More Panels or Trackers? Understanding the Time Value of Solar

Falling Module Prices Are Changing the Solar Debate

Falling solar module prices are changing how developers evaluate solar project design. Adding more DC capacity behind the same AC connection—known as DC oversizing—can become more attractive as panels become cheaper.

However, comparing DC oversizing with solar trackers requires more than looking at annual energy generation. The timing of electricity production and its market value can also influence project economics.

Why the Timing of Solar Generation Matters

Solar trackers follow the sun and can increase generation during morning and late-afternoon hours compared with fixed-tilt systems.

If electricity prices are higher during these periods, the additional generation may earn more than extra electricity produced during lower-priced midday hours.

The actual benefit depends on how closely the generation profile overlaps with market prices. Therefore, higher energy yield does not automatically mean higher revenue.

Comparing DC Oversizing with Solar Trackers

Firstgreen’s latest report, “More Panels or Trackers? The Time Value of Solar,” compares fixed-tilt DC oversizing with tracking systems using simulated generation profiles and Indian Energy Exchange (IEX) day-ahead market prices.

The analysis examines:

• Capture prices: The market value received for electricity generated at different times.
• Lifecycle costs: The costs associated with each system over its operating life.
• Land requirements: The land needed for the respective configurations.
• Future market sensitivity: How changing electricity prices could affect project economics.

This approach helps evaluate solar technologies based on both energy generation and the commercial value of the electricity delivered.

Conclusion

As projects move towards market-linked bids or approach the end of fixed-price Power Purchase Agreements (PPAs), reassessing solar project design becomes increasingly important.

Lower module prices strengthen the case for more panels, while time-dependent electricity prices may strengthen the case for trackers.

The right choice depends on generation profiles, market prices, project costs, and future operating conditions.

See the original Firstgreen LinkedIn post.