Electrical Metering in the Microgrid Age

Gordon Echlin

Microgrids represent a significant shift in electricity supply and distribution, and a burgeoning opportunity for corporate leaders, building owners, and property managers to participate in the growing economy of distributed energy networks.

A microgrid is a localized, closed system that both produces and consumes electricity. Due to the technical challenges involved and the commercial and regulatory issues of pricing and managing market transactions, microgrids have not traditionally been connected to the public grid. The desire to be energy self-sufficient through local, privately owned sources of power and to be able to share that power with others — to be a prosumer (producer/consumer) not just a consumer — is, however, changing all that.

Going Pro

The ability to generate electricity locally is being revolutionized and takes many forms (solar, wind, water and geothermal for example). It can come in massive capacity or small, personal capacities. Rapid advances in battery capabilities are making it possible to save surplus energy created in low price periods to be used locally at a later time or shared in periods of high pricing and electrical deficit on the public grid. Batteries come in massive sizes (e.g., utility-grade or building size) or personal sizes (e.g., electrical vehicle size) and are crucial to managing the inconsistent nature of production and use.

Distributed Energy Resource Management Systems (DERMS)

A vital piece of the prosumer technology puzzle is the ability to coordinate the generation and load of microgrids with each other, and with the public grid. This includes the ability to transact (buy and sell) electricity between multiple stakeholders on multiple grids. The technology of coordination is taking the form of Distributed Energy Resource Management Systems (DERMS) — where the activities of all of the actors in the system are managed to maintain overall grid stability. Technologies such as blockchain (distributed ledger) may provide the means to manage large amounts of real time multi-party transactions.

Bigger Fish Getting in on the Frenzy

It would be difficult to attain a critical mass of energy production and sharing using this model if left to small, individual players. However, the economic opportunity that comes with the prospect of being able to build microgrids that can interact with the public grid is attracting bigger fish. Governments, utilities, corporations, and investors see a tremendous opportunity for developing an aggregator model — a ‘Virtual Power Plant”  that can scale and transform our current centralized, broadcast system to a distributed, aggregated, microgrid model with a relatively low entry cost.

What Does this Have to do with Metering and Submetering?

Accurate measurement and recording need to occur if financial transactions are in the balance. The old model of metering essentially meant measuring the electricity delivered by the local grid operator to the consumer. With the distributed energy model, measurement, recording, and reconciliation have to be bidirectional, real-time and granular.

A meter must, therefore, be able to measure electricity delivered (from the grid to the consumer) and electricity received (by the grid from the local producer on the what has been traditionally termed the customer side of the meter). The meter also needs to be able to report delivered or received electricity on multiple time schedules — from regularly scheduled reporting intervals (monthly) to immediate, on demand requests for information.

In the new world of distributed energy networks, hybrid generation and ownership (multiple types of generation, many stakeholders, various times of use and production) will be the norm. Inexpensive, granular metering that can pinpoint the dynamic "puts and takes" of this new electrical reality are therefore essential.

There are Efficiency Considerations Too

The nature of an electrical load can be either inductive or capacitive — reducing the effectiveness of the power supply and affecting the efficiency of the grid. This occurs most often on big loads such as industrial buildings with large motors and considerable amounts of fluorescent lighting. If big enough this affects electricity pricing and needs to be tracked and reported in real time for grid stability.  

So What Type of Metering Is Required?

First off, a bit of a warning. The term "net meter" has often been used to refer to the type of meter needed in a DERMs model. Some net meters will meet these requirements, but the term is commonly used to refer to devices with a single register that goes up with electricity delivered and goes down with electricity received. These devices are inadequate for the task at hand because they do not discriminate between energy received and energy delivered, or the timing of the respective electricity flow.  

A building should use meters that are capable of functioning in a DERMS model. Metering must, therefore, go beyond net metering to something called "four quadrant" metering — that is meters that measure delivered and received energy, both active and reactive. There's no reason or excuse not to. Meters with these capabilities add minimally to the cost of a project and mean the difference between being able to participate in the growing microgrid opportunity, or not.

‍‍Triacta PowerHawk and Triacta GATEWAY systems are "DERMS—capable

As small footprint electrical generation, storage capabilities, and energy management initiatives continue to advance; microgrid use cases will naturally expand. To take full advantage of the economic opportunity offered, equip new buildings for this new reality from the start and retrofit older ones with the same capability.  Even if a tenant doesn't own a building they may want to fit-up with these capabilities independent of their property owner’s vision.

Triacta PowerHawk and Triacta GATEWAY systems are "DERMS—capable." Every meter point measures four quadrant — delivered and received. All meters are capable of multiple forms of communication — including real-time over MODBUS TCPIP or BACnet/IP.  Moreover, Triacta meters record and maintain four quadrant data onboard for years, so even if there is a communications network failure, critical transactional data is not lost. Traceable, auditable records in an approved instrument of weights and measures is key to turning this Distributed Energy Resources microgrid vision into reali ty.

Finally, Triacta meters are modular and come in a variety of sizes — ensuring optimal and economical meter-point coverage for any type of microgrid metering, big or small.

About the Author

Gordon Echlin is Vice President Marketing and Business Development for Triacta Power Solutions LP, where he has been a management team member since 2009. Prior to Triacta, Gordon was a partner for a boutique venture capital firm, Venture Coaches from 2006 to 2009, and started a telematics company, Netistix Technologies, in 2002. Gordon is a Computer Scientist and technologist by education, and prior to Netistix worked in technical, management and sales roles in Mitel Corporation, Newbridge Corporation and several small startups, since graduating in 1982.

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