Photovoltaic energy storage contract

Who owns the energy in an energy storage tolling agreement?

In an energy storage tolling agreement, the seller develops, owns, and operates the energy storage system, while the offtaker supplies charging energy. Therefore, the energy in the system belongs to the offtaker.

How do energy storage contracts work?

For standalone energy storage contracts, these are typically structured with a fixed monthly capacity payment plus some variable cost per megawatt hour (MWh) of throughput. For a combined renewables-plus-storage project, it may be structured with an energy-only price in lieu of a fixed monthly capacity payment.

What are the benchmarks for PV and energy storage systems?

The benchmarks in this report are bottom-up cost estimates of all major inputs to PV and energy storage system (ESS) installations. Bottom-up costs are based on national averages and do not necessarily represent typical costs in all local markets.

Should a solar project include battery storage?

In either a PPA or self-ownership, solar projects that also include battery storage are more complicated than solar-only projects since they need to carefully establish rules for how and when the battery is used. EECBG Program awardees interested in this option, should review the plans early with their local utility.

Are solar PPAs viable?

Solar PPAs are also viable when the solar project is not located on a government property, but the government receives the delivered electricity output. These so-called “Off-site” PPAs are popular with large energy users with insufficient space to host large solar arrays. A PPA is typically 15 to 30 years long.

Can a PPA buy a solar project?

Buyer Options to Purchase the Project or Special Purpose Entity. Many utilities have shown a strong interest in owning solar energy projects. In PPAs, this interest often takes the form of an option to purchase the project or the entity that owns it on or after a specified date. Such options should be handled carefully.