What Is an Energy Management System (EMS) and Why Do You Need One?


As businesses look to reduce operating costs and limit their environmental impact, many facility managers are turning to clean onsite energy solutions like solar, battery storage, and electric vehicle charging. But there’s a key piece of technology that should be installed in conjunction with these types of assets to maximize financial returns: an energy management system (EMS). Here’s a primer on what an EMS does, why it’s important, and what to look for when considering one for your facility.

What Does an Energy Management System Do?

An energy management system is a collection of computer-aided tools that monitor, control, and optimize the performance of Distributed Energy Resources (DERs), which are technologies that generate, store, and/or dispatch energy when and where it is needed. Common DERs include solar photovoltaic (PV) arrays, battery energy storage systems (BESS), and electric vehicle (EV) charging stations.

Energy management systems have both hardware and software components. At the heart of an EMS is the energy management system controller. Physically installed on site, the EMS controller is a device that maintains communication with the DERs and collects data on their operation. Data is fed into cloud-based software, which processes information in real time and continually optimizes the DERs based on how much energy is being generated and consumed at the facility. Historical data is also stored in the cloud and made available for reporting purposes.  

Why You Need an EMS

In addition to curbing a company’s greenhouse gas emissions, clean energy assets like solar and storage systems can reduce operating costs. By strategically using electricity that’s generated and stored on site, facilities can limit utility consumption and monthly charges. However, these financial benefits can only be fully realized if all onsite assets are working together as efficiently as possible. This is where an energy management system comes in.

An EMS controls and optimizes DERs to maximize energy savings. For example, EMS software coordinates the storage of surplus solar energy during the day to power building loads in the early evening hours, when utilities tend to charge the most for electricity due to increased customer demand on the grid. By using stored energy in this way — a cost-saving strategy called time-of-use arbitrage — a business is able to shave its monthly utility bills while also easing its reliance on harmful fossil fuels.  

What to Look for in an EMS

One of the most important things to keep in mind when considering an energy management system for your property is how your energy needs are likely to evolve over time. You may only have a few rooftop solar arrays now, but what happens when you want to install a storage system or EV charging stations in the future, or layer on microgrid infrastructure to increase your resiliency against utility disruptions? That’s why it’s critical to choose an EMS that is scalable and accounts for all your onsite energy assets and facility consumption. Transparency is also key — robust system data is only as useful as it is accessible.

At PowerFlex, we take a holistic approach to energy management with innovative products that monitor, control, and optimize the entirety of your portfolio:

Cortex is PowerFlex’s cloud-based energy management system. Using patented PowerFlex algorithms, Cortex continually learns from real-time conditions to make performance predictions and orchestrate onsite assets to maximize energy efficiency and financial savings. In addition to optimizing solar and storage systems, Cortex optimizes EV charging via Adaptive Load Management technology, which reduces infrastructure upgrade costs and utility demand charges.

Nexus, PowerFlex’s EMS controller, is the physical bridge between your DERs and the cloud. Discreetly installed on site in a low-profile enclosure, Nexus interfaces with all your DERs via its own cybersecure Wi-Fi network. Its communications are completely scalable and capable of expanding along with your energy assets. Nexus monitors DERs with an onboard energy meter and uploads the data to PowerFlex’s client portal, Axcess.

Axcess gives customers a clear window into how onsite assets are performing, both in real time and historically. Instead of having to log into separate dashboards to track solar, storage, and EV charging, users can view all their DERs with a single sign-in. Axcess is designed with the busy facility manager in mind. Most data — from solar energy production to utility bill savings to EV charging revenue — is easily accessible within 90 seconds of logging in.

An EMS is an essential part of any facility’s distributed energy portfolio, but only an experienced developer like PowerFlex can tailor a solution that meets your specific business needs. We’ve been at it for more than 35 years, and have helped companies from Amazon to Bloomberg to Medline realize their financial and sustainability goals. Ready to see what we can do for you? Reach out using the button below.