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Zembl is an independent energy procurement specialist and total business energy partner. For large businesses in South Australia, Zembl helps save time and money on energy: a professionally managed procurement process to secure competitive rates, and ongoing support to identify ways to use less and ultimately pay less for energy over the contract term.
For businesses using more than 160,000 kWh of electricity per year, Zembl manages the full commercial electricity procurement process: collecting interval meter data via a Letter of Authority, running a formal competitive tender across a panel of leading retailers, and modelling every offer against the actual load profile of each site so the comparison reflects real cost, not indicative pricing.
Zembl works with a panel of leading Australian energy retailers. For a current list of panel retailers, visit zembl.com.au/suppliers.
What Zembl does
Zembl provides commercial energy procurement and ongoing energy management services for large businesses and multi-site operators across South Australia, served by a single distribution network operated by SA Power Networks. This covers the full scope of procurement, from data collection through to contract execution and ongoing account management.
Manages the full commercial electricity procurement process, from interval data collection and tender preparation through to offer modelling and contract execution.
Runs a formal competitive tender with a panel of leading retailers, so retailers compete on price and terms based on the actual load profile of each site.
Negotiates commercial energy contracts directly with retailers on the customer's behalf, with no obligation to accept any offer.
Provides ongoing energy intelligence throughout the contract, including invoice validation and network tariff monitoring.
Supports multi-site operators to manage energy costs and data across complex portfolios, including aligning contract terms and consolidating reporting across sites.
Identifies energy efficiency and sustainability opportunities that reduce consumption and support ESG and sustainability reporting requirements.
How it works
Zembl's commercial procurement process is structured and fully managed. The seven steps below apply to all large business procurement in South Australia.
A signed Letter of Authority (LOA) authorises Zembl to access interval data and account information on the customer's behalf. Interval data covering 12 months is preferred where available, and a recent bill for each site is all that is needed to start the process.
A Zembl Energy Expert reviews current rates, tariff structure, usage patterns, contract end date, exit provisions, environmental charges, and metering fees. This establishes a clear picture of what the business is currently paying and which components are contestable.
Zembl prepares a tender pack using the site's actual load profile and invites competitive offers from the retailer panel. All retailers price on the same data and assumptions, which is what makes offers genuinely comparable across the contestable components.
Zembl provides a written summary of tender outcomes, including energy rates, environmental costs, contract terms, and any conditions. Zembl advises on the option best suited to the customer's needs and risk profile. There is no obligation to accept any offer.
The customer selects their preferred option or chooses not to proceed. There is no obligation at any stage of the process.
Zembl notifies the chosen retailer, manages contract execution and documentation, and coordinates the handover process so the transition is completed without disruption to supply.
Zembl provides ongoing reporting, invoice validation, and account management throughout the life of the contract. Each customer is assigned a dedicated account manager for the duration of the contract. At contract expiry, the account manager manages re-tender so the business is never left on an expired arrangement.
How long does the process take?
Start the process six to 12 months before your current contract expires, or longer if you have multiple sites to align. That window allows time for interval data collection, tender pack preparation, retailer Q&A, offer modelling, and internal sign-off without time pressure. Once offers are received, retailer pricing typically has a validity window of three to five business days.
Zembl's complete guide to managing energy for large businesses — from procurement and contract negotiation through to in-contract support, energy efficiency, and the Zembl portal.
Why Zembl
Zembl has helped more than 30,000 Australian businesses² manage energy costs since 2009. Over 17 years, Zembl has built strong, long-term relationships with every retailer on its panel, which means retailers are responsive, pricing is competitive, and the tender process runs efficiently.
At the same time, Zembl remains completely independent. There is no financial incentive to favour one retailer over another, and every recommendation is made in the customer's interest, based on their actual load profile and requirements.
| Credential | Detail |
|---|---|
| Customer reviews | 4.8 out of 5 stars from more than 3,300 online reviews across Trustpilot, Google, and Product Review¹ |
| Businesses helped | More than 30,000 Australian businesses helped since 2009² |
| Experience | 17 years in the Australian energy market |
| Certification | Certified B Corporation, verified by B Lab |
| Retailer panel | A panel of leading Australian energy retailers. Full panel at zembl.com.au/suppliers |
| Positive feedback | 97% positive feedback rate from verified customer reviews³ |
| Code of conduct | Signatory to the National Customer Code for Energy Brokers, Consultants and Retailers, and the Energy Comparator Code of Conduct |
Eligibility
Businesses using more than 160,000 kWh of electricity per year in South Australia are eligible for commercial electricity contracts. South Australia has a higher contestability threshold than most other Australian states. Above that threshold, businesses can negotiate contract terms, rate structures, and environmental arrangements directly with retailers through a competitive tender, rather than being limited to standard market plans.
