Plant, Nuclear Plant, or\
+ Solar Plant.  A city can only build a Hydro Plant if it is next\
  to (or on) a Mountain or River tile.\
 ")
-; FIXME: add Solar Plant to "can have only one" helptext when Solar
-; Plant added.
 
 [building_library]
 name		= _("Library")
@@ -475,11 +473,9 @@
  production bonus, and a Factory, Mfg. Plant and Nuclear Plant\
  together give a 150% production bonus.\
 \n\n\
-A city can only have one Hydro Plant, Power Plant, or\
- Nuclear Plant.\
+A city can only have one Power Plant, Hydro Plant,\
+ Nuclear Plant, or Solar Plant.\
 ")
-; FIXME: add Solar Plant to "can have only one" helptext when Solar
-; Plant added.
 ; NOTE:
 ; For Civ1/2 there should be a change of meltdown during
 ; civil disorder, but that has not been implemented yet.
@@ -600,8 +596,8 @@
  a 150% production bonus.  The extra production may lead to the city\
  generating more pollution.\
 \n\n\
-A city can only have one Hydro Plant, Power Plant, or\
- Nuclear Plant.\
+A city can only have one Power Plant, Hydro Plant,\
+ Nuclear Plant, or Solar Plant.\
 ")
 
 [building_recycling_center]
@@ -729,18 +725,15 @@
 sound_alt	= "b_generic"
 ; /* xgettext:no-c-format */
 helptext	= _("\
-Eliminates all pollution generated by production in a city. \
- It also\
+Eliminates all pollution generated by production in a city. It also\
  increases the shield production of a Factory or Mfg. Plant in the\
  city: a Factory and a Solar Plant together give a 100% production\
  bonus, and a Factory, Mfg. Plant and Solar Plant together give\
  a 150% production bonus.\
 \n\n\
-A city can only have one Solar Plant, Hydro Plant, Power Plant, or\
- Nuclear Plant.\
+A city can only have one Power Plant, Hydro Plant,\
+ Nuclear Plant, or Solar Plant.\
 ")
-; NOTE:
-; Not implemented.
 
 [building_space_component]
 name		= _("Space Component")
Index: civ2/techs.ruleset
===================================================================
--- civ2/techs.ruleset	(revision 12530)
+++ civ2/techs.ruleset	(working copy)
@@ -192,8 +192,8 @@
 
 [advance_environmentalism]
 name     = _("Environmentalism")
-req1     = "Never"		; "Recycling"
-req2     = "Never"		; "Space Flight"
+req1     = "Recycling"
+req2     = "Space Flight"
 flags    = ""
 
 [advance_espionage]
Index: default/effects.ruleset
===================================================================
--- default/effects.ruleset	(revision 12530)
+++ default/effects.ruleset	(working copy)
@@ -1343,6 +1343,44 @@
       "Building", "Sewer System", "City"
     }
 
+[effect_solar_plant]
+name	= "Output_Bonus"
+value	= 25
+reqs	=
+    { "type", "name", "range"
+      "Building", "Factory", "City"
+      "Building", "Solar Plant", "City"
+      "OutputType", "Shield", "Local"
+    }
+
+[effect_solar_plant_1]
+name	= "Output_Bonus"
+value	= 25
+reqs	=
+    { "type", "name", "range"
+      "Building", "Mfg. Plant", "City"
+      "Building", "Solar Plant", "City"
+      "OutputType", "Shield", "Local"
+    }
+
+[effect_solar_plant_2]
+name	= "Pollu_Prod_Pct"
+value	= -100
+reqs	=
+    { "type", "name", "range"
+      "Building", "Factory", "City"
+      "Building", "Solar Plant", "City"
+    }
+
+[effect_solar_plant_3]
+name	= "Pollu_Prod_Pct"
+value	= -100
+reqs	=
+    { "type", "name", "range"
+      "Building", "Mfg. Plant", "City"
+      "Building", "Solar Plant", "City"
+    }
+
 [effect_space_component]
 name	= "SS_Component"
 value	= 1
Index: default/buildings.ruleset
===================================================================
--- default/buildings.ruleset	(revision 12530)
+++ default/buildings.ruleset	(working copy)
@@ -383,12 +383,10 @@
  bonus, and a Factory, Mfg. Plant and Hydro Plant together give\
  a 150% production bonus.\
 \n\n\
-A city can only have one Hydro Plant, Power Plant, or\
- Nuclear Plant.  A city can only build a Hydro Plant if it is next\
+A city can only have one Power Plant, Hydro Plant, Nuclear Plant, or\
+ Solar Plant.  A city can only build a Hydro Plant if it is next\
  to (or on) a Mountain or River tile.\
 ")
-; FIXME: add Solar Plant to "can have only one" helptext when Solar
-; Plant added.
 ; NOTE:
 ; For Civ1/2 the first shield production number above should be 100%,
 ; but the above describes current freeciv rules.
@@ -500,11 +498,9 @@
  production bonus, and a Factory, Mfg. Plant and Nuclear Plant\
  together give a 150% production bonus.\
 \n\n\
-A city can only have one Hydro Plant, Power Plant, or\
- Nuclear Plant.\
+A city can only have one Power Plant, Hydro Plant,\
+ Nuclear Plant, or Solar Plant.\
 ")
-; FIXME: add Solar Plant to "can have only one" helptext when Solar
-; Plant added.
 ; NOTE:
 ; For Civ1/2 the first number above should be 100%, but the above
 ; describes current freeciv rules.
@@ -635,8 +631,8 @@
  a 150% production bonus.  The extra production may lead to the city\
  generating more pollution.\
 \n\n\
-A city can only have one Hydro Plant, Power Plant, or\
- Nuclear Plant.\
+A city can only have one Power Plant, Hydro Plant,\
+ Nuclear Plant, or Solar Plant.\
 ")
 ; NOTE:
 ; For Civ1/2 the first number above should be 100%, but the above
@@ -750,6 +746,33 @@
  required for a city to grow larger than size 8.\
 ")
 
+[building_solar_plant]
+name		= _("Solar Plant")
+genus		= "Improvement"
+reqs	=
+    { "type", "name", "range"
+      "Tech", "Environmentalism", "Player"
+      "Building", "Factory", "City"
+    }
+graphic	= "b.solar_plant"
+graphic_alt	= "-"
+obsolete_by	= "None"
+build_cost	= 320
+upkeep		= 4
+sabotage	= 100
+sound		= "b_solar_plant"
+sound_alt	= "b_generic"
+helptext	= _("\
+Eliminates all pollution generated by production in a city. It also\
+ increases the shield production of a Factory or Mfg. Plant in\
+ the city: a Factory and a Solar Plant together give a 75%\
+ production bonus, and a Factory, Mfg. Plant and Solar Plant\
+ together give a 150% production bonus.\
+\n\n\
+A city can only have one Power Plant, Hydro Plant,\
+ Nuclear Plant, or Solar Plant.\
+")
+
 [building_space_component]
 name		= _("Space Component")
 genus		= "Special"
Index: default/techs.ruleset
===================================================================
--- default/techs.ruleset	(revision 12530)
+++ default/techs.ruleset	(working copy)
@@ -255,8 +255,8 @@
 
 [advance_environmentalism]
 name     = _("Environmentalism")
-req1     = "Never"		; "Recycling"
-req2     = "Never"		; "Space Flight"
+req1     = "Recycling"
+req2     = "Space Flight"
 flags    = ""
 graphic     = "a.environmentalism"
 graphic_alt = "-"