Wind and solar: the ethical investments to avoid: Renewable energy is the future, say environmentalists. But for green and ethical investors it has turned into a nightmare, with makers of wind and solar power systems among the worst-performing stocks in recent years. Funds that specialise in renewable energy have fallen a long way short of expectations. Impax Environmental, an investment trust, has lost 20% over the past five years, while BlackRock New Energy investment trust has done even worse, falling 49.9% since 2007. It’s a salutary reminder to avoid investment fads and bubbles.