Kristiansand Cut 1400 Tonnes of C02

Stikkord: Energi i bygg, Energibruk, Kristiansand

The energy programme for 60 public buildings in Kristiansand is a success. In two years energy use has been reduced more than 15%. In 2008 the municipality saved NOK 5,3 million thanks to this reduction.

The energy programme for 60 public buildings in Kristiansand is a success. In two years energy use has been reduced more than 15%. In 2008 the municipality saved NOK 5,3 million thanks to this reduction.

It is not surprising that project manager Rune Rosseland and his colleges in Kristiansand Eiendom (Kristiansand Property) are happy. It is exciting to be a part in Kristiansand’s energy-saving programme. The energy consumption has been reduced with 6,4 GWh in two years. 

Rosseland is travelling through Norway telling the tale. Kristiansand is introducing a climate tool with great potential, and not least for the public sector.

Several Millions Saved Already

There’s great potential, especially if there’s a heavy increase in energy prices the next few years. This is realistic Rosseland says, and plays with the following calculation:

With a future energy price of NOK 1,50 and a 22% reduction in energy use in the 60 buildings, compared to the project’s starting point, the savings will be a staggering NOK 500 million (included compound interest) in 20 years time. No wonder the politicians in Kristiansand are willing to spend NOK 10 million on this programme.

In connection with Cities of the Future, the energy programme will most likely be expanded to a number of municipal buildings.

60 buildings in a Computer Network

The main move in the energy saving programme is connecting 60 buildings to the same computer network. Ventilation and heating are controlled through a sub-central in every building. A joint operating central with a server located at Kristiansand Eiendom controls these sub-centrals. The controlling of the buildings is continually adapted to their usage. This is done in several ways:

  • An energy follow-up system is established with routine measuring of the energy consumption. Any divergences are followed and corrected.
  • In the light of data from the energy follow-up system, action plans are made, through which Rosseland and his colleges can pick the «low-hanging fruit».
  • A seasonal wheel is made for each building. Variations caused by weekends, holidays etc. are programmed and manual adjustments can be made.
  • Close collaboration with the users of the building, who report their needs. If an evening meeting takes place at a school, sufficient ventilation and heating are programmed in the buildings profile.

Prioritised Building Comfort

Because of differences in usage, the buildings have been divided in three different categories:

  • Schools
  • Nursing Homes
  • Administration Buildings

Rosseland stresses that energy measures will not effect comfort. User satisfaction is a priority. Kristiansand Eiendom will be strengthened to be able to do follow-up on these buildings.

Results and Goals

 

The achieved results at present are caused by improved measures, running, routines and maintenance. After only two years, the goal of this four-year programme, a ten per cent energy reduction, has been achieved. The programme started in 2007. Compared to 2006 the energy consumption has been reduced by 15,6 per cent, or 6,4 GWh. With an energy price of 85 øre this makes for a total of NOK 5,3 million.

Investments

There are three strategies to reach the goal:

  • Measuring
  • Tight running
  • Investing in better technical solutions

Until now, only small-scale investments have been made. In the future, the investments will grow. The energy reduction potential has not been fully exploited. Rosseland has just ordered frequency converters for ten nursing homes. This equipment regulates ventilation in the homes’ day rooms. The point is to adjust the ventilation up or down according to the amount of people present. Other investments have been heat pumps, technical insulation, automatic controls, heat exchangers and light controls.

Better Climate and other Synergies

  • Reduced greenhouse gas emissions. This is the most important synergy effect. The present result is a reduction of 1400 tonnes of CO2 in 2008.
  • Technical equipment lasts longer. When the ventilation system is turned off over a longer period, it lasts longer. There is no reason to ventilate a building with just a few people, or no people at all. Considerable reductions in maintenance costs are also a result of these savings.
  • Education. Students can learn how to save energy in buildings.
  • Soon the Energy Label will be introduced in Norway. Then, a particular building’s energy consumption will be visible in selling and rental prospectuses as well as influence the commercial value. This point is probably more important in the private sector.