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Going "Green" - some practical issues
Noel's experiences with eco-frieldly solutions

With all the talk about Green Issues and climate change, there have been very few suggestions of practical ways in which something can be done at a sensible level.  With this in mind I started out to prove that "Going Green" could save you money as well as the planet.
I was inspired to do something after visiting the Centre for Alternative Technology in Wales. If it was possible to use solar power in deepest darkest Wales (no disrespect intended) it could be done anywhere!  So over a period of a few years I went ahead and installed solar water heating, PV cells and a wind turbine to generate electricity. This along with running energy saving and low voltage lighting and improved insulation has proved that "Going Green" is good for the wallet!

The rational behind all this was to demonstrate that in a 3 bedroom semi-detached house with teenage children that you could save money.  Being realistic it is more difficult to sell the concept of "it's eco friendly" than "it will save money".

We live in a 1930's style 3 bedroom semi-detached house in Devizes, Wiltshire. The house was originally just the bit to the right of the front porch. We doubled the size of the house (1988-1989) by knocking down the garage and building a 2 story extension and double glazed the windows. If you take a line down from the left hand edge of the solar panel to the porch the bit on the left is the extension.
The house faces East/West, South is to the right of the picture.

Our home in Wiltshire

Heating
All our hot water and central heating used to be powered from a gas fired combi back boiler (replaced when we built the extension with a standard wall mounted combi boiler)).
Over a period of years I monitored the number of units of gas that we used and compared it to what it was before we built the extension and did the installation. Despite the house now being bigger (nearly twice the size) we used on average one third less units of gas than before.  The solar water heating system is based on Thermomax evacuated tubes, these then heat the water in a dual coil double insulated storage cylinder. The bottom coil is the solar heater and the top coil is heated by the gas boiler. In practice the top of the bottom coil and the bottom of the top coil overlap. In winter the bottom coil pre heats the cold water to about 25°C on overcast days. On normal days (summer and sunny days) the temperature in the heat exchanger can be anything between 70°C and 90°C and in tank anything between 65°C up to 90°C. There are temperature sensors at the top, middle and bottom of the hot water cylinder. I also have a 7 day 3 interval programmable boiler controller so that the heating and hot water from the boiler can be varied and independently operated from each other. This in effect means that I can have the heating on and the hot water off. In winter this enables me to take advantage of whatever solar radiation is available to maximum effect.

Diagram of solar heating

Due to the aspect of the house we have had to install solar panels on both sides of the roof as the house faces East and West. There are 2 solar collector arrays of 20 tubes each with a differential controller to switch each panel on as it is exposed to the sun. Although in practice it does not make much difference as once the system has heated up it all stays on.

The total system cost £3,300 in 1993 and took about 10 years to recuperate the cost from the energy saved.. On the maintenance side I have had to tighten the glands on the heat exchanger a couple of times.  I have replaced the pump, which is an ordinary central heating pump, a pressure relief valve which cracked (£14).  The differential controller needs to be replaced, at the moment is running on a timer. It is much cheaper to run than a conventional boiler. The solar controller has now been replaced (November 2007) with a simple single controller which does the job just a well.

Generally speaking the conventional gas boiler goes off in May and is switched back on in September. For the rest of the year the solar collectors are used to pre heat the cold incoming water which is then heated conventionally with a gas boiler. There are very few days when it does not generate some heat. There are also quite a few days when it takes over completely and heats all the water even in the dead of winter!

Solar panels - evacuated tubes for hot water and PV cells for 12 volt charging

On the maintenance side things have started to break down after 15 years (2007). The 3 port main central heating/hot water motorised valve failed, taking the main controller with it. Those cost £200 to replace. Then because we live in a hard water area (& despite using a Permutit® water softener) the main hot water cylinder started to leak round the emersion heater element. So I have had to replace the whole cylinder and all the associated pipe work as the new cylinder is completely different from the old one. That cost £400 with all the new pipe fittings. Needless to say the design of the old tank and the new one were different!

dual coil cylinder one coil above the other conventional coild at the top and solar coil at the bottom dual coil cylinder with both couls overlapping

The cylinder on the left is what was there originally with the bottom coil being the solar one and the second one is the new type with the coils overlapping. When I replaced this tank I did go overboard a bit with the insulation! The tank is housed in a purpose build cabinet and then stuffed all round with glass fibre insulation material and then an outer layer of high insulation factor metal foil wrap

Old Tank New Tank New Tank Insulated
The tanks are the same size. The one on the left is the old tank replaced with the blue one in the middle and the final highly insulated on on the right with the equivalent of 300mm of insulation around it.

