| 10 kW Solar Array | 80% Self Consumption | $3,068 First Year Savings | 6 Yr 6 Mo Payback Time |
Project Overview
Tony retired a couple of years ago and had been watching his winter power bills climb ever since, with most of his household’s usage falling first thing in the morning and again at night, well outside the hours the sun is doing the most work. He also wanted backup power in case of an outage, without necessarily paying for a full battery on day one. Future Energy fitted a 10kW Trina solar array paired with a SolaX X1-VAST-8K battery ready inverter at his Mosgiel home, modelled to save an estimated $3,068 in the first year and pay for itself in 6 years and 6 months, with a clear path to add battery storage for his morning and evening usage pattern whenever he’s ready.
The Challenge
Tony’s biggest power draws happen first thing in the morning and again in the evening, exactly the hours solar panels are producing the least. That usage pattern, combined with retirement and a fixed income, meant winter power bills had become a real concern. He wanted a system that would bring his bill down straight away, but he was equally focused on resilience: if the grid went down, he wanted to know his home could keep running. The challenge was designing a system that delivered on both fronts without requiring him to commit to the full cost of solar and battery storage in one go.
The System
20 x Trina 500W Panels – 10kW Total
Twenty Trina TSM-500NEG18R.28 panels were installed on a north west facing roof at a 23 degree tilt, for a combined 10kW array. Modelled to generate 12,621kWh a year, around 34.6kWh a day, against Tony’s 21kWh of daily consumption, the system meets an estimated 80% of his energy use directly from solar.
SolaX X1-VAST-8K – Battery Ready 8kW Inverter
The SolaX X1-VAST-8K is an 8kW hybrid inverter with dual battery ports built in, chosen specifically so Tony can add battery storage later without an inverter upgrade. It already delivers up to 200% EPS output for 10 seconds and a switchover of under 10 milliseconds once a battery is connected, and its 4 MPPT trackers leave room to expand the array too. For a household whose heaviest use falls in the morning and evening, this is the inverter that makes a future battery addition a straightforward one, not a second installation.
The Results
- 10kW solar array across 20 Trina 500W panels on a north west facing roof
- SolaX X1-VAST-8K 8kW battery ready inverter with dual battery ports
- 12,621kWh of clean electricity generated a year, around 34.6kWh a day
- 80% of daily energy use met directly by solar
- $3,068 estimated first year savings
- Annual power bill cut from around $3,270 to an estimated $205
- $949 estimated annual solar export earnings
- An estimated $84,498 in lifetime savings over 25 years
- An estimated 1.5 tonnes of CO2 offset per year
- Estimated payback in 6 years and 6 months
Retired, not exposed. Solar today, battery ready for tomorrow.
Frequently Asked Questions
Does solar still make sense if most of your power use is morning and night, not midday?
Yes, though it changes what the system needs to do well. Tony’s usage peaks first thing in the morning and again at night, outside the hours his panels generate the most, so the system was sized to maximise self consumption where possible and paired with a battery ready inverter so storage can be added later to shift more of that solar into the hours he actually needs it.
Can you add battery backup to a solar system after it’s installed?
Yes, provided the inverter is chosen with that in mind. Tony’s SolaX X1-VAST-8K has dual battery ports built in, so a battery can be connected later without replacing the inverter, making it straightforward to add backup power whenever budget allows rather than needing to commit to it all upfront.
What does a battery ready inverter mean for backup power during an outage?
On its own, without a battery attached, a grid tied inverter has to shut down during an outage for safety, the same as any standard system. What a battery ready inverter like the SolaX X1-VAST-8K offers is the ability to add a battery later and unlock EPS backup output with a switchover of under 10 milliseconds, which is exactly the resilience Tony was after without paying for it on day one.
Is solar worth it for a retiree on a fixed income?
It can be one of the more reliable ways to bring a fixed income further, particularly where winter power bills are a known, recurring cost. For Tony’s Mosgiel home, Future Energy modelled an estimated $3,068 in first year savings and a payback of 6 years and 6 months, with the system continuing to generate savings well beyond that over its 25 year life.
Thinking about solar and backup power for retirement? Future Energy designs systems around how you actually use power, and with inverters that leave room to add battery storage whenever you’re ready. Talk to us about a system sized for your home, your usage pattern, and your budget.
