Nuclear (£96/MWh), wood combustion (based on CFBC - £103/MWh) and Gas-CCS (£100-105/MWh) all provide a lower levelised cost than offshore wind (£169/MWh). But all three would probably need a large first of a kind (FOAK) contingency added to provide comfort for bankers. Coal-CCS is also estimated to provide a lower levelised cost than offshore wind at about £146/MWh, which is a substantial premium (£35-40/MWh) over gas-CCS. Much of this premium reflects the currently elevated prices of coal equipment versus CCGTs.
Of the other low carbon technologies now being considered for wide deployment, solar PV is quite clearly very expensive at £343-378/MWh. This reflects the early stage of this technology and the low annual capacity factors (~10%) achievable in a UK setting.And the savings on biomass is greater at larger scale:
Of the other bio-energy applications, the smaller wood based technologies tend to have comparatively higher costs with small BFBCs and advanced gasification both around £155/MWh.Available here: MotMac Report to CCC May 2011
As to why smaller bio-energy applications are more expensive than the CFBC based approach: no one would build a small conventional power plant these days because they are terribly inefficient compared to a larger plant - and the same holds for bio-power plants. A larger, 300MW+ plant touches 40% efficiency, whilst smaller 100MW plants are on the low 30s and as size decreases from there, low 20s.
If you double your efficiency, you have halved the amount of biomass needed to produce the same amount of power - big is indeed beautiful.