The price of solar panels has dropped from €3,320/kW in 2008 to under €100/kW by mid-2025. Prices began ticking up slightly in early 2026, with stabilization expected over the coming years. The price of solar panels is now a minor part of the total cost of an installation, which can range between €500 and €1,500/kW depending on location, size, and the solar technology chosen. The other components driving up an installation’s total cost are support structures, the necessary electronics, wiring, installation labor, and so on. In some cases — depending on electricity prices — the payback period can be under a year, but for large self-consumption installations, it’s typically around 6 years.
In this article we analyze the pros and cons of large-scale solar self-consumption installations (above 10 kW). Solar energy is now cheaper than coal or gas. Installing self-consumption solar panels on large industrial, commercial, or service-sector buildings is the most profitable use of solar energy. With returns typically above 15% annually, low risk, and a useful life of over 30 years, it’s an investment few others can match. Yet, surprisingly, a large share of owners of this type of building still haven’t taken the step of installing solar power.
Until not long ago, these kinds of installations were only profitable with subsidies — which still exist, but are no longer at all necessary to achieve high returns on a solar installation. In the past, solar panels were installed for environmental reasons, to project a sustainable image, or for corporate responsibility purposes. Today, above all, it’s simply a very good financial move.
Advantages:
It protects your business against rising electricity prices.
Return on investment between 15% and 25%, depending on available sunlight, financing type, and chosen technology.
Very low risk compared to other high-return investments.
Payback is achieved in under 6 years, but the useful life is 30 years or more. Over the installation’s lifetime, savings amount to 4 to 6 times the original investment.
Solar panels are highly reliable, with few breakdowns and low maintenance.
Risks:
If your company’s electricity bill drops significantly due to lower consumption or falling electricity prices, the savings from your investment may be lower than expected.
Some installers will quote you an oversized installation — not the size that maximizes your investment’s return, but the one that maximizes their own revenue.
The electrical grid is saturated; for this reason, surplus power fed into the grid is increasingly poorly compensated, even as electricity prices continue to rise. You should therefore install just enough solar capacity to cover your own consumption during daylight hours — and not one watt more, to avoid feeding excess production into the grid.
A drawback of conventional solar technology is that it only operates at full output around midday — a time when many businesses are actually less active. Solar trackers greatly improve production in the early morning and late afternoon, but they’re rarely installed on rooftops, since they’re sensitive to wind and require structural supports firmly anchored to the ground. VectHor technology, offered by FutureVoltaics, delivers all the advantages of a solar tracker without any moving parts and with strong wind resistance — standing under 50 cm tall, it can be installed on rooftops just like conventional solar technology.
Annual energy production is the product of installed power multiplied by the Capacity Factor and the number of hours in a year (8,760 hours).
Production = Power × Capacity Factor × Time
The capacity factor depends on location and how the solar panels are mounted (fixed orientation or solar tracker). In the center of the Iberian Peninsula, VectHor has a capacity factor of 28%, while a typical fixed-orientation solar system has a capacity factor of 18%. It’s important not to confuse capacity factor with efficiency: while capacity factor measures how much energy is produced per unit of installed power, efficiency determines how much power is available per unit of area.
Residential installations are also profitable in most cases, but harder to make cost-effective for two reasons: there are fixed costs independent of installation size that raise the relative cost of small installations, and residential consumption is low, intermittent, and concentrated in hours with little sunlight.
