This question has come up because there is an option under the prescriptive path of the stretch code to meet the requirements of one section of the code with on site renewable electricity generation. However, this is not a requirement, it is merely 1 of 3 options under this code approach, and there is also the alternative to meet the commercial stretch code requirements using the 20% better than ASHRAE 90.1-2007 modeling approach.
The 3 options which appear in section 507 of the prescriptive code option for buildings between 5,000 and 100,000 square feet are:
- More efficient heating and cooling equipment – widely available and with utility rebates available to offset much of the incremental cost.
- More efficient lighting – also widely available and eligible for significant utility rebates.
- Providing at least 3% of the on site electric load from on site renewable generation – which qualifies for both large federal tax incentives and significant state renewable energy incentives from the Massachusetts Renewable Energy Trust (MRET).