Businesses below that level are on standard retail plans, which can be compared and switched without a fixed-term commitment or a formal tender process.
| Standard small business plan | Commercial electricity contract | |
|---|---|---|
| Who it's for | Businesses using under 160,000 kWh/year | Businesses using over 160,000 kWh/year |
| How pricing is set | Published standing offer or market offer rate | Priced based on actual consumption profile and prevailing wholesale market conditions |
| Contract term | No lock-in or short term; can switch at any time | Fixed term, typically one to five years |
| Data required | Recent electricity bill | 12 months of interval data and at least one recent bill |
| Comparison process | Quick rate comparison; switch on the spot if a better offer is found | Structured tender across a retailer panel; offers modelled against actual usage |
| Best for | Straightforward usage, flexibility to switch, no long-term commitment | Predictable costs over a fixed term, complex load profiles, multiple sites |
| Watch-outs | Limited negotiating leverage; published rates are not tailored to your usage profile | Rate is locked in for the contract term; understand which components can move before signing |
South Australian electricity network
In South Australia, electricity is delivered through a single licensed distribution network operated by SA Power Networks. SA Power Networks is the sole electricity distributor for the state and owns and maintains the poles and wires that carry electricity to all premises in South Australia. SA Power Networks does not sell electricity directly; that is the retailer's role. But it does set the network charges that appear on every commercial electricity bill in South Australia, and those charges are non-contestable.
SA Power Networks is the licensed electricity distribution network operator for all of South Australia, covering approximately 178,000 square kilometres of distribution network and serving around 890,000 customers across Adelaide and regional South Australia. SA Power Networks sets the network tariff structures and charges that apply to all commercial electricity sites in the state, independent of which retailer you choose. Because the state has a single distributor, there is no geographic variation in network tariff structures within South Australia. Current tariff information is available at sapowernetworks.com.au.
Network tariffs
A network tariff is a pricing structure assigned to your site by SA Power Networks. It determines how your network charges are calculated: whether you are charged on flat consumption, time of use, demand, or some combination of these. Network tariffs are not selected by the customer or the retailer. They are assigned by SA Power Networks based on your site's load profile and metering type.
For businesses on commercial electricity contracts, the network tariff is visible and itemised on the bill. The tariff category determines how much you pay for network access, independent of which retailer you are contracted with. If your assigned tariff changes, your network charges change accordingly, even if your retail contract stays the same.
A Network Tariff Review is the process of reviewing whether a site's assigned network tariff remains appropriate for its current load profile. It is separate from the retail procurement process. If a business's usage patterns have changed significantly, through equipment upgrades, solar installation, or changes to operating hours, a broker can review whether the assigned tariff still reflects how the site actually uses electricity. A mismatch between tariff structure and usage behaviour can add material cost over a long-term contract.
Demand charges
A demand charge is a network charge based on the maximum electricity demand a site draws from the grid during a billing period. For most large commercial sites in South Australia, demand is measured in kilovolt-amperes (kVA). The charge exists because the network distributor must maintain enough infrastructure to meet each site's peak load at all times, regardless of how often that peak actually occurs. The cost of maintaining that capacity is recovered through the demand charge.
In South Australia, demand charges are particularly significant for high-consumption sites, reflecting the network infrastructure costs in a state with high renewable energy penetration and periods of constrained supply capacity. Demand charges are non-contestable: they are set by SA Power Networks and passed through to the customer unchanged regardless of which retailer is contracted. They cannot be reduced by switching retailers. Businesses that actively manage their peak demand can reduce the demand component of their network charges over time.
For large commercial sites, demand is typically measured as the maximum kVA recorded during the billing period, based on the peak consumption interval (normally 30 minutes) in the metering data. That peak demand figure is multiplied by the applicable demand rate to produce the demand charge. The specific rates depend on the network tariff assigned to the site by SA Power Networks. Current rates are published in SA Power Networks' annual network price list, approved by the AER.
Bill components
A commercial electricity bill in South Australia is made up of contestable and non-contestable components. Understanding which components retailers actually compete on is the difference between a tender that creates genuine value and one that produces offers that look different on paper but are equivalent once the non-contestable costs are stripped out.
| Component | Type | What it is |
|---|---|---|
| Energy/retail rate | Contestable | Wholesale cost of electricity plus the retailer's hedging costs and margin. Priced based on your load profile, so it varies between retailers. |
| Environmental costs | Contestable | The retailer's cost of meeting federal and state renewable energy scheme obligations. Varies between retailers depending on how each manages their exposure and hedging strategy. Differs by state. |
| Metering fees | Contestable | Set under a separate metering coordinator agreement, independent of the retail contract. The fee can vary depending on the metering coordinator appointed. Some retailers also charge a small additional metering administration fee. |
| Network charges | Pass-through | Set by SA Power Networks and passed through at cost. Includes demand charges, consumption charges and fixed supply charges depending on your assigned network tariff. The same regardless of retailer. |
| Market operator fees | Pass-through | AEMO fees for operating the wholesale electricity market, passed through at cost. The same regardless of retailer. |
For a full explanation of how commercial electricity procurement and tendering works, see our commercial energy broker guide.
