Price Development of Photovoltaics and Battery Storage
Both solar panels and home batteries have become dramatically cheaper over the past decade, and battery costs are still falling. Below you get the direction of travel first, then what drives it and what it means for your own system.
Solar module prices and lithium-ion battery prices have each fallen by roughly 80-90% since around 2010, according to widely cited industry data (IEA, BloombergNEF). Modules are now the smallest cost item in a PV system; batteries have followed the same curve a few years later. The trend is downward, though year-to-year movements can be flat or briefly rise due to raw-material or supply-chain swings.
Three forces keep pushing costs lower: manufacturing scale (each doubling of global production historically cut costs by a fixed percentage - the learning curve), improved cell and battery chemistry, and fierce competition among manufacturers. Battery storage in particular is still early on its learning curve, so it has more room to fall than mature solar modules.
Price development is not only about buying hardware - it is also about the power price you pay. A study from Austria found that battery storage permanently lowers electricity market prices by shifting cheap midday solar power into expensive evening hours. Fraunhofer IEE similarly estimated that expanding battery storage relieves the German power system by billions of euros per year. More storage flattens the daily price curve.
Falling prices improve payback, but waiting indefinitely rarely pays off: every year you delay is a year of self-generated electricity you do not use. A practical approach is to size the system to your actual consumption and evening load, and value the battery on the price spread it can capture - the gap between cheap solar hours and expensive peak hours - rather than on hardware cost alone.
Compare like with like: net vs. gross prices, module-only vs. fully installed, and battery cell price vs. usable-capacity price (per kWh you can actually cycle). Installed-system prices fall more slowly than component prices because labor, mounting, inverters and permitting do not follow the same curve. Ask any quote to break these out.