Real-World Test: Switching to A-Rated Bulbs Across the Home—How Much Could You Save on Heating and Electricity This Winter?

 With energy prices still volatile and winter putting extra pressure on household budgets, many homes are revisiting a simple question: does switching to A-rated light bulbs actually make a noticeable difference?

Energy labels are everywhere, but their real-world impact is often taken on faith. So instead of repeating marketing claims, let’s walk through a realistic, numbers-driven scenario to understand what switching to A-rated bulbs can (and cannot) save you on both electricity and heating over a winter season.

First, what does “A-rated” really mean?

Under the current EU energy label system, A-rated bulbs represent the most energy-efficient products available today. They typically consume 40–60% less electricity than standard LED bulbs that sit in the D/E/F range.

The test setup: a typical household

Let’s take a realistic home:

- 25 light points (mix of living areas, bedrooms, kitchen, bathroom)

- Average use: 4 hours per day per bulb in winter

- Winter period considered: 5 months (~150 days)

Before switching

Bulbs: standard LED (≈8W per bulb)

After switching

Bulbs: A-rated LED (≈4.5W per bulb)

Electricity savings: modest per bulb, meaningful at scale

Annual winter electricity use for lighting (before):
 25 bulbs × 0.008kW × 4h × 150 days = 120 kWh

After switching to A-rated bulbs:
 25 bulbs × 0.0045kW × 4h × 150 days = 67.5 kWh

Electricity saved over winter:
 ≈ 52.5 kWh

At an electricity price of €0.25–€0.30 per kWh, that equals:

 €13.2–€15.8 saved over the winter on lighting alone

Not spectacular. But also not zero—and this is purely lighting

Running Cooler: Another Sign of Efficiency

Efficiency isn’t just about electricity use it also shows up in how hot a bulb gets.

In our real-world test, both bulbs were measured under the same conditions, with an ambient temperature of 28 °C. The difference was clear. The A-rated bulb reached an enclosure temperature of 56.5 °C, while the E-rated bulb climbed to 94.3 °C, despite delivering similar light output.

This means the A-rated bulb wastes less energy as excess heat. That heat is too localised to meaningfully warm a room, but running cooler puts less thermal stress on the bulb itself. Over time, that can translate into better reliability, a longer lifespan, and safer performance — especially in enclosed fixtures or during long winter evenings when lights stay on for hours.

The overlooked benefit: savings every single year

Unlike many energy upgrades, bulbs:

- Require no behavior change

- Have a very low upfront cost

- Deliver savings every winter for 12–15 years

In practice today, switching to A-rated bulbs typically costs €1.5–€3 more per bulb than standard LEDs.

For 25 bulbs, that represents an extra upfront cost of roughly:

€40–€75 total

Based on the earlier winter electricity savings (≈ €13.2–€15.8), this implies:

Payback time: ~3–5 winters

Lifetime savings: clearly positive over a 10–15 year lifespan

NB: this calculation doesn’t include 2 factors that will clearly give an advantage to A-rated bulbs:

-the summer electricty savings

-the shorter lifespan of E/F-rated bulbs that enhances new upfront costs (when replacing), indeed reducing A-rated switching extra upfront costs.

The bottom line

Switching to A-rated bulbs across your home won’t feel revolutionary. And that’s precisely why it works.

It’s a rare upgrade that is:

- Technically sound

- Financially rational

- Effortless once installed

This winter, the savings may look small on paper. Over the lifetime of the bulbs—and across millions of households—they add up to something far more meaningful: lower energy demand, lower emissions, and smarter consumption without compromise.

Sometimes, the smartest changes are the ones you stop thinking about altogether.

This remains a conservative estimate, as it still doesn’t fully account for:

- Gradual electricity price increases

- Longer lighting use during darker winters