Question 1

Why should I install a battery before 2026?

Accepted Answer

The federal STC rebate decreases every January 1st as it phases out toward 2030. A 6.6kW solar system gets ~$2,500 in STCs if installed in 2025, but only ~$2,200 in 2026 - a $300+ loss. For a full solar+battery system, you could lose $400-$600 waiting. With most installers booked into 2026, booking now means locking in 2025 STC rates even if installation happens in early 2026.

Question 2

How much do STCs decline each year until 2030?

Accepted Answer

STCs are based on 'deeming periods' - years remaining until 2030. In 2025, systems get 9.3 STCs per kW (5 years left). In 2026: 8.4 STCs/kW (4 years). By 2030, STCs drop to zero. For a 6.6kW system, that's approximately $2,500 (2025) → $2,200 (2026) → $1,900 (2027) → $1,600 (2028) → $1,300 (2029) → $0 (2030). Every year you wait costs hundreds of dollars.

Question 3

Are installers really booked out into 2026?

Accepted Answer

Yes, most reputable Perth installers have 3-6 month wait times due to high demand before the STC reductions. Booking in late 2025 typically means installation in Q1-Q2 2026. Some installers honor the STC rate at quote/deposit time rather than installation time, so ask about this policy. Getting quotes now protects you from further rate drops even if physical installation is months away.

Question 4

How much does a solar battery cost in Perth?

Accepted Answer

Battery costs in Perth range from $8,000 for a 5kWh system to $23,000+ for 20kWh systems. The most popular 10-13kWh systems typically cost $12,000-$16,000 installed. Prices vary based on brand, capacity, and installation complexity. Federal and WA state rebates can reduce costs by $3,000-$5,000.

Question 5

What rebates are available for batteries in WA?

Accepted Answer

WA homeowners can access: (1) Federal STC rebate (~$2,200-$2,500 for a 6.6kW solar system in 2025, declining annually), (2) WA Residential Battery Scheme ($1,300 for Synergy customers, $3,800 for Horizon Power), and (3) Distributed Energy Buyback Scheme (DEBS) offering 10c/kWh export rate during peak hours. VPP participation is required for the WA battery rebate.

Question 6

What size battery do I need for my Perth home?

Accepted Answer

Most Perth homes need 10-13kWh capacity. A 10kWh battery suits 3-4 bedroom homes using 20-30kWh/day, while 13kWh+ is better for larger homes, pools, or EV charging. Use our calculator to get a personalized recommendation based on your actual usage, tariff, and solar system size.

Question 7

How long does a solar battery last?

Accepted Answer

Quality batteries last 10-15 years with warranties typically covering 10 years or a specific throughput (e.g., 36-58 MWh). Degradation rates vary by chemistry: LFP batteries (BYD, Tesla) degrade slower (1.8-2.5%/year) than NMC batteries (2.5-3.5%/year). After 10 years, expect 70-85% of original capacity remaining.

Question 8

Can I add a battery to my existing solar system?

Accepted Answer

Yes! AC-coupled batteries (Tesla Powerwall, Alpha ESS) work with any existing solar system. DC-coupled batteries (BYD, Sungrow SBR) require a compatible hybrid inverter. If your current inverter is incompatible, you may need to upgrade or add a second inverter. Our partners can assess your system and recommend the best retrofit option.

Question 9

What is the payback period for a battery in Perth?

Accepted Answer

Typical payback periods in Perth are 8-12 years, depending on usage patterns, tariff, and rebates. Homes on Synergy A1 tariff with high evening usage see faster payback (7-9 years). VPP participation can reduce payback by 1-2 years. Our calculator provides personalized payback estimates based on your specific situation.

Question 10

Do batteries work during blackouts?

Accepted Answer

Most modern batteries support backup power, but it requires specific installation (backup gateway/switchboard). You can choose whole-home backup or essential circuits only (lights, fridge, internet). Backup capability adds $1,000-$2,000 to installation costs. Not all batteries support backup - check specifications before purchasing.

Question 11

What is DEBS and how does it work?

Accepted Answer

The Distributed Energy Buyback Scheme (DEBS) is Synergy's time-of-use export tariff. You earn 10c/kWh for solar exported 3pm-9pm (peak) and 2c/kWh outside those hours. Batteries maximize DEBS value by storing solar during the day and exporting during the 10c window, earning 5x more than off-peak exports.

Question 12

Should I join a VPP program?

Accepted Answer

VPP programs like Synergy Battery Rewards pay $200-$400/year for allowing occasional battery discharge during grid peaks. Benefits include extra income and supporting grid stability. Downsides include reduced backup availability during events (rare) and slightly increased battery cycling. Most Perth battery owners find VPPs worthwhile.

Question 13

AC-coupled or DC-coupled battery - which is better?

Accepted Answer

AC-coupled (Tesla, Enphase) are easier to retrofit and work with any solar system but have slightly lower efficiency (89-93%). DC-coupled (BYD, Sungrow) are more efficient (95%+) but require compatible hybrid inverters. For new installations, DC-coupled is often better. For retrofits, AC-coupled is simpler.

Question 14

Do I need Western Power approval for a battery?

Accepted Answer

Yes, all battery installations require Western Power approval. Your installer handles this via the ESM (Electricity Supply Management) portal. Approval typically takes 5-10 business days. Western Power checks your export limit, inverter capacity, and network compatibility. CEC-accredited installers are familiar with this process.

Question 15

Can I finance a solar battery?

Accepted Answer

Yes, green loans from lenders like NICU, Community First, and Parker Lane offer competitive rates (6-8% p.a.) for battery purchases. Loan terms typically range from 3-7 years. Some installers offer in-house financing. Compare loan costs against cash purchase to ensure financing doesn't eliminate your savings.

Solar Battery FAQ for Perth