Presentation is loading. Please wait.

Presentation is loading. Please wait.

Energy Conservation Energy Management. Role of an energy manager Assess Assess Current energy demand Current energy demand Energy audit Energy audit Analyse.

Similar presentations


Presentation on theme: "Energy Conservation Energy Management. Role of an energy manager Assess Assess Current energy demand Current energy demand Energy audit Energy audit Analyse."— Presentation transcript:

1 Energy Conservation Energy Management

2 Role of an energy manager Assess Assess Current energy demand Current energy demand Energy audit Energy audit Analyse Analyse Energy requirements Energy requirements Advise Advise On technical improvements On technical improvements Advertise Advertise Ways to save energy Ways to save energy Account Account For energy consumption For energy consumption

3 Assess energy demand Keep records Keep records Consumption Consumption Time of readings Time of readings Temperature Temperature Other factors affecting demand Other factors affecting demand Weekday/weekend Weekday/weekend Special events Special events Frequency of readings Frequency of readings Weekly Weekly Daily Daily

4 Energy Audit Feasibility study Feasibility study Establish and quantify energy flows into and within a building or organisation Establish and quantify energy flows into and within a building or organisation Aim Aim Identify viable and cost effective energy saving measures Identify viable and cost effective energy saving measures Enhance operating efficiency and reduce maintenance costs Enhance operating efficiency and reduce maintenance costs Establish a baseline energy consumption Establish a baseline energy consumption Process Process Collect data from energy invoices and meters Collect data from energy invoices and meters Surveys of plant, equipment and buildings Surveys of plant, equipment and buildings Collect information from managers and other staff Collect information from managers and other staff

5 Auditing process Identify energy management Identify energy managementopportunities Can be no cost or low cost measures Can be no cost or low cost measures Change an energy tariff Change an energy tariff Change an energy supplier Change an energy supplier Reschedule production activities Reschedule production activities Preferential tariffsPreferential tariffs Adjust existing controls to match requirements Adjust existing controls to match requirements Implement good housekeeping policies Implement good housekeeping policies Invest in small capital items Invest in small capital items Thermostats & time switchesThermostats & time switches

6 Who does energy audits? Can be undertaken internally – energy manager Can be undertaken internally – energy manager Specialist energy consultants Specialist energy consultants Energy service companies Energy service companies Performance contracts Performance contracts Guarantee organisations energy cost savings in return for a fee Guarantee organisations energy cost savings in return for a fee Main interest is in installing and managing their recommended plant Main interest is in installing and managing their recommended plant May arrange finance of projects May arrange finance of projects Vested interest Vested interest

7 Why is energy wasted? Poorly designed buildings and installations Poorly designed buildings and installations Insufficient insulation Insufficient insulation Undersized ventilation ducts Undersized ventilation ducts Inadequate control systems Inadequate control systems Poor control settings Poor control settings Inefficient plant operation Inefficient plant operation Out of date technology Out of date technology Poor maintenance Poor maintenance Poor operating and working practices Poor operating and working practices

8 Different types of energy audit According to level of detail and depth of analysis According to level of detail and depth of analysis Preliminary Preliminary Targeted Targeted Comprehensive Comprehensive

9 Preliminary audit How much energy is being consumed How much energy is being consumed What type of energy What type of energy Performance of facility compared with similar facilities Performance of facility compared with similar facilities Characteristic performance of building Characteristic performance of building

10 Preliminary energy audit Identification of potential areas of energy saving Identification of potential areas of energy saving Financial energy audits Financial energy audits Collect data Collect data Establish quantity and cost of each form of energy Establish quantity and cost of each form of energy Data from energy invoices and meters for previous year Data from energy invoices and meters for previous year Analyse data Analyse data Present data Present data Establish priorities Establish priorities Make recommendations Make recommendations

11 Targeted energy audit Provide data and analysis on specific targeted projects Provide data and analysis on specific targeted projects e.g. heating of one building or lighting e.g. heating of one building or lighting Detailed survey of target area Detailed survey of target area Analysis of energy flows and costs Analysis of energy flows and costs Recommendations for action Recommendations for action

