Solar panels not included. Many homes in the greater Perth region of Western Australia can’t enjoy the benefits of solar panels due to property incompatibilities (shade, available surface area, etc.) yet still seek to earn greater energy security while reducing their electricity bills. Fortunately, solar energy is available on the grid during peak daylight hours and it’s cheap.
It is so abundant that Synergy is offering the cost of electricity during peak solar production periods at a quarter (8.4050 cents/kWh) of the Home Plan A1 tariff price. Here’s how you can reduce your bills by combining only a home battery system and the Synergy Midday Saver tariff.
Contents
- Net saving scenario of $4.53 daily and improved energy security
- Super Off-Peak (9 am - 3 pm): 8.4050 cents/kWh
- Use a battery to bridge the Peak (3 pm - 9 pm): 52.5313 cents/kWh
- Solar has the lowest wholesale energy cost for Synergy to distribute
A modern energy grid in one paragraph: The decentralisation of energy networks provides greater energy security for users and expanding populations, as they are less subjected to singular supply interruptions. Alongside decentralisation, variable fuel sources offer extra protection from potential supply market wholesale cost volatility. Perhaps even complication, but we’ve never had a more stable grid. Welcome to Western Power’s South West Interconnected System (SWIS for short), also known as ‘The Grid’, where Synergy is the local retailer.
Now, consider that the Western Power grid plays host to an energy market. Daily, the most affordable energy supplied at a nominated period takes preference to satisfy the network’s requirements. In Perth, there is an oversupply of solar energy between 9 am and 3 pm, enticing heavy day-time energy users with a sweeter deal.
Image: Daily solar energy yield between 9 am to 3 pm peak periods.
Quick Tip 1: Load shift when choosing the Synergy Midday Saver tariff, shift programmable appliance use between 9 am and 3 pm. Consider the following appliances: dishwasher, washing machine, dryer, e-mobility charging, pool pump, air conditioner (pre-conditioning), etc., to operate on cheaper grid-supplied solar energy at 8.4050 cents/kWh.
Quick Tip 2: Add a suitable battery to bridge the more costly 3 to 9pm ‘Peak’ period. Suitability depends on individual energy use. Tesla has almost mathed the ideal battery size for most homeowners during this period at 13.5 kWh (so much so that it didn’t change between models: Powerwall 2 vs 3). Many other batteries are either similar in energy density or more modular to achieve an ideal level of energy security. Cost per kWh is where battery customers in this segment must focus.
Need a home battery quote? Perth Solar Warehouse is a Perth local installer for proven technology.
Sarah lives in Perth and is on the Synergy Midday Saver tariff. By knowing how to load shift certain appliances towards cheaper energy, Sarah now has enough energy storage in reserve to ensure she can clear the more expensive ‘Peak’ period. Sarah has a Tesla Powerwall 3 with a usable capacity of 13.5 kWh installed in her home, but she does not have solar panels.
Midday Saver Tariff Rates:
- Peak (3 pm – 9 pm): 52.5313 cents/kWh
- Off-Peak (9 pm – 9 am): 23.1138 cents/kWh
- Super Off-Peak (9 am – 3 pm): 8.4050 cents/kWh
Scenario Calculations:
Charging the Powerwall: Sarah decides to fully charge her Powerwall during the Super Off-Peak period, 9 am to 3 pm.
Energy required: 13.5 kWh
Cost to charge: 13.5 kWh x 8.4050 cents/kWh = $1.134
Using the Powerwall: Sarah uses the entire stored energy in the Powerwall during the Peak period (3 pm to 9 pm) to power her home appliances.
Energy used: 13.5 kWh
Cost avoided during Peak: 13.5 kWh x 52.5313 cents/kWh = $7.054
Net Savings: Calculate the overall savings by subtracting the cost to charge the Powerwall and the daily supply charge from the cost avoided during peak hours.
Net savings: $7.054 – $1.134 – $1.2608 = $4.659
It’s important to note that the daily supply charge of the Synergy Midday Saver tariff is approximately 13c more per day than the Home Plan A1 Tariff. To consider this difference, subtract 13c from the $4.659 saved daily.
$4.659 – $0.13 = $4.53 savings per day
In this scenario, even without solar panels, Sarah is able to save $4.53 by strategically charging her Powerwall during Super Off-Peak hours and utilising the stored energy during Peak hours. This demonstrates how a home battery can be leveraged to optimise energy costs even for those without solar generation.
Additional benefits of the Synergy Midday Saver tariff are the reduced Off-Peak rates (9 pm to 9 am) rates of 23.1138c per kWh off-peak energy cost (vs Home Plan A1 Tariff: 31.5823c per kWh). Consider this an improved base load power supply cost for 24/7 appliances such as refrigerators, freezers, after-hours air conditioning use (if required), fans, and appliances on stand-by mode.
Additional Considerations:
- The actual savings may vary depending on the household’s energy consumption patterns and the specific appliance use during different tariff periods.
- It’s important to analyse your energy usage and tariff rates to determine if a home battery would be a cost-effective solution for your situation.
- Daily supply charges vary between different Synergy tariffs.
- Tariff rates change anually.
