Installing commercial solar can substantially change how a business interacts with the electricity grid. However, many organisations focus primarily on how many kilowatt-hours their solar system will generate and overlook an equally important issue: how solar affects their electricity load profile and energy contract.
A well-structured solar and energy contract strategy considers both sides of the equation. Solar reduces the electricity your business needs from the grid during certain periods, while your retail electricity contract determines the cost and conditions associated with the remaining grid electricity.
Consequently, installing a large solar system while continuing to procure electricity based on your old consumption profile can create a mismatch between your physical energy requirements and contractual arrangements.
Understanding your new load profile helps your business make better procurement decisions, evaluate contract terms and capture more value from its solar investment.
Your electricity load profile shows how much electricity your business consumes at different times throughout the day.
For example, an office building may experience relatively low consumption overnight, a rapid increase when employees arrive, sustained daytime demand and a decline in the evening. In contrast, a manufacturing facility operating around the clock may maintain a much flatter load profile.
Solar changes this profile from the perspective of your electricity retailer.
When panels generate electricity, your business generally consumes that electricity behind the meter first. Therefore, the retailer only supplies the difference between your site's electricity requirements and the solar generation available at that time.
This creates what is commonly called a net load profile.
A simplified example illustrates the difference.
| Time | Site Demand | Solar Generation | Grid Electricity Required |
| 8 am | 400 kW | 80 kW | 320 kW |
| 10 am | 500 kW | 250 kW | 250 kW |
| 12 pm | 550 kW | 400 kW | 150 kW |
| 2 pm | 600 kW | 420 kW | 180 kW |
| 4 pm | 650 kW | 200 kW | 450 kW |
| 6 pm | 550 kW | 20 kW | 530 kW |
Although the site's underlying electricity requirements remain substantial, the amount purchased from the grid changes dramatically throughout the day.
Therefore, solar procurement and electricity contracting should not be treated as completely separate decisions.
The most obvious impact of commercial solar is lower daytime grid consumption.
If a business needs 500 kW at midday and its solar system produces 300 kW, only approximately 200 kW needs to come from the grid at that moment, assuming all solar generation is consumed onsite.
Across a year, this can significantly reduce purchased electricity volumes.
However, the financial value depends on when the solar system generates electricity and when the business consumes it. A business with strong daytime demand can generally consume a larger proportion of its solar generation onsite.
By comparison, a facility with limited daytime consumption may export more electricity. Therefore, simply comparing annual solar production against annual electricity consumption does not provide the full picture.
Before solar, a business might have a relatively predictable daytime grid load.
After solar installation, grid consumption may fall sharply during sunny periods and rise again as solar output declines later in the afternoon.
This can create a distinctive shape in interval meter data.
Cloud cover can also cause solar output to change throughout the day. As a result, grid requirements may become more variable even if the site's underlying operational demand remains stable.
Understanding this new profile is important when assessing your solar and energy contract because retailers price electricity according to the characteristics and risks associated with supplying a customer's load.
One of the most important considerations after installing solar is electricity volume.
Suppose a business previously purchased 5,000 MWh of grid electricity each year. After installing solar, annual grid purchases could fall considerably.
If the business negotiates its next electricity agreement using the old 5,000 MWh profile, the contracted assumptions may no longer accurately represent actual requirements.
Therefore, businesses planning a major solar installation should consider its expected generation before negotiating future electricity supply arrangements.
Retailers commonly use historical interval data when assessing a customer's electricity requirements.
However, historical consumption recorded before solar installation represents a different operating environment.
Businesses should therefore consider:
A forward-looking energy model can provide a more useful picture than historical bills alone.
Reducing energy consumption and reducing maximum demand are not necessarily the same thing.
Solar may substantially reduce kilowatt-hour consumption while having a smaller impact on the site's maximum kilowatt demand.
For example, consider a facility where maximum demand occurs at 5.30 pm. Solar output may already be falling rapidly at that time. Consequently, the solar installation could significantly reduce total daytime grid consumption without eliminating the facility's late-afternoon demand peak.
Alternatively, a warehouse that reaches maximum demand around midday may experience a much greater reduction in grid demand because solar production is typically stronger during that period.
This distinction matters because commercial electricity costs can include both consumption-related charges and demand-related network charges.
Therefore, businesses should model solar against interval data rather than assuming that a reduction in total grid consumption will produce an equivalent reduction in every component of the electricity bill.
A solar installation can alter the economics of an electricity agreement that was originally designed around a higher level of grid consumption.
Your business should review the contract to understand whether reduced consumption creates commercial consequences.
