we use below average amounts of
electricity.
Cooking and heating are done by
gas, and the dishwasher and
washing machine are used
sparingly.
Most of the lights in the house have
been replaced with low energy
bulbs, that use about 1/5th of the
electricity of incandescent types.
As I work form home, I have to
keep a PC on for most of the day.
We have recently audited our
power consumption and reduced it
by 40% to just 6kWh per day, just
by turning off unnecessary
equipment such as TV and PC
when not being used.
Target for 2005/06 2200 kWh
inefficient gas back boiler with a
modern condensing unit made by
Worcester Bosch, resulting in an
immediate saving of 2200 kWh
per year.
In the last 5 years we have driven
down our gas consumption from
31,000 kWh in 2000/2001 to just
over 20,000 kWh in 2004/2005.
We have increased the amount of
insulation in the loft and under the
floor of the kitchen and bathroom
and installed efficient underfloor
heating.
We have a solar water heating
panel which provides most of the
hot water in the summer months.
A woodstove and boiler will be
installed this winter.
Target for 2005/06 14,000kWh
we share a supply with 3 other
houses, which results in poor flow
and poor pressure.
The old lead main, installed in
1890 leaks like a sieve, and we
are in discussion with the water
company to replace our supply,
and probably will have a meter
fitted as a result.
We have installed a low flush
toilet and a water saving shower.
The dishwasher is only used
about twice a week and the
washing machine is set to a water
saving economy program.
We plan to use rainwater and
grey water for gardening where
possible.
Target for 2005/06 20% less
I do about 14,000 miles per year
and get about 44mpg on a typical
motorway journey. I no longer
have to commute so my car is not
being used as often for short
journeys. Walking is an option!
Elaine drives a Peugeot 106
which returns about 58mpg. She
uses it daily for her commute of
about 12 miles, and claims not to
have to fill the tank for 5 weeks at
a time!
We are looking forward to the
time when the UK government
really starts to promote alternative
and renewable road-fuels such as
bio-diesel, and gives the motoring
public a tax incentive to buy
greener fuels.
Target for 2005/2006 20% less
This page looks practical methods for reducing the consumption of conventional
domestic energy that can be applied to any household regardless of its size or age.
Whilst this house because of its type of construction, typical of houses of this age
and type in this area, does not lend itself to energy efficiency in the same way a
modern property would, these pages make suggestions on how to make the best
from what you have got - trying to make a silk purse from a sow's ear!
The page illustrates the current energy consumption recorded over the period of
the last 5 years, including some of the excesses, and describes practical ways of
minimising energy and fuel consumption. A second page looks at ways of making
more use of renewable resources, like solar water heating and wood fired heating,
as renewable alternatives to natural gas. With today's rising energy prices it makes
good sense to cut consumption.
In the 2005/2006 season we hope to reduce our electricity consumption by 40%
and our gas consumption by 30%. This will save £105 on the electricity bill and
about £115 on the gas bill. Whilst £220 is not a huge sum, in energy terms it
equates to nearly 11,400kWh of primary energy being saved, which is enough to
heat nearly two modern homes. Saving energy will have far more effect on your
bills, than can ever be hoped for by switching supplier - a point that is often
missed.
It is interesting to see how over the last 50 years or so, improvements have been
made on a piecemeal basis, probably driven by the need for greater comfort or to
keep up with fashions or make use of the cheapest and most convenient fuel.
It with this in mind that Elaine and I set about improving our house to make it a
comfortable, energy efficient 21st Century home, without having to go to extreme
measures..
Insulate loft with rockwool £250
Install condensing gas boiler £2200
Install DIY solar water heating £600
Total £3050
Annual electricity Savings £105
Annual gas savings £115
Estimated Payback at 2005 prices: 14 years
As the price of electricity and gas are rising steeply,
the payback time is likely to be less than 10 years.
