Solar Mistakes

Solar mistakes are distinctive because solar is sold on a number, expected generation, that depends on roof, shading, weather, household timing and export terms, none of which appear in a headline figure. A system on a shaded or poorly oriented roof, a system whose generation is mostly exported at a low value while the household buys electricity at a high value, or a system fitted to a roof that soon needs repair together produce disappointment that the panels themselves did not cause. This guide explains the solar failure modes, and the proposal checks that prevent them. It is general guidance, and solar for a specific home needs a roof survey, a shading assessment and a written proposal with stated assumptions. No generation or saving is guaranteed here.

Solar performance starts with the roof: orientation, pitch, shading from trees, chimneys, neighbouring buildings and roof features, and the roof's condition and remaining life. A roof that needs re-covering within the system's life should be addressed before panels are fitted, since removing and refitting panels is costly. Self-consumption comes next: electricity used in the home while the sun shines is worth more to the household than electricity exported, so household timing, including daytime occupancy, hot water timing and any storage or diversion, shapes value more than total generation. Export terms, inverter and panel warranties, maintenance access and monitoring complete the picture. A proposal that shows only annual generation, without shading, self-use and export terms, is showing a fraction of the decision.

Ask for a written proposal covering roof survey and condition, shading analysis, orientation and pitch, expected generation with its assumptions, self-consumption assumption with its basis, export terms, inverter and panel warranties, maintenance and cleaning access, and monitoring. Check installer certification for the jurisdiction and measure, and confirm who owns the system, who maintains it, and what happens at a sale or a roof repair. Compare the proposal's assumptions with your household's daytime use, and ask how the figures change if self-consumption is lower or export terms change. Inspect the roof's age and condition independently where possible, and do not let a generation headline substitute for the full proposal. A complete proposal invites those questions; an incomplete one resists them.

Solar support, export arrangements and installer certification are national. In the UK, MCS certification, export tariffs and planning rules for domestic solar follow UK frameworks, with distinct arrangements across the nations. In EU member states, solar support, self-consumption rules, grid connection and installer qualification are national under the broader EPBD and renewables frameworks, so a solar proposition from one country cannot be transferred to another. The homeowner's checks travel: roof and shading survey, self-use and export terms, warranties, maintenance and sale implications, all in writing. The scheme and tariff details that fill those checks are national and time-specific, and should be confirmed live before committing.

The classic solar mistake is buying on headline generation without shading, self-use or export terms, and then discovering that most generation leaves the home at low value. Another is fitting panels to a roof that soon needs repair, paying twice for access. A third is ignoring maintenance access and monitoring, so a failed inverter or a soiled array goes unnoticed for months. A fourth is assuming that solar removes the need for fabric, heating or control improvements, when a leaky home with solar panels is still a leaky home. A fifth is signing a proposal that bundles solar with unrelated work or finance, so the solar decision cannot be judged on its own terms. Each mistake is a proposal-reading failure, and each is caught by asking for the full written proposal.

Keep the solar file together: roof and shading survey, proposal with assumptions, installer certification, warranties, export terms, monitoring access and maintenance notes. Monitor generation against the proposal's assumptions over the first year, allowing for weather, and note self-consumption honestly rather than from the headline. When selling the home, pass the file to the buyer, including warranties and any transfer steps. Solar can serve a home well for decades, and the file that records its roof, its assumptions and its terms is what lets that long service be understood, maintained and transferred without surprise.