How to Save Energy in Industry: 12 Practical Ways
Ways to Save Electricity and Energy Costs in Industry
- Optimize HVAC Systems for Efficiency
- Perform Regular Maintenance for Optimum Performance
- Use VFDs with Motors
- Plan and Schedule Equipment Usage
- Implement Smart Lighting Controls and Automation
- Curtail Water Usage
- Implement Power Factor Correction and Harmonic Mitigation
- Purchase Electricity at a Higher Voltage from Utility
- Performing Demand Side Management for Energy Savings.
- Perform Energy Bench Marking
- Deploy an Energy Management & Monitoring System
- Hire an Energy Management Expert
1. Optimizing HVAC Systems for Energy Efficiency
Improve Cooling Tower's Efficiency
Large cooling towers should be placed as high as possible and must have direct incidence with prevailing wind.
Identify and Optimize Air Conditioning in Unoccupied Areas
Not all interior spaces maintain occupancy every time, some areas such as: corridors, hallways, ancillary rooms and toilets may only be occupied for brief intervals. Identifying and reducing cooling in these less occupied areas can reduce the overall HVAC load of the building. Dampers in duct work may be used to control air flow to these areas.
Add Temperature Control in Habitable Areas
Thermostats help adjust cooling or heating to desired levels and will therefore keep HVAC systems at optimum working level. Although adding individual area temperature control increases costs, it has its advantages:
- Temperature can be set according to occupants preference, which means occupants can decide to keep some areas less cooler then the others, and this will save energy.
- They will automatically adjust the amount of cooling required to maintain a set-point temperature, reducing it or increasing it, depending on external temperatures and occupancy level.
Adjust all Motor Frequencies According to CFM Requirements
AHU motors do not necessarily need to be working at full 50 Hz capacity all the time. A little effort, spent in ascertaining CFM requirements of AHU's serving areas and then tuning supply Air VFDs according to those CFM requirements, will have a huge impact on AHU's energy consumption over an extended period of time.
2. Perform Regular Maintenance for Optimum Performance
A carefully planned preventive maintenance plan is beneficial in:
- Identifying faulty and under performing equipment and hence reducing their energy consumption.
- Improving life and efficiency of existing equipment.
Such maintenance plans should be developed and signed by engineers in each organization, with particular attention to the following, which if left unattended, can act as major energy consuming inefficiencies in the system.
Maintenance of Chillers, Boilers and Pumps
Chillers, boilers and pumps are the key equipment in an HVAC system. Ensure their smooth functioning by:
- Regularly greasing motor bearings and shaft pulleys.
Regular Cleaning of Air Filters
Most HVAC systems have air filters to clean impurities from the air intake and protect air handling units from dust. Taking the following measures will go a long way in saving money and energy, because if filters have lower resistance for passing air through them, the system (AHU motors) will consume less energy to move that air and at the same time, provide better air quality for occupants.
- Choosing an air filter of the correct size.
- Performing regular planned maintenance and filter cleaning.
- Replacing them after the correct interval.
Regular Inspections of Piping and Duct Work
Piping and duct work insulation is very important in saving energy. It ensures that cold air flowing in the ducts and chilled water flowing in the pipes gain minimum heat from the surrounding. This eventually reduces the strain on chillers and reduces their energy consumption.
Regular inspections are thus required to:
- Check for condensation on chilled water pipes and ducts.
- Check for air leaks in ducts.
Similarly, water services including taps, storage facilities and pipework should be inspected on rolling basis for drips, leakages and corrosion, if found, must be fixed immediately, as less water wastage means less energy is spent pumping it.
2. Use VFDs with Motors
Standard direct online and star-delta motor starters bring the motors to full 50 Hz AC frequency and then keep them running at that frequency. Most applications, however, do not require the full 50 Hz frequency. They will just do as good on let's say, 45 Hz rotation frequency to yield an optimum result, as they did on 50 Hz.
Therefore significant amount of electrical energy can be saved by running motors on VFDs with their most optimum operating frequency determined and set through the VFD, since that is expected to be lower then 50Hz, applying this on a number of motors across your facility will have a huge impact.
Typical applications that can benefit from this principle may be:
- Exhaust fans.
- Air Handling Units.
- Centrifugal and other large pumps.
- Mixers and other rotating machinery.
3. Plan and Schedule Equipment Use
Equipment and machinery that is regularly used such as:
- Large pumps
- Air Handling Units
- Electric Chillers
must be committed according to pre-planned schedules. Facility engineers must list down all major loads and then plan their usage on hourly basis before-hand rather then committing each equipment when required.
Planning equipment use before-hand gives you the opportunity to optimize their use by efficiently utilizing the machinery in least possible time. A conspicuous effort to lower run-times of largest machinery will yield the greatest energy and electricity savings.
4. Implement Automated Lighting Solutions
Lighting controls can play a significant role in energy reductions and following strategies can be helpful in achieving this.
Use Photosensors with Lighting Circuits
Photosensors can monitor the amount of natural daylight available and can switch 'on' or 'off' lights over a set-point depending on light intensity. They can also automatically adjust the light output of fixtures based on available external illumination by dimming the lights and yielding extra savings. They are best used in:
- Rooms and interior spaces with large windows and skylights where natural light can enter the room.