The house is of solid brick construction with a Welsh slate roof, and as such was
not well insulated. It is typical of countless others in this area, built in 1904/05 at a
time of suburban expansion of the towns surrounding London.
In 1905 coal was cheap and builder's could not see reason for the expense of
building this type of house with a cavity wall.
Our house was clearly built to a fixed budget using the common building materials
and techniques available at the time. In contrast to modern building, where there
are so many specialist products available to make building easier, this house was
built almost entirely from bricks, mortar, slate, wood and glass. For economy, the
skirting boards were a layer of hard mortar put on with a trowel!
The exterior walls are 9" (225mm) solid brick with no cavity. Heat loss through
this type of wall is one of the main contributing factors to the fairly high heating
bills. The slate roof has no underfelt and no loft insulation until Autumn 2000 after
we moved in.
The property forms one of a pair of semi-detached houses, unfortunately we are
on the north side of the pair. The property consists of two floors and a basic attic
space. The house is 4.4m wide internally (14.5'), with two rooms to the front and
two to the back separated by the staircase which runs across the width of the
house.
The kitchen and bathroom are at the back, in almost a separate extension. This
isolation from the core of the house has meant that they have previously been cold
and seemed uninviting.
The house has two good sized bedrooms about 3.6m x 4.4m, and two reception
rooms of a similar size. There is a smaller 3rd rear bedroom which can only be
accessed through the middle room, and this has previously serves as an office, but
will shortly be converted to an upstairs en-suite bathroom for the master bedroom.
Originally there were open coal fireplaces in every room, and evidence of a large
range in the sitting room or parlour. When built, a single corridor ran from the
front door to the back of the house and the kitchen.
The kitchen looks like an afterthought, and extra £20 in 1905 would buy a
separate kitchen with a small nursery bedroom above it. Prior to this "innovation"
all cooking would have been done in the parlour.
Rooms were separated from the rest of the house by a corridor which ran all the
way through from front to back, effectively isolating the living rooms from
draughts and people moving about the house. When the house relied on coal fires
for heating, rooms sizes were kept small and efforts were made to minimise
draughts. The sitting room has at some point been enlarged to the full width
(4.4m) of the house by removing this corridor wall.
There is evidence to suggest that originally there was only cold water supplied to
the kitchen and to the outside toilet. That was the height of convenience in 1905.
Pipework was later added (1958) to allow a coal fired back boiler to provide hot
water to the kitchen and newly built bathroom extension.
In the 1970's, central heating was finally added by way of a gas fired back boiler
gravity fed from a header tank..
The house offers about 100 square metres of floor area.
Outside there is a fairly level garden of width 5.9m and length 69m. There are 3
sheds on permanent bases and a small greenhouse. Most of the garden is laid to
lawn. The garden is aligned NE/SW so receives good sunshine for most of the
day.
afternoon sunshine. The roof is 100 years old and needs
replacing as a matter of priority. We hope to do this next
season when we proceed with a loft conversion. Solar panels
and Velux roof lights are intended.
the back garden during Summer 2005.
This was temporarily propped up against the fence and
faces almost south. It was plumbed into the hot water
cylinder using narrow bore insulated plastic pipe. A dc
circulation pump powered from a 12V battery charged by a
15W solar panel circulates the water into the hot water
cylinder when the temperature in the panel exceeds 50
degrees centigrade.
From June to September it provided more than enough hot
water for everyday usage. The gas boiler took over in
October as the solar days became shorter.
In the spring it will be mounted on the front roof and
permanently plumbed in to a 200 litre heat store.
passageway. New windows added in the passageway to
improve light in the living room area.
the original yellow and red brickwork and sash windows have
long since gone been covered in notorious pebble-dash.
extension fills in the missing corner providing a larger kitchen and utility
area. The cubicle around the WC has been removed to incorporate it into
the larger bathroom, and an efficient shower added. The old door into the
bathroom is now blocked up and a new door added where the old basin
was.
