Costs and Returns

What a CST project costs, what it saves, and how long it takes to return — using figures from the project's own detailed project reports rather than generic estimates.

Indicative payback

Ranges from project sensitivity analysis and detailed project reports. Actual returns depend on local fuel price, solar resource and process operating hours.

A worked example

A pharmaceutical unit in Sangareddy, Telangana, assessed under the project for boiler feed-water pre-heating using a non-imaging concentrator system:

The system raises make-up water from ambient to 70 °C before it enters the boiler, for about seven hours a day across roughly 300 sunny days. At the 30% incentive level the payback was 7.1 years; with accelerated depreciation applied, 5.3 years. At the current 50% incentive the same project falls within the four-year range.

What else improves the return

• Accelerated depreciation. 40% of capital cost over two years, available to profit-making entities — typically removing one to two years from payback.
• Wider eligible scope. Thermal storage, piping and heat pumps are now covered by the incentive, not only the collector field.
• Carbon credits. Certified emission reductions can be sold where coal is displaced, though at current voluntary-market prices the effect on payback is small.
• BOOT delivery. Where an enterprise cannot commit capital, a supplier builds, owns and operates the system and sells heat — shifting performance risk to the party best able to manage it.