Comparison
String Inverter vs Hybrid: Which Replacement Is Right?
An honest, spec-based comparison to help you choose. Updated August 2026.
Last updated: August 2026 · Next review: February 2027
Verdict (August 2026)
For most homeowners replacing a failed inverter in Scotland, a like-for-like string inverter is the right choice. It is cheaper, faster to install, requires no G99 application, and does not affect your FIT arrangement. Choose a hybrid only if you have firm plans to add battery storage within 2–3 years — the extra cost (£700–£1,500) only pays back through battery savings, not through solar generation alone.
Head-to-Head Comparison
| Factor | String inverter | Hybrid inverter |
|---|---|---|
| Cost installed | £800–£1,500 | £1,500–£3,000 |
| Battery capability | None — solar only | Built-in — add battery any time |
| DNO notification | G98 only (if same kW rating: none) | Usually G99 (approval before install) |
| G99 wait time (SSEN) | Not required | 30–65 working days (longer on islands) |
| FIT/SEG impact | None if same rating. Written notice if different model. | Written notification to licensee required |
| Installation time | Half day (once part arrives) | Full day (wiring changes + battery prep) |
| Total time to generating | 3–5 working days from diagnosis | 3–6 weeks (waiting for G99 approval) |
| Typical warranty | 5–12 years (manufacturer dependent) | 10 years (Hanchu standard) |
| Efficiency | 97–98% (peak, fewer conversion stages) | 95–97% (additional DC-DC stage for battery) |
| VAT | 0% (until 31 March 2027) | 0% (until 31 March 2027) |
| HES grant eligibility | No — standalone inverter replacement not eligible | Possibly — if part of a heat pump installation |
Prices illustrative, August 2026. Your quote reflects your specific system. Source: Home Energy Scotland, checked August 2026.
When Each Option Makes Sense
Choose string inverter when:
- Your existing system works well and you want it back online fast
- You have no plans for battery storage in the next 3–5 years
- You are on the Feed-in Tariff and want to minimise disruption to your arrangement
- Budget is the primary consideration
- You are in an SSEN constrained area where G99 waits are 4–6 weeks
Choose hybrid inverter when:
- You have firm plans to add battery storage within 2–3 years
- You want to install battery at the same time as the inverter swap
- Your electricity usage pattern favours self-consumption over export
- You are on a time-of-use tariff and want to charge from the grid overnight
- You are also installing a heat pump (may qualify for HES grant)
String Configuration Constraints
Not every hybrid inverter is compatible with every existing panel array. Your existing string voltage and panel configuration constrain the replacement options. A 2012-era system with panels wired at high voltage for an older inverter may need rewiring to work with a modern hybrid. We assess compatibility as part of every diagnosis — you do not need to know your string configuration in advance.
Not Sure Which You Need?
We diagnose first and recommend based on your system, not on what costs more.
0141 230 0198Comparison based on manufacturer specifications and installation experience. Updated August 2026.