Image: Synergy Midday Saver tariff provides an energy-saving opportunity for those without solar panels.
Synergy is a retail energy business, so the numbers must provide a level of profitability, regardless of the energy supplied from the grid. Below is a brief comparison of the three main tariffs available in 2024/25:
Home Plan (A1)
Your energy consumption knowledge: Easy
- Supply charge (daily): $1.1322
- All day/night: 0.315823 cents/kWh
The set-and-forget ‘easy’ Synergy electricity rate more appealing to users who choose to be less concerned about how and when they use energy. The rates within the Synergy Home Plan (A1) tariff ensure a mid-range cost of electricity. How much you pay depends on your ‘anytime’ energy consumption.
Bill reduction potential: N/A. Best for those who want to operate energy anytime and not worry about variable cost benefit options.
Midday Saver
Your energy consumption knowledge: Intermediate
- Supply charge (daily): $1.2607
- Peak (3pm – 9pm): 52.5313 cents/kWh
- Off-Peak (9pm – 9am): 23.1138 cents/kWh
- Super Off-Peak (9am – 3pm): 8.4050 cents/kWh
The Synergy Midday Saver tariff is ideal for users who have a finely tuned operational energy sense. You know what appliances you’re using and when you’re using them, and mastering energy bill reduction by optimising habits in line with low-cost energy.
Bill reduction potential: Improved through greater energy market exposure and the ability to capitalise on the opportune time. Strongly consider home energy storage to bridge peak charge costs.
EV Add On
Your energy consumption knowledge: Advanced
- Supply charge (daily): $1.2607
- Peak (3pm – 9pm): 52.5313 cents/kWh
- Off-Peak (6am – 9am / 9pm to 11pm): 23.1138 cents/kWh
- Super Off-Peak (9am – 3pm): 8.4050 cents/kWh
- Overnight electricity charge (11pm to 6am): 18.9113 cents/kWh
The EV Add-On tariff is effectively the same as the Synergy Midday Saver tariff except for one improved cost layer: the Overnight electricity charge between 11pm and 6am (but you must own an electric vehicle). This can effectively be used to top up the home battery alongside an electric vehicle ready for use with the morning’s energy use. EV add-on should only be considered for those with an advanced knowledge of how and when precisely to operate certain loads.
Bill reduction potential: Varied. Primarily, you’re now aiming to supplement petrol energy at a lower cost/km travelled for your vehicle and prepared to schedule home electricity consumption on an advanced level. So, the costs you save through optimising appliance use will host an EV charging component (approx. 10 kWh daily). But if you’re on this plan, you know what you’re doing. Higher or similar Synergy bills are likely, but overall energy spending (Average household energy profile: electric, natural gas, oil/petrochemical) will be reduced if monitored and aligned with low-cost inputs. Strongly consider bidirectional EV charging capabilities or home energy storage to bridge Peak charge costs.
Return on investment calculations are always subjective yet provide a level of insight into the approximate timeframe you are likely to see your initial investment is recovered in savings and the point at a point of where your investment makes money. However, when it comes to batteries, many focus on energy savings alone at the current rate and neglect alternative benefits that may improve calculations:
- Future ‘Peak’ rate increase protection
- Inflationary protection
- Additional energy security, such as blackout protection
- Advanced operational features including energy profiling and solar optimisation [with solar]
Midday Saver with 1 x Battery [no solar]
However, we can assume a scenario with base-level costs and total daily battery cycling with the intention of bridging the Peak period rates at the current tariff rate, which historically increases at approximately 2.5 -3% p/a for fossil fuel-generated energy.
Scenario A: Sarah buys a Tesla Powerwall 3 installed from Perth Solar Warehouse.
Purchase price: $15,990 [current prices]
Daily energy savings: $4.53
Calculated ROI: $15,990 ÷ 4.53 = 3530 days/ 9.7 years
Even without solar panels, Sarah can now power her home from low-cost solar energy plus protect herself from blackouts and future price increases of fossil-fuel-generated energy. With Tesla Powerwall 3’s software and smart tariff utilisation features, she has the ability to improve load shifting to low-cost power hours, further expediting her return on investment.
Midday Saver with 2 x Batteries [no solar]
Sarah draws more power than most homes between 3 p.m. and 9 p.m., so she decides to double down on her investment in a more suitable battery capacity of 27 kWh. Considering the initial battery price factors a major installation component cost, additional capacity is far simpler to install affecting an improved addition capacity cost.
Scenario A: Sarah buys 2 x Tesla Powerwall 3’s installed from Perth Solar Warehouse totalling 27 kWh of power reserve.
Purchase price: $15,990 + $13990 = $29,980
Daily energy savings: $9.06
Calculated ROI: $29,980 ÷ 9.06 = 3309 days/ 9 years
Increasing her energy storage capacity improves Sarah’s initial return on investment calculations while contributing to more sustainable energy sources with added energy security benefits.
Using the Synergy Midday Saver tariff blindly and unprepared will not reduce your electricity bills. However, if you can better optimise energy consumption alongside a battery to skip the more costly Peak period, where opportunities exist with improved energy independence and security.
Synergy: Energy plans
