What Are Energy Performance Indicators?
Energy performance indicators (EnPIs) are metrics used to track and evaluate the energy efficiency of a building or system over time. As defined by the Energy Performance of Buildings Directive, EnPIs provide “an indication of the energy efficiency of the building (or building unit) expressed on a scale of CO2 emissions” [1]. EnPIs allow organizations to establish baselines, set energy savings targets, and benchmark progress, helping to reduce energy usage and costs.
With rising energy prices and climate change concerns, improving energy efficiency is more important than ever. EnPIs are a key tool for tracking efficiency gains and identifying areas for improvement. This article will provide an overview of the different types of EnPIs, how they are used for monitoring and reporting, and strategies to improve energy performance over time.
Types of Energy Performance Indicators
Energy performance indicators (EnPIs) can be grouped into several main categories that provide insight into different aspects of a building’s energy usage and efficiency. Some key types of EnPIs include:
Energy Usage Indicators
These EnPIs track absolute energy consumption over a period of time. Total energy use and energy use per square meter are common examples that allow benchmarking and monitoring of overall usage [1].
Energy Savings Indicators
Savings indicators measure reductions in energy consumption after efficiency improvements. Percentage savings relative to a baseline year is a useful metric [1].
Energy Efficiency Indicators
These EnPIs evaluate how efficiently energy is being used in a building. The energy use per occupant or per unit of building area are common efficiency metrics [2].
Renewable Energy Contribution
Tracking the percentage of total energy consumption from renewable sources shows progress on sustainability goals [1].
Energy Usage Indicators
Total energy consumption measures the total amount of energy used over a period of time, such as annually or monthly. This provides an overall view of energy use and can be broken down by energy source (electricity, natural gas, etc.). It is often measured in kilowatt-hours (kWh) or British thermal units (BTUs) (Source). Tracking total consumption is crucial for establishing baselines, setting reduction targets, and monitoring performance over time.
Energy use per square foot calculates energy usage per unit area of a building, typically in kBtus/sq ft/year. This normalized metric allows comparisons of energy performance across buildings of different sizes. A lower energy use per square foot indicates better efficiency. It can also be used to benchmark against industry averages or standards like Energy Star (Source).
Energy use per occupant measures energy consumption relative to the number of occupants in a space. It is calculated by dividing total energy use by the number of occupants and is expressed as kBtus/occupant/year. A lower figure signifies better efficiency per person. It accounts for changes in occupancy and is useful for spaces with fluctuating user populations like offices or schools (Source).
Energy Savings Indicators
Energy savings indicators track the amount of energy saved through efficiency projects and programs. This allows organizations to quantify the impact of their energy conservation efforts. Some common energy savings indicators include:
Energy saved per year in kilowatt-hours (kWh) or British thermal units (BTUs) – Compares current usage to a baseline before efficiency improvements to calculate total energy savings over a 12-month period. Useful for tracking overall progress.
Energy savings as a percentage of total consumption – Calculates energy savings as a percentage reduction from previous consumption. Normalizes for changes in weather, occupancy, or production.
Cumulative energy savings over multiple years – Tracks total energy savings accrued over several years of efficiency projects. Demonstrates long-term progress in reducing consumption.
Energy savings per square foot – For buildings, calculates energy savings per square foot of space. Normalizes for changes in building size.
Cost savings from energy efficiency – Tracks energy cost savings in dollars from efficiency efforts. Helps make the business case for future projects.
These indicators help set energy savings goals, prioritize investments, and evaluate the performance of conservation initiatives over time. Improving energy savings is a key step towards optimizing energy usage and reducing environmental impact.
Sources:
Sustainable Retrofitting of Commercial Buildings: Warm Climates,
Glossary of Reliability and Maintenance Terms
Energy Efficiency Indicators
Energy efficiency indicators measure how much energy is required to produce a unit of output. Some common examples include:
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Energy consumed per unit of product manufactured. This tracks the energy required to produce each widget, bottle, etc. Lower energy per unit is better (https://www.bieroundtable.com/).
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Equipment efficiency ratings such as kW per ton for chillers. Comparing equipment nameplate data to actual usage reveals performance gaps (https://assets.new.siemens.com/).
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Overall system efficiency like kWh per square foot for a building. This benchmarks energy usage for the entire facility (https://www.datapine.com/).
Tracking energy efficiency KPIs identifies opportunities to reduce waste and optimize processes. Setting targets helps drive continuous improvement.
