Start with the meaning of worth it
“Worth it” can mean lower bills, more energy independence, reduced carbon impact, future EV charging readiness, or a long-term investment. These goals do not always lead to exactly the same system design. A responsible recommendation should start with the customer’s aim.
Factors that strengthen the case
- A usable, reasonably unshaded roof or installation area.
- Meaningful electricity use during solar generation hours.
- A clear ownership horizon and long-term plan.
- A transparent proposal with realistic generation and savings assumptions.
- A design that allows for future EV, battery or heating changes where relevant.
Factors that weaken the case
- Heavy shade or limited usable roof area.
- A roof that needs repair before installation.
- Very low electricity use or little ability to use generation.
- A proposal relying on optimistic tariff, export or generation assumptions.
- Finance or contract terms that are not included in the payback calculation.
How solar creates value
Solar can create value by reducing the amount of electricity imported from the grid when solar generation is used on site. Eligible surplus electricity may also receive export payments through the Smart Export Guarantee, subject to supplier terms and scheme criteria. The two values should be modelled separately.
Why the answer should be a range
Generation, self-consumption, import tariffs, export tariffs and household behaviour can change. A robust assessment should show a central case and a cautious case, rather than relying on one precise-looking payback number.
Questions to ask before deciding
- What is the system expected to generate annually?
- What proportion of generation is expected to be used on site?
- Which import and export tariffs are assumed?
- What happens if generation or tariff values are lower than expected?
- Is battery storage being evaluated separately from solar?
Information and source control
Information correct as of: 17 July 2026
Sources available on request or reviewed during consultation.
