electricity use

8/13/2019 Electricity use

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Nasim Mammadov H00112921| Energy Studies | February 4, 2014

Energy efficiency and useASSIGNMENT 1


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Calculation

SPACE HEATING

Worchester BOSCH boiler9/14CBi GC.The 9/14CBi appliance requires a maximum of

1.62 m3/h of natural gas (G20), 0.63 m3/h propane (G31). 230V - 50Hz. Load 125 watts.My gas meter records gas consumption in cubic meters. Now we should convert it to kWh.

The correction factor (1.02264) takes into account changes in the volume of gas based on

temperature and pressure. It is generally of the order of 1.02264. The calorific value (CV)

is a measurement of the amount of energy contained in the gas. CV is usually quoted in

mega joules per cubic meter (MJ/m3). Gas delivered for domestic uses will have a CV of

between 37.5 MJ/m3 and 43 MJ/m3. We will take it as 39.4, but it might be change. [1]

The table below shows my gas consumption record for previous year:

Months January February March April September October November December Total

Gasusage(m

3)

211 239 204 154 175 211 205 246 1645

Table 1. The annual gas consumption (m3)

( ) ( )

The flat has been shared by 2 people, then the number divided by two:

Shower. The heat capacity of water measures how much energy is required to heat it up,

is 4200 J/litre/C. So the energy required to heat up the water by 40 C is given below: [2]

So, taking a shower uses about 1.4 kWh, then average usage is twice a week at home:

()


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This formula is the general formula to estimate an appliance's energy use:

( ) ()

1 kilowatt (kW) = 1,000 Watts

The annual consumption multiplied in kWh per year (that calculated above) by localutility's rate per kWh consumed to calculate the annual cost to run an appliance. [3]

ELECTRICITY APPLIANCES

Table 2 Household energy consumption 1

1Carbon Footprint Ltd - Household Energy Consumption. 2014. Carbon Footprint Ltd - Household Energy Consumption. [ONLINE]

Available at:http://www.carbonfootprint.com/energyconsumption.html.[Accessed 04 February 2014].
http://www.carbonfootprint.com/energyconsumption.htmlhttp://www.carbonfootprint.com/energyconsumption.html


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Lighting

Quantity

Current bulb

wattage Total kWh

Hours/on

day Annual usage (kWh)

Entryway 1 20 0.02 0.5 3.65

Living room 1 30 0.03 4 43.8

Bathroom 3 15 0.045 0.5 8.2125

Kitchen 2 15 0.03 1 10.95

Bedroom 1 30 0.03 1 10.95

Storage

room 1 15 0.015 0.1 0.5475

Total: 78.11

Table 3. The estimation of annual electricity usage in my house (kWh)By knowing, the annual energy usage in my house, I can estimate my personal electricity

usage:

Vacuum Cleaner, Cylinder with 1.8 kWh motor.

Considering that, I use vacuum cleaner 2 hours per month the annual electricity usage is:

Washing machine, estimated 100 washes per year

EU energy label A-rated gives an average consumption at 40C using a 2kg load to be

0.63 kWh [4]

Hair dryer, 600 W

Laptop: Sony VAIO 40 W

( )

Kettle, 2200 W

Kettle is shared, so my personal electricity usage is:


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Toaster, 1200 W

Toaster is shared, again my personal electricity usage is:

Fridge, freezer, 0.04 kWh (A++)

[5]

Electric oven, Emerges B200, 2200 W

We are using electric oven for daily cooking, since time shortage as a student we are

cooking 5 times a week and each time the electric oven works about 60 minutes. Then,

Electric oven is shared, again my personal electricity usage is:

Smartphone

The energy consumption of smartphones so small that not negligible and doesnt affect

our communal bills. A typical smartphone uses about 5 Watts of electricity while charging,

when the device is plugged in but fully charged, that number drops close to zero.

TRANSPORT

The following formula shows energy used per day for any type of transport.

I am driving a car as a daily transport, so calculations will be based on automobile energy

consumption. Automobile fuels are all hydrocarbons with the calorific value which can be

calculated. The calorific value of car fuel is 3000KJ per 100 g, or about 8 kWh per kg.


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Then we need to turn fuels into energy per unit volume, for petrol it is 10 kWh per litre.

Considering that my average daily drip is 40 km then:2

By knowing, the energy used per day, the annual energy consumption can be estimated,

considering that I am driving an automobile averagely 250 day of a year.