1. Get modern Heating system - An efficient gas central heating provided
by a modern condensing gas boiler.
2. Replacement of old radiators with more efficient double convector units
and substantial underfloor pipe insulation.
3. Re-plumbing the hot water system and properly insulating the pipes, so
that the heat is not lost to the walls and the sub-floor.
4. Upgrade the loft and roof insulation to a minimum of 100mm of
rockwool insulation between the ceiling joists in the loft.
5. Fit a Class L Insulated hot water storage cylinder to replace the badly
insulated existing unit.
6. New kitchen and bathroom extension that effectively improves the
overall insulation value of the rear of the property by using 100mm of
Celotex underfloor insulation throughout new kitchen and bathroom.
7. Underfloor heating provided by hot water pipes buried in screed
flooring. (Screed is a 3:1 mix of sharp sand (grit) and cement)
Existing fuel Bills
In order to get some idea of the existing energy consumption of this
property I have been recording the gas and electricity consumption figures
for the last 5 years.
Gas (kWh) Electricity (kWh) Per Day (kWh)
2000-2001 30910 2251 6.167
2001-2002 24044 2596 7.112
2002-2003 26249 1702 4.663
2003-2004 21477 4108 11.255
2004-2005 20030 3902 10.690
5 year Average 24542 2911 7.975
Note that to produce 1 kWh of electricity uses about 3 to 4 kWh of
fuel (usually coal or gas in the UK) at the power station. Multiply
the electricity consumption figures by 3 to obtain a more realistic
figure of the true energy consumption.
Targets: 30% reduction in gas to 14000 kWh per year. 37.5%
reduction in electricity to 1825kWh per year, or 5kWh per day.
Between 6 and 8kWh were being used each day on the boiler pilot
light. A modern boiler with electronic ignition installed in August
2005 eliminates this wastage.
During the summer of 2004 when the old boiler was out of action,
the gas consumption attributable to cooking amounted to 2.2kWh
per day. However we relied on the electric immersion heater to heat
our water - so the electricity consumption peaked!
It is good to note that the gas consumption figures are generally reducing,
but the electricity consumption is rising. There are two reasons for this:
One of the reasons is that I spent a year working in Birmingham between
April 2002 and April 2003, and so for much of the week I was away.
Without my PC running, the electricity bills are much reduced. Elaine also
likes the heating a bit higher than I do, so that explains the slight increase in
gas consumption for the period I was away!
In April 2003 I returned from Birmingham and started working from home,
which meant that the house was occupied for most of the day, with a
resultant increase in energy consumption.
My desktop PC remained on for much of the day and amounts to 1kWh
for every 6 hours of operation. A PC left on 24 hours a day will consume
4kWh per day, effectively doubling our base load consumption. Use of a
modern laptop will reduce this to just 50W or 1.2kWh in any 24 hour
period.
In April 2004, the gas boiler refused to light due to a faulty gas valve. We
used the electric immersion heater for most of our water heating until
October 13th 2004. This consumed an additional 3 to 4 kWh of electricity
per day, but clearly we used very little gas except for cooking and the
occasional use of the gas fire.
shape. Taken June 2005, the roof was being slated and
scaffolding boards laid at window height to allow access.
Water is a valuable resource and often relies on ancient
infrastructure to pipe it to our homes. My water main was laid
in 1890, and ironically as I type this, there are two guys up to
their shoulders in a trench trying to fix a leak and replace the old
lead main!
As much of the infrastructure was put in place during Victorian
times when consumption was much lower (fewer people, less
wasteful appliances) the service is now creaking and groaning.
The best way to save water is to have a meter fitted! A little
controversial but it focuses the mind as to the true consumption
and then it becomes a challenge to reduce your monthly
readings.
1. A shower uses about 1/3 of the water of a bath. Sharing
bathwater is a good way of reducing consumption!
