Energy in FCPS
FCPS has 220 buildings and 26.5 million square feet of building space. These buildings use a lot of energy and cost tens of millions of dollars to power each year. As the footprint of FCPS continues to grow, conserving energy for cost savings and greenhouse gas emissions reductions is of the utmost importance. FCPS Regulation 8534 Energy Conservation Measures sets guidelines for conserving energy in buildings and FCPS-operated vehicles.
Want to know how much energy your school uses? Get2Green’s Energy Dashboard provides energy data for each building in FCPS. This data comes from utility bills and is manually input in tracking software that automatically updates the dashboard when new data is added. The dashboard is intended to be used as an educational tool and to support conservation efforts in schools. Think your school is using too much energy? Check out Get2Green’s Tips for Conserving Energy at Your School!
Factors That May Affect Utility Use and CostWeather
Severe weather effects put a strain on heating and cooling equipment. Equipment must work harder and run longer on extremely hot or cold days.
Unoccupied buildings use less energy than occupied buildings. Winter break, spring break, and other school holidays are great opportunities for energy savings if buildings are properly shut down.
Equipment upgrades may be needed for outdated and less energy efficient models to reduce energy usage.
Equipment sometimes malfunctions and uses more energy until it is fixed.
The more people a building contains, the more energy it takes equipment to keep rooms at comfortable temperatures. The amount of heat generated by having a roomful of people requires more energy to cool that room.
Square Footage Changes
Generally speaking, the greater the square footage of a school building, the more energy it takes to heat and cool.
Trailer/Modular Additions to schools are not as efficient as the permanent school building.
Renovations typically cause significant temporary increases to energy use due to the changes to the building envelope and energy needed to power construction equipment.
Utility rates can change when contracts when renewed. The rate charged can also vary at some schools due to the amount of energy used being above or below a certain level.
Some utilities are billed on a 30-day cycle while others, like water, are billed on a 90-day (quarterly) cycle. Some utilities are billed as estimates, so we may get rebates back at the end of the year for the difference in actual usage.
Electricity is used to power our computers, lights, air conditioning, and more. Anything you plug into a wall outlet uses electricity. Electricity is directly measured using a power meter located at the building's main electrical entry point. Electricity for most FCPS facilities is provided by Dominion Energy, but a few schools have NOVAC as the provider.
Electricity is measured in kilowatt hours (kWh). A kilowatt hour (kWh) is a measure of how much energy is being used. It doesn't mean how many kW you use in an hour. It is the amount of energy you would use if you left a 1,000 watt appliance plugged in for an hour.
What's the difference between kW and kWh? A killowatt is equal to 1,000 watts, 1.34 horsepower, or an energy consumption rate of 1,000 joules per second. Watts are a measure of power, or the rate that electricity is used. A kWh is a measure of energy. So a 1,000 watt air conditioner needs 1,000 watts of power to run and uses 1 kWh of energy in an hour. A 100 watt light bulb, it would take 10 hours to use 1 kWh of energy.
Electricity usage tends to be higher in warmer months since air conditioning used to cool buildings relies on electricity.
Natural gas is used for heating water and air in buildings. Natural gas for FCPS facilities is provided by Washington Gas.
Natural gas is measured in therms. A therm is the energy equivalent of burning 100 cubic feet (CCF) of natural gas. A therm is equal to 100,000 British thermal units (Btu). Since natural gas meters measure volume and not energy content, a therm factor is used by gas companies to convert the volume of gas used to its heat equivalent, and thus calculate the actual energy use. The therm factor is usually in the units therms/CCF. It will vary with the mix of hydrocarbons in the natural gas. Natural gas with a higher than average concentration of ethane, propane or butane will have a higher therm factor. Impurities, such as carbon dioxide or nitrogen, lower the therm factor. One therm is equal to about 105.5 megajoules, 25,200 kilocalories or 29.3 kilowatt-hours. One therm can also be provided by about 96.7 cubic feet (2.74 m3) of natural gas.
Natural gas usage tends to be higher in colder months when more gas is needed to keep buildings warm.
Energy Use Intensity (EUI)
EUI is a measure of the amount of energy use per square foot. Energy use is electric and natural gas combined as measured in KBtu.
EUI can include electricity, natural gas, propane, or other measurements that can be converted to Kbtu. EUI does not include non-energy items such as water, sewer, trash, and recycling. By combining all of the energy units to one common unit, one building’s EUI can be compared to that of another building to compare the efficiency of the buildings. In August 2018, the EPA reported that the median K-12 school in the United States had an EUI of 104.4 Kbtu/ft2.
A British Thermal Unit (Btu) is a commonly used unit of measure for energy use in heating and cooling equipment. It is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. One kilowatt-hour (kWh) of electricity contains 3,412 Btu. Btu’s are useful for looking at the combined energy used by electricity and natural gas.
Water is essential to life on Earth. We use water for drinking, cooking, cleaning, flushing toilets, bathing, showering, watering plants, and more.
Water for FCPS facilities is provided by Fairfax Water. Water use in FCPS is billed quarterly (four times each year), which is why there isn't data for each month on the quarterly water data graphs. Water use is measured in kilo-gallons (kgal). One kgal is equal to one thousand gallons.
Energy vampires are devices that draw electricity when plugged in even if they are turned off. Common energy vampires in schools include laptop and desktop computers, computer monitors, projectors, TVs, Smart boards, printers, microwaves, and other devices. Vanquish energy vampires by unplugging them when they don’t need to be plugged in.