Solar without a subsidy: when it pays not to wait

One of the questions we hear most often is whether it is worth waiting for a new subsidy to open — Exoikonomo (the national home-energy subsidy), "Allazo Thermansi" (Change My Heating), or whichever programme happens to be in the pipeline — before installing solar, or whether it pays to go ahead straight away, without a subsidy. The intuitive answer is "of course you wait, the subsidy cuts the cost". In practice, though, waiting has a cost of its own, and it is often seriously underestimated.

The hidden cost of waiting

Every month a solar system is not running on your roof is a month of electricity bill you pay in full instead of trimming it through net metering. If, for instance, a correctly sized system would save you around €90 a month, then a twelve-month wait for a new subsidy to open, be announced and finally approved "costs" you roughly €1,080 in lost savings — money you never get back, even if you do secure the subsidy in the end. The question you really need to answer is not "will I save on the upfront cost if I wait?" but "does the saving on the upfront cost exceed the savings lost while waiting?".

In practice, subsidy programmes in Greece have historically gone through phases of delay — between announcement, call, approval of the application and disbursement, 6 to 12 months can easily pass, sometimes more. Add to that the wait for an available installer once the programme opens (demand spikes sharply), and the true "cost of waiting" can easily match or exceed the subsidy itself, especially for households with high consumption.

Where net metering stands today

Subsidies aside, the net-metering mechanism remains available and already works today for residential solar: your roof's production is netted off against your consumption at regular intervals, cutting your electricity bill from the very first day the system runs. This mechanism does not depend on a subsidy existing — it works the same whether you paid for the system entirely yourself or bought it at a subsidised cost. With a typical payback of 5 to 7 years without a subsidy, and a system lifespan of over 25 years, a solar system installed today without a subsidy pays for itself in full and delivers a full fifteen-plus years of pure benefit before you even need to think about replacing equipment.

Shading and orientation: the point usually overlooked

One factor that affects the decision far more than owners usually believe is shading from neighbouring buildings and the orientation of the roof. Two identical homes, with the same roof area and the same number of panels, can have completely different energy output depending on whether the roof is shaded in the morning or afternoon hours by a taller building next door. Shading does not simply reduce output proportionally; it can "cut" entire strings of panels depending on the wiring, so the real loss is disproportionately larger than the share of shaded surface.

Orientation plays an equally decisive role: a south-facing roof with a pitch of 25–35 degrees delivers close to the maximum possible, while an east- or west-facing roof can lose 15% to 20% of potential output, and a roof with significant shading combined with poor orientation may not justify the investment at all, subsidy or no subsidy. That is exactly why any serious estimate must factor in shading from the surrounding buildings before quoting any number — something our own calculator does automatically, taking into account the height of the buildings around your roof.

How to weigh your own decision

Rather than relying on rules of thumb, a practical way to decide is to ask yourself four questions in this order. First: how tall are the buildings around your roof, and on which side? If the shading mainly affects the morning or afternoon hours, the impact on total annual output is usually smaller than most owners fear. Second: what are the orientation and pitch of your roof — a simple photo and a compass app on your phone are enough for a first estimate. Third: how much capital do you have available today, without resorting to borrowing on punishing terms? Fourth: how certain, and how close in time, is the subsidy you are waiting for — "sometime in 2027" is a very different thing from a specific, already announced date.

Answering these four questions honestly, most owners arrive fairly quickly at a clear direction, without having to guess the future of Greek subsidy programmes — which, let us admit, nobody can predict with complete certainty.

When waiting is nevertheless worth it

Not every case is the same. If your household has no capital available at all and cannot secure borrowing on reasonable terms, then waiting for a subsidy — or choosing a no-upfront-cost model such as PPC (ΔΕΗ) SolarSmart — may be the only realistic option, regardless of what the arithmetic says is optimal. Likewise, if you are already very close to the opening of a programme with a clear, announced date and little expected delay, waiting a few weeks obviously does not change the conclusions.

There is a third category where waiting makes sense: when your roof needs maintenance or replacement work anyway (waterproofing, new tiles) before it can safely host a solar system. In that case, the time the roof works would take regardless coincides with the subsidy waiting period, and there is no real opportunity cost to the delay.

In most cases, though, where at least some capital is available and the roof has good orientation with limited shading, the cost of waiting tends to outweigh the benefit of a future, uncertain subsidy. The one sure step is to measure the real numbers for your own roof. Use our solar calculator, which also checks shading from the neighbouring buildings, to see whether in your case it pays to go ahead now or to wait.