12 Comprehensive energy audits Similar to preliminary audits but in far more detail Similar to preliminary audits but in far more detail Detailed data on energy flows into and within organisation or facility Detailed data on energy flows into and within organisation or facility Often requires use of sub-metering to accurately determine component energy flows Often requires use of sub-metering to accurately determine component energy flows Or estimate energy use Or estimate energy use (Plant power output (kWh)/efficiency of plant) *operating hours per year (Plant power output (kWh)/efficiency of plant) *operating hours per year Use of thermal imaging Use of thermal imaging May use complex energy simulation software May use complex energy simulation software Detailed energy survey Detailed energy survey Energy project implementation plans Energy project implementation plans

13

14 Collect data Build up picture of pattern of energy consumption and cost from energy invoices Build up picture of pattern of energy consumption and cost from energy invoices All invoices for relevant time period All invoices for relevant time period Delivery notes for oil, solid fuel, LPG Delivery notes for oil, solid fuel, LPG Identify estimated meter readings – check with previous years Identify estimated meter readings – check with previous years Inadequate/unavailable invoices – contact utility company/fuel supplier Inadequate/unavailable invoices – contact utility company/fuel supplier Collect geographic data Collect geographic data Location, altitude, orientation Location, altitude, orientation Weather data, degree day data Weather data, degree day data Manufacturing data (if appropriate) Manufacturing data (if appropriate) Production output Production output Check data for anomalies Check data for anomalies Small building using more energy than larger one Small building using more energy than larger one High energy use at night when unoccupied High energy use at night when unoccupied

15 Understanding invoices: electricity Date of meter reading Date of meter reading Monthly standing charge Monthly standing charge Present and previous meter reading Present and previous meter reading Daytime – peak rate Daytime – peak rate Night time – off-peak rate Night time – off-peak rate Charges for each rate Charges for each rate Some tariffs have a higher unit charge for first 1000 kWh Some tariffs have a higher unit charge for first 1000 kWh Monthly maximum demand charge Monthly maximum demand charge For every kW of the peak power demand during the month For every kW of the peak power demand during the month Penalise users make heavy demands during peak periods Penalise users make heavy demands during peak periods Supply capacity – annual maximum demand Supply capacity – annual maximum demand Monthly charge Monthly charge Total cost + VAT Total cost + VAT

16 Gas invoices Much less complicated than electricity Much less complicated than electricity Date of meter reading or estimate Date of meter reading or estimate Calorific value of gas Calorific value of gas Present and previous meter readings Present and previous meter readings Amount of gas used Amount of gas used ft 3, kWh or therms ft 3, kWh or therms Unit price per kWh Unit price per kWh Standing charge Standing charge Monthly or quarterly Monthly or quarterly Total cost + VAT Total cost + VAT

17 Other fuels Fuel oil Fuel oil Measured by volume Measured by volume Varies with temperature corrected to standard condition of CVaries with temperature corrected to standard condition of C Date of delivery Date of delivery Unit cost per standard litre Unit cost per standard litre Calorific value (?) Calorific value (?) Total cost + VAT Total cost + VAT Solid fuel Solid fuel Weight delivered Weight delivered Date of delivery Date of delivery Total cost + VAT Total cost + VAT No calorific value No calorific value

18 Analysing energy records Key variables Key variables Heating Heating External temperature - dominant External temperature - dominant Wind speed ) Wind speed ) Humidity ) <=10% variation Humidity ) <=10% variation Solar gain ) Solar gain ) Lighting Lighting Hours of darkness Hours of darkness

19 Data analysis Many different ways of analysing data Annual energy consumption Annual energy consumption Analysis of heating requirements Analysis of heating requirements Degree day method Degree day method Mean temperature method Mean temperature method Cumulative deviation method Cumulative deviation method (Details in Keiths lecture notes) (Details in Keiths lecture notes) Normalised performance indicators (NPI) (Beggs, 2002) Normalised performance indicators (NPI) (Beggs, 2002) Time dependent energy analysis Time dependent energy analysis Linear regression analysis Linear regression analysis CUSUM – cumulative sum deviation method CUSUM – cumulative sum deviation method

