Estimating Energy Demand in Totnes & District
So How Much Energy is Consumed in Totnes and District Today?
To estimate energy supply and demand, UK national statistics1 for average consumption are used and calculated using the 2001 Devon County Council census and Family Health Service Estimates (FHSE) 2008 for populations and households in the parishes. Both per capita and household annual estimates are provided and calculated for the district to assist those who wish to understand and estimate individual usage (e.g. individual carbon footprint assessment) and by household (based on an average 3 bed semi).
It is also anticipated that household size is likely to change (from the current 3 bed semi current basis to perhaps larger extended family units of 6-7 persons sharing) during the 21 years of the EDAP timeline and as this is the functional system of domestic energy use, we may need to revert to per capita estimates to make or adjust future evaluations. However as indicated in the table below, estimates for increasing population based on DCC predictions are calculated as per capita increases but, but calculations for increasing energy demand are scaled within limits of likely increases in households, in the context of increasing household size2. The DARE / BERR estimates also enable separation of the domestic, transportation, industrial and services usage, information which can further inform the EDAP across the timeline as the relative proportions of these uses are likely to change over the next 21 years
Per capita consumption
So how much energy do we, in Totnes and District each use every year? According to Devon County Council and FHSE population estimates from 2008, there are 23,863 persons in the 16 parishes of Totnes & District. If we multiply this by the national average energy consumption for different activities, we get the table below.
| Annual Energy Usage 2008 - Individual / per capita - By Sector | ||
|---|---|---|
| Sector | UK Average Usage Per capita (MWh/y) | UK Average Usage All persons T & D (MWh/y) |
| Electricity | 5.75 | 137,212 |
| Personal Transport | 10.83 | 258,436 |
| Heating, Cooling, Cooking | 13.51 | 322,389 |
| All else (services, goods etc) | 0.47 | 11,216 |
| Annual Total (est.) | 30.56 | 729,253* |
Notes
* these totals vary slightly due to the different systems of calculating UK averages
30.56 MWh/y equates to 82 kWh/d per capita, significantly less than Prof. David MacKay’s figure of 125 kWh/d; however the former is a 2003 figure and would reflect energy consumption pre-installation of domestic renewables and insulation retrofits. To ascertain accurate average consumption in a local area is difficult and so for simplicity the former data is used
So each one of us, on average, uses around 30 MWh of energy every year. That’s a lot of energy. As you can see, the highest use is domestic, cooking, heating and so on, but also our car dependency is also a substantial energy drain.
Per household consumption
It can also be useful to look at energy demand, based per average household. If we turn again to Devon County Council and FHSE, they estimate that there are 9,481 households in the 16 parishes of Totnes & District.
Annual Domestic Energy Consumption
by end use for an average
3 bed semi-detached house3
= 22.45* MWh
But what percentage of our total energy demand is used in other sectors? This is easy to establish. UK energy consumption statistics are divided into 4 categories, Domestic, Transport and Services (which includes agriculture) and Industry. Energy distribution is spread across these sectors in the following proportions (see table below) by DTI / BERR. From the estimation of average domestic use per household, we can calculate estimated sectoral and total consumption in Totnes & District as follows.
| Total Annual Energy Demand (2008) per Household in Totnes & District - By Sector | ||||
|---|---|---|---|---|
| Sector | Energy use % | Annual demand all households T & D GWh/y | Annual demand all households T & D MWh/y | Annual demand per household MWh/y |
| Domestic | 30% | 212.8 | 212,848* | 22.45 |
| Transport | 36% | 255.4 | 255,418 | 26.94 |
| Services | 13% | 92.3 | 92,250 | 9.73 |
| Industry | 21% | 149 | 148,947 | 15.71 |
| Total | 100% | 709.5 | 709,463* | 74.83 |
Notes
* These totals vary slightly due to the different systems of calculating UK averages
see Appendix C for a break down of estimates of energy per capita and household by parish
Increasing Population and Energy Efficiency
The population in South Hams is predicated to rise by almost 20% by 2030 from a 2006 baseline. This has substantial implications for energy demand. Similarly development plans are in place to build a number of new houses, to bring people off the current housing lists and to prepare for the increasing population, many of whom will be older people. It is difficult to estimate how all these changes will fit together, however since there is substantial embodied energy in the building of an average 3 bedroom semi4 and we are entering energy declines, a very conservative (gu)estimate has been made in table 3 of just 519 additional houses being built to cater for these additional needs, since we are likely to be accessing empty 2nd homes and increasing the number of people sharing existing buildings. The estimates below enable us to calculate the changes in energy demand over the timeline of this EDAP including a phased increase in energy efficiency.