Furthermore, I am using a public transport also. The bus is the most common publictransport I am using among them, so the calculations will based on a bus fuel

consumption. Fuel consumption achieved during the double deck vehicle route test cycle

was 24.18 l/100 km under identical conditions, carried out by an independent evaluation

facility. [7]

It means double deck vehicle consumes 1 litre fuel for 4 km distance, then by using the

same technique we can estimate the energy consumption by thinking my average daily

trip with bus is 20 km then:

Air travel

As an international student from Azerbaijan I am making at least two intercontinental tripper year by plane. The plane which carrying out is Airbus A320 family with 30030 litres of

fuel carries 220 passengers and the distance to destination (London-Baku flight) is about

2480 miles (4000 km). From previous calculations we know that fuels calorific value is 10

kWh per litre. So the energy cost of one full-distance roundtrip on such a plane, if divided

equally among the passengers, is:3

2 David JC MacKay, 2009. Sustainable Energy - Without the Hot Air. Edition. UIT Cambridge Ltd. Page 29

3 David JC MacKay, 2009. Sustainable Energy - Without the Hot Air. Edition. UIT Cambridge Ltd. Page 35


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( )

Now the all calculations are done for each device that consume energy. Additionally, my

travel footprint including trips abroad, daily transport and commuting are calculated by

using given formulas and converted to kilo Watt per hour. The table below shows all

energy consumptive devices and activities I am using with detailed calculations. Now, we

can calculate personal annual energy usage for further calculations.

Device and activities Units Quantity Time Annual usage Units

Boiler Gas usage (m^3) 1645 year 9787.5 KWh

Shower 30 L water (40 C) 146 KWh

Lighting 9 bulbs 39.1 KWh

Vacuum cleaner kWh 1.8 12 hours/ month 43.2 KWh

Washing machine kWh 0.63 150 washes/year 94.5 KWh

Hair dryer kWh 0.6 12 hours/year 7.2 KWh

Laptop 0.04 6 hours/day 87.6 KWh

Kettle kWh 2.2 0.5 hours/day 200.1 KWh

Toaster kWh 1.2 0.2 hours/day 43.8 KWh

Fridge, freezer kWh 0.04 24hours/365 days 350.42 KWh

Electric oven kWh 2.2 5 hours/week 286 KWh

Smartphone kWh 0.005 2 hours/365 days 3.65 KWh

Car kWh 33.3 200 days/year 8333.3 KWh

Bus kWh 50 200 days/year 10000

Plane kWh 2 roundtrips/year 10355 KWh

Total 39777.37 KWh

Table 4. My estimated annual personal energy usage (kWh)

Now by using the data given in the carbon trust fact Sheet CTL018 we should convert thisfigure to kg of CO2and to tonnes of burning oil.

Energy conversion factors

()


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Using factors given above we can estimate total kg of CO2:4

Energyconversionfactors

FuelNumber ofunits

Conversionfactor

Units KgCO2e

Grid electricity 1301.57 0.44548 kWh 579.8234036

Natural gas 9787.5 0.18404 kWh 1801.2915

Grid electricity 5.39421 therms 579.8234036

LPG0.21452 kWh

6.28578 therms

LPGGas oil

1.4929 litres

3427.2 tonnes

0.27176 kWh

Gas oil

Fuel oil

2.9343 litres

3232.7 tonnes

0.26876 kWh

Burning oil

3164.9 tonnes

0.24555 kWh

Diesel3100.1 tonnes

0.24512 kWh

Diesel

Petrol

2.6008 litres

9305.5179383005.8 tonnes

39777.37 0.23394 kWh

Petrol

Industrial coal

2.2144 litres

9305.5179382339.1 tonnes

0.31304 kWh

Wood pellets 0 tonnes0 kWh

Total kgCO2e 11686.63284

4http://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdf


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By knowing that 1 tonne of oil equivalent (TOE) is 11.360 kWh. So we can estimate my

annual TOE by operation shown below

()

Official numbers says that the average UK per capita consumption is about 4 TOE, then it

shows that my calculated number is slightly lower than this.

(a) Identify one item of energy saving equipment which you could incorporate in your house/flat/room to

replace one of your existing items mentioned above.

In my case replacement of my old, inefficient boiler might significantly help energy

savings. Boiler efficiency has an important influence on heating related energy costs and

carbon emissions. A boiler is a device in which a fossil fuel is burnt and the heat produced

is transferred to water. For most types of conventional boiler, efficiency drops dramatically

below about 30% of rated capacity. [8]

(b) Estimate the installed cost of the item and the annual savings (energy and financial) which

would result.

My yearly gas usage 19.575 kWh is significantly higher than the national

average (15.000 kWh). My old boiler Worchester BOSCH boiler 9/14CBi GC

running at below 67% efficiency. The table can be found on the right, and boilershould sit at G on that scale. New boilers aren't cheap and prices vary greatly

based on the different brands, sizes and types available. Typically new boiler

prices range from close to 500 all the way to 2,000, so it's important to do

simple calculations before purchasing it.

The boiler with 91% efficiency costing 1400, the calculation below shows how

much I could expect to save on a typical gas bill and how long it would take to

pay for itself.