20 Annual energy consumption Simplest analysis Simplest analysis Assess overall energy performance of building Assess overall energy performance of building Produces a percentage breakdown of annual energy consumption and cost data Produces a percentage breakdown of annual energy consumption and cost data Convert all energy consumption data into standard units (kWh) Convert all energy consumption data into standard units (kWh) Standard conversion factors & gross calorific valuesStandard conversion factors & gross calorific values Percentage breakdowns of total consumption and cost of each energy type Percentage breakdowns of total consumption and cost of each energy type Present data Present data Total annual energy consumptionTotal annual energy consumption CostCost Percentage breakdown of each fuel typePercentage breakdown of each fuel type Historical trendsHistorical trends

21 Analysis of heating requirements Degree day method Degree day method Quicker Quicker Oil & coal heating difficult – general estimates of consumption Oil & coal heating difficult – general estimates of consumption Mean temperature method Mean temperature method More accurate More accurate Plot mean consumption against mean external temperature Plot mean consumption against mean external temperature

22 Degree day method Two component parts Temperature related Temperature related Independent of temperature Independent of temperature Hot water & cooking if by gasHot water & cooking if by gas E = W + H*degree days*86400 E = W + H*degree days*86400 Where E is total energy consumedWhere E is total energy consumed W energy for hot water + cooking (gas)W energy for hot water + cooking (gas) W approx constant for given house – 7-10 GJ/quarter W approx constant for given house – 7-10 GJ/quarter H is heat loss rate for the homeH is heat loss rate for the home Two unknowns W & H, Two unknowns W & H, Know degree days & energy consumption Know degree days & energy consumption Estimate heat loss & steady energy requirement Estimate heat loss & steady energy requirement

23 Degree day method - example Energy consumption 2 successive quarters & GJ & GJ Corresponding degree days 1100 and and 500 E = W + H * degree days* * H * W = (1) 500 * H * W = (2) 500 * H * W = (2) Simultaneous equations (subtract 2 from 1) H = (31.76 – 18.80) * 10 9 = 250 Watts ( )*86400 ( )*86400 Substitute for H in either equation to get W W = * * 250 * = 8 * 10 9 = 8GJ = 8 * 10 9 = 8GJ H - heat loss W - hot water

24 Degree day method Once H & W have been calculated Performance for subsequent quarters can be estimated Performance for subsequent quarters can be estimated If degree days for 3 rd quarter = 400 If degree days for 3 rd quarter = 400 Consumption predicted to be Consumption predicted to be 400 * 250 * * 10 9 = GJ 400 * 250 * * 10 9 = GJ If actual consumption is 17.5 GJ then energy has been wasted If actual consumption is 17.5 GJ then energy has been wasted

25 Mean temperature method (non electrical heating) Plot the mean consumption over a specific period against mean external temperature Plot the mean consumption over a specific period against mean external temperature For 1 week or 1 day - less time than previous method For 1 week or 1 day - less time than previous method

26 Analysis of lighting (non-electrically heated house) Lighting varies throughout the year with hours of darkness Lighting varies throughout the year with hours of darkness Need to assess a realistic time for lighting Need to assess a realistic time for lighting There is constant load (A) from appliances and refrigeration use and an increasing amount from lighting. There is constant load (A) from appliances and refrigeration use and an increasing amount from lighting. Increase in lighting hours is used to obtain L & A in same way for H & W in heating example Increase in lighting hours is used to obtain L & A in same way for H & W in heating example

