Which energy technology is described as having relatively low operating costs once built?

• A. Tidal energy
• B. Solar PV panels
• C. Waste-to-Energy plants
• D. Coal-fired plants

Answer: (A)

Operating costs after construction are driven mainly by the need to purchase fuel or feedstock. Technologies that don’t require ongoing fuel typically run with lower ongoing expenses. Tidal energy, once the underwater turbines are installed, doesn’t need fuel or another continuous consumable, so the main ongoing costs are maintenance, inspections, and intermittent component replacement. Those expenses are generally smaller on a per‑unit-of-electricity basis than the recurring fuel and emissions/ash handling costs associated with coal, or the fuel logistics and waste handling costs of waste‑to‑energy plants. Solar PV also has very low operating costs, but the question’s emphasis is on the lack of a continuous fuel requirement, which makes tidal energy a clear example of relatively low operating costs after build.