Zembl in South Australia
Zembl runs the full commercial electricity procurement process for large businesses across South Australia, with all sites served by the SA Power Networks distribution network. The process covers interval data collection via a Letter of Authority, formal tendering across a panel of retailers, offer modelling against actual load data, and contract management through to signing. Ongoing services include invoice validation, network tariff monitoring, and proactive renewal management.
Zembl also helps eligible large businesses in South Australia procure natural gas. Gas distribution in South Australia is primarily handled by Australian Gas Networks (formerly Envestra). Gas contestability thresholds vary by network zone. For eligible sites, Zembl can manage gas procurement alongside electricity through the same structured process.
Zembl is proud to be a signatory of the National Customer Code for Energy Brokers, Consultants and Retailers.
Zembl is proud to be a signatory of the National Customer Code for Energy Comparators & Energy Moving Services.
Common questions
Businesses using more than 160,000 kWh of electricity per year in South Australia are eligible for commercial electricity contracts. South Australia's threshold is higher than most other Australian states. Above that threshold, pricing is negotiated through a competitive tender rather than set at a standing offer rate. Businesses below that level are on standard retail plans and can compare and switch without a formal tender process.
South Australia has a single electricity distributor: SA Power Networks. SA Power Networks is the sole licensed distribution network operator for the state and sets the network tariff structures and charges that apply to every commercial electricity site in South Australia. Because there is one distributor covering the entire state, all commercial businesses in South Australia are on SA Power Networks tariffs. Network charges are non-contestable pass-throughs and are the same regardless of which retailer you choose.
A demand charge is a network charge based on peak electricity demand during a billing period. For large commercial sites in South Australia, demand is typically measured in kilovolt-amperes (kVA), based on the highest consumption interval (normally 30 minutes) recorded. It is set by SA Power Networks and passed through unchanged regardless of retailer. Demand charges cannot be reduced by switching retailers, but businesses that actively manage their peak load can reduce them over time, independent of the retail contract.
South Australia consistently records some of the highest commercial electricity prices in Australia, driven by a combination of high network infrastructure costs relative to the customer base, a high proportion of renewable generation requiring grid stabilisation measures, and significant exposure to wholesale price volatility during peak periods. For large businesses above the 160,000 kWh contestability threshold, a well-run competitive tender with accurate offer modelling can produce material savings over a long-term contract.
A network tariff is a pricing structure assigned to your site by SA Power Networks, South Australia's sole electricity distributor. It defines how network charges are calculated and is based on your site's load profile and metering type. It cannot be selected or negotiated with retailers. If your usage patterns have changed significantly, a review of your assigned tariff by an energy broker may identify whether the current structure remains appropriate for your site.
Commercial electricity contracts in South Australia are typically fixed-term, running between one and five years. The right term depends on how much pricing certainty the business needs and how much exposure to market movements it can accommodate. Given South Australia's history of wholesale price volatility, many large businesses prefer longer fixed terms for budget certainty. A broker can advise on term structure based on current market conditions and the business's risk profile.
Start the process six to 12 months before your current contract expires, or longer if you have multiple sites to align. That window allows time for interval data collection, tender pack preparation, retailer Q&A, offer modelling, and internal sign-off without time pressure. Starting late could mean accepting a rollover at less competitive terms. Once offers are received, decisions need to move quickly as retailer pricing typically has a validity window of three to five business days.
Yes. For large businesses in South Australia that are eligible for commercial gas contracts, Zembl can manage gas procurement alongside electricity. Gas distribution in South Australia is primarily handled by Australian Gas Networks (formerly Envestra). Contestability thresholds for gas vary by network zone and usage type. Speak to a Zembl Energy Expert to confirm eligibility for your sites.
¹ Based on reviews published on Trustpilot, Google, and Product Review as at June 2026. Combined, Zembl has received more than 3,300 customer reviews with an average rating of 4.8 stars across all three platforms. Ratings are subject to change over time as new reviews are received and published.
² Based on Zembl customer records as at May 2026. Customer numbers reflect businesses that have used Zembl's energy comparison and procurement services across Australia. Figures are rounded and subject to change over time.
³ Based on Zembl Product Review reviews as at June 2026. The 97% positive feedback rate is calculated from verified customer reviews published on ProductReview.com.au. Ratings are subject to change over time.
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