The diversity of investors in renewable energy has increased, opening up the pre-existing range of investment opportunities in renewables to greater scrutiny of risk and return. Renewable energy is not an asset class in itself but is a sub-category within several asset classes. Key risks which may need to be computed into the APT model are: price interaction with fossil fuel technologies, complexity of storing renewable-derived commodities, unknown future risks of renewable technologies, the capital-intensive nature of renewable “real estate”, the differing levels of commercial readiness of renewable technologies, regulatory volatility in the jurisdictions in which renewable energy projects are based.