ZETDC has started setting up smart meters and Harare Polytechnic College was their first site to use it. We got to check out its highlight features like network connectivity and remote monitoring and control. These smart meters are pretty important if we are to dive into the age of smart grids that ZETDC is working on.
The rollout of these smart meters is starting in Harare and the target is 2500 clients. ZETDC Commercial Director Eng. Katsande stated that the rollout will be starting with high-priority clients that have a negative balance. These are medium to large businesses with a minimum power demand of 200KVA. So smart meters will not be issued to domestic users for the time being.
Domestic users also will be getting second-generation prepaid meters. These will not be smart but will come with Bluetooth functionality so that you can use your phone as the Customer Interface Unit (CIU). This requires you to have the ZETDC app installed on your smartphone which you will use to view your token balance, recharge your tokens and monitor your energy usage. It’s a data-free app that connects your phone to the meter via Bluetooth. So you will not be able to monitor it remotely. You’ll need to be at most 30m away from the meter itself.
How does a smart meter work?
The basic function of a meter is to give out a reading of whatever it is that is going through it. In the case of ZETDC, their meters are measuring how much electricity you are consuming. From there the meters then use a set tariff to deduct units equivalent to the amount of electricity you have used.
A smart meter can do this task and a couple more. Built inside it are features for remote monitoring and control and a broader selection of connectivity options to help with this feature. ZETDC is making use of internet-based connections on their smart meters riding on mobile networks using 3G or 4G, ethernet connection, or even a direct fiber optic cable connection.
The meter will be recording power consumption at particular points in time (Instantaneous Power) as well as maintain a history of all events on the meter including power consumption, current draw, power cuts, and voltage readings. And it can locally store this data on the meter for up to a year. This can certainly be extended by logging the data onto an off-site server which ZETDC implemented.
Smart meter benefits
ZETDC stands to benefit a lot from these. A smart meter is an extension of ZETDC’s power monitoring and control system. All aspects of power being consumed at a customer’s site are visible to ZETDC. This data is then used to manage the grid more precisely.
Tamper & bypass detection
ZETDC claims it is owed over ZW$42 billion through a combination of unpaid bills and illegal power connections that bypass the meter. Smart meters have a real-time connection to the server for aspects of monitoring and control and also meter tampering alerts. So if it detects any form of tempering, it sends an alarm to the central control in real-time.
More precise grid control
Smart meters are also very helpful to a power utility in managing the distribution of electricity on the grid. At present, ZETDC can only control its network up to the substation/feeder level. So in the event of load shedding, they will be switching off a blanket area when they could have maybe switched off a few individuals. With the meters on the customer premises being smart, it can allow ZETDC to execute load shedding for specific loads. So ZETDC can remotely switch off loads like air conditioning and geysers for a premise remotely and still provide power for more business-critical operations.
Smarter power grids
Managing the grid is also made easier. Currently, ZETDC can manage the grid to the feeder level which is not really an efficient way to do so. With smart meters, the grid will get to a point where it can manage itself based on the load characteristics of the grid at any point in time. The objective is to maintain a high level of uptime which is what smart grids enable. Beyond just the consumer side of the grid, smart grids enable multiple sources of power to be efficiently plugged into the grid. That is if a solar farm exists, it will be utilized by the grid during the day and supplemented by thermal power stations. On overcast days, the grid will rely more on thermal and hydropower sources and it does this via software.
Cheaper electricity bill
Domestic power consumers are charged in consumption bands. The lower the consumption band you are in, the cheaper the power will be per unit. This is different for commercial power consumers. They enjoy a standard rate, off-peak rate, and on-peak rate. So depending on the time of day, electricity can be cheap or expensive. With a smart meter, a business can manage its power consumption to take advantage of this and use the majority of its electricity when it’s at its cheapest. A smart meter will have these tariffs and times loaded onto it and will adjust the tariffs according to the rate for that particular time of day.
Enables net metering
Smart meters are also essential for net metering. Net metering is a process where a power consumer is producing excess energy which they can feed back into the grid. This excess energy can come from solar or wind. Regular meters are designed to measure the flow of electricity in one direction which is normally into the premises of the consumer. Smart meters can measure flow of electricity in both directions which then makes net metering possible. So this excess power you generate is recorded by the meter and credited to your account. Just make sure your solar inverter is a grid-tied inverter if you wish to dive into net metering.
Meter rollout plan
The project will cost US$35 million and will be done in phases. Smart meters are the second phase of the project with a planned 12 770 meters to be installed with Harare getting around 2 500 of them. As stated the minimum capacity of these meters will be 200kVA which limits access to medium and large institutions.
The region will also witness installation of 2500 smart meters to high priority customers and those companies with negative debt history.ZETDC Commercial Director Eng. Katsande
There are 2 meter brands being used. Iskraemeko and Secure meters with the former being the one installed at the Harare Polytechnic College.
The rollout plan is set to have been completed by June 2023 with remote disconnection hardware installation being completed by July 2023.