Have you ever counted the number of times you turn on a faucet, flush a toilet, or run the dishwasher each day? Imagine how different your life would be without the convenience of water. Although Alaska has the greatest groundwater resource of any state in the United States, it also has the largest volume of frozen groundwater.Today, permafrost underlies about 85% of the state of Alaska, creating an impermeable layer that can affect groundwater flow.
Permafrost, or soil that has remained frozen for at least 2 years in a row, is an important driver of Denali’s ecosystem. The temperature of the ground directly controls and indirectly influences Denali’s local hydrology, vegetation growth, wildlife communities, and the rate that organic matter is able to decompose. The small black spruce trees on DEC’s campus are just one indicator of the presence of permafrost on our landscape.
It is estimated that even today over half of the households in Denali lack indoor plumbing and the homes that do have running water often do so by drilling a well. Heating our water from the cold extractive temperatures is a major consumer of energy within Alaska.
It may surprise you to learn that the majority of our energy consumption in Alaska does not come with our cold winters but happens in our summers. Like the rest of our state, Denali Education Center’s energy load peaks during our summer months- at the height of our tourism season. Much of the energy used in our summers is the result of heating our ground water to temperatures that allow us to take hot showers, do dishes, or wash clothing.
As a part of a global community, we at DEC are always thinking about our global impact. How we can contribute to a sustainable future in a rapidly changing climate. The Solar Water Heating System is an example of harnessing a renewable and natural energy source, the sun, to warm water while positively impacting our carbon footprint. Our Solar Water Heating System operates from May to mid-September, supplementing the energy needed to meet our hot water demand. These heating needs were previously met by using a combination of electric and propane water heaters.Thanks to the use of our Solar Water Heating System we are able to offset up to 36,000 kilowatt-hours of energy each year!
WHAT IS A SOLAR THERMAL ARRAY?
To put it simply, it is a solar water heating system but it is also one way to use the sun to heat the cold water that is pumped out of the ground. The cold water from the ground is pumped into a tank that contains coiled copper piping. Glycol heated from the sun warms the copper which then pre-heats the water via conduction. This hot water is then pumped into the hot water tanks on DEC’s campus and presto- we have pre-heated our water naturally by using heat from the sun.
HOW DOES IT WORK?
1) Solar Panels collect energy from the sun.
2) The sun’s energy heats glycol from the thermal buffer tank.
3) Warm glycol transfers heat to adjacent copper pipes filled with groundwater.
4) Warmed groundwater is distributed through the DEC campus.
The creative energy and desire to be a part of the energy solution were the driving forces behind building our Solar Water Heating System. Our system was a pilot project and helps to serve as an example of a viable way for rural communities to offset their demand for electrically heated water with water heated by solar energy.
It takes communities of all sizes to make an impact. We are all part of a larger global community that has a responsibility to our planet and future generations to care for our resources. We hope that our Solar Water Heating System serves as an inspiration for you to influence you and your community to consider using renewable energy solutions in your community.