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.

Ranking · Data 2025 · Source: BFS

The greatest solar potential in canton Valais

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	37'844
2	Val de Bagnes	167 GWh	11'044
3	Martigny-Bourg	161 GWh	22'513
4	Sierre	157 GWh	18'059
5	Crans-Montana	137 GWh	10'782
6	Conthey	112 GWh	9'661
7	Monthey	109 GWh	19'351
8	Nendaz	103 GWh	7'354
9	Brig-Glis	100 GWh	14'197
10	Savièse	91 GWh	8'453
11	Fully	87 GWh	9'407
12	Collombey-Muraz	85 GWh	10'188
13	Naters	81 GWh	10'791
14	Visp	80 GWh	9'075
15	Anniviers	64 GWh	2'785
16	Zermatt	63 GWh	6'113
17	Lens	61 GWh	4'590
18	Vétroz	60 GWh	6'725
19	Saxon	60 GWh	7'605
20	Ayent	58 GWh	4'509
21	Troistorrents	54 GWh	5'068
22	Leuk	54 GWh	4'349
23	Orsières	44 GWh	3'339
24	Riddes	44 GWh	3'831
25	Leytron	44 GWh	3'594
26	Chamoson	43 GWh	4'486
27	Chalais	43 GWh	3'981
28	Vouvry	40 GWh	4'936
29	Noble-Contrée	40 GWh	4'727
30	Goms	38 GWh	1'163
31	Saillon	36 GWh	3'226
32	Evolène	35 GWh	1'673
33	Grimisuat	33 GWh	3'979
34	Saint-Maurice	33 GWh	4'656
35	Ardon	32 GWh	3'938
36	Port-Valais	31 GWh	4'528
37	Steg-Hohtenn	30 GWh	1'768
38	Vex	29 GWh	1'970
39	Raron	28 GWh	2'030
40	Val-d'Illiez	28 GWh	2'149
41	Saas-Fee	26 GWh	1'637
42	St. Niklaus	26 GWh	2'347
43	Grône	25 GWh	2'598
44	Gampel-Bratsch	25 GWh	2'260
45	Mont-Noble	25 GWh	1'188
46	Grächen	24 GWh	1'321
47	Hérémence	24 GWh	1'553
48	Obergoms	24 GWh	662
49	Champéry	23 GWh	1'415
50	Vionnaz	23 GWh	3'080
51	Leukerbad	23 GWh	1'401
52	Ried-Brig	22 GWh	2'327
53	Turtmann-Unterems	21 GWh	1'193
54	Arbaz	21 GWh	1'474
55	Salgesch	21 GWh	1'777
56	Saint-Léonard	20 GWh	2'618
57	Bürchen	20 GWh	774
58	Bettmeralp	19 GWh	468
59	Riederalp	19 GWh	445
60	Martigny-Combe	19 GWh	2'416
61	Visperterminen	18 GWh	1'301
62	Fiesch	17 GWh	894
63	Evionnaz	17 GWh	1'535
64	Salvan	16 GWh	1'521
65	Bellwald	15 GWh	364
66	Massongex	15 GWh	2'149
67	Saint-Martin	15 GWh	841
68	Termen	15 GWh	1'203
69	Vernayaz	15 GWh	1'978
70	Sembrancher	14 GWh	1'113
71	Liddes	14 GWh	790
72	Saas-Grund	14 GWh	1'043
73	Chippis	14 GWh	1'627
74	Wiler	13 GWh	522
75	Ernen	13 GWh	538
76	Täsch	12 GWh	1'341
77	Törbel	12 GWh	514
78	Baltschieder	12 GWh	1'406
79	Ausserberg	11 GWh	639
80	Icogne	11 GWh	625
81	Stalden	11 GWh	1'140
82	Lalden	10 GWh	773
83	Eischoll	10 GWh	460
84	Grengiols	10 GWh	409
85	Niedergesteln	10 GWh	731
86	Unterbäch	10 GWh	483
87	Bitsch	10 GWh	1'219
88	Mörel-Filet	10 GWh	743
89	Dorénaz	10 GWh	1'120
90	Isérables	9 GWh	793
91	Simplon	9 GWh	287
92	Agarn	9 GWh	743
93	Albinen	9 GWh	245
94	Guttet-Feschel	9 GWh	426
95	Varen	9 GWh	701
96	Veysonnaz	8 GWh	614
97	Blatten	8 GWh	291
98	Bourg-Saint-Pierre	8 GWh	242
99	Vérossaz	7 GWh	945
100	Finhaut	7 GWh	422
101	Collonges	7 GWh	866
102	Zeneggen	7 GWh	369
103	Eggerberg	6 GWh	345
104	Lax	6 GWh	340
105	Oberems	6 GWh	141
106	Staldenried	6 GWh	559
107	Fieschertal	6 GWh	359
108	Bovernier	6 GWh	952
109	Saas-Balen	6 GWh	340
110	Randa	6 GWh	448
111	Saas-Almagell	5 GWh	376
112	Ergisch	5 GWh	184
113	Binn	5 GWh	126
114	Saint-Gingolph	5 GWh	1'104
115	Embd	5 GWh	298
116	Kippel	5 GWh	334
117	Ferden	5 GWh	248
118	Trient	4 GWh	181
119	Inden	2 GWh	118
120	Eisten	2 GWh	189
121	Zwischbergen	1 GWh	75
122	Bister	1 GWh	39

Swiss Federal Office of Energy (SFOE), retrieved 24.09.2026

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.