In the early summer of 2007 the boiler started playing up. We had intended replacing it anyway, however, this made the change a necessity so we opted for a GLOWWORM 24HXI HE COND BOILER NG to replace the existing one. This is a condensing gas boiler for both central heating and hot water. This is of a higher rating than the old one and much more efficient and quieter! We also replaced the remainder of the radiator valves with TRV's (thermostatic radiator valves).

Ventilation
With the house so well insulated it is necessary to get rid of moist/stale air. We do have an open fire which does help with general ventilation. However, my wife does like this odd concept of "fresh air"; which in practice means opening the windows and letting out all the precious warm air replacing it with cold air. I do find this an odd concept since air is air, either warm or cold. Cold does not equal fresh. So I got round this one as well by fitting a loft mounted heat recovery unit. A simple enough device, it sucks out the stale/warm air (like your bathroom extractor - yes we have those too!) and forces clean air back into the house and on the way the air being vented out passes through a heat exchanger warming the air coming in. Yes there is some heat loss, but again the unit is well insulated. So we get stale air removed and warm "fresh air" from outside brought in. The air is extracted from the living room downstairs and the bedrooms & bathroom upstairs. The replacement air is forced into the central stairwell creating a forced air flow down through the centre of the house and using simple thermal convection to create the circulation.

Electricity
On the electricity side, this was a bit more difficult.  The concept of teenagers switching off lights in unoccupied rooms is a difficult one as most parents will know. So I decided that each time a bulb blew it would be replaced with a low energy bulb.  Now in those days these bulbs cost £29 each (cost now under £5).  Even so I managed to get the total wattage down to 300 watts. That meant that if all the lights were left on it would still cost less than it would with conventional incandescent lamps.

I then installed 2 x 48 watt 12 volt DC photovoltaic panels on the roof to generate 12 volts. These cost about £250 each and work really well providing a trickle charge all day to top up the batteries. I also installed a Rutland wind turbine which I have to say was not as good as I had hoped as the wind speeds here are not as high as is needed. The turbine cost about £350. It will generate up to 10 amps on gusts of over 20 mph and about 1 or 2 at 10 mph. (You can monitor the wind speed here as I have an automatic weather station) I had to take it down as it stopped charging and I had to cut down the tree it was mounted through! On top of that I started to fit low voltage lighting; again before it was common.  Now low voltage dichroic lamps are quite common. I was lucky that the batteries that I used to store the power came free; they were being disposed of by a NHS installation because the UPS that they were part of was not big enough!.
I have also replaced some of the lights with 12 volt 11 watt low energy bulbs bought on eBay from Andy Shepherd. These work very well and use very little power.

For the remainder of electricity supply we used to get our power from Good Energy based in Chippenham.  All their power is sourced from renewable energy sources such as wind and hydro power stations. However, we discovered that Scottish Power also could supply 100% renewable energy so I'm afraid we switched because of the deal they could do with both gas and electricity. It was simply a bit cheaper!

Apart from using gas for some cooking and central heating our house is just about as energy efficient and low in carbon emissions as possible.

Windows
The windows were replaced back in the late '80's with PVCu double glazed units. However, they did not really last the test of time and there were large gaps appearing around the windows where the insulated strips had degraded. So we took the decision to replace all the windows in one go. We contacted Zenith who were in the area to look at Staybrite Double Glazing. Yep that was expensive with 20 window units to replace! The salesman couldn't believe his luck - we must have hit his bonus in one go! Any way we went ahead and replaced the lot.

Front Windows Back Windows
I have to say that this was a good decision as the draughts have stopped and the traffic noise has been reduced and less warm air escapes to the outside world. From a security point of view these windows are much better built than the ones they replaced! We are not allowed to say exactly what we paid for this work, but the original quote was about £20k. However, we agreed to become a show home and got the price reduced considerably!

Cavity wall insulation
If I had known before what a simple process this was and how cheap I would have done this years ago! I contacted a local firm Warm-Space who came and did a survey, sorted out the grant application and did the work for under £300.

Cars
For many years I have been attempting to make car run further on less fuel and with lower environmental impact.  When I was in the motor trade I spent quite a bit of time developing systems of water/steam injection to improve the performance of petrol engine cars.  This was partially successful but not a very convenient way of fueling cars.  We recorded about 10% fuel efficiency improvement.  However, since then I have been running diesel engine vehicles.

