Big lie about feed-in meters for selling electricity

South African municipalities’ insistence that customers buy and install an approved bidirectional meter to sell back electricity to the grid might be nonsense.

Instead, they could use an additional one-way meter to measure electricity fed back into the grid in addition to their regular meter that records grid power consumption.

This is according to Techsolutions CEO Eon de Koker, a qualified electrical and electronic engineer.

De Koker recently told MyBroadband that municipalities were missing out on the excess electricity generated by many of their customers’ rooftop solar systems.

De Koker highlighted a recent report on the adoption of small-scale embedded generation (SSEG) by the South African Local Government Association (SALGA).

The report flagged expensive bidirectional meters as one of the stumbling blocks to buying electricity from households and businesses.

“To allow embedded generation systems to feed into the grid and compensate customers accordingly, most municipalities require the installation of bi-directional meters at the customer’s cost,” the report said.

“While this is a necessary requirement to measure energy exports, customers have complained that several municipalities are requiring overly expensive meters when cheaper meters can do the same job.”

“These additional costs often contribute to customers not wanting to register their embedded generation systems.”

However, De Koker does not believe that a bidirectional meter is necessary in the first place and that a regular additional meter can serve the same purpose.

One reason the municipalities might want to install new meters for feed-in is that they want those customers to be on a time-of-use (ToU) tariff to allow for smart grid balancing.

Eskom already makes it mandatory for customers with grid-tied generation feeding back electricity to move to its Homeflex ToU tariff.

These tariff structures can help ensure stability in the grid by making it more affordable to consume electricity during off-peak hours and most expensive during peak hours.

The value of electricity credits is also based on when the customers feed electricity back to the grid.

Time-of-use not mandatory for municipalities

However, time-of-use tariffs are not always applicable for customers who feed in excess electricity.

For example, the City of Cape Town, which has perhaps the most progressive SSEG policy in the country, does not demand users switch to ToU tariff. Neither does the City of Ethekwini.

Both metros let users feed in electricity at a flat tariff, which raises questions over the need for a bidirectional meter with ToU capability.

It can take a long time to make up the high costs of the bidirectional meter with electricity credits.

In many municipalities, the maximum credit that can be earned back cannot exceed the value of the consumption.

Therefore, the biggest possible discount will be the total monthly bill, which is already much lower for many grid-tied solar users.

Cape Town is the only municipality that pays households and businesses in cash if the value of their feed-in exceeds the value of consumption.

As a result, the programme has seen substantial uptake, with around 80MWp capacity registered by 2023.

That is even though it offers a feed-in rate of R1.20 per kWh — signficantly lower than what it pays for electricity from Eskom.

Nevertheless, the programme is a big win for Cape Town, which gains extra capacity at a minimal cost.

In stark contrast, De Koker criticised the City of Tshwane for spending R50 million on consultants to formulate a plan to restart mothballed power stations with a private provider, instead of focusing on existing rooftop solar installation capacity.

“Why rather not spend the money to automate applications and install subsidised meters?” he said.

Tshwane invited interested households and businesses to apply for admission to its SSEG programme in March 2024.

However, a MyBroadband journalist has repeatedly emailed the city’s official channel for SSEG but has not received any response in a month and a half.

Bidirectional meters appear overpriced

MyBroadband also found that bidirectional meter fees set by municipalities are substantially higher than models sold online.

Many major metros with bidirectional meter charges in their tariff books charge around R10,000 or more.

Cape Town offers the most affordable bidirectional meter in South Africa, priced at R6,043 from 2024. It previously also cost over R10,000.

However, even CoCT’s much-reduced fee is substantially more expensive than meters from reputable brands selling online.

For example, Utilitypal sells a Hexing bi-directional single-phase meter for R2,099, while Sunstore South Africa sells a Fronius model for R2,473.

In May, Tshwane told MyBroadband it would offer single-phase meters priced between R2,500 and R3,000 a unit from the financial year starting on 1 July 2024.

However, its latest tariff book has a single-phase bidirectional meter priced at about R12,356.