Renewable Energy Contribution
The percentage of renewable energy used and renewable energy generated onsite are two important energy performance indicators related to renewable energy contribution. Many organizations are looking to increase their use of renewable energy as part of sustainability commitments. Tracking the percentage of total energy usage from renewable sources allows organizations to monitor their progress towards renewable energy goals.
According to [Qbi Solutions](https://www.qbisolutions.com/blog/kpis-energy-management), the percentage of renewable energy used can be calculated by dividing energy consumption from renewable sources like solar or wind by total energy consumption. This provides a metric to benchmark and track over time. Goals for increasing renewable energy usage, such as 25% by 2025, can motivate progress.
Monitoring renewable energy generated onsite specifically tracks energy production from installed solar panels, wind turbines, etc. Onsite renewable generation reduces reliance on the grid and offsets greenhouse gas emissions. The [Renewable Energy Valuation Institute](https://courses.renewablesvaluationinstitute.com/pages/academy/understanding-kpis-for-renewable-energy-projects) notes that tracking onsite renewable energy as a percentage of total consumption indicates progress towards energy independence and emission reduction targets.
According to [Hardik Shah](https://www.linkedin.com/pulse/green-energy-smart-business-kpis-every-renewable-should-hardik-shah), organizations set goals like generating 25% of annual energy needs from onsite solar. Monitoring indicators for both total renewable energy usage and onsite generation shows a more complete picture of an organization’s transition to renewables.
Benchmarks and Targets
Industry benchmarks provide a standard for comparing a building’s energy performance to similar buildings nationwide. For example, the EPA ENERGY STAR Portfolio Manager allows you to benchmark building energy performance and receive a 1-100 ENERGY STAR score. Comparing your score to the national median provides perspective on your building’s efficiency.
Organizations can also use their own historical energy usage as a baseline to set performance targets. By analyzing previous utility bills and weather normalized data, you can set a realistic goal for energy reduction over time. For example, you may aim to reduce weather-normalized energy usage by 10% over 5 years from a historical baseline.
Setting clear benchmarks and targets is key to managing and improving energy performance over time. Targets help motivate action by quantifying desired results. Continued benchmarking shows progress towards goals and indicates when adjustments may be needed.
Monitoring and Tracking
Regular monitoring of energy performance indicators is crucial for understanding energy usage patterns and identifying opportunities for savings. Automated energy management systems (EMS) allow facility managers to continuously track energy performance by collecting interval data from advanced metering systems.
EMS provide real-time visibility into equipment performance and quickly alert staff to anomalies. This enables a rapid response to issues that could be wasting energy, such as equipment malfunctions or changes in occupancy schedules. According to Best Tools for Monitoring Energy Performance Indicators, leading EMS platforms integrate meter data analytics, fault detection diagnostics, and automated reporting.
Interval data analysis allows energy managers to pinpoint the times of peak demand. This information enables load shifting to optimize demand charges. Data mining can also identify seasonal usage patterns and changes over time to prioritize efficiency projects with the greatest potential savings.
Reporting and Communication
Communication and reporting on energy performance is crucial to meeting energy targets and identifying areas for improvement. Companies use both internal and external reporting to track progress and demonstrate commitment to improvement.
Internally, companies track and analyze energy performance through monitoring systems and internal reports. This allows them to identify problems, set priorities, and develop solutions. Regular internal reporting provides continuity and ensures energy stays on the agenda (Netcad).
Externally, companies report energy use and emissions through corporate sustainability reports, CDP disclosures, and other frameworks. Public reporting demonstrates commitment and progress to stakeholders. Major reporting frameworks like GRI and CDP provide guidance and standard metrics (Neumayer).
Effective reporting, both internal and external, is key to driving continuous improvement in energy performance.
Improving Performance
There are several strategies organizations can implement to improve their energy performance indicators over time. This requires taking a continuous improvement approach focused on optimizing energy use across operations.
One of the most effective strategies is establishing an energy management system (EMS) aligned with ISO 50001 standards. According to research, implementing an ISO 50001-aligned EMS resulted in average energy performance improvements of 14.1% over two years across a range of industries [1].
Within the EMS, organizations should set SMART (Specific, Measurable, Achievable, Relevant, Time-bound) goals for improving EPIs. Teams can then implement energy conservation measures and track progress through monitoring and periodic audits [2].
Other effective strategies include investing in energy-efficient technologies, optimizing HVAC and lighting, improving building insulation, engaging staff through training and incentives, and utilizing data analytics to identify optimization opportunities.
By taking a holistic approach focused on continuous improvement, organizations can steadily enhance energy performance over time. This delivers significant cost savings, environmental benefits, and competitive advantage.
