Sustainable Schools: Teaching By Example
See how Charlotte-Mecklenburg Schools weathered an economic downturn through efficiency, managing to use less energy while adding facilities.
Providing high-quality education for our nation’s children in grades K-12 has never been more important than it is today. The world is changing fast, and we need to provide an educational system that prepares them for this fast paced world in which we live.
Charlotte-Mecklenburg Schools (CMS) is the second-largest public school district in North Carolina and the 18th-largest in the U.S. The district, which has more than 18,000 employees, operates 159 schools with more than 143,000 students in pre-kindergarten through grade 12. It has an annual operating budget of $1.2 billion, operating and maintaining more than 20 million square feet of conditioned space, 600 permanent buildings, and 1,200 mobile classrooms on 5,000 acres of land.
As a public entity and one of the largest employers and consumers in the region, CMS has a responsibility and an opportunity to lead the way in sustainable use of resources. Therefore, the district identified sustainability and stewardship as key strategic goals. Its strategic plan for 2014 set goals to reduce all utility consumption by 20%, solid wastes by 5%, and pollutants by 20%. CMS currently is on track to achieve these goals.
CMS has been following many of the principals and resources from the EPA’s Energy Star website to help achieve its success. The district has been an Energy Star partner since 2003.
CMS choose to implement Energy Star because it was a well mapped out, easy to use external system (not created by the school district), backed by the federal government, and was low-cost /no-cost to the tax payers of Mecklenburg County, with the exception of staff time. The software was free, and we could benchmark our buildings vs. other buildings of similar type throughout the state and country, with adjustments made for weather and other factors.
In 2010, CMS was recognized by EPA as an Energy Star Leader for improving its energy performance across the board by 10% from a 2008-09 baseline period. To achieve this reduction, the district consolidated non-educational programs into fewer facilities, refined a summer energy-savings plan that used a four-day workweek to save about $500,000 in cooling costs, and used posters and the district’s television station to promote energy efficiency. It also identified site-based energy coordinators who receive energy-consumption information about their schools and share it with staff and the public to raise awareness about conservation practices. The Energy Coordinators are typically administrative staff or other leaders in the school.
The energy coordinators receive checklists and other energy-related information from the CMS Building Services Group, which is the maintenance department for most other groups, expanded to include, custodial, energy management, architectural, mobiles, energy, environmental health and safety. The coordinators work with the group to further reduce energy in their facilities. Successful efficiency measures have included lighting upgrades (T-12 to T-8; HID and sodium to T8, T5, or induction; as well as wall packs from metal halide to induction; or LED in new construction), domestic water replacements, HVAC schedule optimization, HVAC checks (off-hours via remote software as well as onsite checks), mobile classroom thermostat, and lighting projects. Projects were chosen using many factors to determine priority. Some of those factors included (but were not limited to) payback calculations; available incentives; available value-added components, such as better quality of lights, color index, etc.; reduced maintenance costs; whether or not it is a joint-use facility that equals higher run hours; and the current Energy Star rating of the facility.
Student and staff participation is also central to the program’s success. Teachers and students receive monthly reports of energy use and help increase efficiency by turning off lights and computers when not in use.
Like most K-12 school systems, CMS struggles for funding to accomplish energy efficiency-type improvements. While lighting may be the easy low hanging fruit, HVAC can be an equally important aspect, if pursued responsibly.
The majority of CMS schools are serviced by Duke Energy, and CMS is an active participant in that energy provider’s energy-efficiency rebate programs. By participating in this program, CMS is able to buy down the added cost difference for higher efficiency equipment in its new construction and renovated projects.
As most know, the upfront costs of the project pale in comparison to the life-cycle cost of operating the building, not to mention the costs of personnel (students, teachers, staff, public) who occupy the building. Although CMS has received incentive payments from more than just Duke Energy, CMS has received over $700,000 in incentive payments since 2009 from Duke Energy, with over $225,000 in the HVAC category (e.g., chillers). CMS engineering and mechanical staff are always looking for projects with a short-term payback that can increase the students comfort level.
CMS prefers to use air cooled chillers with multiple circuits on systems that are less than 200 tons. This provides a level of redundancy; if one circuit fails, we are not without cooling for the entire school. When the facility is over 200 tons, we have our architects and engineers determine the best life-cycle costs between air cooled and water cooled machines. Unfortunately, in some of the smaller tonnage ranges, the major equipment manufacturers have not yet been able to meet the IPLV requirement for the Duke program. However, the manufacturer reps have told us they are working to provide manufacturer machines that will meet this requirement. Being a school district CMS is typically not in session during a design degree day, and our chillers typically run at partial load, which is another reason why this is so important in addition to being good stewards of the environment.
As funding allows, we have also been working to remove as many R-22 pieces of equipment as possible and replacing them with the new 134a or 410 refrigerants. CMS has a guideline for all new and renovated projects that outlines what we require the designers and architects to specify.
To meet its 2014 strategic goals, CMS used the 2007-08 school year as a baseline, which consists of a district-wide kBtu/sq ft of 59.96. As of the school year ending June 2012, CMS has achieved 46 kBtu/sq ft, well beyond the established goal of a 20% reduction.
