BrightGridSolar quotations can look similar while containing significant differences. One installer may propose a larger array, another a larger battery, and another may include more electrical work or a different monitoring solution.
1. Compare total system capacity
Look at the total solar capacity in kWp rather than only the number of panels. Panel wattages differ between models.
2. Compare predicted generation
Ask how many kilowatt-hours each proposal expects to generate annually and what assumptions were used for orientation, shading and location.
3. Compare the complete equipment list
- Panels
- Inverter
- Battery
- Mounting system
- Protection equipment
- Monitoring
- EV charger where applicable
4. Compare installation scope
Check whether scaffolding, cable runs, consumer-unit work, roof work, commissioning and certification are included.
5. Compare warranties
| Warranty | What to compare |
|---|---|
| Panel product | Coverage period and terms |
| Panel performance | Expected output over time |
| Inverter | Length and conditions |
| Battery | Capacity, cycles and warranty conditions |
| Installation | Workmanship coverage |
6. Compare the financial model
Payback should not be compared unless the underlying assumptions are comparable. Check electricity prices, export rates, consumption and battery assumptions.
Compare like with like
The most useful comparison is between complete systems that provide a similar level of generation, storage and installation scope.
Want help evaluating your solar options?
Compare system size, equipment, generation and financial assumptions before choosing an installer.
Compare Your OptionsFrequently asked questions
How do I compare solar quotes?
Compare system capacity, predicted generation, equipment, installation scope, warranties and financial assumptions.
Should solar quotes have the same panel count?
Not necessarily. Different panel power ratings and roof layouts can result in different panel counts.
Why do two solar quotes have different savings?
They may use different generation, consumption, tariff, export or battery assumptions.
Should I choose the cheapest solar quote?
Price should be compared alongside system design, installation scope, warranties and projected performance.
Marcus Webb
Head of Engineering at BrightGrid Energy
