Research The Sun Buckets PEP testing program is intended for increasing the use of high-quality solar cookers worldwide. PEP test stations automate a protocol that harmonizes with guidelines published by the International Organization for Standardization (ISO). PEP test results allow manufacturers to share evidence-based claims for their solar cookers. Just like miles-per-gallon ratings are important to car customers, the standard cooking power for solar cookers is helpful for customers to make informed decisions. The Performance Evaluation Process (PEP), developed by Sun Buckets, provides that standard in Watts.