In the baseline year, the district used 226 million kWh of electrical power to operate schools and offices. It used 3.5 million therms of natural gas. It served 23.5 million meals. It consumed more than 256 million gal of potable water. The district generated more than 20 million lbs of solid waste. For the school-year ending June 2012, CMS used less than 190 million kWh and less than 2.7 million therms while opening two new high schools, two new middle schools, and eleven new elementary schools, as well as completing multiple additions and renovations. This savings allowed the district to avoid more than $22 million in costs during the economic downturn that squeezed school funding, which consequently reduced the number of district layoffs and redirected some funds to classrooms.
CMS tracks all utility usage with a utility-manager software program. The district has also worked with the region’s three largest utility providers to receive bills electronically so they can be directly uploaded into the software program, reducing labor costs. All but about 100 of the 1,400 monthly utility bills received by the district are handled electronically. Mecklenburg County has seven municipalities, and several of them retain small local utility operations that can’t support electronic billing. Electronic billing has allowed the district to use a part-time data-processing technician, an energy manager, and one support employee to manage its energy program.
By using the software, CMS is easily able to identify schools with high consumption, low consumption, or significant variances in consumption (typically we look at monthly data and year-to-date data, however any timeframe can be used and we have data going back in excess of 10 years). By identifying these facilities, CMS is better able to utilize the limited resources in a manner that save the district as much money as possible.
With the combined efforts of maintenance, property managers, custodians, engineers, students and teachers, CMS has raised its portfolio average Energy Star rating to 74 from less than 50. The performance rating is an external benchmark that helps energy managers assess how efficiently their buildings use energy relative to similar buildings nationwide. A rating of 50 indicates average energy performance, while a rating of 75 or better indicates top performance. Commercial buildings with the Energy Star designation use, on average, 35% less energy than other buildings. They also release 35% less carbon dioxide into the atmosphere.
Sixty-five CMS buildings, representing 7.2 million square feet, have received Energy Star certification, meaning they have achieved a rating of 75 or better. The increase in rating comes from many factors, including behavioral changes, controls modifications, lighting upgrades, and utility tracking. CMS was also able to take a building that rated well below 30, spend less than a couple of thousand dollars recommissioning the control system, bring the Energy Star score up above 75. The building is now Energy Star certified. This building, which was in construction in 2003, had performed poorly for several years, costing the district tens of thousands of dollars over the school average in utilities cost.
The district’s schools have also participated in EPA’s Battle of the Buildings Competition, a national challenge in which thousands of buildings compete to reduce their energy waste. CMS participated as part of ongoing efforts to reduce utility consumption. The schools chosen included both low and high performers as well as new and older facilities. Five schools entered last year’s competition (Bradley Middle, Chantilly Montessori, Elizabeth Traditional, Myers Park Traditional Elementary, and Providence Spring Elementary). CMS best school in the competition, Myers Park Traditional, finished in the top 15% of all buildings. The competition aided in our efforts throughout the district by drawing attention to some of the good work we are doing. Several of these schools were showcased in local publications, in television, and radio stories.
This year, CMS has 12 buildings entered: Alexander Graham Middle, Briarwood Elementary, Cochrane Middle, Crestdale Middle, Hawkridge Elementary, Hickory Grove Pre-K, Highland Renaissance Academy, J.W. Grier Academy, Olde Providence Elementary, Randolph Middle, Ranson Middle, and Southwest Middle. Our expectations are not necessarily to win the competition, because our program is more mature than a lot of other programs out there, so we probably don’t have as much to lose as some others. However, we are working to reduce our energy consumption as much as practical without affecting the educational environment and by participating in this free contest, we are able to better spread the message of energy conservation. Lessons that are learned in the school house will hopefully translate into the home, which, in the long run, will aid future generations in energy independence. Mid-year results indicate three schools showing reductions in excess of 10% and savings in excess of $100,000.
Perhaps the most significant improvement in practice for the district has come in the planning phase of new schools. CMS has used Energy Star’s Target Finder to support future energy goals and improve construction practices and plans. Target Finder is a free online tool that enables architects and building owners to set energy targets and receive an EPA energy performance score for projects during the design process.
Pineville Elementary, which is expected to be ready for occupancy in Summer 2013, will operate at the highest environmental standard and earn the Energy Star designation.
“We have reduced the money we spend on electricity and other utilities by more than $5 million during the past two years,” said Guy Chamberlain, Associate Superintendent for Auxiliary Services.
Pineville Elementary School is designed with both a new high-efficiency air cooled chiller (scheduled to receive a) high-efficiency Trane chiller Model RTAC200, with a full-load efficiency of 10.3 EER and part-load efficiency (IPLV) of 14.1 EER. Energy savings from pumping will also be realized by optimizing the water temperatures to reduce the water flow requirement through the chilled water loop.
“The Pineville replacement school is another example of our commitment to good environmental stewardship. We want to build the most energy-efficient schools that we can because it’s good business practice and good for the community,” Chamberlain added.