Recently, dynamo hubs have been undergoing a revival of sorts, with a number of new (relatively) lightweight energy efficient models. Here's a brief summary of what's available as at 2014:
| Manufacturer / Model | Weight | Output | Centre lock | 6-bolt | Notes |
|---|---|---|---|---|---|
| SONdelux | 395g | 6V / 3W | X | 20,24,28,32,36 hole drillings available, radial spoking permitted, centre lock disc mount | |
| SON28 | 6-bolt: 460g center lock 430g | 6V / 3W | X | X | 32, 36 hole drillings available, 6-bolt and center lock versions |
| Supernova INFINITY S | 399g | X | 32 hole only, Center lock only | ||
| Shimano 3D71 | 490g | X | |||
| SP Dynamo System SD-8 | 385g | 6V / 2,4W (on 700C wheels) | X | 20,24,28 and 32 hole drillings available | |
| SP Dynamo System PD-8 | 410g | 6V / 3W | X | 32 and 36 hole drillings | |
| Biologic JouleHG | 656g | 6V / 2.4W | X | 32 hole, 6-bolt disc, claimed to have almost zero drag when switched off (mechanically). | |
| Biologic Joule3 | 416g | 6V / 3W | X | 32 hole, 6-bolt disc, 73% claimed efficiency. | |
| SRAM I-Light Dynamo 730 | 720g | 6V / 3W | X | 32 and 36 hole drillings, 6-bolt disc. Cheap - often available for less than $100 |
There's some good test information on dynamo hubs here.
15mm thru-axle dynamo hubs
| Manufacturer / Model | Weight | Output | Centre lock | 6-bolt | Notes |
|---|---|---|---|---|---|
| SON28 15 | 460g | 6V / 3W | X | 32, 36 hole drillings available | |
| SP Dynamo System PD-8x | 420g | 6V / 2.4W | X | X | 32 and 36 hole drillings |