Juneau District Heating- An Introduction

District Heating is a concept where many buildings are heated with hot water piped to them from a central source. It is advantageous because it is easier to take care of than having individual heat generation systems at each location. It is also less expensive and less polluting because it can replace individual boilers that burn fossil fuels like diesel. To make the centralized hot water, you need a heat source that creates it from burning something (i.e coal, oil, biomass, or natural gas), or capturing it from some other process. In the case of Juneau District Heating, we will be getting our heat from seawater without the need to burn anything. It is a truly revolutionary process.

The idea of District Heating for Juneau is actually not a new one. The concept for a downtown system has been talked about and studied in Juneau for a couple of decades. Believe it or not, Juneau had a centralized district heating system at the Douglas Treadwell mine over a century ago and pipes supplied heat to the buildings from a central location. Many buildings at Front and Franklin also had a centralized coal boiler that piped heat and hot water to several close by buildings.

Today, the City and Borough of Juneau Comprehensive Plan, Climate Action Plan and Draft Energy Plan all remark on the fact that Juneau is an ideal community for district heating. But until now, the overwhelming cost of building the infrastructure with a traditional district heating feedstock i.e. oil, biomass, or natural gas made district heating an economically unfeasible concept. The unique innovations of the Seawater Heat Pump technology, which will be used for the Juneau District Heating system is so efficient that it greatly offsets the other necessary infrastructure and piping costs making the overall project not only economically viable, but economically attractive for capital investment and customer energy savings. The Juneau District Heating system sets itself apart from past studies and discussions since the seawater heat pump system negates the need to burn any fossil fuels and is completely driven by locally produced renewable and sustainable energy sources. The Sweetheart Lake Hydroelectric Facility will power the Juneau District Heating heat pumps and infrastructure. This powerful combination of totally renewable energy that will be used to convert totally renewable heat from the sea into usable heat energy for Juneau, will be the first of its kind in the US and a key component to Juneau’s sustainable future.

What is District Heating?

District energy systems produce hot water at a central plant. The hot water is then piped in insulated pipes to individual buildings for space heating and domestic hot water heating. As a result, individual buildings served by a district energy system don’t need their own boilers or furnaces The district energy system does that work for them, providing valuable benefits including:

  • Improved energy efficiency
  • Enhanced environmental protection
  • Safer operations. There are no combustible fuels or oil storage tank hazards
  • Ease of operation and maintenance
  • Reliability
  • Comfort and convenience for customers
  • Decreased life-cycle costs
  • Decreased building capital costs
  • Improved architectural design flexibility
  • Lower fire risk and potentially lower insurance costs

As mentioned in the introduction section, to make the centralized hot water, you need a heat source that creates it from burning something (i.e coal, oil, biomass, or natural gas), or capturing it from some other process. This can create additional advantages in the area of reducing greenhouse gas emissions, if the heat is generated from a non polluting source.  In the case of Juneau District Heating, we have a “zero carbon” load since nothing is burned.  We will be getting our heat from seawater We also will be getting the electricity to run the pumps and equipment from the Sweetheart Lake Facility which is a 100% renewable hydropower operation, which also burns nothing.

In fact, this unique joining and synergistic combination of innovative technologies will result in an estimated avoidance and displacement of 166,003,411 kilograms of carbon emissions for Juneau which is the equivalent of replacing 8,488,033 gallons of #2 diesel fuel currently used in Juneau every year.  Not only is this good for the environment and the air that you breathe, but it provides Juneau with the long term energy security that is independent and immune to the short term and long term fluctuations of fossil fuel prices.

Juneau District Heating Innovation Video