Full Cost Breakdown for a Typical 6 kW System
Here is what a typical residential solar installation looks like when you break it down by component (US pricing):
| Component | Cost Range | % of Total |
|---|---|---|
| Solar panels (15 × 400W) | $3,000–$5,400 | 30–35% |
| Inverter | $1,500–$3,000 | 10–15% |
| Mounting and racking | $800–$1,500 | 5–8% |
| Electrical and wiring | $1,000–$2,000 | 7–10% |
| Labour | $3,000–$5,000 | 25–30% |
| Permits and inspection | $500–$1,500 | 3–8% |
| Grid connection | $200–$500 | 1–3% |
Total: approximately $10,000–$18,900 for a 6 kW system before incentives.
Use our installation cost calculator to see a personalised breakdown for your country and system size.
Labour: The Biggest Variable
Labour is where installation quotes differ most. A straightforward installation on a simple pitched roof takes a two-person crew one to two days. But costs increase with:
- Roof access difficulty — multi-storey homes need taller scaffolding.
- Roof type — slate, tile, and flat roofs require specialised mounting.
- Electrical upgrades — older homes may need a new consumer unit or meter upgrade.
- Location — installers in major cities charge more than those in rural areas.
The best way to control labour costs is to get at least three quotes and check what each includes. Some installers bundle scaffolding; others charge it separately.
Inverter Costs: String vs Microinverters
Your inverter choice significantly affects both cost and long-term performance:
- String inverter (SMA, Fronius, GoodWe) — $1,000–$2,000 for a 6 kW unit. One device handles all panels. Simple, proven, and cost-effective for unshaded roofs.
- Microinverters (Enphase) — $150–$250 per panel ($2,250–$3,750 for 15 panels). Each panel has its own inverter. Better for partially shaded or multi-orientation roofs.
- Optimisers + string inverter (SolarEdge) — middle ground. Panel-level optimisation with a central inverter. $1,800–$3,200 total.
For most installations with good sun exposure and consistent orientation, a string inverter is the best value. Microinverters make sense when panels face different directions or experience partial shading.
Installation Costs by Country
Labour costs drive most of the international variation:
- United States — $2,400–$3,200 per kW installed. Higher labour costs but generous federal tax credit (30%).
- United Kingdom — £1,500–£2,200 per kW installed. No VAT on residential solar (0% since 2022).
- Australia — A$1,000–$1,600 per kW installed. The world's most competitive residential solar market.
- Canada — C$2,600–$3,400 per kW installed. Similar to US pricing but with provincial rebates varying widely.
- Ireland — €1,600–€2,400 per kW installed. SEAI grants of up to €2,100 available.
Hidden Costs to Watch For
Some costs catch homeowners by surprise. Watch for these in your quotes:
- Scaffolding — can add $500–$1,500 if not included in the installation quote.
- Electrical panel upgrade — older homes may need a $500–$2,000 panel upgrade to handle solar.
- Roof repairs — if your roof needs work, it's cheaper to do it before panels go on.
- Tree removal — shading trees may need trimming or removal ($200–$1,000+).
- Monitoring system — some quotes include app-based monitoring; others charge extra.
A reputable installer will flag all of these during the site survey before you commit.