According to a Renewable Power Purchase Arrangement (PPA), a Renewable Energy Service Company (RESCO) will install and maintain a customer's solar power plant at their site. The RP, which refers to a typical 10-year contract, results in monthly payments for a percentage of the customer's power generated.
The Opex model reduces investment risk and avoids the expense of creating a Capex investment, enabling customers to pay for only the actual power produced with zero large assets. This creates a more cost-effective Opex model upfront. Even with a Power Purchase Agreement, the energy is significantly cheaper than grid power.
However, not all OPEX contractors may be able or willing to do projects smaller than those in which customers are interested. Major project installation specialists are usually interested in medium to large-size projects under this model.
The OPEX model is well-suited to small businesses with planned growth aiming to incorporate more environmentally friendly processes.