Consumption impact in electricity contracts — how your usage affects the bill

”Consumption impact” (Finnish: kulutusvaikutus) refers to how your own electricity usage — its volume, timing and seasonal pattern — affects your bill and which contract type is cheapest for you. This is one of the most underappreciated factors in electricity contract selection. Two households with identical contracts but different usage patterns can have very different bills.

The three dimensions of consumption impact

1. Volume (annual kWh) — how much you use over a year.
2. Timing (hourly distribution) — when during the day you use power.
3. Seasonality (monthly pattern) — how usage varies winter vs summer.

Volume — annual kWh

Annual consumption is the single biggest factor. Typical Finnish profiles:

• Apartment (1 500–3 000 kWh/yr): Energy cost is small (€100–300). Choice between contract types matters less in absolute terms.
• Row house (4 000–8 000 kWh/yr): €350–800/year. Contract choice starts to matter.
• Detached, district heated (5 000–10 000 kWh/yr): €500–1 000/year.
• Detached, electrically heated (15 000–25 000 kWh/yr): €1 500–2 500/year. Contract choice has biggest absolute impact.

Timing — hourly distribution

Critical for spot contracts. Two main profile types:

• Flat consumer: Uses electricity steadily 24/7. Hourly variation has minimal effect. Suitable for any contract type.
• Peaky consumer: Heavy use during evening peaks (cooking, heating). On spot, this means paying expensive hours — bill is higher than average.

If you can shift major loads (EV charging, washing machine, sauna) to 00:00–06:00, you cut your spot bill by 20–40 %. This is the single biggest consumer-controllable factor.

Seasonality — monthly pattern

Finnish electrical-heat households use 50–70 % of annual consumption in November–March. This coincides with the highest spot prices. Combined effect: ~75 % of annual electricity cost falls in 5 months. Consequence: cold-month spot spikes have disproportionate impact on your annual bill.

How to estimate your annual consumption

• Check your annual report from the distribution company (Caruna, Helen Sähköverkko, etc.)
• Log into the distribution company’s online service — most show hourly data for the past 12 months
• If you just moved: estimate from the dwelling type (use ranges above)
• Use your most recent monthly bill × 12 (rough)

Reduce consumption — quick wins

• Lower indoor temperature by 1°C: saves 5–8 % on heating energy.
• Switch all bulbs to LED: saves 5–10 % of lighting energy.
• Use eco-mode on appliances: saves 5–15 % of appliance energy.
• Shift EV charging and washing machine to 00–06: 30–50 % cheaper kWh on spot.
• Insulate windows and doors: 5–15 % heating savings (depending on starting state).

Frequently asked questions