- External lights, e.g roadside lights.
Use Occupancy and Motion Sensors
Occupancy and motion sensors ensure that lights are 'on' only when occupants occupy the space. As soon as the occupants leave the space lights are turned off by the sensors, that are connected to lighting circuits. They can be effectively used in public use spaces where people are least bothered to switch off lights e.g:
- Common rooms and lounges.
- Less frequently used corridors and hallways.
Automate Lights with Timers
Timers can be used to control light 'on' and 'off' at specific times. Commonly it is used to turn them 'off' during daylight hours and 'on' during evening and night hours. They may be conveniently used for:
- Roadside lights
- Parking lot lights
- Walkway lights
Reduce Light Trespass
Light trespass is when a luminary's light spills out into an area which was originally not intended to be lit up. Lighting that illuminates unwanted areas is a wastage of energy, hence carefully targeted full cutoff lights, that only light up the desired area must be used instead of non-cutoff lights.
5. Curtail Water Usage
Curtailing water usage and consumption will eventually reduce the energy required to pump that water and at the same time, lower utility water bill. One of the ways to achieve this is to:
Use Flow Restricting Faucets to Curtail Water Use
Faucets and showers are the key equipment which occupants engage when they use water. Faucets and showers can be optimized in the following ways:
- Using tap restrictors — They provide equal flow at a number of taps in a washroom and can reduce water flow by 15%.
- Using Push taps — The only operate when pressed, turn off after a brief time period and are ideal for areas where taps may be left running.
- Shower regulators and water-efficient shower heads — these decrease the volume of water coming out of a tap or shower and can reduce water flow by 20%.
- Infrared controllers — They provide water only when required, switch off automatically and can save between 5 and 15% of water per tap per year.
- Faucets with aerators — They decrease volume of water coming out of a tap by blending the stream with air bubbles.
8. Implement Power Factor Correction and Harmonic Mitigation
They are surefire ways to avoid additional levies from utility companies and also saving energy within the distribution systems.
Power Factor Correction
Reactive power compensation at appropriate points throughout the distribution network will:
- Reduce reactive power demand on generators and reduce their consumption.
- Avoiding low power factor penalties from utilities.
- Stabilize voltage levels and reduce load current demand.
Facilities such as hospitals, which run a large number of LED lights and electronic equipment usually have their secondary distribution systems polluted with harmonics.
- Active harmonic filters will help in reducing these harmonics and increase power quality. This will have a direct impact on billed energy.
- Passive harmonic filters can be designed after a Power Quality Study to filter out specific harmonic orders.
9. Purchase Electricity at a Higher Voltage from Utility
Most utility companies provide a lower rate per kWh when electricity is purchased at a higher distribution voltage. This is because the utility saves the cost of investing and maintaining secondary distribution infrastructures. Purchasing electricity at 11 kV is cheaper then a 400 V service entrance, and purchasing the same electricity at 132 kV is even cheaper for larger facilities.
10. Demand Side Management for Energy Savings
Altering consumption behaviors of facility occupants is a crucial demand side response tactic, aimed at avoiding consumption during peak hours and minimizing energy usage by individuals. Key initiatives to be taken in demand side management may include:
- Shaving peak demand using on-site renewable generation or battery storage will help escape maximum demand penalties, and avoid high unit charges during peak hours.
- Energy awareness campaigns can persuade occupants to do voluntary energy savings by reducing the amount of lighting and cooling, each individual might prefer in his own space.
11. Perform Energy Benchmarking
After you have implemented the above practices, how will you quantify them and prove energy savings? The answer is Energy Bench-marking.
It works by:
- Normalizing the amount of energy consumed in a facility in either kWh / Sqft. or BTUs / Sqft.
- Setting a baseline year as a benchmark for example, in 2010 the average yearly energy consumption of a facility was 50 kWh / sqft.
- Tracking-down the reduction or increase in energy consumption factor from the baseline year.
- Reporting quantified energy savings or losses that have concrete proof.
11. Deploy an Energy Management & Monitoring System
While free tools are available for energy bench-marking, more advanced Energy management & monitoring systems can perform complex calculations in an automated way. Deploying an energy management software will help you:
- Gather real time data from a plethora of energy consumption meters (energy analyzers, gas and water flow meters) scattered across the facility on one screen.
- Visualize this data in real-time.
- Perform complex energy bench-marking calculations after monitoring data of energy consumption devices.
- Keep historical record of facility energy consumption.
Aside from that, real-time monitoring helps pinpoint exactly where and when energy is being consumed. That will eventually help you iron out the inefficiencies in the system and will be a huge aid to equipment scheduling efforts. The possibilities depend on the extent of energy monitoring infrastructure deployed in the facility.
12. Hire an Energy Management Expert
An energy management expert will lead and mange all the energy saving initiatives in the facility.
Hiring one may help add value to your organization by:
- Monitoring energy consumption in HVAC assets on regular basis.
- Devising and implementing equipment operation schedules.
- Administering energy awareness campaigns.
- Performing energy bench-marking and all the measures mentioned in the preceding discussion.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
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