It will be well worth coming to the Dyfi - you won't be disappointed!
As for accommodation, it's difficult if you don't drive as the project is situated next to a main road. There is a B&B within walking distance called Morben Isaf - https://www.facebook.com/pages/Morben-Isaf-Bed-and-Breakfast-Morben-Isaf-House/360785093994580
There is also Tynohir Farm, self-catering accommodation - https://www.facebook.com/tyohirselfcateringacc.derwenlas?fref=ts
There is a regular bus service in the local area, which runs between Aberystwyth and the local town, Machynlleth. There is also a train service in the area. There are a couple of hotels in Machynlleth, which may suit you better, and just get a bus to 'Morben Isaf', and then it's a short walk to the project.
Awesome, thank you!
Must make it a day your in so i have someone who knows whats going on! haha