25 April 2026

home solar

One Year of Home Solar – Was it Worth it? A Real-World ROI Analysis

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Is a £24,000 home solar panel system actually worth it? After one full year of measuring real data from my solar panels, Tesla Powerwall 3 battery, and myenergi Eddi hot water diverter, I crunched the numbers to find out. Using 12 months of half-hourly grid import/export data, EV charging records, and solar generation figures, I calculated the true ROI – not from installer projections, but from actual measured consumption. The results surprised me: a total annual value of £3,534.79, giving a payback period of just 6.8 years on a £24,000 investment. The biggest insight? Electricity savings – what you don’t have to buy from the grid – are worth more than double the export earnings. This post breaks down the full methodology, the maths, the seasonal patterns, and practical lessons for anyone considering solar in the UK.