A green power purchase agreement (PPA) is a long-term contract where a buyer commits to purchasing electricity from renewable energy sources, typically tied to a specific wind or solar project. It helps organizations secure renewable supply, manage energy price risk, and support credible sustainability claims through defined energy attributes and reporting rules.
What Is a Green Power Purchase Agreement?
A green PPA is an agreement between a renewable generator (or project owner) and an electricity buyer.
– The buyer agrees to purchase a defined volume of renewable electricity over a set term
– The seller agrees to deliver energy and associated renewable attributes under agreed conditions
– The contract defines price structure, volume, delivery method, and certificate handling
Why Green PPAs Matter for EV Charging
For EV charging operators and fleet depots, electricity sourcing affects both cost and carbon reporting.
– Enables renewable-backed supply for depot charging, destination charging, and public networks
– Improves energy cost predictability compared to spot market exposure
– Supports tender requirements where renewable sourcing is requested
– Strengthens market-based emissions reporting when structured with clear attribute ownership and cancellation
– Scales across multi-site portfolios where on-site renewables cannot cover all demand
How Green PPAs Work
A typical green PPA includes governance steps that support credibility and auditability.
– Contract defines renewable source, term, volume (MWh), and pricing model
– Energy attributes are assigned to the buyer under agreed rules
– Settlement and delivery follow the selected structure (physical, sleeved, or virtual)
– Reporting supports allocation, certificate cancellation, and impact metrics as needed
Common Green PPA Types
Green PPAs are often categorized by how energy is delivered and settled.
– Physical PPA – electricity is supplied to the buyer through the grid and supplier arrangements
– Sleeved PPA – a utility/supplier manages delivery, billing, and balancing while linking supply to the renewable project
– Virtual PPA (VPPA) – a financial contract for differences where the generator sells into the market and the buyer settles price differences while receiving renewable attributes
– On-site PPA – renewable generation is installed at the buyer’s site (e.g., rooftop or canopy PV), often used to increase self-consumption
Green PPAs vs Green Energy Tariffs
Both can support renewable electricity claims, but they differ in structure and risk.
– Green tariffs are retail electricity products typically backed by certificates
– PPAs are longer-term procurement contracts often linked to a specific renewable project
– PPAs usually provide stronger long-term sourcing and pricing structure, while tariffs are simpler to implement
Key Elements to Define Clearly
– Renewable attribute ownership and certificate cancellation rules
– Matching approach: annual vs tighter time-matching expectations where relevant
– Geographic boundary and location matching requirements for stakeholders
– Volume definition: baseload, as-produced, or shaped supply
– Risk allocation: curtailment, imbalance costs, and force majeure
– Reporting scope for audits, ESG disclosures, and customer-facing claims
Key Benefits
– Long-term renewable sourcing with credible documentation
– Improved energy price visibility and hedging potential
– Stronger “additionality” narrative compared to certificate-only approaches, depending on structure
– Scalable for multi-site operators and fleets with significant electricity demand
– Can be combined with DER (PV, BESS) and dynamic load management for deeper optimization
Limitations to Consider
– Higher complexity and negotiation effort than standard supply contracts
– Mismatch risk between renewable generation profile and charging demand profile
– Claims require transparent methodology to avoid greenwashing risk
– Grid constraints and peak charges still need operational controls even with green procurement
Related Glossary Terms
Power purchase agreement (PPA)
Green energy certificates
Guarantees of Origin (GO)
Green energy tariffs
Market-based emissions
Carbon intensity (gCO₂/kWh)
Renewable integration
Self-consumption
Battery energy storage system (BESS)