Balancing Bornholm
The Danish island of Bornholm finds the key to efficient electricity markets (hint: it's you and me).
The Bornholmians are on the path to energy independence (photo: elthenerd/flickr.com)
In the Baltic sea, south of Sweden and east of the Danish mainland, lies Bornholm, a small island in many ways resembling a mini version of what Denmark might look like in the future. Denmark aims at 100% renewable energy by 2050. The Bornholmians already get more than half of their energy from renewable sources, and their goal is to become a sustainable, carbon-neutral society that is self sufficient in renewable energy by 2025. But to achieve this, new technology is only part of the solution. A major factor determining the efficiency of an energy system based on renewable sources is the consumers, and their ability to adjust to variable supply.
A perishable good
A challenging aspect of electricity is that it's very difficult to store without huge losses. Electric currents travel through our cables at the speed of light, so at the same moment electricity is produced, there has to be a consumer at the other end. Therefore, there always has to be an instant balance between production and consumption of electricity. This is solved by reducing production in periods with little consumption, like in the middle of the night, and boosting production when everyone gets home and starts cooking dinner.
Modern renewable energy is usually based on variable sources like wind and solar energy. With the variation in output, combined with increasing electricity demand from heat pumps and electric vehicles, keeping the grid in balance represents a huge challenge. The introduction of renewable energy not only means changing our power sources. It will also alter the way producers and consumers interact, from production that is adjusted to consumption demand, to a system where consumers also adjust to the available electricity supply.
The intelligent grid
Some electricity consumption is independent on the time of the day. Electric cars can be charged at night, when consumption is low, and the laundry doesn't have to be done at peak hours in the evening. A heat pump could be turned off for half an hour if supply is short. When the supply of electricity is higher than the demand, the price will automatically go down. By switching some energy intensive consumption to times where the price is low, grid capacity can be saved during peak hours, and less energy will be wasted when there is too much of it available. The solution lies with the flexibility of the consumer, but to make it work it is crucial that people understand and accept the new concept and get used to thinking differently about electricity consumption.
Preparing Bornholmians for the new market
The island of Bornholm has a broad mix of renewable energy sources, with 30 MW of wind power, 16 MW of Combined Heat and Power (CHP) production from biomass, and 2 MW each from biogas and photovoltaic cells. On average, this is enough to cover half of Bornholm’s energy needs, but with huge variation in wind strength and solar radiation, the energy isn’t always there when needed.
The EcoGrid EU project has been started to collect information about how to prepare citizens for the new energy system, and to show that flexible consumption can contribute to balancing the electricity market. 2000 Bornholmians will be equipped with smart meters giving the instant price of electricity every five minutes. This makes it possible for everyone to participate directly in the electricity market, adjusting consumption up or down depending on the price. This way, peaks of power consumption and production can be flattened out, making the system more resilient towards fluctuations.
Of course, most people have better things to do than sitting in front of the price meter with a hand on their washing machine, turning it on and off depending on the price. Instead, every house will be equipped with a smart controller that can switch on appliances when the price signal gets below a level set by the user.
The efficiency of the controller relies heavily on the understanding and flexibility of the consumer. If, for example, a family decides they’ll only do the laundry when the price is below 0.1 euro, they might end up never getting it done. And as prices usually go down at night, they might need to get into the habit of preparing the laundry in the evening and getting up in time to hang up the clothes before leaving for work. Therefore, the project also features an awareness building and behaviour change campaign including the distribution of brochures, ads on TV and in newspapers, and energy consulting for the participants.
The project will give new insight into how consumer demand responds to price signals, and how a real-time marketplace can function with a broad mix of distributed energy sources. Hopefully, the participants will get used to thinking about the cost of electricity and understand the need to change some of their habits concerning electricity consumption.
Other activities
A strong political commitment and local support for green initiatives, makes the island ideal as a real life laboratory for testing new energy technologies. Several different projects are being tested on the island, drawing lessons and help from each other, and together they are creating the basis for the EcoGrid EU project. These are some of the activities that are going on right now:
PowerLab DK: A fully implemented test facility for smart grids research and development.
PVIB: 2 MW of photovoltaic panels are installed on the island to test how PV as a fluctuating energy source can be implemented in a future intelligent power system.
EDISON: Electric vehicle project that will demonstrate how they can function as electricity storage when connected to the grid.
The Bornholm Power System : Simulation of a power system with 50% wind energy.
