Net Zero Energy Modeling

Combining Energy Efficiency and Photovoltaic to Reach Net Zero

In the building and design business we know that reaching Net Zero is good for the climate and our customers’ bottom line. But we struggle with how to achieve it. Frequently we ask, what measures are the best return on investment (ROI) for my customers? If I use energy efficiency (EE) alone is that enough? How can I include photovoltaic (PV) measures that are right for my climate, and my design? If I want to add solar panels how many do I need, what does it cost, and how does that affect my design?

With NEO’s new PV strategy you can reach Net Zero cost effectively by combining EE and PV. And NEO guides you step-by-step, demonstrating which measures reduce your energy use for the best
return on investment, as you move the needle to achieve Net Zero. NEO provides all the information you need to present your cost effective and efficient design to your customers in an easy to digest way.

Let’s take a deeper look at how NEO can help you reach Net Zero.

Step 1. Perform an HVAC Life Cycle Cost Analysis

One of the best ways to achieve Net Zero is by starting off with the most efficient building you can afford. NEO’s life cycle cost analysis will help you consider the trade-offs between energy, cost, and environment before you’ve even put pen to paper.

Need a refresher on performing an HVAC life-cycle cost analysis in NEO? Please see our September 2020 NEO article “Trusted Data When You Need It Most”.

In this example we’ve performed a comparison of three different HVAC systems – a ground source heat pump (GSHP), VRF, and VAV with a chiller/boiler – the results of the life cycle cost analysis show that the GSHP has the lowest EUI and life cycle cost over the life of the building.

In addition to being the lowest cost option, the GSHP also has the least amount of annual energy use measured by Energy Use Intensity (EUI) in KBtu/ft2/yr making the it the ideal candidate to cost effectively achieve Net Zero.

Step 2. Refine the Model

Having selected the GSHP system, we now transition to a Rating Analysis. This allows us to see what energy efficiency options we can implement to get closer to a Net Zero design. The Rating Analysis quickly compares hundreds of EE measures for the mechanical, architectural, lighting, plug, and service water heating systems. This analysis helps you make informed decisions about what EE measures make the most impact while providing insight into how much PV may be needed to achieve Net Zero.

Through informed modeling of the HVAC system selection and EE measures alone we’ve reduced the building’s site energy use by 50% beyond the baseline and realized an 8.1-year payback
However, we are still 23.5 kBtu/sf/yr over the Net Zero goal.

By implementing NEO’s new on-site solar PV measure and inputting a system capacity of 275 kW (~15,000 sq ft array assuming PV panels generate 18 W/sq ft) we can see in real-time the energy, cost, and environmental impacts of the efficient system design coupled with a holistic EE approach and topped off with a right-sized solar array.

With a final click of the rating button, you can see that by adding PV you have achieved, or in this case, exceeded your Net Zero goal. And although PV may seem cost and/or site prohibitive – with NEO you minimize the PV required by maximizing EE to optimize ROI.