Wales' largest community energy project is due to go live for the first time in Swansea.
After 18 years of planning the Awel Aman Tawe wind farm is to be connected to the National Grid on Friday.
A pair of 330ft (100m) turbines will produce enough electricity to power 2,500 homes.
Over their lifetime, they are expected to generate about £3m and it is hoped the profits will be spent in the local community.
The project has been funded by a community share offer, which has so far raised £1.6m, a £3.55m Welsh Government loan and other grants.
Investors have been offered a 5% return.
One of the oldest local investors is 84-year-old Eric Bowen from Cilmaengwyn.
Mr Bowen said: "I've never invested in anything in my life but I thought it's a local thing to start with. It's something for the future and it seems to me that we have enough wind in Wales.
"There's a lot more to be done with regards to renewable energy but you have to go step by step I suppose."
Programme director at Renew Wales, Robert Proctor said it "has always been and remains a very difficult process" to develop community energy projects, as most communities do not have access to land or buildings to install the systems.
But he said there are signs that the planning system in Wales is improving.