The bank has previously raised capital through similar investment schemes in Belgium and the Netherlands, but this is the first time that shares have become available to customers in other countries. The group target is to sell EUR40m (£27m) of shares across Europe.
"This will resonate with our customers because they can see that their money is already working well with the projects that we support," said James Vaccaro, head of investment banking at Triodos.
"It is aimed at those who are seeking to fulfil a social mission and gain from their financial investment. This is just a way of contributing to the next stage of the organisation's development."
Vaccaro added that the shares, which are being sold for £46 each, would be a sensible investment for charitable trusts and foundations that work with financial inclusion, because a Triodos buy would fulfil the relevant criteria for programme-related investment.
Charles Middleton, UK managing director at Triodos, said: "We're a radically different kind of bank because we put people and the environment alongside profit.
"We start from the idea that money can transform the world, and we connect people who have money to invest and want to change the world with organisations doing just that."