Capacity in properties: charging, heat pumps and simultaneous loads

Simultaneous loads are the new issue

In a property, a lot of electricity goes to things that previously did not run on electricity: charging for tenants' cars, heat pumps that have replaced district heating or oil, and electric immersion heaters as top-up heating on the coldest days. Individually they are manageable. The problem arises when they run at the same time, which they often do on a weekday evening in January.

A property with a main fuse above 63 A has a capacity subscription (effektabonnemang), and nothing there was affected by the halt on capacity charges (effektavgifter) in March 2026. Smaller properties with a fuse-based subscription (säkringsabonnemang) may have had the capacity charge removed or paused, but a new model linked to peak hours may come once the Swedish Energy Markets Inspectorate (Ei) has submitted its proposal in 2027. Background is available in Capacity charges for businesses in 2026.

Where the peak occurs in a property

• Charging. Tenants or members come home between 17:00 and 19:00 and plug in their cars at the same time. Without control, every charger charges at full capacity immediately.
• Heat pumps and immersion heaters. The heat pump normally covers the need, but in severe cold the immersion heater kicks in as top-up. It often draws more than the heat pump itself.
• Hot water. The hot water system reheats when consumption is highest, morning and evening.
• Shared loads. The laundry room, lift, ventilation and garage door come on top.

The dangerous hour is when all four coincide, which happens on the coldest weekday evenings. If the grid company has peak hours on winter weekdays, that hour also falls right in the window.

Worked example: charging and heat pump

Example: A property has 20 charging points with 11 kW chargers and a heat pump with a 30 kW immersion heater. Other load on a winter evening is 60 kW.

• Without control: if ten cars charge at the same time, that is 110 kW. With the immersion heater and other load, the peak becomes 110 + 30 + 60 = 200 kW.
• With load balancing that limits charging to a total of 44 kW when the property's load is high: 44 + 30 + 60 = 134 kW.
• With controls that also block the immersion heater during the hours when charging is highest: 44 + 60 = 104 kW.

With an assumed capacity price of 50 kr per kW per month, the difference between 200 and 104 kW, 96 kW, is worth 57,600 kr per year if the highest hour is set every month. In practice the peak is lower in summer, so the actual saving depends on your tariff and load profile. Calculate using your grid company's price list.

Load balancing should be set so that the cars are still charged by the morning. Ten cars charging 25 kWh each need 250 kWh, which at 44 kW takes roughly six hours.

The immersion heater should only be blocked as long as the heating can cope. A building has thermal inertia and can tolerate a short block, but comfort and the risk of frost damage come first.

What does the peak cost with your grid company?

How capacity is charged differs between grid companies, and that determines where to focus your efforts. If the grid company charges for the highest hour each month, each month counts separately. If you have a peak load charge, only weekdays during the day in winter count, and then charging after 22:00 does not affect that charge, although it may still count towards a monthly capacity charge that applies to all hours. If you have an annual subscribed capacity, it is the coldest evening of the entire year that decides.

Read the price list and terms of application for your tariff and write down three things: the time interval over which capacity is measured, which hours count and how often the subscription may be changed.

Before you expand charging

Charging is often expanded step by step, and each new step looks small. Do this before ordering:

1. Find the highest hour last winter and compare it with the subscribed capacity and main fuse.
2. Calculate how many charging points fit with load balancing before the subscription or fuse must be raised. Raising the fuse may mean switching to a capacity subscription with different fees.
3. Require that the charging system can limit total capacity and, if possible, take the property's other loads into account.
4. Decide how charging will be billed to tenants. Read more in Re-invoicing electricity to tenants.
5. Check what applies for grants. Klimatklivet (the Swedish climate investment programme) has a 2026 call for public charging, but the conditions change and a given project is not guaranteed funding.

Heat pump replacing district heating

Replacing district heating with a heat pump moves a cost from the heat supplier to the electricity grid. The calculation is often based on seasonal efficiency and kWh, but capacity on the coldest days is missing. It is precisely on those days that the heat pump has its lowest efficiency and the immersion heater kicks in, while the rest of the property is also at a high load. Ask for a calculation of the capacity requirement at the design outdoor temperature, including the immersion heater, and compare it with your subscription before deciding.

Several properties

If you have a portfolio, each property has its own subscription and its own peak. Set up a table with the highest hour and subscribed capacity per facility. Properties that subscribe to far more than they use, and properties close to the limit ahead of a charging expansion, stand out immediately. In depth: Reviewing a property company's electricity bills.

If you are a housing cooperative (BRF), there is a separate guide: Charging points and capacity in housing cooperatives.

If you would like help calculating capacity ahead of an expansion, Savera can carry out an independent review.