There are a variety of reasons our customers look to collect their energy usage data. There are also a variety of pathways to accomplish their site metering and sub-metering goals.
The way that we define site metering is basically the simplest form of meter data collection. This is when we integrate the utility meter's data into our metering platform through pulsed outputs directly from the utility meter. The data captured is meant to be high level (site wide) data that tracks electric, gas and water data from the main utility meters. These 3 meters provide an order of magnitude data value for the site to use to measure overall capacity against targets and provides utility data that can be used to forecast energy spend prior to receiving their utility bill.
The process of submetering involves the use of individual meters to measure utility usage for each individual circuit, tenant unit, or process where a utility is being used. Submetering a utility has its specific benefits and provides distinct value to the facility and might differ for each building owner. For this reason, the submetering system is often installed and used by the building owners and property managers. The meters are owned and maintained by the property owner and readings are taken as often as necessary to bill each unit in a tenant billing situation.
Through the use of the (Basic Site Level Metering) Utility Meter Pulses, quite a few objectives can be achieved. These include:
- Benchmarking of site performance against prior years. Since many our customers are looking to reduce operating cost, this site level data is basically the billing data that will be used for their bills. As a whole, this site level metric will provide the needed guidance on year over year performance.
- Demand Response participation - Demand Response providers are basically running their entire program based on the main electric meter's pulse feedback for guidance on the site's peak load reduction.
- Bill Parity - These utility meters can be used to compare against their utility bills to ensure errors are captured and addressed.
- Peak Load Management - In regions where peak electric rates can be significant, the utility pulses can be used to manage site peak demand to reduce utility costs.
- Collection of energy or water consumed for an entire property or building.
Although these utility meters can provide some guidance on site performance, this utility meter primarily acts as a feedback device. Since the main utility meter is far away from a specific process or equipment, energy management at the equipment level is not possible. For this reason, sub-metering is needed to capture data at the equipment level.
How difficult is it to install an electric submeter?
The cost of installing an electric sub meter can vary depending on the model, installation requirements, and and labor costs. Emergent Metering offers our technical understanding to develop and deliver metering projects through a variety of hardware options. As we are product agnostic, we support our customers with identifying metering products that will fit their needs. Our typical approach is to evaluate the cost per metering point and find opportunities to drive down the cost of each data point captured. We see singular meter installations carrying a higher cost of data acquisition than a well deployed panel level monitoring project as networking, installation and engineering efforts are effectively pooled to reduce the burdened cost per metering point.
How difficult is it to install a gas submeter?
Similar to installing an electric sub meter, the cost for a gas submeter can also vary significantly depending on pipe size and availability of power.
The simplest process of gas submetering is the installation of a rotary style inline meter. This meter is a mechanical meter that relies on gas pressure to operate. It does not require power and provides an analog display that shows the volumetric consumption value. The challenge with this meter is that it will not come equipped with gas temperature or pressure compensation since it is purely a volumetric meter. Although utility meters are volumetric meters, they are typically equipped with temperature and volume compensation capabilities that enhances the meter's accuracy.
For this reason, we do not recommend using these inline meters natural gas submeters unless there is no available power in the area.
For reasons previously stated, we recommend the use of insertion thermal mass meters for gas submetering needs. Since the gas meter is an insertion probe, the cost of the meter will be the same regardless of the pipe size (this is the case for non-utility scale implementations where pipes can exceed 20" in diameter). With available power and data connectivity, the insertion thermal mass meters provide both pressure and temperature compensation of the natural gas and provides readings with accuracy. Since these meters are equipped with onboard electronics, a variety of communication options are available. These options include analog, pulse and open protocol (BACNET & MODBUS).
How difficult is it to install a water submeter?
Water submeter selection based on the application is an essential step in the process. Similar to natural gas submetering, there is a sizing and selection process based on pipe size and anticipated flow volume. At Emergent Metering, we recommend either the use of inline turbine or ultrasonic water meters. The span of the flow meter's ability to measure minimum flow conditions relative to peak flow conditions can vary significantly when comparing different metering technologies. For this reason, on applications that can feed flows that fall below a 1% of the peak flow potential of a service water line to utilize inline meters.
As an example of why this this minimum flow velocity is a critical metric, we see large warehouse spaces that are being constructed with large service mains. Since the developer has no control over who the tenant might be and what their water demand will be, the service lines are typically oversized to meet a variety of possible tenants. If the site is leased by a water intensive process, this water line will be properly sized, but if the space is leased by a general warehouse with only restrooms and minor water use, the 4 - 6" water line will be oversized and minimum flow situations will impact flow meter selection for tenant level submetering.
Inline Water submeter installations for lines that are less than 2" can be completed relatively easily. It will become more challenging as line sizes increase beyond 2" where possible welding and flange installations, we would look to migrate to an ultrasonic water meter installation. Ultrasonic water meters have higher minimum flow velocity requirements so this will also need to be considered during the meter selection process.
Integration (Energy Management Systems)
Due to the significant number of possible submeters within a site, the data read process is typically performed by an energy management system. This system will provide monitoring, control and possible optimization of energy usage. By combining submetering with these systems, the building owners and tenants gain access to real-time data and analytics that help identify energy-saving opportunities. The integration and the ease of access to energy metrics enhances the effectiveness of energy efficiency measures and promotes sustainable practices within buildings and facilities. We recognize the significance of NYC's Local Law 88 (LL88) and Local Law 97 (LL97) as the submetering requirements from these local laws will increase the of submetering technology to track energy usage in commercial and industrial buildings.
Conclusion
Submetering is an essential step in understanding energy use at specific processes or tenant spaces. The overall system should be well designed with proper hardware submetering components, integration, networking and dashboarding being considered throughout the process.
To learn more about how we can help you with your submetering needs. Please reach out to us at sales@emergentenergy.us