27 Analysis of heating & lighting in an electrically heated house More complex as both H & L are unknown More complex as both H & L are unknown Combine A & W to give overall appliance + hot water load (A) Combine A & W to give overall appliance + hot water load (A) E = (degree days * H + lighting hours * L) * A E = (degree days * H + lighting hours * L) * A Where E = energy consumption Where E = energy consumption H = heat loss rate H = heat loss rate L = lighting (units of L are Watts per hour) L = lighting (units of L are Watts per hour) A = appliance + hot water A = appliance + hot water 3 unknowns – H, L & A 3 unknowns – H, L & A If we have data for 3 quarters If we have data for 3 quarters Estimate values for H, L & A by solving 3 simultaneous equations Estimate values for H, L & A by solving 3 simultaneous equations If appliance load is known calculation is easier If appliance load is known calculation is easier

28 Cumulative deviation method 1. No energy conservation – horizontal line 2. Winter following improved insulation 3. Summer – no savings – heat conservation only 4. Winter – parallel to 2 5. Summer - improved management of hot water 6. Should be (4) + (5) but less - energy conservation performance is reduced

29 Normalised Performance Indicators (NPIs) Provides an indication of the energy performance of a building Provides an indication of the energy performance of a building Compares actual annual energy consumption and costs with those achieved by buildings of a similar type and function Compares actual annual energy consumption and costs with those achieved by buildings of a similar type and function Problems Problems Buildings may be different sizes Buildings may be different sizes Locations may have different climates Locations may have different climates Locations may have different levels of exposure Locations may have different levels of exposure Maybe different operating hours Maybe different operating hours Correct the building energy consumption data Correct the building energy consumption data allow for variables such as occupancy and weather. allow for variables such as occupancy and weather. NPIs developed to address these problems. Used to NPIs developed to address these problems. Used to compare with other buildings of a similar type and function compare with other buildings of a similar type and function compare with standard energy benchmark for different building types compare with standard energy benchmark for different building types Benchmarks Benchmarks Many countries have national energy benchmarks for different types of buildings Many countries have national energy benchmarks for different types of buildings Usually kWh/m2 of floor area (volume) Usually kWh/m2 of floor area (volume) Provide guidance, not absolute values to achieve Provide guidance, not absolute values to achieve

30 How to calculate NPIs Establish total building energy use in standard units Establish total building energy use in standard units Calculate the annual energy use for space heating Calculate the annual energy use for space heating Sub-metering, or analytical techniques Sub-metering, or analytical techniques Correct space heating energy data for climate & exposure Correct space heating energy data for climate & exposure Weather coefficient = std annual heating degree days/ annual heating degree days experienced by building Weather coefficient = std annual heating degree days/ annual heating degree days experienced by building Exposure coefficients Exposure coefficients Sheltered (city centre) = 1.1Sheltered (city centre) = 1.1 Normal (urban/rural) = 1.0Normal (urban/rural) = 1.0 Exposed (coastal/hilly site) = 0.9Exposed (coastal/hilly site) = 0.9 Non-heating energy consumption + corrected space heating = non- time corrected energy consumption Non-heating energy consumption + corrected space heating = non- time corrected energy consumption To calculate normalised annual energy consumption need to correct for hours of use To calculate normalised annual energy consumption need to correct for hours of use non-time corrected energy consumption * coefficient non-time corrected energy consumption * coefficient Hours of use coefficient = std annual hours of use/actual annual hours of use Hours of use coefficient = std annual hours of use/actual annual hours of use NPI = normalised annual energy consumption/building floor area NPI = normalised annual energy consumption/building floor area

31 Energy Surveys Integral part of energy audit Integral part of energy audit Helps to understand energy flows within a facility/building Helps to understand energy flows within a facility/building Helps to identify energy wastage Helps to identify energy wastage Can be comprehensive or targeted Can be comprehensive or targeted Objectives Objectives Determine energy performance of facility/building or specific plant/equipment Determine energy performance of facility/building or specific plant/equipment Identify and quantify the principal energy flows & energy cost savings Identify and quantify the principal energy flows & energy cost savings Produce costed recommendations to achieve energy cost savings Produce costed recommendations to achieve energy cost savings Make recommendations on future energy management of facility Make recommendations on future energy management of facility

