3. Supply any remaining demand through responsible sources
Once every avenue has been exhausted to insulate buildings, reduce demand, and generate on site, the final step in the process is to procure renewable energy to achieve 100% Net Zero Energy. In Europe and North America, some aspects of the market are well developed and authenticated sources are generally available. Elsewhere, the International Renewable Energy Certificate Standard, or I-REC, and alternative opportunities, will be sought to track the supply.