2. You can wash dishes in 2 gallons of hand hot water, not the
10 gallons consumed by the average dishwasher. If you must
use a dishwasher (i.e. have kids) plumb it into the hot supply
and set your water temperature thermostat to less than 60
degrees centigrade. Even 50 C is hot enough for most purposes
3. Use the economy programme on your washing machine
whenever possible. - this uses less water, less electricity and is
much quicker. Plan the washing to use the machine efficiently
without overloading it.
4. Install a low flush or dual flush toilet cistern , or consider
using the grey water from the bath and shower to flush the loo.
Alternatively place a couple of bricks in the cistern. A solid
house brick displaces close to 2 litres of water.
5. Use grey water or rainwater for gardening purposes.
6. Turn off the cold tap when cleaning teeth!
7. Controversial - but ask to have a water meter fitted. If you
are billed for the water you use, you will naturally try to use it
more sparingly!
8. Try to dry clothes outside on a washing line in good weather.
Avoid using a tumble drier during the summer months.
9. If the sink is a long way from the tank, and the hot pipe is old
and uninsulated, you may waste up to 3 gallons of dead water
waiting for the tap to run hot. You could use this otherwise
wasted run off for rinsing vegetables, filling the kettle or washing
hands. Think ahead of what you can use cold water for before
you need the hot.
10. Finally - Here is a water saving tip from Penney Poyzer,
who has an eco-home in Nottingham, and hosts BBC TV "No
Waste Like Home" - Thanks Penney
If it's brown, flush it down!
1. Don't use electricity for water or space heating. This includes
electric fires, immersion heaters, electric showers and even kettles.
These are all high wattage devices and consume a lot of power.
2. A typical modern desktop PC will consume about 150 watts. A
modern laptop will use about 1/3rd of this. Switch off the PC and
monitor and all peripheral when not in use.
3. Fit low energy compact fluorescent lamps to all light fittings.
These use 1/5 of the electricity of incandescent bulbs and will pay
for themselves within 300 hours of operation.
4. Try to purchase appliances that have the best energy rating "A".
If you are using old appliances, make sure that fridges and freezers
are kept defrosted and possibly consider adding additional external
insulation. This can improve power consumption by up to 30%
5. Dishwashers consume unnecessary gallons of water and then heat
up cold water to 90 degrees C. Either wash up by hand - or plumb
the dishwasher into the hot tap, having set the hot water temperature
to no more than 60 degrees.
6. During the summer months, consider using solar water heating to
provide your domestic hot water. Low cost DIY kits are now
available starting at around £400. This will considerably reduce
your gas bill during the summer
7. Use efficient gas heating and underfloor heating to minimise on
electricity consumption. A modern condensing gs boiler can run at
close to 90% efficiency, compared to about 65% for a 30 year old
back boiler. Use modern efficient radiators or consider hot water
underfloor heating where appropriate.
8. Turn down the central heating thermostat, 20 degrees C is
generally sufficient for most homes.
9. Fit thermostatic radiator valves and set them to suit the
temperature required on a room by room basis. Bedrooms
generally require less heating than living rooms. TRVs are available
at all DIY stores for less than £10 each (Try Screwfix or Wickes
for bulk saver packs)
10. Wherever possible, increase the amount of insulation in the
walls, ceiling, floor and loft space.
11. Consider installing a woodburning stove with a back boiler to
provide some of your space heating. Not only are these cosy in
winter, but they use renewable fuels and will help to reduce your
reliance on fossil fuels.
12. Low cost , plug in, energy meters (£5 from Lidl's), allow you to
measure where your electricity is being used.
The electricity consumed during a typical day, is drawn by devices that are
used occasionally for a few minutes, such as kettles, toasters etc, those
that we use for a few hours such as the PC, TV and lights and those that
we leave on all the time such as the fridge, freezer and VCR.
It is this last category that can use a surprisingly large amount of electricity
over the course of the year. Modern electronic devices such as TVs,
VCRs, DVDs and Satellite Set Top Boxes can be responsible for a large
consumption even when you are not watching them.
