The energy company will separate its organisation into a Nordic unit and a continental European unit.
The write down equates to 29.7 billion Swedish Kronor “as a consequence of market development and higher business risks.”
In a statement, the company said it did not expect the market to recover “in the foreseeable future”.
Vattenfall’s chairman of the board of directors Lars G Nordström and chief executive Øystein Løseth said: “The impairments are significant and this is obviously a difficult task. But this is the reality we are facing and we have to react according to what we know about the marketplace today.
“It means that we must adjust the book value of our assets. It also means that we have to take steps that we deem are necessary to ensure in the long term a sustainable and strong Vattenfall.”
Vattenfall said the write-downs announced today included gas and hard coal-fired power plants in the Netherlands amounting to 14.5 billion Swedish Kronor (SEK) and hard coal-fired power plants in Germany amounting to SEK 4.1 billion.
In a statement the company said: “Vattenfall is changing its organisational structure to achieve greater financial and strategic flexibility. As of 1 January 2014, the Group’s operations will be split up into two regional units: Nordic and Continental Europe/UK.
“The background to the changes is the increased uncertainty about the development of the single energy market in Europe, especially in continental Europe.”
According to the Vattenfall, the write-downs will not affect its cash flow.