32 What to include in an energy survey Management and operation characteristics of a facility or organisation Management and operation characteristics of a facility or organisation Energy supply to an organisations various facilities Energy supply to an organisations various facilities Energy use within an organisations facilities Energy use within an organisations facilities The plant and equipment within a facility The plant and equipment within a facility The fabric of the organisations buildings The fabric of the organisations buildings

33 Management and operating characteristics Management culture Management culture Can have considerable influence on energy consumption Can have considerable influence on energy consumption Determine management structure and practices relating to energy procurement and consumption Determine management structure and practices relating to energy procurement and consumption Identify cost centres Identify cost centres Are the managers accountable for operating costs also responsible for energy consumption?Are the managers accountable for operating costs also responsible for energy consumption? Maintenance procedures Maintenance procedures Frequency and qualityFrequency and quality Identify new maintenance measures to improve energy efficiencyIdentify new maintenance measures to improve energy efficiency

34 Operating practices: data collection Use of particular space or building Use of particular space or building Mechanical/electrical services in building Mechanical/electrical services in building Number & type of occupants e.g. stationary or active Number & type of occupants e.g. stationary or active Occupancy patterns Occupancy patterns Environmental conditions Environmental conditions Air temp, humidity, lighting Air temp, humidity, lighting Operating practices of plant/equipment Operating practices of plant/equipment Identify where actual practices deviate from that stated by management Identify where actual practices deviate from that stated by management Overheated rooms, open windows, computers left on Overheated rooms, open windows, computers left on

35 Energy Supply Identify tariffs and supply contracts of organisation Identify tariffs and supply contracts of organisation Ensure organisation is using correct electricity tariff to suite its load profile Ensure organisation is using correct electricity tariff to suite its load profile Calculate load profile Calculate load profile Regular meter readings – include daytime, night time & weekends Regular meter readings – include daytime, night time & weekends For large electrical loads For large electrical loads Need to be more accurateNeed to be more accurate Measure every 30 mins, use portable meters if necessaryMeasure every 30 mins, use portable meters if necessary Investigate large peaks in load Investigate large peaks in load

36 Plant and equipment Survey major items of plant and equipment to determine their operating efficiency Survey major items of plant and equipment to determine their operating efficiency Include pipe distribution networks Include pipe distribution networks Boilers Boilers tune to minimise flue gas heat loss tune to minimise flue gas heat loss Identify if flue gas heat recovery is feasible Identify if flue gas heat recovery is feasible Refrigeration Refrigeration Check efficiency Check efficiency Opening practices Opening practices Is heat recovery feasible Is heat recovery feasible Pipework Pipework Insulation & leaks Insulation & leaks Planned replacement of old plant Planned replacement of old plant Building fabric Identify using U values areas of greatest heat loss Identify using U values areas of greatest heat loss Thermal imaging Thermal imaging Excess ventilation – open doors Excess ventilation – open doors

37 Energy management: recommendations Recommendations will relate to cost of fuel – more interested in saving money than energy/carbon Recommendations will relate to cost of fuel – more interested in saving money than energy/carbon Technical Technical Insulation, draft exclusion, thermostatic radiator valves, heating control Insulation, draft exclusion, thermostatic radiator valves, heating control Low energy lighting, efficient refrigeration Low energy lighting, efficient refrigeration Power factor corrections Power factor corrections Relocation of switches, movement sensors Relocation of switches, movement sensors Energy management Energy management Checking performance Checking performance Record keeping Record keeping Financial Financial Make sub-sections responsible for their own energy budget Make sub-sections responsible for their own energy budget Carrots for those who save energy Carrots for those who save energy Other factors Other factors Change patterns of working Change patterns of working Working practices Working practices Use of space Use of space


Download ppt "Energy Conservation Energy Management. Role of an energy manager Assess Assess Current energy demand Current energy demand Energy audit Energy audit Analyse."

Similar presentations


Ads by Google