Insights

Utility Tariffs and the Hidden Economics of Solar and Storage

Many solar proposals focus primarily on system size, equipment specifications, or projected annual production. While these factors are important, they often overlook the most significant driver of project economics for commercial facilities: utility tariff structure.

Understanding how electricity is billed — including energy charges, demand charges, and time-of-use pricing — is essential before committing capital to solar generation or battery storage infrastructure.

Without this analysis, projects may appear attractive on paper while delivering far less financial value in practice.

How Commercial Utility Tariffs Work

Commercial electricity bills typically consist of several components:

• Energy charges – the cost per kilowatt-hour consumed
• Demand charges – fees based on the facility’s peak power usage during the billing period
• Time-of-use pricing – higher energy rates during peak grid hours
• Fixed service charges

In many commercial tariffs, demand charges can represent a large portion of the total electricity cost. As a result, projects that only evaluate annual energy production may miss key opportunities — or risks — associated with peak demand behavior.

Why Demand Charges Change Solar Economics

Solar production is often evaluated based on total annual generation. However, solar systems only offset energy costs when they are producing power.

If a facility’s peak demand occurs in the evening or early morning, solar generation may have little impact on the demand charges that drive a significant portion of the utility bill.

This means two facilities with identical annual consumption can experience very different financial outcomes from the same solar system depending on their load profile.

Understanding when peak demand occurs is therefore critical to determining optimal system sizing.

The Importance of Historical Load Profile Analysis

Before evaluating solar or storage investments, a detailed review of the facility’s historical load profile is necessary.

Load profile analysis helps identify:

• When peak demand occurs
• Seasonal variations in consumption
• Opportunities to reduce demand charges
• How solar production aligns with facility usage

This information allows infrastructure investments to be modeled using actual operating behavior rather than simplified assumptions.

Before committing capital to solar, storage, or backup power infrastructure, evaluate the long-term financial and operational implications.