Prioritize Greenhouse Gas Mitigation Strategies Using Renewable Energy in Buildings
At this point in the analysis for using renewable energy in buildings, after estimating costs to implement strategies, there should be a list of sites and promising renewable energy technologies. The next step in the analysis is to prioritize those sites and technologies to achieve cost-effective reductions in greenhouse (GHG) emissions.
In prioritizing the locations for cost-effective renewable energy project development, start with the sites that have the:
- Best resources
- Best financial incentives
- Highest energy rates.
These factors are the most important for determining the economic viability of a renewable energy project.
Another metric that can be used to prioritize projects is the cost of avoided emissions (COAE). The COAE is the ratio of this difference in levelized cost of energy (LCOE) and utility energy rate to the eGRID emissions rate (see Eq 2, below).
Eq (2) COAE [$/MT] = (LCOE [$/kWh] - Utility Rate [$/kWh]) ÷ CO2e Emissions Rate (MT/MWh) ÷ 1000 [kWh/MWh]
This metric reflects the cost per ton of carbon dioxide equivalent (CO2e) avoided using different RE technologies ad can be used to rank projects by the lowest cost of CO2e emissions. Table 1 below illustrates the differences in COAE for a 200kW solar photovoltaic (PV) project installed in each of the five cities.
From Table 1 below, Las Vegas has the lowest COAE, even though it has a fairly clean grid and relatively low electric rates. This is because Las Vegas has more sunny days per year than the other cities, so the PV system is able to generate more electricity than the other cities. Using the COAE along with the resource maps, it appears that the Las Vegas site would be a good site for a PV project. However, Miami might also be a good candidate site and warrants further consideration.
Table 1. Example Cost of Avoided Emissions for a 200-kW PV System
|City||Non-baseload Emissions Rate (MT/MWh)||Annual Emissions Reductions (MT CO2e)||Electric Rate (¢/kWh)||LCOE ($/kWh)||Cost of Avoided Emissions ($/MT CO2e)|
Table 2 illustrates a first order analysis that can be completed quickly without requiring detailed analysis. Note that this analysis only examined one renewable energy technology per site. It's likely that multiple technologies can be applied at multiple sites. For instance, solar ventilation preheat (SVP) technology is cost effective in many places around the United States. So this SVP project can be combined with other renewable energy technologies at most of the example sites.
Table 2. Example of Renewable Energy Project Analysis
|City||Technology||Annual Emissions Reductions (MT CO2e)||Electric Rate (¢/kWh)||RE LCOE ($/kWh)||Cost of Avoided Emissions ($/MT CO2e)|
|Chicago||Solar Space Heat1||96||8.99||$0.21||$132|
|Duluth||Solar Space Heat1||108||7.92||$0.21||$133|
|Las Vegas||Solar PV||101||8.94||$0.18||$153|
1 Based on replacing electric space heating.
Based on the analysis in Table 2, an agency can prioritize projects by amount of CO2e reductions and cost of avoided emissions. In this case, biomass in Miami and Seattle appear to be good first projects to investigate further in terms of the cost of emissions. However, Duluth and Las Vegas also appear to be good projects based on the amount of emissions reductions.
- Step 1
Assess Agency Size Changes
- Step 2
Evaluate Emissions Profile
- Step 3
Evaluate Reduction Strategies
- Step 4
Estimate Implementation Costs
- Step 5
Did you find the information that you needed? Please let us know. FEMP welcomes any feedback on its GHG mitigation content. To provide feedback, see Contacts.