For example a TV that uses 5W on standby will consume 43.8kWh of
power per year without you even turning it on to watch. Multiply this by 4
or 5 for the usual "home entertainment stack" and between 5% an 10% of
your overall home electricity consumption is consumed by idle electronic
boxes.
The fridge and freezer are essential in any modern home, are turned on
continuously and generally use about 1.5kWh per day. Over the course of
the year this amounts to between 500 and 600 units of electricity or
between 15% and 25% of typical usage.
Anyone working from home is likely to have a PC, printer and router
turned on for about 10 hours per day. My system which is a 2 year old
desktop machine and an all in one printer/scanner uses approximately
200W, or 2kWh if used for 10 hours per day. If the machine gets left on,
this can amount for nearly 5kWh per day or roughly 50% of electricity
usage.
Nobody expects to have to sit in the dark, but a conventional 100W light
bulb used for 6 hours per evening in the sitting room uses 0.6kWh. In
winter this usage could increase to 1kWh. By fitting low energy lightbulbs,
this consumption could be reduced to a quarter.
So where does all the rest go? Well it's a mix of occasionally used high
wattage devices like washing machines, dishwashers and tumble driers, and
permanently plugged mains adaptors for telephones, faxes, chargers and
the like. Typically a modern washing machine on a 40 degrees cycle will
consume about 0.42kWh in about 1hour 35 minutes. (Hotpoint Aquarius
on D cycle).
I recently found that my PC, monitor and printer were drawing 32 watts
between them - even when supposedly switched off! At night, I now
unplug them, saving an estimated 140kWh per year.
Dividing the annual consumption by 8760 gives the mean load or base
load, which is an indication of what is being drawn all the time from the
supply. An electrically efficient home should have a mean load well below
500W. In my case I have eliminated all high wattage devices and hope to
achieve the low consumption we had in 2002 - 2003, but this is proving
difficult with having a PC on for much of the day, and the extra hours of
occupancy as a result of me working from home. A laptop machine, or
TFT monitor would help to reduce overall consumption.
Modern electronic devices are notorious for consuming power even at idle.
I discovered that my office deskphone was using 2 watts, whereas a
conventional phone, is powered by the telephone line and uses no
additional power from the grid.
The all in one printer, copier and fax (HP 2500) consumes 11 watts when
turned off and 19 watts when on standby - what is it doing? In real terms
that is enough to light a low energy lightbulb with the equivalent light of a
100W incandescent lamp.
Desktop PC (3 GHz) 100W
17" TFT Monitor 40W
Wireless DSL Router 8W
20W Low energy lamp 20W
HP 2500 Printer, copier, fax 19W
Telephone 2W
Coffee Allowance 20W
(0.2kWh in 10 hrs)
Total 209W
These are worst case figures, which assume winter
working with the printer always on. By using the laptop on
a wireless link, a conventional phone and turning off the
printer when not being used, this could easily become The
100W Office, consuming only 1kWh in a typical 10 hour
working day.
It's time to put the house on a diet, the electricity bill is getting too fat.
Here is a suggested daily consumption plan:
Fridge and Freezer 1.5kWh
Office 1.0kWh
TV and entertainment 0.5kWh
Lighting 1.0kWh
Miscellaneous 1.0kWh
Total 5.0kWh
The miscellaneous includes occasional use of high wattage appliances like
dishwashers, washing machines, toaster, microwave and the like. As
these appliances are only used two or three times per week it should be
possible to get by on an average daily allowance of 1kWh.
Fortunately in our house the cooker and oven are gas, as is the central
heating so we have very few high wattage appliances.
Whether I can stick to this diet is yet to be seen!
October Update - the diet is almost going to plan with a 40% reduction
in electricity. Down from 10kWh per day to 6kWh.
two doors to the left was undertaking a loft conversion in
Summer 2005. We are considering this as a future possibility.