Important areas can include contracted volumes, minimum consumption conditions, pricing structures, demand arrangements, contract flexibility, metering requirements, renewable energy provisions and early termination conditions.
The exact impact will depend on the individual agreement. Therefore, businesses should review the actual contractual terms rather than assume that lower grid consumption automatically produces proportional savings.
This becomes particularly important when a major solar project is planned during an existing electricity contract term.
Ideally, solar planning and electricity procurement should form part of the same energy strategy.
If your electricity contract expires soon and a commercial solar installation is also planned, modelling the solar system before approaching the retail market can provide a clearer forecast of future grid requirements.
A useful sequence is:
| Stage | Action |
| 1 | Analyse historical interval electricity data |
| 2 | Model the proposed solar generation profile |
| 3 | Calculate expected onsite solar consumption |
| 4 | Estimate the new grid load profile |
| 5 | Account for business growth and operational changes |
| 6 | Assess suitable electricity contract structures |
| 7 | Compare retailer offers against the forecast profile |
This approach helps align procurement with the electricity the business expects to purchase rather than the electricity it used before solar.
A commercial solar system may occasionally generate more electricity than the site consumes.
When this happens, surplus electricity can potentially flow back to the grid, subject to the site's connection arrangements and relevant commercial terms.
However, the value received for exported solar electricity may differ substantially from the price the business pays when purchasing electricity.
For this reason, maximising onsite consumption can often be an important consideration when designing a commercial solar system.
Businesses should assess their daytime demand carefully and consider whether the proposed solar capacity aligns with that demand rather than focusing solely on installing the largest possible system.
Battery storage can further reshape the load profile created by solar.
Instead of exporting excess daytime generation, a battery can store some of that electricity for use later. For example, stored solar energy may support the business during late-afternoon periods when solar generation falls but electricity demand remains high.
Depending on the site's circumstances, batteries may also support peak demand management and other energy strategies.
However, battery economics depend on factors including consumption patterns, tariffs, system costs and operating strategy. Therefore, businesses should assess batteries using detailed interval data rather than assuming storage will automatically deliver attractive savings.
The strongest energy strategies look at solar generation, electricity procurement and operational demand together.
Before committing to either a new solar project or electricity contract, businesses should understand three profiles: the underlying site load, expected solar generation and resulting net grid load.
Together, these profiles provide a clearer view of future electricity requirements.
This analysis can also identify opportunities to shift flexible operations into periods of stronger solar production. For example, charging equipment, running certain machinery or scheduling energy-intensive processes during daylight hours may increase solar self-consumption.
As a result, businesses can potentially capture greater value from their solar investment while reducing exposure to grid electricity costs.
Installing commercial solar changes more than your electricity bill. It changes the amount of electricity your business purchases from the grid, the timing of those purchases and potentially the commercial assumptions underpinning your electricity agreement.
Therefore, your solar and energy contract strategies should work together.
Before installing a major solar system or renewing an electricity agreement, analyse interval data, forecast solar generation and model your future net grid load. Doing so can help your organisation choose contract terms that better reflect its actual electricity requirements.
Energy Action helps Australian businesses understand energy consumption, procurement options and renewable energy strategies. By bringing energy data, procurement expertise and energy solutions together, Energy Action can help businesses make more informed decisions about solar and electricity contracting. Visit Energy Action to explore how a coordinated energy strategy can support better cost management and long-term business objectives.
Solar reduces the amount of electricity your business purchases from the grid during periods when the system is generating power. Consequently, your historical electricity consumption may no longer accurately represent your future requirements. Reviewing your solar and energy contract together can help ensure that electricity procurement reflects your new net load profile.
Not necessarily. Solar can reduce peak grid demand when your maximum demand occurs during periods of strong solar production, but it may have less impact when the peak occurs in the evening or during periods of weak generation. Businesses should compare interval demand data with expected solar output to estimate the potential impact accurately.
A significant solar installation can materially change your grid consumption profile, so businesses should review their electricity contract and relevant requirements before proceeding. Contract terms, metering arrangements and connection requirements may need consideration. For large commercial installations, professional advice can help identify contractual implications before the system becomes operational.
Oversizing a system relative to daytime demand can increase the amount of electricity exported rather than consumed onsite. Because exported electricity may have a different value from electricity avoided through self-consumption, a larger system does not automatically produce a better financial outcome. System sizing should therefore consider interval consumption, export arrangements and future operational requirements.
Ideally, review your energy contract before committing to a major solar project and again before your electricity agreement expires. This gives your business an opportunity to model the new load profile and incorporate expected solar generation into procurement decisions. Regular reviews are also valuable when operating hours, production levels, battery storage or other major electricity requirements change.
