Support Services · KNOWLEDGE GUIDE
FCR-D and Batteries - Understanding Readiness, Bids and Replacement
Separate installed power from assumed reserve capacity and follow how a market price becomes something other than your paid amount.
THE MOST IMPORTANT THING IN ONE MINUTE
- FCR-D är frekvenshållning vid störningar; upp och ned är separata produkter.
- Installed, offered and assumed power may differ.
- The market capacity price is not a promise of what your battery will earn.
What is being bought?
FCR-D is a frequency holding reserve for disturbances. FCR-D up helps the system at low frequency and FCR-D down at high frequency. The products are automatically activated within their technical conditions.
The capacity market refers to readiness to deliver. It must therefore be distinguished from ordinary sales of electricity per kWh. Always ask to know if the figure in an offer applies to capacity, energy or the household's allowance after deductions.
Source material: Swedish power grid: FCR-D up ↗
The battery label is just the beginning
A plant's rated power does not alone describe how much reserve it can supply. Units or groups need to be qualified for the service in question and participation requires the right actor and agreement.
Ask if your facility is connected to an approved solution and from which date. Distinguish future planned participation from active duty. Feel free to collect product, approved function and contractual counterparty on the same page in your documentation.
Source material: Swedish power grid: pre-qualification ↗
Three power values to keep apart
Installed power is the capacity of the equipment under specified conditions. Offered effect is what is left to the market. Assumed effect is the volume actually procured. There are different steps and they can give different numbers.
A personal example: a plant has a rated output of 10 kW, but a service offers 5 kW during a certain hour. If only part of the offer is accepted, you must not count as if all 10 kW had been accepted. The agreement's distribution also needs to be applied.
Source material: Swedish power grid: pre-qualification ↗ · Swedish power grid: FCR-D up ↗
Read the replacement with the correct unit
Svenska kraftnät describes FCR-D as a capacity market with procurement the day before. The market price refers to a product and delivery period. An information in EUR/MW should therefore not be compared directly with an electricity price in öre/kWh.
For a unit exercise: 5 kW is 0.005 MW. If a purely hypothetical price is 10 EUR/MW for an assumed hour, the product will be 0.05 EUR. After that, among other things, agreement distribution, fees, currency and delivery conditions remain.
Source material: Swedish power grid: FCR-D up ↗
Make a calculation with multiple outcomes
Request an account that shows assumed capacity and period and how the compensation reaches you. Separate historical outcome from future assumptions. Also check what applies when the battery is not available.
Feel free to count on your own cautious scenario without reserve income and one with an uncertain income. It shows how dependent your decision is on the market. Do not simultaneously count the same stored energy as fully available for reserve, evening consumption and reserve power.
Source material: The Swedish Energy Agency: batteries for solar cells ↗ · Swedish power grid: pre-qualification ↗
Try the capacity substitution unit.
Change assumed power and a hypothetical hourly price.
Immerse Yourself
FAQ.
Is historical earnings a guarantee?
Nope. Price, assumed volume, availability and agreement are subject to change. Ask for clear assumptions and a scenario without the uncertain revenue.
Can I use the whole battery by myself at the same time?
It depends on the service's requirements and how the control prioritizes. Ask for a concrete description of reserved power, energy levels and use at home.
FROM KNOWLEDGE TO EVERYDAY
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The material was checked on 26 October 2026. Follow the links for current terms and conditions.