Renewable energy projects, including a combined heat and power
system using a 50 year old diesel engine running on waste vegetable oil.
Also under evaluation are some evacuated tube solar water heating
panels obtained at moderately low cost from China.
Below is a summary of what I have been up to in 2005.
These and other projects I am currently working on can be found
elsewhere on this site - accessed on my Renewables Page
vegetable oil. It can produce 2kWh of electricity from just a
litre of waste vegetable oil.
This page has looked at minimising conventional energy and resources
such as electricity, gas and water. These days there are several exciting
options for utilising renewable energy sources such as solar, wind and
biofuels.
Solar Gain
Windows that face from south east to south west will receive the
majority of the direct sunlight. This is often reflected in house design
where southerly windows are large and those towards the north are
kept as small as possible.
If possible, downstairs rooms fitted with south facing windows should
have solid insulated floors to act as a large thermal mass to absorb as
much of the incident solar radiation as possible. In summer these rooms
may become uncomfortably hot and stuffy, but could be fitted with
blinds to reduce the sunlight or with a ducted ventilation system to
circulate hot air from near the ceiling replacing it with cooler air from the
other rooms.
If the back of the house faces south, then there are options for solar
porches or conservatories, which help to preheat the air in winter and
the cooler spring and autumn months.
Solar Water Heating.
This has been around for about 30 years now and is a mature
technology. Low cost DIY kits from China have recently appeared on
the market, using evacuated tubes. Kits for a 2m2 panel of 20 tubes
now start at around £400, and a DIY installation can be done for a
total of about £600. Available from Sustainable Technology Ltd,
Maidstone, Kent. Tel. 01622 843068 and ask for John!
On fine days from April to October, such a system will heat a 110 litre
tank of water to around 65 degrees C and may be sufficient to allow
you to minimise your boiler usage during the summer months.
Other Renewables
Whilst solar water heating is a practical possibility on most private
homes, wind power generally is not. Photovoltaic panels are also
available but are still very expensive and unlikely to replace the power
drawn from the grid.
A more practical proposition is to consider fitting a woodstove with
accompanying water heating jacket. Whilst this may not entirely
replace your gas or oil fired central heating, it will reduce your total
dependency on fossil fuels, by perhaps as much as 50% during the
winter months.
Woodstoves require a fair amount of effort in collecting suitable
firewood, lighting, and cleaning, but if you are prepared to work at it, it
could save a fortune in gas at a time when gas prices are rising sharply.
At a time when domestic energy prices are rising rapidly, it is
relatively straight forward and cost effective to minimise energy
consumption and save up to 40% on domestic energy bills.
It is also time to consider renewable energy alternatives, which
are now becoming cost effective add-ons to existing systems.
Low cost solar water heating is now available with systems
being imported from China.
A woodstove with a backboiler for use in the autumn and winter
months, is the perfect complement to the solar water heating,
and with some thought can share system components like tanks,
pumps and plumbing. Both of these will make a significant
impact on the amount of fossil fuel being consumed.
Energy can be conserved with very little loss to overall comfort.
The simplest way is to make use of modern thermostats and
timeswitches, and learn how to set them to minimise
consumption and at the same time maximise home comfort.
Just turning off unused equipment and lights will save a surprising
amount of electricity.
Fitting low energy bulbs is cost effective in areas where lights
are needed for several hours per day. They will generally pay
for themselves and make net savings after only 300 hours.
Avoid having to heat water or rooms using electricity, this
consumes 4 times the overall energy compared to burning a fuel
(oil or gas) directly in a boiler. Cheap rate night-time electricity
is for the convenience of the power companies - NOT for
yours!
Make full use of insulation in lofts, ceilings and walls. It is
obligatory for new build construction. Grants may be available
for existing properties.
Renewable energy projects may qualify for a grant from the
Clear Skies Initiative funded by the DTI in the UK.
Embracing renewable energy technologies now will put
you at the head of the pack - do not wait to just follow the
herd!
