Monitoring energy consumption data

Principle

It is most highly recommended that energy consumption data be monitored to obtain essential information on energy use in the hotel. Data collection can reveal problems (abnormal changes in consumption, etc.), and identify opportunities for energy savings, as well as ascertaining that energy-saving measures taken are effective.
Energy utility bills are in general the main source of this data. It is important to keep utility bills and analyse them on a regular basis.
If you operate a large hotel, it may be useful to determine energy consumption for certain zones and specific types of services within the hotel (administrative offices, kitchens, rooms floor by floor, suites, etc.). The simplest way to obtain this information is to install submeters. But before deciding to install submeters, you must have an action plan in mind, so that employees can apply simple corrective action on the basis of information gathered via the submeters.

Explanations

Implementation

How do I go about analysing energy consumption?
• Gather data: Collect all your monthly energy utility invoices and make sure that they all give the following information: total amount of energy consumed, unit cost, total cost. Compile all invoices from the two preceding years.
• Analyse data:
- Record annual consumption: For each year for which you have invoices, prepare a table displaying total annual consumption, and the cost of each type of energy (electricity, gas, etc.). List the main final uses for the different energy resources (heating, lighting, etc.). Lastly, calculate the energy performance index (energy consumed per m² of indoor surface area) and energy consumption per overnight stay sold (to compare with other establishments).
How much energy does your hotel use, and what is it used for?
Energy source Main final uses
Annual consumption (kWh)
% of total consumption
Total annual
(*) cost
Electricity Lighting... (…) (…) (…)
Natural gas (…) (…) (…) (…)
Diesel fuel (…) (…) (…) (…)
District heating (…) (…) (…) (…)
(…) (…) (…) (…) (…)
Total energy consumption and cost (…) 100%
• Energy consumption per m²: (...)
• Energy consumption per overnight stay: (...)
(*)Prepare a table for conversion of different units into kWh, and save it in your files.
Conversion table (standard conversions are given as estimates):
Energy source Unit generally used
kWh equivalent
Natural Gas m3 1 m3 = 11.9 kWh
Diesel fuel litre l litre = 10.9 kWh
Heating oil litre 1 litre = 11.4 kWh
Fuelwood kg 1 kg = 4.1 kWh
Remark: Request other conversion factors from your energy supplier(s).
- Energy consumption trends over time: Observe whether your energy consumption has changed significantly from one year to another, and then from one month to another (overall consumption, and for each resource separately). Attempt to determine the correlation between energy consumption and occupancy rate (number of overnight stays), and between consumption and climate/weather conditions.
Total energy consumption for the period in question:
Period Occupancy Energy consumption Cost
(month / year) (kWh or other unit)
(...) (...) (...)
Draw up a table for each type of energy (electricity, gas, etc.)
How can I determine energy use for a specific zone or appliance?
• Quite often, the more direct solution is to install a submeter that measures consumption on a single circuit. When more than one circuit is to be monitored, sophisticated systems can be used to link meters and transmit data to a computer.
• To monitor wired equipment or subcircuits, energy consumption monitors can be fitted on connection cables. These controllers measure energy use for a given period and record this data until it can be downloaded to a computer for analysis.

Costs

Approximate cost:
• Measuring energy consumption: €0
• Submeters: €40-45 + labour
Approximate payback time:
• < 1 year

It should be noted that costs and payback times are highly dependent on the local setting and the initial situation of the hotel.

Examples

Benefits

Cost savings
Energy savings:
Corrective action based on energy consumption monitoring can save up to 8 to 10% of consumption.
Establish the right contract with your energy supplier:
• Knowing your energy consumption habits will help you get a more advantageous contract from your energy supplier.
Staff awareness and involvement:
• Informing your employees of hotel energy consumption is a good way to encourage them to participate in energy saving action.
Some hotels give bonuses to their employees if energy consumption drops.
Reduced CO2 emissions
• For a hotel of 1,000 m² with total annual energy consumption of 350 kWh/m², and applying emission factors for France, a 10% savings in electricity and gas consumption represents:
4.05 t CO2 eq of avoided emissions each year
Emission factors for electricity in France: 84.3 g CO2 / kWh.
Emission factors for natural gas in France: 331 g CO2 / kWh (Source: ADEME).