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Energy managers who are looking for ways to show the effectiveness of energy-saving measures need to understand weather normalization. The effect of variances and failing to normalize for weather can cause the organization to overestimate future savings.

Hotter summers usually result in an increase in air conditioning load and higher utility bills, while colder winters can lead to higher gas consumption. Energy managers who are looking for ways to show the effectiveness of energy-saving measures need to understand the effect of these variances; failing to normalize for weather can cause the organization to overestimate future savings.

PK offers weather normalized energy data to account for these fluctuations in temperature. Data can be accessed online, in a hosted environment, through managed reporting or via web service feeds that integrate with your native systems, or those of your energy management partners.

HEATING AND COOLING DEGREE DAYS

With any building that uses heating or cooling equipment, facility and energy managers try to achieve a certain indoor temperature regardless of how hot or cold it is outside. The building’s thermostat kick-starts and initiates an attempt to cool or heat the interior in response to outside temperatures. Heating Degree Days (HDD) and Cooling Degree Days (CDD) allow organizations to measure the effect of outside temperatures on the air conditioning equipment inside a building.

The concept is based on the fact that at a certain temperature, air conditioning and heating equipment is idle. Variations above or below this temperature cause the equipment to start acting and use energy. Outside temperature variances need to be quantified in order to plot them against usage patterns and normalize the data.

PK takes the complexity out of degree days and makes them customizable by site, facility and meter. Our team has built monthly weather data services with reputed weather data sources to obtain average temperature, humidity, wind speed and precipitation factors in 15-minute intervals for the previous calendar month.

PK determines HDD and CDD values by taking the difference from the standard set off point, or the base temperature of the building’s heating and air conditioning systems — typically 65 degrees Fahrenheit or 18 degrees Celsius. For example, if on a given day the average temperature outside is 70 degrees Fahrenheit, the building’s air conditioning equipment would cool the building by about 5 degrees Fahrenheit, making the CDD value for the day 5, or 5CDD.

PK can calculate HDD/CDD values based on average temperature or “feels-like temperature,” which takes humidity, wind speeds and precipitation factors into account. To accommodate differences in heating and cooling setups, PK allows customers to customize their own set off points by each site, facility or meter. Clients can also define which commodity (electricity or gas) provides heating and cooling by site and facility.

PK’S WEATHER NORMALIZATION ENABLES BETTER PLANNING AND ANALYSIS

1. Configuration of site and meters by ZIP codes, weather station codes and applicability for weather normalization.

2. Configuration of set off points for calculations and commodities on HDD and CDD values used in heating and cooling.

3. Baseline selection to create the regression curves using best-fit algorithms and not a simple straight-line fit. This is usually the beginning of an energy optimization period.

4. Regression analysis on the baseline period selected by the customer is used to analyze and remove “noise” of weather factors on energy usage and demand. The ‘weather normalized’ values are then compared to calendar-normalized usage data at the meter-commodity level.

5. Value-added reports and optimization allow users to plan and implement energy-saving projects across the enterprise. Among the key graphical reports with drill-down capabilities are temperature graphs and usage reports comparing two periods; HDD/CDD values and usage trends over 24 months; and fixed vs. weather-dependent usage per site over 24 months.

Combining best-of-breed solutions within PK’s Energy Management Solutions platform allows organizations across industries to optimize their energy management. PK’s weather normalization reports can be linked to other PK offerings, including savings reporting, budgeting and forecasting, analytics business intelligence engines and spend analysis. The result is a comprehensive system that allows customers to plan and report on project expenditure and savings and work on specific projects to reduce the fixed, non-weather-dependent spend within a single platform. Users can also benchmark sites using fixed costs and operational dimensions such as the number of employees, revenue generated, sales/turnover and square footage.