| Estimating annual Total Energy demand 2009–2030 by Household in Totnes & District in line with predicted increasing population, increasing energy efficiency & energy reduction measures (to achieve ZCB 50% of 2009 demand) | ||||||||
|---|---|---|---|---|---|---|---|---|
| Year | Estimated % population increase[i] | Calculated population (based on estimated % increase) | Est. no. of persons per house-hold[ii] | Est. no. of house-holds | Est. total energy demand based on 2008 usage per household 74.83 MWh) | |||
| BAU* Based on 100% usage in 2008 MWh/y | Drop in (2008) energy demand -towards ZCB 50% | WTC** Est. total demand T&D WITH % reduction MWh/y | Est. total demand per household with % reduction MWh/y | |||||
| 2008 | Baseline | 23,863 | 2.52 | 9,481 | 709,463 | Baseline 0% | 709,463 | 74.83 |
| 2011 | 3% | 24,579 | 2.55 | 9,631 | 720,688 | 15% | 603,075 | 62.62 |
| 2016 | 7% | 25,533 | 2.61 | 9,780 | 731,837 | 25% | 532,125 | 54.41 |
| 2021 | 11% | 26,488 | 2.69 | 9,850 | 737,076 | 35% | 461,175 | 46.82 |
| 2026 | 15% | 27,442 | 2.76 | 9,930 | 743,062 | 45% | 390,225 | 39.3 |
| 2031 | 19% | 28,397 | 2.84 | 10,000 | 748,300 | 50% | 354,732 | 35.47 (52.6%) |
Notes
* County Council data with TTT calculations of T&D as a % (based on 2008) of South Hams population
** See Population estimates and discussion in ‘Joined up Thinking’ section
*** Based on 2008 usage per household 74.83 MWh
**** Business as Usual
***** Willing to Change
So, in the next section, we will use the following baseline (from Tables 1-3) when we try and answer the question, ‘can Totnes and District power itself?’
In 2009 the current total
energy demand for T&D is
709,463 MWh/y (709.46 GWh/y)
based on an average annual usage of all energy of
74.83 MWh/y per household
By 2030 we anticipate an increase of population
of around 19%
but expect to have achieved a
50% reduction of total energy demand for T&D to
354,732 MWh/y (354.73 GWh/y)
based on an average annual usage
of all energy of
35.47 MWh/y per household
Footnotes
- DTI online data [↩]
- Transition Town Totnes / Jacqi Hodgson calculations loosely based on current SHDC Development Plans and the South Hams District Council Local Development Framework to 2016 [↩]
- DARE report / Domestic Energy Fact File 2003 [↩]
- See Appendix C Calculation which includes amounts of embodied energy in buildings [↩]
7 comments on “Estimating Energy Demand in Totnes & District”
Leave a comment
If you wish to comment on a particular paragraph
and quote the relevant number in your comment.
I just wondered why you are using national rather than the local energy statistics available on the DECC website? Gas and electricity are available at a very local level (LLSOA) while transport is available at local authority level. http://www.decc.gov.uk/en/content/cms/statistics/regional/mlsoa_2007/mlsoa_2007.aspx Will you use local statistics to help measure progress?
We used national statistics to enable us to tap into a broader range of information and reference such as Zero Carbon Britain Report which could then be used to look at other energy use, oil in our lives such as consumables, food etc.
Totnes EDAP
Estimating Energy Demand in Totnes & District
Hi
I am working towards producing an EDAP for Transition Calon Teifi. So I have been reading your EDAP with some care. Please don’t take offence at my comments…
Comment 1
——–
Table: “Annual Energy Usage 2008 – Individual / per capita – By Sector”
There seems to be some confusion here.
The figure of 30.56 MWh/y/person corresponds to the “Final energy consumption” as defined in e.g. “Digest of United Kingdom Energy Statistic 2009 (DUKES)”, Chapter 1, p13&14.
This gives final energy consumption for yr1998 of 164.9 Mtoe which is some 31.2 MWh/y/person i.e. the 30.56 figure is not consumption in the home, but includes manufacturing, transport, construction, etc..
