Teaching the importance of conserving energy
The best place to teach children about sustainability is in school.  Including sustainable practices in the curriculum will allow students to practice what is being taught, eight hours a day.  Turning off lights when possible, keeping doors closed and recycling materials are great habits for students to learn at school and hopefully take home to share with others in the family.

Teaching tomorrow today
Today’s students will be the consumers of tomorrow and teaching children about renewable energy will allow the next generation of consumers to make better choices regarding energy. So how can we teach these sustainable practices? What if the building could harvest light during the day? Teachers could share with students why it’s important and students could see the light being used. What if the building used less water by capturing rain water and then used it for flushing toilets and watering the landscape?  Teachers could share with students why saving water is important and students could see the rainwater being used. What if the building used renewable nighttime energy to power a hybrid cooling system?  Teachers could share with students what renewable energy is and why it is important and students could see the hybrid cooling system being used.  Students could see these practices being used first-hand by the school leaders, teachers, and the community and bring those practices into their lives and homes – now and in the future.

Today’s Energy Teaching Points
Electric utilities are experiencing record demand this summer.  Most of the summer demand comes from seasonal air conditioning loads.  To meet this increased demand utilities must invest in new generation, transmission, efficiency, and load shifting.  The question utilities and regulators must answer is what is the priority and cost of these investments and what can be done now?

The need to reduce our dependence on fossil fuels and greenhouse gas emissions has put an emphasis on using renewable energy to increase generation.  Unlike fossil fuels, which are stored energy, renewable energy is intermittent in its availability and more expensive to install.  Renewable energy can include wind, solar, and geothermal.  The most popular forms of renewable energy today are wind and solar.

Although installed cost is a factor in how much we use these renewable energy forms, the real issue for widespread use is capacity factor. The average coal plant has a capacity factor (output/installed capacity) of 90 percent or more and most nuclear plants around 99 percent, depending on the dispatch. A good solar plant in the Mojave Desert may be able to have a capacity factor of up to 25 percent. The same system in upstate New York will be lucky to get a 15 percent capacity factor. Wind farms in the best locations are lucky to get a capacity factor of 40 percent.

Doing more with less
So the challenge becomes how can buildings do more with less? How does nature balance supply and demand?  If you are thirsty, do you hold up a glass and wait for it to rain? And how does a bear survive winter hibernation? The answer, you’ll find, is storage. Water is stored in reservoirs and aquifers and the bear stores energy in body fat. Like nature, hybrid cooling systems store energy for lean times.  In the case of cooling, the lean times are defined as periods of expensive electricity or heavy cooling loads.

Just as nature’s storage fills our glass full of water or helps the bear survive winter, hybrid cooling systems with storage help renewable energy to be more viable economically, and operationally.   These systems can boost the daytime cooling systems if the wind is low or it’s a cloudy day to help lower the grid traffic to improve reliability. Energy storage can also capture renewable energy created at night when the wind blows the most or it can capture inexpensive, efficient, clean electricity produced at night. This stored energy is now in the form needed to help cool the facility during peak demand periods to reduce stress on the grid, emissions, and operating costs.

If renewable energy is not available, hybrid cooling systems with storage can store energy created from more efficient nighttime generation.   Most studies have demonstrated that off peak generation and transmission is more efficient.  The California Energy Commission[1] study says there are many reasons for this including utilization of base load plants, lower line losses and lower spinning reserves.  Source energy savings were anywhere from eight to 34 percent depending upon location and generation mix.

Hybrid cooling systems that use storage are not much different than conventional cooling systems.  Think of a hybrid car.  Hybrid cars consist of an energy efficient and smaller conventional engine.  The engine gets great mileage in most cases but can feel sluggish.  To help the hybrid when more performance is needed the stored energy can boost performance to help merge or optimize performance during stop and go traffic.  Hybrid cooling uses a smaller refrigeration system which is very efficient for most times.  During times of high load or high prices, the storage kicks in to boost performance.

Commercial hybrid cooling systems with stored energy featuring ice are very affordable in new construction and in existing buildings where the cooling system is going to be replaced.  Simple paybacks in new construction can be three years or less and sometimes immediate while existing buildings have a simple payback from three to five years.  Why the quick payback? Storage systems are a good investment because cooling operating cost savings are typically from 20 to 40 percent.

Hybrid cooling systems that use energy storage are sometimes called thermal energy storage systems or TES.  Thermal energy storage systems can use water as a storage medium, ice, or a phase change material.  Water storage tends to be applied on large district cooling projects and very large universities while ice storage tends be applied on churches, K-12 schools, offices, community colleges and universities.  The technology that is used depends upon many factors such as utility rates, building usage, size, and space available so a life cycle analysis may be required to help select the best system for the building owner.

A great case study is shown on the USGBC website’s Certified Project List[2]. Fossil Ridge High School in Ft. Collins Colorado is a 296,000 sq. ft. facility that uses an air-cooled 125-ton chiller and energy storage to cool the building, which requires 250 tons at design conditions.  That is about 2000 sq. ft. per ton – over 5 times the average!  Optimum performance from the cooling system is due to the “right-sized” chiller and a boost that comes from the stored energy when electricity prices or cooling loads are high.  Other sustainable design features include a good building envelope, day lighting, and photovoltaic cells.  Energy consumption is reduced energy by a whopping 60 percent and the project was comparable in cost to conventional designs!

Storage is the answer
How do we educate the public to create an understanding of the environmental issues and how do we get people to understand the need for change?  I know it is hard for me to adapt and change every time a new version of Windows comes out the older I get.   I’m also very entrenched in the ways I use energy.

Educating children at an early age will make it easier for them to develop a healthy lifestyle for themselves and the environment. Young people have great ideas and are searching for ways to make a difference, so teaching sustainability in school and about the school itself will make for increased awareness and change.  Students can make posters and chart energy consumption and cost data and provide tours of the building to help administrators, other children, and parents understand the design strategy for their school’s sustainable design.

Children should understand that we use fossil fuels for almost everything and that they account for roughly 80 percent of all carbon dioxide emissions.  One of the cheapest ways to reduce CO2 emissions and reduce our use of fossil fuels is through energy efficiency – using less energy to provide the same service or using the same energy to provide more services and consuming renewable energy.  Combining efficiency, renewable energy, and energy storage will allow us to operate a smart grid as efficiently as possible.   A sustainable home can achieve over a 50 percent improvement in energy efficiency compared to ‘a normal home’ and one of the best ways to teach proper energy consumption is to have our schools demonstrate sustainable design with features like daylighting, using renewable energy, and thermal energy storage along with sustainable living practices.  Maybe we can learn some new tricks from our children!

[1] California Energy Commission. 1996 “source Energy and Environment Impacts of Thermal Energy Storage.”  Report # 500-95-005

[2] http://leedcasestudies.usgbc.org/energy.cfm?ProjectID=672

About the Author
Paul Valenta is North American Sales Manager for CALMAC and is responsible for Marketing and Sales of Ice Storage in North America, Central America, and The Caribbean. Paul has an Electrical Engineering degree from the University of Nebraska and has been in the HVAC industry for 24 years, the last 19 with CALMAC.  Currently, Paul is a member of ASHRAE, AEE, and is a LEED Accredited Professional.