Page 187 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

LEED Ener gy and Atmospher e 165

4.2 EA Credit 2: On-Site Renewable Energy
The intention of EAc2 is to encourage the production of renewable energy sources on-
site. This will serve to decrease the load on the off-site energy resources and also improve
energy distribution efficiencies, as the potential energy losses that can be allocated to
transport to the site are decreased. The energy offsets can earn one to seven points in
LEED 2009.

USGBC Rating System
LEED-NC 2.2 lists the Intent, Requirements, and Potential Technologies and Strategies
for EAc2 for which the following are also valid in LEED 2009 as follows:

Intent
Encourage and recognize increasing levels of on-site renewable energy self-supply in order to
reduce environmental and economic impacts associated with fossil fuel energy use.
Requirements
Use on-site renewable energy systems to offset building energy cost. Calculate project
performance by expressing the energy produced by the renewable systems as a percentage
of the building annual energy cost. Use the building annual energy cost calculated in EA
Credit 1 or use the Department of Energy (DOE) Commercial Buildings Energy Consumption
Survey (CBECS) database to determine the estimated electricity use.
Potential Technologies and Strategies
Assess the project for nonpolluting and renewable energy potential including solar, wind,
geothermal, low-impact hydro, biomass and bio-gas strategies. When applying these
strategies, take advantage of net metering with the local utility. (The two versions of LEED
give different point values for various levels of on-site renewable energy as a percentage of
the building energy costs. These values are listed in Table 4.2.1.)

LEED 2009 On-Site Renewable
Energy as Percent of Proposed LEED 2.2 On-Site Renewable Energy
Points Energy Use * as Percent of Proposed Energy Use *
1 1 2.5
2 3 7.5
3 5 12.5
4 7 −
5 9 −
6 11 −
7 13 −
7 + 1 EP 15 −

∗ For both versions, use the design energy usage (on-site renewable energy not excluded) as per EAc1
Option 1 if applied. Otherwise use the Department of Energy (DOE) Commercial Buildings Energy
Consumptions Survey (CBECS) database for estimated energy requirements based on proposed
building use.
TABLE 4.2.1 EAc2 Point Differences between Versions 2.2 and 2009