Vogtle vs. Solar and Lithium-ion batteries

There has been an ongoing discussion of the costs of Vogtle in Georgia and the cost of “cheap” solar PV and storage. Below is a simple scenario that compares the cost of the two. This is one of hundreds of possible scenarios, and depends on enough storage to firm the solar every day to provide 2 GW (48 GWH) every day of the year.

The scenario looks at the worst solar production day for solar in Atlanta Georgia. Many of the scenarios would be of a lower cost – but they require different assumptions and additional pieces (e.g., DSM, Wind, non-battery storage, etc.)

Assumptions:
1)     NREL cost numbers are correct for solar and storage
2)     Solar life time is 20 years
3)     Lithium-ion no less than 12 years
4)     Vogtle costs are per the numbers reported in the press
5)     Vogtle runs at 2GW of output
6)     PVWatts for Atlanta is the production of solar PV, standard fixed panels are used
7)     Vogtle and Solar have identical transmission and distribution losses
8)     For the purpose of this exercise Vogtle will run for 80 years
9)     Losses in and out of the batteries (combined are 10% including inverter losses)
10) Solar and storage need to daily produce enough power to match the 2 GW every hour, so the lowest day solar production in December is the benchmark for power produced and storage needed.
11) Batteries can charge when solar is present, That charging has to hold enough power to supply the 2 GW for the balance of the day (solar without storage + storage without solar has to total 48 GWH [24 hours times 2 GW])
12) All other options are off the table for this scenario (yes we could run hundreds of scenarios – they are not this one)
13) All systems are assumed to be the lowest cost options for solar and storage within the parameters of the scenario, and the assumptions above.

NREL PV Watts low day for Atlanta GA is 925 kWh for 1 KW of solar (total production for 24 hours)

This results in approximately 51 GW of installed solar.

That 51 GW of solar produced enough power to not require storage 7 hours per day, meaning that 17 hours a day storage is required. And that that storage has to be 36 GWH of storage.

NREL Cost of solar $1,161 per MW-DC (we will ignore the roughly 14% difference in DC vs AC output

NREL Cost of storage $323/kWh without installation costs or balance of systems costs.

NREL O&M costs $51.88/kW/Year

Source: https://www.nrel.gov/docs/fy23osti/87303.pdf

51 GW of solar is $59 Billion dollars in solar and 36 GWH of storage is $ 12 billion in storage or a total initial capital cost (without financing or subsidy) of $71 billion.

Remember we need to replace the solar 3 times in 80 years and the batteries 6 times. The initial capital cost of Vogtle was 1/10 of what solar+storage would cost.

51 GW of solar at $51 million a year in O&M would result in $2.6 billion in annual maintenance.