Which municipality in canton Valais has the greatest solar potential?

Sion, whose roofs could generate about 263 GWh of electricity a year (2025) — the greatest modelled roof potential of any municipality in canton Valais.

Does this mean the municipality actually produces this much solar power?

No. It is the modelled potential of the available roof surfaces — the electricity they could generate if fully used. Actual installed photovoltaics produce far less. The figure comes from the BFE solar model and scales with how much roof area a municipality has.

← Canton Valais overview

Ranking · Data 2025 · Source: BFS

The greatest solar potential in canton Valais

Name: Solar potential in canton Valais (VS): full ranking (2025)
Creator: Bundesamt für Energie (BFE)

National ranking →

Sion has the greatest solar-energy potential in canton Valais: its roofs could generate about 263 GWh of electricity a year. Next come Val de Bagnes (167 GWh) and Martigny-Bourg (161 GWh). This is modelled roof potential — largest where there is the most roof area, not current generation. Source: BFE.

Ranking

BFE · 2025

Rank	Municipality	Roof potential	Residents
1	Sion	263 GWh	36'624
2	Val de Bagnes	167 GWh	10'814
3	Martigny-Bourg	161 GWh	21'759
4	Sierre	157 GWh	17'663
5	Crans-Montana	137 GWh	10'488
6	Conthey	112 GWh	9'073
7	Monthey	109 GWh	18'886
8	Nendaz	103 GWh	7'196
9	Brig-Glis	100 GWh	13'976
10	Savièse	91 GWh	8'182
11	Fully	87 GWh	9'160
12	Collombey-Muraz	85 GWh	9'903
13	Naters	81 GWh	10'605
14	Visp	80 GWh	8'483
15	Anniviers	64 GWh	2'773
16	Zermatt	63 GWh	6'023
17	Lens	61 GWh	4'536
18	Vétroz	60 GWh	6'604
19	Saxon	60 GWh	7'114
20	Ayent	58 GWh	4'350
21	Troistorrents	54 GWh	5'008
22	Leuk	54 GWh	4'307
23	Orsières	44 GWh	3'292
24	Riddes	44 GWh	3'701
25	Leytron	44 GWh	3'357
26	Chamoson	43 GWh	4'291
27	Chalais	43 GWh	3'905
28	Vouvry	40 GWh	4'621
29	Noble-Contrée	40 GWh	4'677
30	Goms	38 GWh	1'157
31	Saillon	36 GWh	3'094
32	Evolène	35 GWh	1'670
33	Grimisuat	33 GWh	3'906
34	Saint-Maurice	33 GWh	4'574
35	Ardon	32 GWh	3'709
36	Port-Valais	31 GWh	4'485
37	Steg-Hohtenn	30 GWh	1'691
38	Vex	29 GWh	1'929
39	Raron	28 GWh	2'002
40	Val-d'Illiez	28 GWh	2'129
41	Saas-Fee	26 GWh	1'592
42	St. Niklaus	26 GWh	2'268
43	Grône	25 GWh	2'557
44	Gampel-Bratsch	25 GWh	2'167
45	Mont-Noble	25 GWh	1'174
46	Grächen	24 GWh	1'295
47	Hérémence	24 GWh	1'491
48	Obergoms	24 GWh	640
49	Champéry	23 GWh	1'399
50	Vionnaz	23 GWh	2'934
51	Leukerbad	23 GWh	1'396
52	Ried-Brig	22 GWh	2'254
53	Turtmann-Unterems	21 GWh	1'191
54	Arbaz	21 GWh	1'462
55	Salgesch	21 GWh	1'693
56	Saint-Léonard	20 GWh	2'613
57	Bürchen	20 GWh	766
58	Bettmeralp	19 GWh	474
59	Riederalp	19 GWh	437
60	Martigny-Combe	19 GWh	2'332
61	Visperterminen	18 GWh	1'324
62	Fiesch	17 GWh	912
63	Evionnaz	17 GWh	1'482
64	Salvan	16 GWh	1'483
65	Bellwald	15 GWh	349
66	Massongex	15 GWh	2'044
67	Saint-Martin	15 GWh	841
68	Termen	15 GWh	1'187
69	Vernayaz	15 GWh	1'864
70	Sembrancher	14 GWh	1'093
71	Liddes	14 GWh	755
72	Saas-Grund	14 GWh	1'067
73	Chippis	14 GWh	1'599
74	Wiler	13 GWh	539
75	Ernen	13 GWh	550
76	Täsch	12 GWh	1'366
77	Törbel	12 GWh	494
78	Baltschieder	12 GWh	1'367
79	Ausserberg	11 GWh	637
80	Icogne	11 GWh	634
81	Stalden	11 GWh	1'112
82	Lalden	10 GWh	733
83	Eischoll	10 GWh	453
84	Grengiols	10 GWh	424
85	Niedergesteln	10 GWh	750
86	Unterbäch	10 GWh	483
87	Bitsch	10 GWh	1'116
88	Mörel-Filet	10 GWh	745
89	Dorénaz	10 GWh	1'103
90	Isérables	9 GWh	809
91	Simplon	9 GWh	281
92	Agarn	9 GWh	729
93	Albinen	9 GWh	262
94	Guttet-Feschel	9 GWh	440
95	Varen	9 GWh	691
96	Veysonnaz	8 GWh	621
97	Blatten	8 GWh	303
98	Bourg-Saint-Pierre	8 GWh	215
99	Vérossaz	7 GWh	893
100	Finhaut	7 GWh	400
101	Collonges	7 GWh	865
102	Zeneggen	7 GWh	324
103	Eggerberg	6 GWh	329
104	Lax	6 GWh	336
105	Oberems	6 GWh	139
106	Staldenried	6 GWh	541
107	Fieschertal	6 GWh	359
108	Bovernier	6 GWh	924
109	Saas-Balen	6 GWh	362
110	Randa	6 GWh	461
111	Saas-Almagell	5 GWh	379
112	Ergisch	5 GWh	184
113	Binn	5 GWh	123
114	Saint-Gingolph	5 GWh	1'049
115	Embd	5 GWh	294
116	Kippel	5 GWh	331
117	Ferden	5 GWh	253
118	Trient	4 GWh	160
119	Inden	2 GWh	118
120	Eisten	2 GWh	191
121	Zwischbergen	1 GWh	81
122	Bister	1 GWh	39

Bundesamt für Energie (BFE), retrieved 10.08.2026

How we measure this

BFE

Modelled annual electricity that rooftop photovoltaics could produce across the whole municipality, in gigawatt-hours per year, from the BFE «Solarenergiepotenziale der Schweizer Gemeinden» model (2025 snapshot). It is a potential, not installed capacity or actual generation, and it scales with roof area — so large towns lead simply because they have more roofs. It is a rolling model snapshot, not an annual survey. The companion roofs-plus-façades scenario adds vertical surfaces.

Frequently asked questions

Which municipality in canton Valais has the greatest solar potential?: Sion, whose roofs could generate about 263 GWh of electricity a year (2025) — the greatest modelled roof potential of any municipality in canton Valais.
Does this mean the municipality actually produces this much solar power?: No. It is the modelled potential of the available roof surfaces — the electricity they could generate if fully used. Actual installed photovoltaics produce far less. The figure comes from the BFE solar model and scales with how much roof area a municipality has.