Hey everyone, looking for some experienced eyes on a solar quote we've received. Wanting to make sure I'm not missing red flags before signing.

Our situation

We're a family of 4 in Christchurch, NZ. The house is a bit unusual which I think pushes the price up:

• 4-storey cascading hillside home on a sloping section in Cashmere
• Architect-designed, built 2016
• Butynol membrane roof (grey 1.5mm fully adhered over plywood, 2° fall)
• Multiple separate roof areas across different levels: L0 garage 50m², L1 entry 132m², L2 living 71m², L3 bedrooms 66m²
• Quote covers panels on L2 + L3 only (top two levels)
• Currently single-phase 63A supply (consent plans originally specced 3-phase capability but only single-phase was installed during construction)

Energy usage (verified from 12 months of half-hourly meter data):

• 14,044 kWh/yr currently
• Annual energy spend was ~$7,247 ($5,967 electricity + $1,280 LPG gas)
• We've since switched to Mercury (27c peak / 15c off-peak / $2 daily) which dropped electricity to ~$3,500/yr
• Planning to transition gas to electric (Rinnai 340L heat pump hot water + induction cooktop) which adds ~1,800 kWh/yr
• Post-transition total usage: ~15,844 kWh/yr
• Two heat pumps for heating (no central system)

The two quotes from the installer

Option 1 - No Battery: NZ$29,871 inc GST ($2,464/kW)

• 24× Suntech STP505S-H54-Nfb+ panels (505W each = 12.12 kWp DC)
• 1× SigenStor EC 12.0SP single-phase hybrid inverter (12kW)
• Estimated annual generation: 13,919 kWh
• Installer's Y1 savings estimate: $2,963
• 25yr panel product warranty, 30yr performance warranty
• 10yr inverter warranty

Option 2 - With Battery: NZ$42,586 inc GST ($2,635/kW)

• 32× same Suntech panels (16.16 kWp DC)
• Same SigenStor EC 12.0SP inverter
• 1× SigenStor BAT 10.0 battery (9.04 kWh usable)
• Estimated annual generation: 18,385 kWh
• Installer's Y1 savings estimate: $4,090
• Same warranties

Payment terms (both quotes):

• 50% deposit on acceptance
• 25% 7 days before install
• 25% on completion

Installer has confirmed full roof setup is included (scaffolding for 4-storey access, butynol membrane considerations, all labour).

What are our thoughts? Ive got a few quotes still to come in of course!

Hey all,

I have seen that, previous to this post, there has been some chatter about installers and products in Christchurch.

We are very heavy users of power. Large home, 4 people, I work from home. We use approximately 12000-14000kwh per year and have a average power bill of $500 a month (I know, I know lol).

We are commited to making energy changes and, we have ditched gas (prettt much) and installing a hot water heatpump next week.

We have an architectural home in Cashmere with flat butonoyl roof. I know this isn't an issue, but understand that a roofer would have to do some pre setup before panels are placed.

We have three roof lines/areas essentially but, the rear roof would be best for asethetic.

One more thing to note is, we have a eGolf.

What has been everyone's experience and recommdations on companies to go with?

We are commited to making the change and would move quickly!

TIA!