Study tour to Finland on grid management and renewable energy – first impressions

Introduction

During the site visit various stakeholders from the Finnish electricity market provided their views on future energy trends. The visits included a research organization, the national grid company, major power system and equipment suppliers, the weather forecasting institution, a wind power company and a solar panel manufacturer. Each organization presented their particular views which shared  common similarities. All agreed that: renewable power is already established and it will increase remarkably; climate is changing and mitigation activities are needed; and companies are developing short term and long term solutions for future energy systems.


Team listening to Hannele Holttinen presentation in VTT

Role of renewable power

Biomass power is well predictable; it may operate as conventional power plant but when operated in energy efficient mode as CHP, the output depends on the heat load and may vary. Wind and solar are clearly variable production methods but still growing strong. Both VTT researchers and Wärtsilä representatives clearly predicted that there is no turning back, solar and wind will take major role and the role of other power plants is to produce peak power. The peak production is difficult for most conventional base load plants. Some relatively new plants are already closed due to poor economics in peak production. As an indication to future, during our visit in Finland a wind power company Tuuliwatti announced that they will build a 5 x 4,2 MWe wind park on commercial terms without any subsidies and produce market power.

Power trading

Most of the energy in Europe is traded through exchanges. The main trading method is day ahead, where each producer and power user (whole sale) gives sale and purchase bids for every hour for the next day and the price for each hour for is formed. This means that each party needs good forecast for energy production and energy consumption. If noted that power will be needed more or less than originally agreed, there is intraday trading where energy can be sold or bought on short notice. If retailers fail to acquire their energy purchases in balance with the producers’ energy sales, the national grid operator steps in covering the deficit, and charge for the service. The grid company does not operate power plants, thus, the additional capacity is bought from preagreed partners as and when needed. The grid is balanced mainly by trading. Power is traded both ways internationally either through AC connections between countries in the same phase or through DC stations. Undersea cables are DC due to long transfer distance.


Heidi Uimonen of Fingrid explaining how the network is kept in balance through trading. She also gave introduction to Nordic/European power trading system.

Forecasting

The weather forecasting is critical in wind and solar production. Meteorological institute makes weather forecasts and have algorithms to translate weather forecast to wind or solar production power production forecasts for energy companies. The real power production follows well the forecasted power, but on hourly basis there are sometimes differences. In solar power production the cloudiness forecast is sometimes challenging.


Riikka Pusa and Jussi Kaurola Finnish Meteorological service and its services to energy industry.

Energy storage

A short term solution for variable energy production and consumption is power storages. Storage solutions with up to 20 MWh capacity were introduced to the participants. These may give 1 MW power for 20 hours or 5 MW for 4 hours depending on the need the storage. At present the storages are based on lithium ion technology.


Saara Kujala from Wätrsilä explaining that there is no turning back, renewable power is coming and traditional baseload power production is facing serious challenges.

Power quality

Power quality is critical in energy production as well as in industrial energy consumption. Linking solar to network solar requires converters to convert DC to AC and ensure the power quality meets the grid standards. Wind parks will benefit from power filtering devices to ensure power quality. Some industries cause distortion to power grid, and active filters may help to sort out the power quality problem as well as save energy.