The breakdown in the DUKES document gives
“Domestic” consumption as 27.5%, i.e. some 8.6 MWh/y/person.
This compares well with the box that follows in the EDAP:
“Annual Domestic Energy Consumption 22.45MWh”,
i.e. some 9.4 MWh/y/person (23,863 people in 9,481 households).
So I have to ask where do the sector categories and corresponding figures in the table come from?
Cooking, heating and so on, certainly accounts for most of our domestic usage, but is not the largest component of total energy usage as the text states.
Cooling (line 3 in the table) is all surely done by electricity, which is at line 1.
Transport, within the 30.56 figure, includes all road haulage, but there is no allowance for that.
I think it would help if this table were sorted out or removed.
Comment 2
———
The note below the table compares the figures against Prof Mackay’s figures. But the latter are for “Primary Demand” as defined e.g. in the DUKES document, i.e. the number 125kWh/day includes all the energy that goes into making electricity, etc.
The corresponding figure for “Final Demand” (the energy at point of use) would be some 87 kWh/day and, if we allow for “non-energy usage” (see DUKES) we get some 82 kWh/day.
So your figure of 30.56 MWh/y – which is actually 83.67 kWh/day – is not “significantly less than Prof. David MacKay’s”
Sorry to be a pain.
regards
Tim Swann
Thank you for your detailed enquiry. The figures set out in table 3.24 are based on Dept. of Trade and Industry on line data. http://www.berr.gov.uk. I calculated these for the population figures for Totnes & District as outlined in the accompanying text in the EDAP. I think this table is useful as it helps people to understand where their main usage of energy is and demonstrates the value of taking practical actions in the home to cut carbon dependency. I take your point about some of the details, but the aim was to keep this as a simple guide, which most readers have found this serves to provide. Regarding table 3.25 thanks for your points regarding the difference between the BERR (extrapolated) data and McKay’s.
Thanks for your replies. But:
1. EDAP Table 3.24
I have tried to follow the link http://www.berr.gov.uk but it just goes to http://www.bis.gov.uk/ and I can’t find any relevant documents there. Could you supply an actual document reference?
I have found:
Digest of United Kingdom Energy Statistics 2009 (DUKES), which has figures for 2008. This gives a figure of about 30MWh/yr/person so I assume it is basically the same number as the EDAP. But the sector breakdown is wholly different.
My concern is that Table 3.24 in the EDAP gives the impression that these figures are for domestic & personal usage, whereas national per capita domestic usage plus personal transport (car, bus, etc.) accounts for only some 16 MWh/y or so out of the total 30 (about 9 MWh domestic and 7 MWh personal transport).
This matches the EDAP p3.25 figure for Annual Domestic Energy Consumption of 22.45 MWh (which for T&D gives 8.9 MWh/person/yr).
The other 14 MWh of the 30 is used by industry, haulage, etc. doing things on our behalf.
I think it is quite misleading to say that the table ” helps people to understand where their main usage of energy is”. Rather it confuses the issue. For example, domestic electricity accounts for only some 1.9 MWh/y/person (calculated from DUKES 2009). If I compared our electricity bill of 1.25 MWh/y/person against the 5.75 in the Table I would feel rather smug. A table showing how I cause electricity usage by buying stuff, etc., would be more helpful.
2. Annual Domestic Energy Consumption
Sorry, I don’t have access to the DARE report. The EDAP figure of 22.45 MWh for “an average 3 bed semi-detached house” is very close to the 22.44 MWh which can be derived from “BRE Domestic Energy Fact File 2003″. But this latter figure is for all households: Semi-detached, Terraced, Flat, Detached, etc. I am surprised to se the two figures so close. Does the DARE report actually say “average 3 bed semi-detached house” or just “average household”, which could be very different?
And: Oh dear, I meant 24,422 thousands of households (BRE Page 29).
I forgot to mention, under “Per household consumption” the blue box saying
“Annual Domestic Energy Consumption
by end use for an average
3 bed semi-detached house3
= 22.45* MWh”
This figure is actually the average over all the 24,422 households in the country, which includes terraced houses, flats, institutions, etc.. Do you have any reason to suppose that the figure for the “average semi” is near to this overall average?
As stated in the text this average household figure was taken from the DARE report. Where do you get your figure of 24,422 households in the country, this seems very low for a total population of over 60 million?