Ask a 3R expert: Energy systems and energy efficiency measures

In our “Ask a 3R Expert” series, 3R’s knowledgeable and experienced team members answer common client questions.

Joe Lewis

Joe Lewis

Joe Lewis, Senior Technical Specialist II, answers questions regarding energy systems and energy efficiency measures. 

Question:  A key recommendation in a recent energy audit is to install a renewable energy system. What are my options?  What would it take to cover my building’s energy consumption?

Answer: The amount of renewables, such as solar, that it would take to cover your building’s energy consumption varies based upon how much sun is available at your location as well as mitigating features, such as shading from local trees. You can estimate for yourself how much solar you can generate on your site with this online tool offered by the National Renewable Energy labs.  

If you are looking into wind power, the available tools are more involved and come in the form of an excel template. Fortunately, the Department of Energy has several useful templates to start the process which you can find here

If you are unsure what is available to you in your area, there is a geospatial energy mapper that can identify cost effective alternative low emissions electricity sources available in your area.We can also perform a more formal renewable energy study which includes estimated construction cost, pay back analysis, and identify oversizing needed to meet expected future growth.

Question: Our project is over budget, so we need to value engineer out some of the energy efficiency measures to get the project into construction. Which measures are the most important to keep? 

Answer: What is your current funding strategy?  We may be able to save some of these features by looking into alternative funding options. 

If you don’t have the time to apply and secure this funding, the most important feature is your high efficiency lighting and lighting controls (e.g daylighting and occupancy sensors). Also, the sub-metering system is key to ensure that your building operates as desired and that you can troubleshoot operational issues that develop over the life of the building. We can scale back the envelope to be code compliant; but I would recommend the unit cost of the glazing area vs. the opaque area be evaluated. Placing windows efficiently will provide just as effective a connection to the outdoor environment as having a large number of them. Key features of the HVAC include having heat recovery and for your climate zone economizer controls. If you work with 3R, we will draw up a more formal analysis with numbers in the energy model we develop for you as part of your LEED submission.    

Learn more about 3R’s built environment services.