My yearly gas usage is 19575 kWh with old G boiler (67% efficient) is converting only 67%

of the gas used for hot water/heat into usable energy

This shows the heat/hot water demand requiring 13115.25 kWh of usable energy. By

dividing the amount of usable energy required as calculated by the efficiency rating of my

new A band boiler (91%), you get the new total amount of gas used for heat/hot water in

the dwelling when using a Band A boiler.

To work out the cost of the new usable energy amount as calculated above, we need tomultiply the new figure by the unit cost per /kWh of gas.


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To calculate my saving, I need subtract the new total from my current gas bill

( )

(c) Hence estimate the simple payback period.

(d) Why have you not installed this equipment? (Note: if you live on Campus or rent a room, imagine you

own the flat etc. when answering this question).

The cost of a new, A Band Boiler (1400) is matter of concern to me the replacing my

boiler. My low student budget doesnt allow to replace it with new one. Currently, UK

government launched the new government grant, where free boilers supplied and installed

to certain eligible people with income below 15,860 per year. Furthermore, the energy

companies are tempting to change the old boilers with new ones by different long-term

offers. In the future I might take the advantage of these schemes.


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References

1. Convert Gas Meter Readings to kWhs. 2014. Convert Gas Meter Readings to kWhs.[ONLINE] Available at:http://www.energylinx.co.uk/gas_meter_conversion.html.[Accessed 03

February 2014].

2. David JC MacKay, 2009. Sustainable Energy - Without the Hot Air. Edition. UIT CambridgeLtd.

3. Estimating Appliance and Home Electronic Energy Use | Department of Energy. 2014. Estimating

Appliance and Home Electronic Energy Use | Department of Energy. [ONLINE] Available

at:http://energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-use.[Accessed

04 February 2014].

4. Carbon Footprint Ltd - Household Energy Consumption. 2014. Carbon Footprint Ltd - HouseholdEnergy Consumption. [ONLINE] Available at:http://www.carbonfootprint.com/energyconsumption.html.

[Accessed 04 February 2014].

5. Electricity Usage . 2014. Electricity Usage . [ONLINE] Available at:http://www.t2c.org.uk/saving-energy/electricity-usage/.[Accessed 04 February 2014].

6. . 2014. . [ONLINE] Available at:http://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdf.

[Accessed 04 February 2014].

7. Fuel consumption of prototype NB4L - a Freedom of Information request to Transport for London -WhatDoTheyKnow . 2014. Fuel consumption of prototype NB4L - a Freedom of Information request

to Transport for London - WhatDoTheyKnow . [ONLINE] Available

at:https://www.whatdotheyknow.com/request/fuel_consumption_of_prototype_nb.[Accessed 04 February

2014].

8. New boiler: What's the real cost of a new boiler?. 2014. New boiler: What's the real cost of a newboiler?. [ONLINE] Available at:http://www.uswitch.com/boilers/guides/new-boiler-cost/.[Accessed 05

February 2014].

9. Robert A. Ristinen, 1998. Energy and the Environment. 1 Edition. Wiley.
http://www.energylinx.co.uk/gas_meter_conversion.htmlhttp://www.energylinx.co.uk/gas_meter_conversion.htmlhttp://www.energylinx.co.uk/gas_meter_conversion.htmlhttp://energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-usehttp://energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-usehttp://energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-usehttp://www.carbonfootprint.com/energyconsumption.htmlhttp://www.carbonfootprint.com/energyconsumption.htmlhttp://www.carbonfootprint.com/energyconsumption.htmlhttp://www.t2c.org.uk/saving-energy/electricity-usage/http://www.t2c.org.uk/saving-energy/electricity-usage/http://www.t2c.org.uk/saving-energy/electricity-usage/http://www.t2c.org.uk/saving-energy/electricity-usage/http://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdfhttp://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdfhttp://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdfhttps://www.whatdotheyknow.com/request/fuel_consumption_of_prototype_nbhttps://www.whatdotheyknow.com/request/fuel_consumption_of_prototype_nbhttps://www.whatdotheyknow.com/request/fuel_consumption_of_prototype_nbhttp://www.uswitch.com/boilers/guides/new-boiler-cost/http://www.uswitch.com/boilers/guides/new-boiler-cost/http://www.uswitch.com/boilers/guides/new-boiler-cost/http://www.uswitch.com/boilers/guides/new-boiler-cost/https://www.whatdotheyknow.com/request/fuel_consumption_of_prototype_nbhttp://www.carbontrust.com/media/18223/ctl153_conversion_factors.pdfhttp://www.t2c.org.uk/saving-energy/electricity-usage/http://www.t2c.org.uk/saving-energy/electricity-usage/http://www.carbonfootprint.com/energyconsumption.htmlhttp://energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-usehttp://www.energylinx.co.uk/gas_meter_conversion.html

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