It is agreed by everyone (except the nuclear industry) that nuclear power is the most expensive form of electricity – more expensive than wind energy, solar photovoltaic (PV) and more expensive that concentrated solar power (CSP) with six hours of energy storage.
The South African government has researched this during the Integrated Resource Plan (IRP) process, and come to the same conclusion. This graph, extracted from the final IRP report, clearly shows that if the 40% cost overruns (which are inevitable in nuclear power) are included, then all the other forms of power generation are cheaper to build. Note, however, that these are the construction costs per kW peak only. Calculating the cost per kWh is complex, and requires many assumptions around capital costs and repayment terms, load factor, plant life time and in the case of nuclear, decommissioning costs, long term waste management, fuel costs and insurance premiums.
The reason for the costs of renewable energy falling over time, is that as the technology and volume of sales improves for renewable technologies, the cost will fall. Every year, nuclear power looks like a more and more stupid option. This is why the nuclear industry is pushing so hard for an order to be signed now.