While looking at recycling of computers I came across a man (a chap called Rob who was visiting us about recycling old computers) who was driving a VW Touareg which was fueled by vegetable oil.  Being a skeptical type I started to do some research into running engines on vegetable oil. 

To my surprise I discovered that Dr Rudolf Diesel originally designed the compression ignition engine (diesel engine) to run on peanut oil. Rumors and mystery still surround the circumstances of his death. Mid Channel on route to the UK he disappeared.. After quite a bit more research I felt that it was time to do something about the vehicles I use as all of them are diesel.  It became apparent that one could do something to reduce pollution without any capital outlay. It took a bit of a leap of faith to pour vegetable oil into the fuel tank letting it mix with the diesel in the tank.  Well I can conclusively confirm that it works.  You can put up to 40% in summer months and 10% for the rest of the year.  There are side effects, the exhaust smells like cooking doughnuts. Other than that the engine sounds quieter and runs more smoothly and returns a better mpg (I regularly get more than 30 mpg).  What I cannot understand is why this is such a well kept secret.  OK I understand that this would not be popular with the oil producers, also the government derives considerable revenue from fuel tax. However, if the government were serious about reducing the levels of vehicle pollution then they could encourage drivers to switch to eco fuels rather than simply raising fuel duty or road fund licence.  The cost of converting a car to run on veg oil is about £500 for a DIY kit and £1000 - £1500 for a professionally fitted system.  The cost of SVO (Straight Vegetable Oil) is 64p per litre - much cheaper than pump diesel.  If you can find a source of waste vegetable oil (the stuff chip shops have to get rid of) then the cost is reduced still further. H M Revenue & Customs have now changed their position on using vegetable oil in road going vehicles. Revenue & Customs Brief 37/07 - Introduction of biofuels simplification. This in effect means that if you use less than 2,500 litres of fuel per year you do not have to register or pay duty. That in simple terms = 50% reduction in fuel costs + 50% reduction in carbon footprint = got to be good for the environment and for the wallet!!
.

Land Rover Discovery 200 Series 2.5 TDiTry this experiment, put 10% veg oil in your fuel tank, that is 3 litres of veg oil into 30 litres of derv.  When you are convinced up the level to 20%.  Therefore it stands to reason that at a stroke it would be possible to reduce pollution from diesel by 10% immediately.  In deed it should be able to mix veg oil with diesel fuel at source so that it was delivered at the pump.
Modern diesel engines cannot be run on SVO without modification as the oil is too thick.  The conversion involves fitting fuel pre heaters (glow plugs or heat exchangers) to bring up the temperature to above 70ºC this is done using standard diesel glow plugs and the engine's own coolant water and a heat exchanger.  You still have to make provision for conventional diesel as the engine has to be started on diesel from cold before switching over to SVO.  SVO is a carbon neutral fuel. Yes it does still produce Carbon Dioxide , however, this is absorbed by the new growing crop; but more importantly is used 50% less energy to produce than fossil fuels! So your carbon footprint is instantly halved.
Any one thinking of converting their vehicles to run on vegetable oil would do well to research it on the Internet before going ahead as there are come technical details that may be specific to your engine and injector system, there are loads of websites dealing with this in detail.

However, if you don't want to go down the route of converting your engine, I have now discovered a source of bio-diesel that is made from 50% used waste oil mixed with 50% new oil. Having done a certain amount of research on the internet I tracked this source more by accident than design! On eBay I found a good source of bio-fuel. This comes in a 1000 litre IBC on a pallet. All you do is put it in your tank and drive away! If you run out of bio fuel all you do is revert to normal pump diesel.


Conclusions
So in practical terms it is quite possible to "go green" and save money.  Over the last 20 years I have spent a considerable amount of time investigating ways of saving energy and reducing costs. Overall with a reasonable investment it is quite possible to see a return on that capital in the longer term.  The biggest investment we made was the solar water heating, it now provides us with free hot water and then the replacement double glazing.

To sumarise we have :-
1. A high efficiency condensing gas boiler.
2. Solar water heating providing between 50 & 60% of our hot water (it could be more).
3. PV solar collectors with 12 volt batteries & 12 volt lighting.
4. Energy saving lights.
5. Full double glazing.
6.Cavity wall insulation.
7. Loft insulation.
8. Heat recovery ventilation.
9. Vehicles that run on waste vegetable oil.

And yes it is just a normal house!

Warning - Legal Disclaimer

Opinions expressed on this website are my opinions and should not be taken as the absolute truth. If you act upon any information and find it doesn't work it is your fault and not mine. You should take independent advice and do your own research.

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