A new report from Lux compares four contending large-scale solar-powered generation systems: three CSP approaches and photovoltaic generation. The three CSP technologies covered in the report, “Solar Thermal Update: The Renaissance of Concentrating Solar Power,” are parabolic trough, power tower and Stirling thermal systems. The three, plus a photovoltaic mode, are compared and modeled using a hypothetical 100 MW plant.
Lux’s strength is always on real-world business factors, and this report produces some interesting findings by dwelling on “levelized cost of electricity“, capital costs and internal rate of return.
Ted Sullivan, lead author of the report, says in a news release that things haven’t always been shining for CSP. “After a few fits and starts, solar thermal projects have begun to make a big impact on the generation mix in both Spain and the Southwest U.S. Though trough technologies have been dominant to date, we expect power tower solutions to gain increasing prominence as the technology is proven, because their integration with thermal storage technologies smashes through the fundamental constraint that has held solar back to date: intermittency,” says Sullivan, senior analyst at the company.
Here’s how the four technologies shook out:
- Winner: Stirling dish systems (because of modularity and relatively cheap Stirling engines).
- Runners up: Photovoltaic and CSP tower systems.
- At the bottom: Parabolic troughs (because of mirror field costs).
- Winners: Trough and tower systems (Parabolic troughs have best peak efficiency but tower systems have better system yields and capacity factors).
- At the bottom: Stirling dish and photovoltaic systems (lower capacity factors and lower energy yield, in kilowatt-hours output per kilowatt of peak power).
Levelized Cost Of Electricity (measured as $/kWh)
- Winner: Stirling dish systems (because their low cost and “decent” performances provide better internal rate of return to investors.
- Runner up: Power-tower technology.
- At the bottom: Trough and PV systems (of CSP systems, troughs have the most expensive capital expenditures, plus high operation and maintenance costs; PV have relatively high capex and “mediocre” performance).