As currently proposed, the feed-in-tariffs are likely to be the exclusive domain of the middle class with lower income households shut out from participating.
To prevent the FiT being accessible only to the middle classes, it needs to be set at a level that allows banks and private equity providers to step in and cover the capital costs of PV while sharing some of the benefit with householders.
In order to be attractive, the return needs to be between 7.5% and 8.5% (ungeared) depending on interest rate and how the FiT revenues are taxed. Some institutional investors say it needs to be higher, but if we stick to this figure we stay on the conservative side.
Taking PV as an example, the FiT as currently proposed would generate a 3-4% return in a mature market (e.g. £4700/kWp installed for a household system as we’re seeing in Italy). In a less mature market (e.g. £5.5k/kWp) the return would be 1.9%.
Looking at it another way, in order to achieve a 7.5% return in the real world based on the proposed FiT, the installed price of PV would need to be £3350/kWp! The other £1.35k is value shortfall (i.e. the difference between £3.35k and £4.7), which might be covered by an eco-minded middle income household but will certainly not be attractive to a low income household.
Bottom line: the proposed FiT for PV is too low. In order to provide an 8% return in a mature market (£4.7k/kWp installed for a small system), the FiT needs to be set at around 55p/kWh. For the largest schemes (>100kW), this would step down to 37p.
Sorry I’ve departed from my usual policy of putting all the underlying numbers up. The calculations are pretty straightforward but they require a spreadsheet and I don’t have a public facing version yet.