Structures depend on aim of client and level of 'greenness' which should be achieved
Some might be satisfied with just buying certificates
Others do want to have a physical cable to the generator
And there are lots of possibilities in between including pure financial ones
Usual tenors are 8 - 15 years
Prices
Pricing mechanism often also depend on structure
Starting point is always what fits best to clients need
For corporates this is often a kind of fixed price but also other mechanism are possible
In general splitting power and certificates is possible but summing up their single value does not necessarily reach value of combined product for some clients